Category Archives: Space Exploration

Jeff Friesen's latest Lego book, "Lego Space Projects" (No Starch Press, 2021) shows space enthusiasts how to build little spacecraft, from more realistic-looking vessels to science fiction dreamcraft.

The book also includes step-by-step instructions to guide you through the process of transforming your Lego blocks into celestial destinations, ranging from comets to the sun to deep-space experimental drive testing on other worlds.

Friesen's book comes at a time when Lego is releasing ambitious adult-themed sets about famous space machines, ranging from the Apollo lunar lander to the Saturn V moon rocket to the Discovery space shuttle.

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But Friesen prefers a more experimental building approach. "I don't actually build Lego sets by their instructions; I usually like to build my own thing," he told Space.com.

Space appeals to Friesen because of his fascination with engineering, he said. He cited Lego's Roman Colosseum set as an example of engineering on a large scale, while Friesen is more interested in the small scale. Space, he said, includes "some of the greatest engineering projects of all time."

"I think great engineering wonders capture people's imagination," he added, "and space captures their imagination even more because that's our new frontier right now, as opposed to discovering new continents."

Space.com received a sample of Friesen's book, which begins by explaining that Lego space bricks can be reinterpreted even in the most simple form for the basic parts of a spacecraft. Friesen shows that it takes only three small bricks to recreate the fuselage, propulsion system and cockpit of a crewed spacecraft which the book demonstrates with Lego pieces 4589 (a cone), 3005 (a cube) and 54200 (a glass triangle).

From there, the book assures readers, you can learn to make adaptations of your own. To help you, the book also includes a multi-page set of "greatest bricks for spacecraft," a sample constructable stand upon which you can place your creations, and tips for ordering individual bricks via the online shop website BrickLink. More advanced and confident Lego builders will likely love this stuff.

"I don't build digitally; I built it all with physical pieces," Friesen explained. "Sometimes, instead of going from an idea for a ship, I'll actually start with the pieces and experiment with how they fit together to make something interesting. That was kind of the inspiration for this book, actually, because they [Lego] often build architecture. Because architecture has no moving parts, I put a lot of moving parts into these builds so the book is also an exploration of how to use parts."

Friesen wrote another book about Lego microbuilds ("Lego Micro Cities," No Starch Press, 2018), and he said that his experiences from that book also came into play in the new book about space. "Micro scale has an additional challenge, because you have to make the few parts that are in each build very meaningful. There are no wasted parts; it's like the microscale is the sort of essence of building. It's like minimalist art, [in that] almost everything has to mean something."

For people who are better with guided instructions like myself the book has 52 guided sets of various kinds. Each set has metrics for difficulty and number of pieces, and also includes a list of bricks you'll need to buy or acquire. If you're used to Lego's multi-hundred- or multi-thousand-piece sets, you may find the included sets somewhat minimalistic or, for the easy ones, simplistic but this also makes the sets fun to adapt. The easier ones are also kid-friendly, which Friesen said is by design.

"If I wrote the book when I was 8 years old, it would all be 'Star Wars' styles," Friesen said when asked to reflect on his own childhood interest in Lego. "But I wanted to make it so that there was a few more civilian crafts, so it wasn't all just warfare in space. I wanted to put some utility crafts of a normal functioning society."

My favorite design of the included sets in my sample was "Bebot," described as "an explorer mecha" that looks almost like a flying Pixar WALL-E. I also enjoyed the concepts for a "bounce buggy" (a rover equipped with "jump jets" for rugged terrain) and a "cloud skimmer" designed to emit no pollution during hypersonic exploration of other planets' atmospheres. I didn't get the chance to construct any of the sets, but the instructions look to me as intuitive as Lego's typical space set books.

Friesen said he is working on another book focused on Lego engineering, which will likely include allusions to real-life space projects like SpaceX's spacecraft or the International Space Station. "People really like engineering projects," he said of his decision to pivot harder in this direction, adding that he plans to bring in some elements from mechanical and structural engineering to the new sets.

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Learn how to create extraordinary Lego spacecraft with the 'Lego Space Projects' guidebook - Space.com

WEVE BEEN ON quite the journey here at The Good Information Project over the last few weeks, diving into modern space exploration and answering the question of what is Irelands place in space.

As always, we looked for our readers to get in touch with their questions and queries and many did via the usual social channels, as well as through our reader polland open thread.

So nearly three weeks on from our launch, what have we all learned?

A common comment that crops up whenever space exploration is brought up is essentially why bother when there are so many pressing issues that could be addressed instead?.

Space commentator Leo Enright addresses that very question in an opinion piece for ushere- outlining how space technologies impact our everyday lives.

For many, questions around space exploration arent at the forefront of minds like they may have been during the US-Soviet Space Race in the 60s.

Nevertheless, the coverage of some high-profile billionaires is playing an increasing role in renewing public interest in the sector companies backed by the likes of Bezos and Musk are involved in everything from launching rockets and satellites to transporting cargo and crew.

With the help of Ireland Thinks, we wanted to gauge Irish public opinion on who they think is winning the space race if they think space tourism will become commonplace in the future, and most importantly, whether they would undertake such a trip.

We found that 35% of the public believe space tourism will become commonplace within the next 50 years, while just 28% would be willing to go at all.

When it came to the space race, the Americans remain ahead with NASA the answer for 27% of Irish people surveyed. The enterprise founded by Elon Musk SpaceX was second in our poll with 23%.

The European Space Agency (ESA) was cited by just 2% as leading the modern space race, so it should come as no surprise that further polling revealed that some 40% of people Irelands annual contribution of 20 million to the ESA should decrease. Some 37% of those surveyed believe the contribution should stay the same.

The ESAs budget for this year is 6.49 billion, with Irelands contribution making up just 1% of that. The ESA currently operates on a pro-rata basis, meaning the more money nations put in the greater number of lucrative contracts they can be awarded. So, a decrease in funding would likely mean fewer opportunities for Irish industry and academics.

In the five decades since Ireland became a member of the European Space Agency, it has contributed to a wide range of research projects and been awarded countless commercial contracts worth millions benefiting both our educational and commercial space sectors. Only in 2019 however, did the then-government decide to put together a National Space Strategy for Enterprise.

As CJ McKinney explains, the strategy measures success not only in the number of ESA contracts won, but in turnover and employment at space-active Irish companies. The goal is for both to double by 2025.

The global commercial space sector is estimated to grow to a trillion-dollar business in a matter of years, and Ireland is eager to get its fair share. Part of the strategys function is to persuade relevant multinationals to take Ireland seriously as an investment destination, and the best way to do this is by building on our existing tech sector.

But without sustained private investment, Irelands space sector is firmly tethered to the ESA for the foreseeable future.

A progress report on the strategy is due by year-end, but over the course of this cycle, weve learned that ESA membership is worth more than the monetary return. Given Ireland has no national space agency, the ESA is the main way Irish companies can qualify their technologies for space flight, and ultimately commercialise them for the space market.

Likewise, in the absence of a national space agency, the ESA provides training opportunities that otherwise wouldnt be available to Irish students be that at ESA HQ or in Ireland through the agencys educational programme.

One benefactor of the ESAs Fly Your Satellite Programme is a team of students and academics in UCD who are now in the final stages of trying to get the first-ever Irish-made satellite off the ground.

Once orbit the satellite will collect data from the three science experiments on-board while powering itself, orientating itself, and communicating back to UCD. One problem the team hopes it wont run into is space junk.

The increase in man-made space objects is a more or less direct consequence of the rise of the private space industry. Ian Curran took a look at the impact its having on space exploration, and what is being done about it.

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And when it comes to the question of when will have an Irish born-astronaut, were probably closer to that than ever been, thanks to the ESA.

Fewer than 600 people have ever made the trip to space in the history of humanity, so there was naturally a lot of interest earlier this year when the ESA opened applications for its astronaut training programme for the first time since 2008.

Out of the 23,000 applied, 270 of them were Irish.

Cillian Murphy (not that one) is one of the Irish hopefuls who is eagerly awaiting an update from the ESA expected this November. Cillian, who currently works as an engineer for a biofuels company in Budapest, spoke with Cormac Fitzgerald about pursuing his dream of getting to space and the risks that come with it.

For anyone looking for inspiration on how to take space exploration into your own hands, look no further than Raheny Observatory. The man behind the back garden observatory is Dave Greenan, an amateur astronomer living in North Dublin whos made five independent discoveries from his back garden.

The future of Irelands space sector certainly looks bright, before we sign off and move to the next cycle of the Good Information Project (watch this space) but lets not forget Irelands ancient astronomers.

Early dwellers built clever structures to work in harmony with the cosmos, most notably the winter solstice sunrise illumination at Newgrange. But according to Anthony Murphy, it is unlikely that their curiosity about astronomy stopped with the sun, given they had the advantage of clearer night skies.

Without the hindrance of light pollution and atmospheric haze, the people of the New Stone Age would have enjoyed a pristine night sky, allowing them to track the monthly movements of the Moon against the background stars of an ancient zodiac, Murphy writes here.

And lastly, to see how much attention youve really been paying to this series, test out or quiz on the modern space race.

This work is co-funded by Journal Media and a grant programme from the European Parliament. Any opinions or conclusions expressed in this work is the authors own. The European Parliament has no involvement in nor responsibility for the editorial content published by the project. For more information, see here.

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We're signing off from The Good Information Project's 'space module' - TheJournal.ie

David Baxter

1954 - 2021

John David Baxter died September 8th, 2021. He was born August 21st, 1954, in Salt Lake City to John Keith Baxter and Dalene Leone Armstrong Baxter.

David grew up in the Avenues of Salt Lake, attending Ensign Elementary, Bryant Jr., and East High School. He earned a B.S. in Communications at the University of Utah.

David was an avid enthusiast of space exploration. He advocated for a strong and active manned space program. In his youth, he enlisted the aid of many sponsors in the aerospace industry to bring about United States Space Week and Space Exploration Day, which resulted in the signing of proclamations by dozens of State Governors and several US Presidents. He was president of the Utah Space Association. David pursued his interests with great passion.

As a faithful member of the Church of Jesus Christ of Latter-Day Saints, David served in many Church callings, and studied the gospel of Jesus Christ diligently. He served a full-time mission in the Arizona, Tempe Mission.

David is preceded in death by his parents, his sister Susan, and his sister-in-law, Holly. He is survived by his siblings, Janet (Randy) Bartholomew, Marilyn (Skip) Riggs, Robert (Ann) Baxter, Richard (Amy) Baxter, and Karen (Mirek) Gruszkiewicz, and many nieces and nephews.

Services will be held at his ward meeting house at 668 2nd Avenue in Salt Lake on Tuesday, September 14th at 11:00 a.m. A viewing will precede the services from 9:30-10:45. A Zoom link to the service will be provided on the Larkin Mortuary website. Interment will be at Redwood Estates Memorial Cemetery.

Published by The Salt Lake Tribune from Sep. 9 to Sep. 13, 2021.

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David Baxter Obituary (1954 - 2021) The Salt Lake Tribune - Legacy.com

Ruing the lack of cooperation between military and civil framework for space technology, Vice Chief of Air Force, Air Marshal Vivek Ram Chaudhari, said that space is becoming a playground for the best scientists, engineers and entrepreneurs to continue evolving and breaking new grounds.

He also highlighted that the Air Force is looking to expand its footprint in space exploration and would like to fully integrate air and space capabilities so that there is a common operating picture for aerospace.

Speaking at a symposium on Space Technologies for National Defence, organised by industry chamber FICCI, the Air Marshal said that in the absence of an independent military space programme, the military has been dependent on the civilian space programme of ISRO. He said that there is a lack of a robust military-civil fusion framework, which is a hindrance in innovating future space technologies. There is a need for a concerted focus on this regard, he said.

The IAF, he said, is aiming to expand its footprint in space exploration in partnership with ISRO and added that the Kargil war served as a trigger for having additional satellites towards enhancing our operations. In recent times, increased focus on military space application has been one of the accelerating key factors, he said.

The ability to use aircraft as launch platforms may well be the future. Space tech capabilities have become crucial component for our military operations. Our strategy is to fully integrate air and space capabilities to have a common operating picture in the aerospace medium. We also need to acknowledge that there is a lot of scope for capability development in the realm of military satellite applications.

Another key focus area, he said, should be supplementing the ground-based ballistic missile architecture by creating space-based ballistic missile defence capabilities, he said. It should enable early warning detection and destruction of ICBMs (intercontinental ballistic missiles) along with location for launch pads and prediction of impact points.

The Vice Chief also lamented that India lacks indigenous capability to observe, track and identify non-cooperative objects in outer space.

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Lack of military-civil fusion framework barrier to space tech innovation: IAF Vice Chief - The Indian Express

Figure 1: The NASA Haughton-Mars Project returns to Apollo era training and spacesuit testing sites in Oregon. Left: Apollo astronaut Walter Cunningham in a spacesuit for analog studies at the Big Obsidian Lava Flow, Oregon in September 1964. Right: Spacesuit engineer Ashley Himmelmann in a Collins Aerospace spacesuit for analog studies with integrated Information Technologies and Informatics Subsystem (IT IS) at the same location in August 2021. (Photo NASA Haughton-Mars Project / P. Lee). Download Image.

September 9, 2021, Mountain View, CA --The NASA Haughton-Mars Project (HMP) and collaborating organizations SETI Institute, Mars Institute, Collins Aerospace, and Ntention are announcing the successful field testing of new spacesuit technologies for future astronaut science and exploration operations on the Moon and Mars.

The field tests were conducted in Oregons High Desert region, at the same sites once used by Apollo astronauts to train and test spacesuits in preparation for their historic journeys to the Moon. Several new sites also considered relevant for future Moon and Mars exploration in hindsight of the lessons from Apollo and from recent robotic missions to the Moon and Mars, were also visited.

It was exciting to be in Oregon to revisit some of the very locations where, in 1964 and 1966, the Apollo astronauts received field training in geology and tested spacesuits, saidDr. Pascal Lee, a planetary scientist with the SETI Institute and the Mars Institute, and director of the NASA Haughton-Mars Project at NASA Ames Research Center. We have also identified new candidate sites for Moon and Mars exploration preparation, now that we knowmore, compared to the mid-60s, about the Moon and Mars.

The sites visited by the NASA Haughton-Mars Project team included the main Apollo legacy training and spacesuit test sites in Oregon: Lava Butte, Big Obsidian Lava Flow, Fort Rock, Hole in the Ground, and Yapoah Lava Flow at McKenzie Pass. New sites visited in preparation for exploring the Moons south polar highlands and lunar caves, and eventually Mars, included Pumice Slope at Crater Lake National Park, the Painted Hills at John Day Fossil Beds National Monument, and Skylight Cave, a lava tube with multiple roof collapse openings. The sites were accessed with support from the United States Forestry Service Deschutes National Forest and the National Park Service.

NASAs current Artemis Program aims to land the first woman and next man on the Moon, near the lunar South Pole, by the end of this decade and build on this experience to eventually send humans to Mars. In anticipation of the science and exploration needs of future Moon and Mars astronauts, several new technologies are undergoing development and testing to help optimize the safety, productivity, and cost-effectiveness of future EVAs (Extra-Vehicular Activities) or spacewalks.

Central to the weeks field tests was Collins Aerospaces innovative, integratedInformation Technologies and Informatics Subsystem(IT IS). Currently, astronauts on spacewalks rely on spiral-bound notebooks attached to their elbows to flip through checklists. The CollinsIT ISallows astronauts to autonomously track these checklists and act upon the status of their health and that of their EVA companions (vital signs, exertion levels) through a display system in their helmets. They can also monitor the performance of a wide range of EVA systems - power, oxygen, water reserves - the astronauts location, EVA elapsed time, EVA time remaining, and range from supplies. TheIT ISalso displays maps and a wide array of other data supporting astronaut science and exploration activities, such as imaging, note-taking, and sample management.

We see the integration of our Information Technologies and Informatics Subsystem into a spacesuit as a game-changer for conducting EVAs, says Greg Quinn, lead for advanced spacesuit development at Collins Aerospace. The CollinsIT ISwill help enhance the autonomy, productivity, and safety of future explorers.

While real-time mission support from Earth will remain important, exploring the lunar poles, where NASA intends to land Artemis astronauts, means that direct-to-earth communications will not, at times, be possible, even via orbital relays. So we need to provide future lunar explorers with the means to safely perform more autonomous EVAs, explains Lee. The need for autonomy will be further compounded in the case of Mars, where communications delays will drastically limit real-time mission support from Earth.

Field tests in Oregon began at dawn hours each morning to take advantage of grazing solar illumination in anticipation of challenging lighting conditions at the lunar South Pole. The field sites accessed offered a wide range of terrain roughness, slopes, topographic complexity, and scales of operation anticipated during future EVAs in the lunar South Pole region. EVA systems requirements for future lunar pit and cave exploration were also investigated, a first for a spacesuit manufacturer.

One of the field campaigns key achievements was successfully integrating the Norwegian company Ntentions innovativeAstronaut Smart Glove(ASG) system with Collins AerospacesIT IS. TheASGis an advanced human-machine interface (HMI) integrated into the spacesuit helmet and glove. It allows an astronaut to remotely operate a wide range of possible robotic assets such as robotic arms, cranes, rovers, and even drones, with minimal hand gestures compatible with wearing a constricting and rigid pressurized spacesuit. TheASGfield test demonstrated the successful collection of rock sample materials from remote locations not directly accessible to the astronaut.

Our field test this year demonstrated how an HMI like ourAstronaut Smart Glovesystem can be seamlessly integrated into a spacesuit and offer future astronauts on the Moon and Mars much greater perception, reach, and control of their surroundings, said Moina Tamuly, Co-CEO and Co-Founder of Ntention.

By coming to Oregon, we wanted to recapture Apollos historic legacy, but also scout out new experiences for future astronaut training and spacesuit testing as we take on this centurys new challenges, the lunar poles and Mars, said Lee. Im excited to report that we did catch a glimpse of this exciting future this week.

About the Haughton-Mars ProjectThe Haughton-Mars Project (HMP) is a field research project centered on the scientific study of the Haughton impact crater and surrounding terrain on Devon Island, High Arctic, viewed as a Moon and Mars analog. The HMP also leads field exploration studies to help plan the future robotic and human exploration of the Moon and Mars.

The Haughton-Mars Project engages several collaborating organizations and is supported in part by the National Aeronautics and Space Administration (NASA) under Cooperative Agreement NNX14AT27A between NASA and the SETI Institute. The HMP is headquartered at NASA Ames Research Center in Mountain View, California.

The HMPs base camp on Devon Island, the Haughton-Mars Project Research Station (HMPRS), is operated by the Mars Institute. The HMPRS is the largest privately-operated polar research station on Earth and a leading field research facility dedicated to planetary science and exploration. Dr Pascal Lee of the Mars Institute and SETI Institute serves as the projects director. Due to travel restrictions to the Arctic associated with the COVID-19 pandemic, the HMP-2021 summer field campaign was rescoped and replanned to take place in Oregon in August, 2021.

For more information on the HMP:https://www.nasa.gov/analogs/hmphttps://www.marsinstitute.no/hmp

About Mars InstituteThe Mars Institute is a non-profit research organization dedicated to the advancement of Mars science, exploration, and the public understanding of Mars. Research at the Mars Institute focuses Mars and other planetary destinations that may serve as stepping-stones to Mars, in particular Mars moons, our Moon, and near-Earth objects. The Mars Institute investigates the technologies and strategies that will enable and optimize the future human exploration of Mars. The Mars Institute operates the Haughton-Mars Project Research Station on Devon Island, High Arctic.

About the SETI InstituteFounded in 1984, the SETI Institute is a non-profit, multidisciplinary research and education organization whose mission is to lead humanitys quest to understand the origins and prevalence of life and intelligence in the universe and share that knowledge with the world. Research at the SETI Institute encompasses the physical and biological sciences and leverages expertise in data analytics, machine learning and advanced signal detection technologies. The SETI Institute is a distinguished research partner for industry, academia and government agencies, including NASA and NSF.

About Collins AerospaceCollins Aerospace is a leader in technologically advanced and intelligent solutions for the global aerospace and defense industry. Collins Aerospace has the capabilities, comprehensive portfolio and expertise to solve customers toughest challenges and to meet the demands of a rapidly evolving global market. It is one of the four businesses that form Raytheon Technologies.

About NtentionNtention is a Norwegian deep tech start-up founded by a group of engineering students from the Norwegian University of Science and Technology (NTNU) with a passion for human-machine interaction. The aim of the company is to radically improve the way one interacts with technology. Ntention is developing a user-centered interaction framework, that captures the usersintentionthrough multi-modal input methods (such as motion capture, eye-tracking, and voice commands) and translates it into machine command. The system is called the Ntention Interaction Framework (NIF). NIF will be a game changer in several industries, ranging from interaction systems for astronauts, to meeting solutions using VR in the construction industry and has previously been demonstrated in several use-cases, including a music production and performance glove, and the control of robotic arms.

For more information, contact:

Dr Pascal LeeDirector, NASA Haughton-Mars ProjectMars Institute & SETI InstituteNASA Ames Research CenterMS 245-3Moffett Field, CA 94035-1000USAE-mail:pascal.lee@marsinstitute.net

Rebecca McDonaldDirector of CommunicationsSETI Institute189 Bernardo Ave, Suite 200Mountain View, CA 94043USAE-mail:rmcdonald@seti.orgTel: 650-960-4526

Jessica NapoliSr. Mgr External CommunicationsCollins AerospaceE-mail:Jessica.napoli@collins.comTel: 704-713-7282

Alison LalCommunications SpecialistNtentionE-mail:Alison@ntention.comTel: +47462 49 351Norway Time Zone: CET (EST+6)

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New Spacesuit Technologies for Moon and Mars Exploration Tested In Oregon Where Apollo Astronauts Once Trained and Tested Spacesuits - SETI Institute

Significance

Humans shift their gaze more frequently than their heart beats. These rapid eye movements (saccades) enable high visual acuity by redirecting the tiny high-resolution region of the retina (the foveola). But in doing so, they abruptly sweep the image across receptors, raising questions on how the visual system achieves stable percepts. It is well established that visual sensitivity is transiently attenuated during saccades. However, little is known about the time course of foveal vision despite its disproportionate importance, as technical challenges have so far prevented study of how saccades affect the foveola. Here we show that saccades modulate this region in a nonuniform manner, providing stronger and faster changes at its very center, a locus with higher sensitivity.

Humans use rapid eye movements (saccades) to inspect stimuli with the foveola, the region of the retina where receptors are most densely packed. It is well established that visual sensitivity is generally attenuated during these movements, a phenomenon known as saccadic suppression. This effect is commonly studied with large, often peripheral, stimuli presented during instructed saccades. However, little is known about how saccades modulate the foveola and how the resulting dynamics unfold during natural visual exploration. Here we measured the foveal dynamics of saccadic suppression in a naturalistic high-acuity task, a task designed after primates social grooming, whichlike most explorations of fine patternsprimarily elicits minute saccades (microsaccades). Leveraging on recent advances in gaze-contingent display control, we were able to systematically map the perisaccadic time course of sensitivity across the foveola. We show that contrast sensitivity is not uniform across this region and that both the extent and dynamics of saccadic suppression vary within the foveola. Suppression is stronger and faster in the most central portion, where sensitivity is generally higher and selectively rebounds at the onset of a new fixation. These results shed light on the modulations experienced by foveal vision during the saccade-fixation cycle and explain some of the benefits of microsaccades.

Human vision is not uniform across space. While the retina collects information from a broad field, only a minuscule fractionless than 0.01%is examined at high resolution. This is the area covered by the foveola, the region void of rods and capillaries, where cones are most densely packed. Because of this organization, rapid eye movements, known as saccades, are necessary to redirect gaze toward the objects of interest, abruptly translating the image across the retina every few hundreds of milliseconds. It is remarkable that the visual system appears unperturbed by these sudden visual transitions and seamlessly integrates fixations into a stable representation of the visual scene.

It has long been observed that visual sensitivity is transiently attenuated around the time of saccades, a phenomenon believed to play a role in perceptually suppressing retinal image motion during eye movements. This effect, known as saccadic suppression, consists of the elevation of contrast thresholds to briefly flashed stimuli, which precedes the initiation of the saccade and outlasts it by as much as 100 ms (15). Saccadic suppression is typically investigated with stimuli that cover large portions of the visual field, often in the periphery. However, limitations in the precision of stimulus delivery, both spatial and temporal, have so far prevented mapping of the saccade-induced dynamics of visibility within the foveola. Thus, despite the disproportionate importance of foveal vision, little is currently known about its time course around the time of saccades.

Studies on saccadic suppression also commonly focus on large saccades under well-controlled, but artificial, laboratory conditions. However, an examination of the time course of foveal vision needs to take into account that natural execution of high-acuity tasksthe tasks that require foveal visionnormally tends to elicit saccades with very small amplitudes (6). Microsaccades, gaze shifts so small that the attended stimulus remains within the foveola, are the most frequent saccades when examining a distant face (7), threading a needle (8), or reading fine print (9), tasks in which they shift the line of sight with surprising precision. Because of their minute amplitudes, microsaccades pose specific challenges to the mechanisms traditionally held responsible for saccadic suppression (1019). These movements yield broadly overlapping pre- and postsaccadic images within the fovea, which would appear to provide little masking in visual stimulation (20). They also result in reduced retinal smear (21), as they rotate the eye at much lower speeds than larger saccades, delivering luminance modulations that are well within the range of human temporal sensitivity. Furthermore, it is unknown whether possible corollary discharges associated with microsaccades exert similar effects to those of their larger counterparts (22).

Despite these observations, microsaccades have been found to suppress sensitivity to relatively large test stimuli (2325). However, the only two studies that specifically examined foveal vision during microsaccades reached diametrically opposite conclusions, with one arguing for a normal reduction in sensitivity (26) and the other for a complete lack of suppression (27), leaving open the question of whether suppression extends to the foveola. While several factors could have been responsible for these discrepant results, two important considerations are worth emphasizing. First, selectively testing foveal dynamics is technically challenging, since the entire foveola is comparable in size to the region of uncertainty in gaze localization resulting from standard eye-tracking methods. Second, the common intuition gained by conceptualizing the visual signals delivered by saccades as uniformi.e., constant-velocitytranslations of the image on the retina (28) does not apply well to microsaccades, whose relatively brief durations and well-defined dynamics yield substantially lower power on the retina than predicted by a uniform translation (29). Thus, even a moderate suppression may be sufficient to prevent visibility of stationary scenes during small saccades.

Recent advances in methods for gaze-contingent display control now enable determination of the line of sight with accuracy sufficient to selectively test a desired foveal region during normal eye movements. Leveraging on these recent advances, here we mapped the perisaccadic dynamics of contrast sensitivity across the foveola during natural visual exploration. We developed a gaze-contingent high-acuity task that resembles primate social grooming, a task that very naturally integrates visual search and detection of brief stimuli and that spontaneously elicits frequent microsaccades, and presented probes at desired retinal locations with high spatial and temporal resolution. Our results show that microsaccades are accompanied by an elevation of visual thresholds at the center of gaze that starts before the initiation of the movement but dissipates very rapidly as the saccade ends. The extent and dynamics of this suppression vary with eccentricity across the foveola, so that a stronger modulation occurs in the most central region, where vision is selectively enhanced after a saccade.

In a simulated grooming task, observers reported the occurrence of flea jumps (the probes), brief changes in the luminance of otherwise dark dots located within the central 2 region of a wide naturalistic noise field. Subjects freely moved their eyes, searching for the locations at which these contrast pulses would occur, while their eye movements were continually recorded.

In reality, unbeknownst to the subject, the probes were activated on the basis of the position and movement of the eye to measure visibility within selected regions of the fovea and at various time lags around saccades. This was possible due to three state-of-the-art components: 1) high-resolution eye tracking achieved via the Dual Purkinje image method (30); 2) accurate gaze localization obtained by means of an iterative gaze-contingent calibration, a procedure that improves accuracy by approximately one order of magnitude over standard methods (6); and 3) real-time control of retinal stimulation, obtained via a custom system for flexible gaze-contingent display control, Eye movement Real-time Integrated System (EyeRIS) (31).

As expected, this high-acuity task resulted in the frequent occurrence of minute saccades. On average, observers executed 2.5 saccades per second, almost all of them smaller than 1 (average saccade amplitude and SD across subjects, 286; mean 99th percentile of the amplitude distributions, 68; Fig. 1E). In fact, the majority of saccades (68%) were smaller than 30, an amplitude range that maintains an initially foveated probe well within the foveola. These tiny gaze shifts occurred at a rate (1.6 microsaccades per second) much higher than those normally encountered in tasks that do not involve high visual acuity (typically <0.2 microsaccades per second) (29), an observation consistent with the notion that microsaccades are normally part of the strategy for examining fine spatial detail (6, 7).

A virtual grooming task. Observers were instructed to search for fleas hiding within the animals fur (a naturalistic noise field). (A) Thirty dots (5 width) were distributed at random test locations across the central 2 region of the display. Subjects were told that a few of these dots were fleas and would distinguish themselves from the remaining dust particles by occasionally jumping (a 10-ms contrast pulse; the probe). The subjects goal was to catch each flea as soon as it jumped by pressing a button on a joypad. (BD) Example of a trial. (B) Following an initial familiarization period (1 s), the onset of a saccade triggered, with variable delay, a probe (Tk) at one of the test locations. Both location and timing were selected in real time according to the observers eye movements to test performance at various positions in the fovea and lags relative to saccades. The yellow cross and cyan segments represents the center of gaze and eye movements, respectively. (C) Gaze position during the course of the trial. Each probe was associated with the closest saccade (Sk in C). Only probes with no more than one saccade within a 200-ms window were selected for data analysis. (D and E) Characteristics of eye movements. Shown are average distributions of saccade amplitude (D) and intersaccadic intervals (E) across N = 6 observers. Error bars represent SEM. Vertical dashed lines mark the means of the distributions. (F) Power spectrum of the luminance flow delivered to the retina by the recorded saccades. The black line marks contrast sensitivity thresholds in humans [data from Kelly (33)]. The small saccades recorded in this experiment yield visual signals well within the ranges of spatiotemporal sensitivity.

Because of their small amplitudes and stereotypical dynamics (32), the saccades performed in this task resulted in relatively slow changes in visual stimulation. This, combined with the characteristics of the visual scene, which, like natural images, possessed predominant power at low spatial frequencies, resulted in luminance signals to the retina that were well within the range of human temporal sensitivity as measured previously (Fig. 1F) (33). Yet, as happens for larger saccades, subjects were not aware of the resulting translations of the images on their retinasthe well-known phenomenon of saccadic omission (3).

To quantitatively examine the consequences of saccades on foveal sensitivity, we binned contrast pulses according to their combinations of retinal locations and lags relative to saccade occurrence and separately estimated contrast sensitivity in each spatiotemporal interval (Fig. 2A). Fig. 2B shows the psychometric functions of contrast sensitivity measured for one subject in three spatiotemporal bins. As these examples show, sensitivity varied considerably not only with the timing of the probe relative to saccades, but also with its position on the retina, reaching, in some instances, low values even at the highest possible contrast.

Changes in foveal sensitivity at the time of saccades. (A) Contrast sensitivity was measured in 24 spatiotemporal bins around saccades: three distinct regions within the fovea (eccentricity 0 to 15, 15 to 30, and 30 to 60; Top); and eight time intervals around a saccade (Bottom). (B) Contrast sensitivity functions in three spatiotemporal intervals for one observer. Colored lines and shaded regions represent, respectively, the maximum-likelihood fitting and its SEM of a cumulative log-normal function to the data (gray circles; size proportional to the number of samples). The thick horizontal segment represents the SEM of the estimated 25% threshold. (C) Dynamics of contrast sensitivity relative to saccade onset. Each line represents mean sensitivity across observers (N=6) in a foveal region. Error bars are SEMs. For comparison, sensitivity measured at fixation, when the probe appeared at saccade lags larger than 200 ms, is also shown (shaded region). Horizontal bars indicate the intervals in which sensitivity deviated significantly from fixation (P<0.05, post hoc TukeyKramer comparisons). marks significant differences across foveal regions (P<0.05, one-way ANOVA). (D) The same data after normalizing each foveal region by its sensitivity at fixation to highlight differences in dynamics. (E) Mean perisaccadic suppression strength across the foveola. Suppression is strongest in the central region (P<0.05, post hoc TukeyKramer comparisons).

We first examined sensitivity far from saccades. The data points in the shaded region in Fig. 2C represent the average thresholds across observers estimated during fixation, i.e., when no saccade occurred in the surrounding 200 ms of a probe. Strikingly, despite being separated by just a few arcminutes, the three considered foveal regions exhibited marked differences in sensitivity. Contrast sensitivity was always larger at the very center of gaze and decreased with increasing eccentricity, so that sensitivity in the most central region (the region within 15) was on average 8% higher than in the range 15 to 30, which was in turn 9% higher than sensitivity in the range 30 to 60 (one-way ANOVA, F(2,17)=4.8; P=0.02). These measurements reveal how contrast sensitivity varies across the central foveola. They show that, contrary to its anatomical homogeneity, sensitivity is not uniform within this region: Optimal sensitivity is restricted to a very narrow region around the center of gaze during normal fixation.

As the probe approaches the onset of a saccade, drastic changes in visual sensitivity occur. Sensitivity drops sharply from the fixation baseline starting 50 ms before the saccade and continues to be affected up to 100 ms after the saccade onset, a time at which the saccade has typically already ended (Fig. 2C). At all the considered foveal locations, suppression was strongest in the 25-ms interval immediately preceding the saccade, when sensitivity dropped by 38% on average. The dynamics of this effect were highly stereotypical across subjects, all of whom individually exhibited a similar and statistically significant attenuation in sensitivity (P<0.05, nonparametric bootstrap; individual subject data in SI Appendix, Fig. S1). Thus, the minute saccades performed in our experiment were accompanied by a strong attenuation in sensitivity throughout the foveola, an effect qualitatively similar to the saccadic suppression observed elsewhere in the retina for larger saccades.

While suppression occurred over the entire foveola, the extent and time course of the process differed across foveal regions. All regions ended up with similar visibility levels at the peak of the suppression. However, since sensitivity in distinct regions started from different fixation baselines, the amplitude and speed of the process also varied, so that the change in sensitivity was larger and faster in the most central region of the foveola than at other locations. On average in the 100-ms interval centered at saccade onset, sensitivity was attenuated by 33% in the central region with eccentricity smaller than 15, whereas it was reduced by only 23% in the 30to60 region (P<0.001; post hoc TukeyKramer comparison; Fig. 2E). Thus, given the similar overall duration of the effect across the foveola, both suppression and recovery were faster at the very center of gaze than at larger eccentricities (Fig. 2D).

These results were robust relative to the specific methods for data analysis. Very similar results were obtained by measuring sensitivity to changes in the Weber contrast of the probe relative to its surroundings rather than the Michelson contrast of the probe alone (SI Appendix, Fig. S2). Furthermore, differences in foveal dynamics were also reflected in the reaction times of manual responses, which were longer when the probes were less visible (r=0.50, P<0.01; SI Appendix, Fig. S3A). At the time of microsaccade onset, the reaction times for probes displayed at the very center of gaze were on average 23% longer than for probes just a few arcminutes away (one-way ANOVA, F(2,16)=8.59, P=0.004; SI Appendix, Fig. S3B).

To better examine the temporal evolution of saccadic suppression, we recomputed the time course of sensitivity relative to two distinct temporal events, the end of a saccade and the time at which a saccade reaches its peak speed. Visibility recovers extremely rapidly following a saccade. On average across foveal regions, sensitivity has returned to about 90% of its presaccadic value less than 25 ms after the saccade ends and is fully restored within an additional 25 ms (Fig. 3A). This happens because suppression largely precedes the actual movement of the eye. Suppression is already recovering by the time a saccade is in midflight and has reached its peak velocity (Fig. 3B), an asymmetric temporal evolution that is evident when comparing sensitivity with equal speed of the retina before and after saccade peak speed (SI Appendix, Fig. S4).

Dynamics of foveal sensitivity. (A and B, Top) Average contrast thresholds are now aligned relative to either (A) the time at which the saccade ends or (B) the time at which the saccade reaches its peak speed. Graphic conventions are as in Fig. 2C with the horizontal bars indicating statistically significant differences relative to fixation (P<0.05, post hoc TukeyKramer comparisons). (A and B, Bottom) The mean instantaneous eye speed. (C and D) The same data normalized relative to the first sample to emphasize differences in dynamics across foveal regions. marks significant differences across foveal regions (P<0.05, one-way ANOVA).

Normalizing each foveal region by its initial sensitivity further emphasizes the different dynamics occurring at distinct eccentricities. Changes in sensitivity proceed faster in the central region (<15), yielding a greater change around 100 to 50 ms before saccade offset than at larger eccentricities (P=0.021; post hoc TukeyKramer comparison; Fig. 3C). As a consequence, sensitivity is already at its lowest level 25 ms earlier in this central region relative to the more peripheral foveola (Fig. 3D). These dynamics are little influenced by saccade amplitude. The temporal courses of visibility were almost identical for saccades smaller or larger than 30, despite the former retaining more power within the range of human temporal sensitivity (SI Appendix, Fig. S5).

Interestingly, sensitivity rebounds following a saccade, but only in the central portion of the foveola. This effect is clear in the data of Fig. 3A, which show that postsaccadic sensitivity continues to increase at the very center of gaze (<15) 100 ms after a saccade, a time at which sensitivity has already saturated in more eccentric regions (P<0.04; post hoc TukeyKramer comparison). To examine in detail this postsaccadic enhancement, we directly compared levels of performance during presaccadic fixation, before suppression started, and in the fixation period that immediately followed a saccade (Fig. 4A). In the central foveola at eccentricity smaller than 20, saccades were followed by higher sensitivity, resulting in an average improvement across observers of 12% (P = 0.027; paired two-tailed t test). Such improvement did not occur in the more peripheral region of the foveola (20), where sensitivity decreased slightly following a saccade (P = 0.308; paired two-tailed t test), so that these two regions were differently affected by saccades (P=0.001, paired two-tailed t test).

Perisaccadic enhancements in foveal vision. (A) Sensitivity is selectively enhanced in the central foveola after a saccade. Black symbols represent average sensitivity measured at least 150 ms before and 50 to 300 ms after a saccade in both the central and peripheral regions of the foveola. Colored symbols are the individual subject data. Error bars represent SEM ( P=0.027, paired two-tailed t test). (B and C) Sensitivity is enhanced in the peripheral foveola before a saccade that lands on the probe (Foveated; landing distance <15) relative to a saccade that terminates farther away (Non-foveated). B and C show data for the two considered peripheral foveal regions ( P<0.05, one-sided nonparametric bootstrap test).

This postsaccadic enhancement is likely the consequence of attention. A similar improvement in sensitivity was also observed before a saccade that landed close to the activated probe, but only outside the central region of the foveola (Fig. 4 B and C). On average, sensitivity improved by 12% when the planned saccade was toward the probe, suggesting that attention had already moved to this location before shifting gaze. These results further emphasize the different modulations experienced by the distinct portions of the foveola in correspondence of saccades.

The data in Figs. 24 show that saccades profoundly modulate foveal vision. To probe into the mechanisms responsible for these effects, we decoupled the visual consequences of saccades from their motor production by passively exposing subjects to the same visual input signals normally resulting from eye movements. In this condition, rather than actively exploring the stimulus, subjects maintained fixation for the entire duration of the trial and reported the activation of the probes in movies that reconstructed the spatiotemporal visual signals previously experienced during normal (i.e., active) execution of the task.

Passive exposure to saccade motion greatly altered the dynamics of foveal sensitivity (Fig. 5). Performance was impaired in correspondence of the simulated saccades, an effect that may superficially resemble the suppression occurring during real saccades. However, important quantitative differences emerged. With simulated saccades, the reduction in sensitivity was delayed relative to that with real saccades, with peak occurring well after the start of the motion rather than before saccade onset. This reduction was also considerably weaker and persisted for much longer than that observed with real saccades, with sensitivity still impaired 200 ms following motion onset (P<0.02, two-tailed nonparametric bootstrap test). These results point to a combination of retinal and extraretinal mechanisms acting on foveal vision, with an important role played by extraretinal modulations in first suppressing and then enhancing sensitivity respectively before and immediately after a saccade.

Decoupling the retinal and motor consequences of saccades. Shown are dynamics of contrast sensitivity in correspondence of a saccade (active) and during passive exposure to saccade motion while maintaining fixation (passive). In the latter condition, subjects detected the activation of the probes in movies reconstructing the visual input signals experienced during normal execution of the task. Movies were presented under retinal stabilization to accurately replicate input signals. Data in both conditions are normalized by the sensitivity values measured with probes at least 200 ms away from real or simulated saccades. marks significant differences between the two conditions (P<0.05, two-tailed nonparametric bootstrap test).

Despite its functional importance, vision within the foveola has been critically understudied. Here, we examined the dynamics of foveal vision relative to the minute saccades that naturally emerge during fine spatial exploration. By implementing a naturalistic, yet highly controlled, high-acuity task, we were able to map contrast sensitivity at distinct foveal locations and follow their temporal evolution as eye movements occurred. Our results show that the foveola is accompanied by a general reduction in visual sensitivity in proximity of microsaccades. However, the extent and dynamics of this modulation are not uniform across this region: The attenuation is stronger and faster around the very center of gaze, where sensitivity rapidly rebounds at the end of the movement and remains higher than in the surrounding regions throughout postsaccadic fixation.

By mapping contrast sensitivity and its perisaccadic dynamics across the foveola, our results advance current knowledge of foveal vision in several ways. A first important finding is the observation that during normal intersaccadic fixation, far from the occurrence of saccades, contrast sensitivity is not uniform in the central visual field, but varies by 20%. This is a considerable change in such a small region and is consistent with previously reported impairments in discriminating small stimuli located slightly off the preferred retinal locus (34). Previous studies did not measure contrast sensitivity across the fovea, but our results suggest that the way sensitivity declines with increasing eccentricity may have contributed to these impairments. It remains to be determined whether this attenuation in sensitivity originates from attentional modulations that transiently enhance performance at the very center of gaze or more sustained differences in neural processing with eccentricity. But irrespective of the specific mechanisms, our findings further highlight the importance of precisely controlling eye movements in tasks that involve fine spatial judgments, as the preferred retinal locus has a perceptual advantage relative to other foveal regions.

As the time of a saccade approaches, contrast sensitivity to briefly presented stimuli is attenuated throughout the foveola, a deficit that starts 50 ms before the onset of the movement and dissipates very rapidly at saccade offset. As it happens outside the fovea for larger saccades, the recovery is faster than the preceding attenuation, leading to greater suppression in the first part of the saccade, before reaching peak speed. Interestingly, differences in modulations occur across foveal regions: Since sensitivity is similarly impaired at the peak of the suppression, but its starting level depends on eccentricity, the amplitude and speed of the process vary across the foveola, so that the change in sensitivity is larger and faster in the most central region. These differences in dynamics are not captured by a simple multiplicative gain, as has been proposed for larger saccades (35), but represent more complex deviations in the shape of the modulations. They persist after normalizing each region by its presaccadic baseline to discount gain differences (Fig. 3). Even after normalization, sensitivity proceeds faster in the most central region, deviates significantly from the other regions before the peak of the suppression (Fig. 3C), and levels off 25 ms earlier (Fig. 3D). In addition, sensitivity rebounds in the central portion of the foveola, an effect that leads to a considerable postsaccadic enhancement at the very center of gaze.

Both retinal and extraretinal processes contribute to these effects. An impairment in detection of the probes was also measured during simulated saccades, when subjects were passively exposed, while maintaining fixation, to the visual input signals normally generated by saccades. This result is not surprising, as the backward masking consequences of saccades have long been discussed in the literature (3, 11, 20), and it is well established that masking also occurs in the foveola (36, 37). However, backward masking was not the sole contributor to foveal suppression, as clear extraretinal influences were visible. Sensitivity dropped faster with real saccades and reached its lowest value before saccade onset, rather than after the onset of motion as with simulated saccades. Sensitivity also recovered much faster with real saccades, an effect similar to that previously observed outside the foveola (11, 38). In addition, enhancements in sensitivity, likely associated with attentional shifts (39, 40), were visible before and after real saccades in the peripheral foveola and at the very center of gaze, respectively.

Qualitatively, these measurements resemble those previously reported outside the foveola, but important quantitative differences occur. Most evident is the overall strength of the effect, which is considerably weaker than the attenuation typically observed with larger saccades (1, 11, 35)the commonly reported 0.5 to 1 log units suppression. On average across the foveola, sensitivity changed in our experiments by approximately half as much, 0.21 log units, a 38% suppression. While multiple factors could have contributed to this effect, it is worth pointing out that this reduction is consistent with the strength of the visual signals resulting from saccades during viewing of stationary scenes. Saccades possess stereotypical dynamics (41) that profoundly affect their luminance modulations, yielding a continuum with the modulations delivered by ocular drift (29)the incessant intersaccadic motion of the eye (42). On the retina, both saccades and drifts equalize (whiten) the power spectra of natural scenes within a low spatial frequency range. But a trade-off exists between power and bandwidth in this region: The larger a saccade is, the narrower the whitening bandwidth and the higher the power it contains (29). Because of this input reformatting, the power delivered by saccades at low spatial frequencies is considerably less than one may intuitively expect, implying that a strong suppression may not be necessary during natural viewing. Furthermore, this power decreases with decreasing saccade amplitude, providing a possible explanation for the weaker saccadic suppression observed with smaller saccades (43).

Our work differs from previous investigations of visual sensitivity at the time of microsaccades in several important ways. A crucial one is our focus on the foveola, a disproportionally important region of the retina. Most previous examinations used stimuli that covered large visual areas, often excluding the fovea (2325, 44). Two notable exceptions that specifically focused on foveal vision reached opposite conclusions (26, 27), with the latter reporting lack of suppression during microsaccades. The reduced sensitivity measured in our experiments may help reconcile these previous findings, particularly in the light thatat least for larger movements (45)suppression tends to be further attenuated for involuntary saccades. Importantly, no previous study has mapped the perisaccadic time course of sensitivity across the fovea, primarily because of the technical challenges inherent in the required spatiotemporal precision of retinal stimulation. These challenges were here overcome by leveraging on recent technological advances in gaze-contingent display (31), which enabled coupling of high-resolution eye tracking with accurate gaze localization and real-time control of stimulus delivery.

This study also differs from previous investigations for its focus on natural visual exploration. Our naturalistic task differs substantially from the simplified stimuli often used by studies of saccade suppression. In these studies, probes are typically easily detectable when saccades do not occur. In contrast, in our experiments, the detection of probe was not always immediate even in the absence of saccades: The average values of sensitivity during fixation were such that it required 50% contrast modulation to reach threshold. Furthermore, studies on saccadic suppression typically focus on instructed saccades when dealing with larger movements and forced fixation when examining microsaccades. Both conditions occur rarely during natural viewing, when subjects typically react to stimuli by redirecting their gaze. Forced fixation, a condition in which observers maintain steady gaze on a marker, also creates a dissociation between the attentional demands of the motor task (the maintenance of fixation) and those of the perceptual task (the detection of a briefly presented stimulus), raising the possibility that disruptions and corrections for fixation mediated by microsaccades may temporarily distract from the visual task, transiently lowering performance.

Here, we focused on the minute saccades that spontaneously emerge during normal examination of fine details. Many of these movements are so small that they maintain the stimulus of interest well within the foveola. Given that subjects could not predict which probe would be activated next, their perseverance with this oculomotor strategy, even after hours of practice, speaks for the importance of this behavior during natural viewing. Previous studies with accurate gaze localization have shown that microsaccades tend to precisely center the stimulus on task-relevant visual details (79). Our present results show that this behavior would benefit from at least from two factors, the higher sensitivity around the preferred retinal locus and the sensitivity enhancements that occur around microsaccades. Further benefits may come from the visual transients resulting from saccades, as argued by the proposal of active spacetime encoding (42, 46). According to this view, rather than being insensitive to the visual changes caused by saccades, the visual system uses these luminance modulations to encode information during postsaccadic fixation (29, 4749). These signals likely contribute to the strong neural responses following a saccade (5052), and their structure is consistent with the sensitivity enhancement measured at low spatial frequencies (53), as well as with its dependence on saccade amplitude (54).

Our results show that contrast sensitivity is not uniform in the central fovea and is modulated by saccades in complex ways. Further work is needed to investigate how these incessant foveal modulations influence oculomotor strategies and how humans actively deal with them to enhance visual performance.

Data were collected from eight subjects (six females and two males; age range 23 to 33 y). Six subjects participated in the main experiment (Figs. 14) and two in the comparison between active and passive exposure (Fig. 5). To ensure high quality of eye tracking and gaze-contingent display control, only emmetropic observers with at least 20/20 acuity, as tested with a standard eye-chart examination, were allowed to participate. With the exception of two of the authors, all observers were naive about the purposes of the experiments and were compensated for their participation. This study was approved by both the Boston University Charles River Campus Institutional Review Board and the Research Subjects Review Board at the University of Rochester. Informed consent was obtained from all participants.

Stimuli were displayed on a fast-phosphor calibrated cathode ray tube display (Iiyama HM204DT) at a resolution of 800600 pixels and a refresh rate of 200 Hz. Observers were maintained at a fixed distance from the display, so that each pixel on the monitor subtended an angle of 1.3. Movements of the head were minimized by means of a head rest and a custom dental-imprint bite bar. Stimuli were viewed monocularly with the right eye while the left eye was patched.

Eye movements were recorded by means of the Dual Purkinje Image (DPI) method, via a generation 6 analog DPI eye tracker (Fourward Technologies). The internal noise of this device has root mean square smaller than 20 s of arc, enabling measurement of eye movements with 1 min of arc resolution as assessed by means of an artificial eye. In the activepassive comparison of Fig. 5, stimuli were displayed on a calibrated liquid crystal display (ASUS ROG Swift PG258; 1,9201,080 resolution and 200-Hz refresh rate), and eye movements were acquired by a custom digital DPI eye tracker with subarcminute resolution (55). Vertical and horizontal eye positions were sampled at 1 kHz, following low-pass filtering (cutoff frequency 500 Hz) of the analog data.

Stimuli were designed to loosely replicate the visual input signals experienced by primates while engaged in grooming. They consisted of 30 gray dots (the test locations; each a 5 dark square at 2.8 cd/m2 luminance) simulating fleas and dust particles, which were randomly distributed within the central 2 region of the display. These objects were displayed over a naturalistic noise-field background, which simulated the fur of the animal and covered the entire display, approximately 17 of visual angle. The power spectrum of the background decreased proportionally to the square of the spatial frequency as happens in natural scenes. The average luminance of the display was 7 cd/m2. An example of the central portion of the stimulus in a trialthe region containing the dotsis shown in Fig. 1A. A different noise pattern and a different array of dots were displayed on each trial. Stimuli were rendered in OpenGL and modified in real time according to the observers eye movements using EyeRIS, a custom system for gaze-contingent display control (31). This system is designed to guarantee precise timing between changes in the stimulus and oculomotor events (typical delay 7.5 ms) and has been tested extensively and continually refined over the course of a decade.

Data were collected in separate sessions, each lasting approximately 1 h. Every session started with preliminary procedures to ensure optimal eye tracking and gaze-contingent control. Data were then collected in blocks lasting 10 to 15 min, with breaks between blocks to allow the subject to rest. Every experimental session consisted of five blocks of 40 trials.

Accurate localization of the line of sight was achieved by means of a gaze-contingent two-step calibration already described in previous publications (6, 34). During the first stage of this procedure, subjects completed a standard nine-point calibration by sequentially looking at markers of a 3 3 grid. In the second stage, observers used a joypad to finely refine the estimated location of the center of gaze, which was displayed in real time on the monitor. This refinement was also repeated after every trial for the central point of the grid to compensate for possible drifts in the apparatus and/or small head adjustments that may also occur under head immobilization. We have previously shown that this gaze-contingent calibration improves localization of the line of sight by approximately one order of magnitude over standard methods (6).

To measure contrast sensitivity during normal oculomotor activity, we developed a grooming task, a high-acuity task designed after primates social grooming that naturally incorporates visual search and detection of transient events (Fig. 1B). Observers were instructed to search for fleas (dark dots) hidden within the fur of an animal (the noise field). They were told that some of the dots at the test locations were fleas whereas others were dust particles and that the fleas would occasionally reveal themselves by jumping, a 10-ms pulse in luminance (the probe) that randomly occurred during the trial. Observers were asked to catch each flea as soon as they saw it jumping by pressing a button on a joypad.

To assess sensitivity at various retinal positions and different times relative to saccades, the eye movements of six observers were continually monitored, and the probes delivered in a gaze-contingent fashion timed to the onset of saccades, as signaled in real time by EyeRIS (estimated instantaneous speed >9/s). Following detection of a saccade, one of the test locations was selected and the probe activated after a random delay (0 to 400 ms). Selection of the probe location was based on the current location of gaze, to uniformly sample the two quadrants on the retina centered on the horizontal meridian at eccentricities smaller than 1 (Fig. 2A). To test one specific retinal location and temporal delay, a saccade could activate only one probe, and each probe was followed by a 700-ms refractory period during which no other contrast pulse occurred. Precise timing of all relevant events was saved by EyeRIS for offline analysis. Subjects were not informed of any of the rules determining the presentation of the probes and remained fully unaware that changes in the display were triggered by their eye movements.

Every trial had a fixed duration of 5 s. It started with the presentation of a new stimulus (a new noise field and pattern of dots) and consisted of two phases: familiarization and search (Fig. 1B). No probe was activated during the initial 1-s familiarization phase. Probes were displayed during the search phase and marked as hits if they were followed by a button press within 0.3 to 1 s, an interval chosen based on the typical range of reaction times in this experiment (median 492 ms; 95% confidence interval 311 to 780 ms). In each trial, the change in luminance (the amplitude of the pulse) varied randomly among 20 possible values ranging from 2.8 to 11 cd/m2, with the formerthe resting luminance level of the probecorresponding to an intermediate intensity value chosen to minimize phosphor persistence and the latter corresponding to the maximum intensity allowed by the monitors settings. Luminance steps varied occasionally across experimental sessions to ensure accurate fitting of the psychometric functions. The number of probes in a trial varied, depending on the numbers of saccades performed by the observer. Subjects were run extensively to estimate contrast sensitivity functions at three retinal eccentricities and eight times relative to saccades. On average, 17,000 probes in 6,000 trials were collected from each observer in 30 experimental sessions.

To disentangle the motor and retinal consequences of saccades, an additional condition was introduced in Fig. 5, in which subjects were passively exposed to the same visual signals previously experienced during normal execution of the task. In this condition, subjects reported the activation of the probes in movies that reconstructed the spatiotemporal patterns resulting on the retina from the combinations of the stimuli on the display and the recorded sequences of eye movements. Each movie replicated the visual input of a previously executed normal trial. Subjects maintained fixation for the entire duration of the trial and movies were rendered under retinal stabilization; i.e., they shifted on the display to counteract the ongoing fixational movements of the eye, to replicate retinal stimulation with the greatest possible accuracy.

Recorded oculomotor traces and the events data saved by EyeRIS were examined offline to determine the precise position of each probe on the retina and its timing relative to saccades. Only blink-free trials with optimal, uninterrupted eye tracking were selected for analysis.

We first segmented each trace into complementary periods of saccades and fixations based on the eye speed. Data segments in which the eye displaced by more than 3 reaching a speed of 3/s were marked as possible saccades, and their onset and offset were defined as the initial and final times at which the eye speed exceeded and returned to below 2/s, respectively. Consecutive events closer than 15 ms were merged together, a method that automatically takes care of possible postsaccadic overshoots. Segmentation of the traces was performed automatically and then validated by manual inspection. Saccade amplitude was defined as the modulus of the vector connecting the eye positions at onset and offset.

Each probe was associated with the closest saccade based on temporal proximity. This event was not necessarily the one that triggered the probe during the course of the trial, as other saccades could have occurred closer to the probe, as in the examples S3 and S4 in Fig. 1C. Only probes with no more than one saccade within 200 ms and associated with saccades smaller than 1 were considered in the analyses. To examine visual sensitivity at various visual eccentricities and lags relative to saccades, probes were clustered in 24 spatiotemporal bins (Fig. 2A). In space, we mapped performance in three eccentricity ranges in the 45 circular sectors centered on the horizontal median: 0 to 15, 15 to 30, and 30 to 60. In time, we examined the evolution of contrast sensitivity at eight intervals around selected saccadic events: saccade onset, offset, and peak velocity.

Psychometric functions of contrast sensitivity were independently evaluated in each of these bins via a maximum-likelihood procedure (examples in Fig. 2B). A cumulative log-normal function was fitted to the performance data measured at various contrasts by means of the Psignifit Matlab toolbox (56). The contrast sensitivity values reported in Figs. 25 are the inverse of the Michelson contrast,C=II0I+I0=I2I0+I,where I0 represents the baseline intensity of the probe (3 cd/m2) and I is the change in luminance of the pulse (I=I0+I). Virtually identical results were obtained by measuring changes in Weber contrast of the probe relative to its surroundings (SI Appendix, Fig. S2). To follow the dynamics of the low visibility measured around the time of saccades, we summarized performance by the contrast thresholds yielding 25% correct detection. For each subject and spatiotemporal bin, variability in the estimated threshold was assessed by nonparametric bootstrap over 1,000 random samples of the probes (error bars in SI Appendix, Fig. S1). Subjects were run extensively to collect a sufficient amount of data for a reliable estimation of contrast thresholds in all bins. On average, 10,000 probes were used to construct the spatiotemporal map of contrast sensitivity for each individual, corresponding to 65% of the total number of probes.

The spectral density map in Fig. 1F was obtained by reconstructing the luminance signals delivered by the recorded saccades and estimating their power spectra. The spectral analysis was conducted using an approach that allows high spatial resolution, as previously described in the literature (29), and then averaged across subjects. The lines mapping the range of visibility are typical contrast thresholds taken from classical measurements of human sensitivity in the absence of retinal image motion (33).

In the analysis of Fig. 4 B and C, we compared presaccadic sensitivity when the probe location was targeted by the saccade (the saccade landed within 15 of probe) and when the saccade landed farther away. To reach sufficient numbers of trials in which the saccade relocated gaze on the activated probe, we estimated thresholds via bootstrap on the ensemble of trials pooled across subjects.

The contrast thresholds data and matlab scripts used to produce the figures in the main text have been deposited into the Open Science Framework repository (https://osf.io/jqg59/).

This work was supported by NIH Grants F31EY029565 (to J.I.) and R01EY18363 (to M.R.) and NSF Grants BCS-1457238 (to M.R.). We thank Martina Poletti for helpful comments and discussion during the course of this research.

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Fast and nonuniform dynamics of perisaccadic vision in the central fovea - pnas.org

On June 3, 1965, NASA Astronaut (and former Scout) Ed White made history by completing the first American spacewalk. Tucked into a pocket of his spacesuit was the Space Exploration merit badge. (Photo courtesy of NASA)

All new merit badges get introduced. Only one has gotten launched.

On June 3, 1965, two astronauts (both former Scouts) rocketed into space aboard NASAs Gemini 4. They carried with them an extra special payload: a small round emblem representing the Space Exploration merit badge, which was then the BSAs newest merit badge.

When astronaut Ed White took his walk into space the first ever spacewalk by an American that small circle of embroidered threads and khaki cloth was tucked into the pocket of his spacesuit.

I think that Scouting teaches us to be independent, to rely on ourselves and to solve our problems in the best way as they come up, White later told Scouting magazine. The things they are learning will equip them to be good citizens, and that is really the big value in Scouting.

The Space Exploration merit badge debuted during the height of the space race. In the 1960s, young people around the world were transfixed by the steady stream of out-of-this-world firsts achieved by American astronauts and Soviet cosmonauts.

The badge was developed in close cooperation with NASA, demonstrating how top experts in science, industry, education and government are helping develop requirements for modern merit badges, Scouting magazine wrote in its March 1966 issue. That trend continues today.

The launch of the Space Exploration merit badge could not have come at a better time. Just four years after its release came the biggest milestone in the space race: Eagle Scout Neil Armstrongs 1969 walk on the moon.

At 56 years old, the merit badge remains popular among Scouts. With commercial space travel, return visits to the moon and manned trips to Mars on the horizon, the badge remains relevant, too.

The 50-Miler Award honors any youth or adult member who completes a trek of at least 50 miles by boat, by canoe, on foot, by horse or by bicycle.

Notably missing from that list of transportation options: a two-stage liquid-fuel rocket like the one used to carry former Scouts White and James A. McDivitt into orbit.

But just this once, the Boy Scouts of America made an exception. After White and McDivitt safely returned to Earth, the BSA presented the Gemini 4 astronauts with an honorary 50-Miler Award.

In exchange, Robert R. Gilruth, director of NASAs Manned Spacecraft Center (later renamed the Lyndon B. Johnson Space Center), presented the BSA with the actual merit badge that had flown in space.

So wheres the badge now? That important piece of NASA, American and BSA history is currently displayed at the National Scouting Museum at Philmont Scout Ranch in New Mexico.

The badge is part of an entire exhibit devoted to the strong ties between NASA and Scouting. About two-thirds of all astronauts and 11 of the 12 men who walked on the moon were Scouts.

The exhibit also includes photographs, mission patches, the spacesuit gloves that belonged to Eagle Scout James A. Lovell Jr. and an American flag taken to the surface of the moon by Eagle Scout Charles M. Duke Jr.

See more in the museums virtual tour.

In December 1965, NASA astronauts pulled off the worlds first rendezvous in space.

The crews aboard Gemini 6 and Gemini 7 met in space at an altitude of 160 miles. At one point during the encounter, the two capsules were a mere 1 foot apart.

While these Gemini missions made front-page news for scoring another point in the space race, they made headlines in the BSA for a different reason: All astronauts involved were Scouts.

In Gemini 6, Walter M. Schirra Jr. was a First Class Scout, and Thomas P. Stafford was a Star Scout. Gemini 7 contained Eagle Scout James A. Lovell and Tenderfoot Scout Frank Borman.

This quartet of former Scouts inspired Scouting magazine to dub this rendezvous the first patrol meeting in space.

Even before the cloth version of the Space Exploration merit badge made its way to orbit, news of the badge made its way to The New York Times.

In a front-page story from March 6, 1965, the above-the-fold headline declared that Scouts Keep Pace With Atomic Age.

Scout merit badges used to be awarded for such homely skills as Blacksmithing, Pathfinding and Stalking (to take three, now obsolete, from the 1919 Scout Handbook), the article says. Today the badge program is setting youths toward new horizons. And the old Pathfinding badge may soon have its modern equivalent in one awarded for Space Exploration.

Then: These were the requirements for the Space Exploration merit badge when it launched in 1965.

Now: Here are the current* requirement for the Space Exploration merit badge.

*Requirements current as of the post date for this story. For the latest merit badge requirements, go here.

Want more merit badge history? Go here.

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How the BSA and NASA launched the Space Exploration merit badge - Scouting Magazine

SETI Institute expands Science Advisory Board, adding multidisciplinary expertise

September 2, 2021, Mountain View, CA The SETI Institute has appointed three new members to its Science Advisory Board (SAB) bringing expertise in space governance, science advocacy, international engagement and the ethics of space exploration: Timiebi Aganaba (Arizona State University), Kathryn Denning (York University) and Emily Lakdawalla (author and science communicator). These new members bring experience and networks to the SAB comprised of leaders, scientific pioneers, researchers, and educators. The SAB is responsible for advising SETI Institute leadership on its scientific priorities, possible partnerships and collaborations and potential funding sources. SAB members serve renewable two-year terms.

The SETI Institutes Science Advisory Board provides vitally important external perspectives and counsel to better understand relevant national and global science priorities to help guide our research and education programs, said Bill Diamond, SETI Institute CEO. Timiebi, Kathryn and Emily each bring unique and invaluable capabilities and expertise to the Board, and were delighted to count them among its members.

"I am thrilled to welcome our new Science Advisory Board members, who help to broaden the range of expertise the SETI Institute brings to the search for life beyond Earth, said Lucianne Walkowicz, Chair of the SETI Institutes SAB. Given the truly multidisciplinary challenge of the SETI Institute'swork, I am particularly happy to see our advisory board branch out to include social scientists, policy experts, and professional communicators, in addition to our members in the natural sciences."

Timiebi Aganaba

Timiebi brings an extraordinary perspective to the Space world, having worked in 5 different countries (UK, France, Nigeria, Canada, USA) across 3 continents in 6 fields (law firm, consulting firm, govt., academia, NGO, think tank) and 4 different functions (legal, research, teaching, executive) over her 15 year career. She is an assistant professor of Space and Society, in the School for the Future of Innovation in Society within the College of Global Futures, with a courtesy appointment at the Sandra Day O'Connor College of Law at Arizona State University. She was a post-doctoral fellow and fellow at the Centre for International Governance Innovation (CIGI) based in Waterloo, Ontario, Canada, where she focused on Climate change and environmental law and governance.

Previously, Timiebi was Executive Director of the World Space Week Association, coordinating the global response to the UN 1999 declaration that World Space Week should be celebrated from October 4-10 annually. She is currently on the Advisory Board for the Space Generation Advisory Council supporting the UN Program on Space Applications. She is also on the ScienceAdvisory Board of World View Enterprises, working to spearhead the stratospheric economy.

Kathryn Denning

Kathryn Denning, PhD, is a Canadian anthropologist and archaeologist. She specializes in the long view of humanity's history, both past and future, and is particularly interested in ethics -- how we engage with other humans across time, and how we engage with other species, including the extinct, extant, and as-yet-unknown. All this combines in her long-term research focus on humanity's cultural expansion into space, how we imagine our future beyond Earth, and how we anticipate other life that has yet to be discovered.

Kathryns degrees (McMaster, Sheffield) were in four-field anthropology and archaeology. After early work focusing on the public understanding of archaeology, her research turned primarily to outer space. She has collaborated with scientists at the NASA Astrobiology Institute and SETI Institute, guest lectures regularly at the International Space University, and is a member of the International Academic of Astronautics SETI Permanent Committee. On the subject of space, ethics, and the public, she regularly speaks to journalists, including Wired, New Yorker, NYT, Motherboard, Space.com, BBC, and participates in public events such as the Royal Society, New York Festival of Science, and SXSW. She is passionate about fair and accurate space education for all.

Emily Lakdawalla

Emily is a freelance science writer and speaker with expertise in planetary geology, robotic exploration of the solar system, and science education. She has taught middle-grade science, written for numerous websites and magazines including those of The Planetary Society, Sky & Telescope, and BBC Sky at Night, and advised space professionals on effective science communication. She is an illustrator and leader in a global community of amateur space image data processors. Her first book,The Design and Engineering of Curiosity: How the Mars Rover Performs Its Job, was published in 2018.

She is a member of NASAs Planetary Data System Ring-Moon Node Advisory Council, managed by the SETI Institute, and the Board of Open Planetary, and the Advisory Board for the Society for Women in Space Exploration. The Open University awarded her an honorary doctorate in 2017 in recognition of her contributions to communicating space science to the public.

About the SETI InstituteFounded in 1984, the SETI Institute is a non-profit, multidisciplinary research and education organization whose mission is to lead humanity's quest to understand the origins and prevalence of life and intelligence in the universe and share that knowledge with the world. Our research encompasses the physical and biological sciences and leverages expertise in data analytics, machine learning and advanced signal detection technologies. The SETI Institute is a distinguished research partner for industry, academia and government agencies, including NASA and NSF.

Contact Information:Rebecca McDonaldDirector of CommunicationsSETI Institutermcdonald@SETI.org

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SETI Institute Adds Experts in Space Governance, Science Advocacy and the Ethics of Space Exploration to Science Advisory Board - SETI Institute

NASA has sometimes been scrutinized for spending billions of dollars on space exploration and travel. The argument goes like this, why do we need to spend billions of dollars and the energy of the most creative people on space explorations when we can actually send that capital and mental energy to solve problems on Earth.

According to a Space News report, an opinion poll on completing 50 years since Man stepped on Moon revealed that only 27% of people think that expeditions to Mars are important.

By the looks of it, it does look like a valid, well-intentioned argument. However, there are glaring gaps in it, which brings it to the brink of being an absurd question. In reality, space explorations and space-related research have immensely benefitted people on Earth.

Be it technology, medicine, health, roads, shoes, NASAs research projects have given birth to numerous tools and techniques that have made peoples lives easier than ever.

Neil DeGrasse Tyson, the famous astrophysicist, once extensively discussed the same argument in a podcast with Joe Rogan. He claimed that the third of the worlds GDP comes from computing and the Information Technology sector, the origin of which could be traced back to Quantum Physics, discovered in the 1920s.

He then mentions about one of his professors, who was an avid observer of the universe. He was researching on detection of gas clouds between stars, which led him to discover a new phenomenon in Physics called Nuclear Magnetic Resonance.

This phenomenon, when came under the observation of a medical technologist, gave birth to the Magnetic Resonance Imager (MRI), which is one of the most important inventions in medical science. This goes on to prove how exploring space, which, to a layman taxpayer, looks trivial, holds utmost significance.

Technologies like GPS, power tools, things like athletic shoes, memory foam, scratch-resistant glass, smoke detectors, and safety grooves on roads all came from space-related researches.

Space not only solves the problems of the present but also maps the road to solutions to future problems. Do you still think space exploration is a waste of capital and human energy?

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'Need for Space': How Have Humans Benefited From Exploration of the Universe? - News18

China's moon-sampling mission spacecraft is continuing its extended mission with its destination currently unknown.

HELSINKI The Change-5 orbiter module which facilitated Chinas complex lunar sample return last year is on its way to the moon following deep space tests.

The orbiter, one of four distinct Change-5 mission spacecraft, delivered a return module containing 1.731 kilograms of lunar samples to Earth Dec. 16 before firing its engines to deep space for an extended mission.

The Change-5 orbiter later successfully entered an intended orbit around Sun-Earth Lagrange point 1, roughly 1.5 million kilometers, in March. There it carried out tests related to orbit control and observations of the Earth and Sun.

New data from satellite trackers now suggests Change-5 has left its orbit around Sun-Earth L1 and is destined for a lunar flyby early September 9 Eastern time.

It was noted that Change-5 may have altered its orbit Aug. 30 based on observations by and data from amateur satellite trackers Daniel Estevez and Scott Tilley and independent astronomy software developer Bill Gray.

The spacecraft is under the control of the Beijing Aerospace Flight Control Center (BACC), which is responsible for telemetry, tracking and command of spacecraft. BACC has not yet provided an update on the plans for Change-5.

Potential maneuvers such as entering lunar orbit, heading for another Sun-Earth Lagrange point or an Earth-moon Lagrange point depend on how much propellant the orbiter has remaining. Another possibility could be using the flyby to set Change-5 on a trajectory to flyby 469219 Kamooalewa, a quasi-satellite of Earth and the target for Chinas 2024 near Earth asteroid sample-return mission.

Jing Peng, deputy chief designer of the Change-5 spacecraft system at the China Academy of Space Technology (CAST), said during the Global Space Exploration (GLEX) conference in St. Petersburg, Russia, in June, that a visit to a planetary body such as Venus may not be possible due to a lack of propellant.

I dont think there will be many opportunities for the orbiter to perform more complex orbit maneuvers with other bodies, he said. I think it will stay in Lagrange point 1 or the Earth-moon system, Peng said.

Samples collected by the Change-5 lander from near Mons Rmker in Oceanus Procellarum in the northwest of the near side of the moon are now being analyzed. Applications for sample materials are now open to domestic and international institutions.

NASA currently has no plans to trade any of its Apollo-era lunar samples with those returned by Chinas Change-5 mission, although the agencys chief scientist Jim Green expressed hope for such an exchange in the future.

China is planning a followup lunar sample-return, Change-6, in 2024 which is nominally part of the joint China-Russia International Lunar Research Station. The French space agency will contribute a science payload to Change-6.

Chinas Lunar and Planetary Data System earlier this month provided a rare update on the ongoing Change-4 lunar far side mission. The Yutu-2 rover has now covered roughly 799 metres across 33 completed lunar days since landing in Von Krmn crater in January 2019.

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China's Chang'e-5 orbiter is heading back to the moon - SpaceNews