Category Archives: Astronomy

The world of astronomy has already offered a pretty fascinating start to 2024. In just the first five days of the year, we've seen incredible discoveries like the true colors of Neptune and Uranus as well as a massive cyclone raging on a distant exoplanet thanks to the trusty Hubble Space Telescope. But things are only going to ramp up over the next week. By a lot.

From Jan. 7 to Jan. 11, the 243rd meeting of the American Astronomical Society will convene in the vibrant city of New Orleans, Louisiana.

Thousands of scientists specializing in an absolutely incredible array of subjects ranging from dark matter mysteries to star explosions and the search for habitable exoplanets to the technology required to propel spacecraft across the solar system will gather in one area. They'll get ready to announce some of the best and brightest studies they've been working on; meanwhile, they'll be figuring out how to get even bigger and brighter with their next by listening to wild ideas, strange contradictions and telescopic achievements their colleagues will lay out. Some have even called this event the "Super Bowl of Astronomy."

Related: The Magellanic Clouds must be renamed, astronomers say

NASA will be there too, to offer updates on major missions like the trailblazing, $10 billion James Webb Space Telescope and the upcoming, highly anticipated, Habitable Worlds Observatory. According to a statement released on Jan. 5, NASA will also be discussing the 2024 total solar eclipse, which will take place on April 8, the Transiting Exoplanet Survey Satellite (TESS), the Nancy Grace Roman Telescope currently under construction and even its scientific balloon program.

"Experts will discuss new research from NASA missions at the 243rd meeting of the American Astronomical Society (AAS) on topics ranging from planets outside our solar system to fleeting, high-energy explosions in the universe," the agency said in the statement.

All NASA press conferences will be streamed for the public to view on AAS's Press Office YouTube channel; other conferences during the meeting will be found there as well. After the meeting concludes, the streams will be available to view on an online archive provided by the organization. You'll notice that this archive includes a wealth of presentations from previous years as well.

Beyond NASA, teams from other iconic space facilities, current and upcoming, are scheduled to speak, too. Members of the Rubin Observatory, for instance, are expected to let everyone know how things are going with their efforts to discover tens of billions of galaxies once its construction is complete in Chile. But, as we'd mentioned, perhaps the most interesting and hopefully mind-blowing presentations will be coming from researchers speaking during the event.

Though we don't have a ton of information yet on each of those talks, we're able to see some of the study headlines. And they look quite intriguing. For instance, Jan. 8 is poised to bring us an update on a "dark galaxy," the origins of "odd radio circles," and a "famous exploded star in its best light." Jan. 9 appears to have information concerning an exoplanet's tail-like escaping atmosphere and a highly distant fast radio burst seen by the Hubble Space Telescope. Jan. 10 has something about a "supernova imposter" on its schedule and Jan. 11 beholds an entire category of presentation dubbed "Oddities in the Sky." This honestly barely scratches the surface. You can have a look at the full list of presentations here.

Briefings are scheduled to begin between (and including) Jan. 8 to Jan. 11 at 10:15 a.m. CST (11:15 a.m. EST) and then again at 2:15 p.m. CST (3:15 p.m. EST). During the week, you can follow along with Space.com as we bring you some of the AAS's 243rd meeting highlights.

Read this article:

The 'Super Bowl of Astronomy' begins next week in New Orleans - Space.com

Oops! Scientific American did it again, this time with an op-ed that could have been ripped from the pages of The Onion. As is so common these days, the piece proposes that we change the language of science (astronomy in this case), since some of its terms are bad in four ways:

a. They are violent, sexist, and triggering

b. They are not beautiful and elegant like astronomy is, but grating; and they are not kind

c. They are non-inclusive, presumably helping keep minorities out of astronomy.

d. They are untruthful and distort astronomy

In my view, none of these claims holds up, for the article is all Pecksniffian assertion with not a shred of evidence. Author Juan Madrid assumes the role of a bomb-sniffing dog, snuffling the field of astronomy for linguistic mines.

Click the headline below to read and weep, or find the piece archived here. The author is identified this way (my link):

Juan P. Madridis an assistant professor in the department of physics and astronomy at the University of Texas Rio Grande Valley.

The piece begins by describing a collision that will take place, 4 to 7 billion years hence, between the Milky Way and its closest galaxy, Andromeda. Immediately the word collision is seen as triggering. One of Madrids students described the future collision instead as a giant galactic hug. But the person who sent me this link added this comment:

My wife says that if Andromeda doesnt want the Milky Way to hug her then its interstellar sexual assault.

Indeed! But Madrid hastens to instruct us why using collision is not only grating, but misleading:

The kindness, but also the accuracy, of the language my student used was in sharp contrast to the standard description we use in astronomy to explain the final destiny of Andromeda and the Milky Way: a collision. But as astronomers have predicted, when Andromeda and the Milky Way finally meet, their stars will entwine and create a larger cosmic structure, a process that is more creating than destroying, which is what we envision when we use the termcollision. A galactic hug is scientifically truthful, and its led me to believe that astronomers should reconsider the language we use.

First of all collision doesnt mean destroying, but simply two objects hitting each other. In this case, two galaxies collide, but their stars are spread so far apart that theyll simply merge into one big galaxy and star will not hit star. You could say merge instead of collide, but that also implies that perhaps the stars will absorb each other. If you want to convey the idea that nothing gets banged up, then, Madrid suggests using galactic hug. He actually wants astronomers, their classes, and their textbooks, to adopt this new, kind, and romantic term. (There are, of course, more salacious terms that could be used.) But they wont be because they sound dumb, and in fact galactic hug is just as inaccurate as the other terms, for hug implies that there is some mutual enfolding, when in fact, the entities merge and do not remain separate, as humans do when they have a (temporary) hug. When Fred and Sue hug each other, they dont merge into one person. . .

And so Madrid, combing the literature for other terms that are jarring and, he says, misleading, finds more, as of course he would. (You can do this in any field of biology, chemistry. or physics; all you need is a sufficiently diligent Pecksniff). Ive singled out Madrids instances of bad language below by adding my own links, and putting those words in bold.

For instance, in galaxy evolution we invoke imagery strikingly similar to what you would expect if you were eavesdropping on Hannibal Lecter: words like cannibalism, harassment [JAC: no instance found], starvation, strangulation, strippingorsuffocation. There is a rather long list of foul analogies that have entered, and are now entrenched, in the lexicon of professional astronomy. We have grown accustomed to this violent language and as a community, weseldom questionor reflect on its use.

Strangulationis a particularly cringeworthy term in astronomy, referring to the decline of the number of stars born in some types of galaxies. This is a vicious crime where most often thevictim is a woman; the perpetrator, a man. Yet, we use this word mindlessly to describe a slow astronomical process that takes millions of years. Under certain conditions, some galaxies use up or lose the gas that is the primordial ingredient to form stars. When that happens, galaxies make new stars at a lower rate. But these galaxies do not die or suffer great harm. They will continue to shine and will live their natural evolution.

This is but one of many examples of violent language in our field that actually describes something gradual, slow and perhaps even gentle.

Madrid was savvy enough to impute misogyny to one of these terms: strangulation, giving some woke heft to his thesis. But if you look at how the terms are used, only someone who wants to be offended would be. Moreover, they are not inaccurate. Starvation, for example, refers to something that cuts off the flow of gas that galaxies need for new star formation. I dont find it inaccurate at all. In fact, none of these terms are inaccuratewhat Madrid really objects to is that they are triggering and unwelcoming. He tries to sell his campaign to deep-six these terms as being untruthful, because he doesnt want to look like an ideologue, but Im not buying it. Also he allows explosion for the creation of a supernova, in most cases he finds this language needlessly vicious and [promoting] inaccurate connotations.

In short, Madrid finds this language triggering, for thats the only explanation for why we should avoid this kind of vicious language. And, as he says below,

The use of hypercharged words in our field ignores the fact that this violent imagery can trigger distress in colleagues who might have been victims of violence.

But there are two points to be made here. First, as I noted in a recent post, giving the relevant studies, Trigger warnings dont work and can even causemore trauma. There is no evidence that using this sort of language somehow harms the students. In fact, the remedy for those who are traumatized by certain words is not to avoid exposure to them, but to learn to not be upset when you are exposed. There is therapy for this.

Second, as is so often the case in these screeds, Madrid gives no examples of how the bad language upsets people. He should be able to produce at least a dozen cases on the spot, like Jane got upset and left the class when she heard the word strangulation', or Bob reported Professor Basement Cat to the university for using the term cannibalism on the astronomy exam, which, he said, made him think of the Donner Party and prevented him from completing the exam. In nearly all of these language-policing articles, there is a surfeit of outrage and a dearth of examples or evidence of harm.

But Madrid circumvents the lack of evidence and simply suggests ways that we can censor this language, again pretending hes interested mainly in scientific truth:

To shift toward more welcoming and truthful language in astronomy, scientific journals can push to change the currently accepted language. The referee, or the scientific editor, can ask the authors to consider more appropriate descriptions of the physical processes involved. Referees, editors and editorial boards can step up to enforce scientific accuracy and stop the use of violent, misogynistic language that is now pervasive. This is a call for scientific precision. The use of hypercharged words in our field ignores the fact that this violent imagery can trigger distress in colleagues who might have been victims of violence.

Can, could have, might have. Where are the examples of this? The sweating professor gives none. And isnt it amazing that the more accurate language is always the kinder language?

And, as expected, Madrid manages to drag race, inclusion, and diversity into his discussion, even though none of the terms above have anything to do with race. And this belies his faux concern mainly for scientific accuracy:

As astronomers, we must strive to create a more inclusive and diverse community that reflects the composition of our society.Valuable effortsto provide opportunities for women and minorities to succeed in astronomy have been created. However,by many metrics, the progress made towards gender equality and true diversity has beenpainfully slow.

We must listen to the new generation of astronomers. My student showed me that while some astronomical processes can be intense, the universe revealed through astronomy provides us with the most fascinating sights known to humankind. Like many other young scientists, she thinks that when we explain astronomical phenomena with wording and phrases that share our excitement and appreciation, it also encourages others to join in and wonder what else we can discover together.

The universe is beautiful, elegant and ever-changing. Astronomy would be wise to follow its lead.

And so, in the end, we see that this kind of misguided effort, concentrating on words rather than science itself, is part of the corruption that has entered science via DEI and its ideology. What we have is one more attempt to control thought by controlling language.

There is no evidence that minorities and women are being kept out of astronomy because they dont find its language inclusive,, though thats really the thesis of Madrids piece. But the very idea that this thesis is true is laughable. Promoting the idea that galaxies hug each other is not going to bring people pouring into astronomy.

Once again Scientific American, trying to ride the woke bandwagon, has fallen off the train. Blame not only the author, but the editor, who actually approved this nonsense.

Read the original:

Scientific American proposes policing the language of astronomy to make it beautiful and elegant, as well as ... - Why Evolution Is True

In summer 2022, astronomers detected the most powerful fast radio burst (FRB) ever observed. And coming from a location that dates halfway back to the Big Bang, it also was the farthest known FRB spotted to date.

Now, astronomers led by Northwestern University have pinpointed the extraordinary objects birthplace and its rather curious, indeed.

Using images from NASAs Hubble Space Telescope, the researchers traced the FRB back to not one galaxy but a group of at least seven galaxies. The galaxies in the collection appear to be interacting with one another perhaps even on the path to a potential merger. Such groups of galaxies are rare and possibly led to conditions that triggered the FRB.

The unexpected finding might challenge scientific models of how FRBs are produced and what produces them.

Without the Hubbles imaging, it would still remain a mystery as to whether this FRB originated from one monolithic galaxy or from some type of interacting system, said Northwesterns Alexa Gordon, who led the study. Its these types of environments these weird ones that drive us toward a better understanding of the mystery of FRBs.

Gordon will present this research during the 243rd meeting of the American Astronomical Society in New Orleans, Louisiana. Revealing the Environment of the Most Distant Fast Radio Burst with the Hubble Space Telescope will take place at 2:15 p.m. CST on Tuesday (Jan. 9) as a part of a session on High-Energy Phenomena and Their Origins. Reporters can register here.

Gordon is a graduate student in astronomy at Northwesterns Weinberg College of Arts and Sciences, where she is advised by study co-author Wen-fai Fong, an associate professor of physics and astronomy. Fong and Gordon also are members of the Center for Interdisciplinary Exploration and Research in Astrophysics (CIERA).

Flaring up and disappearing within milliseconds, FRBs are brief, powerful radio blasts that generate more energy in one quick burst than our sun emits in an entire year. And the record-breaking FRB (dubbed FRB 20220610A) was even more extreme than its predecessors.

Not only was it four times more energetic than closer FRBs, it also clocked in as the most distant FRB yet discovered. When FRB 20220610A originated, the universe was just 5 billion years old. (For comparison, the universe is now 13.8 billion years old.)

In early observations, the burst appeared to have originated near an unidentifiable, amorphous blob, which astronomers initially thought was either a single, irregular galaxy or a group of three distant galaxies. But, in a new twist, the Hubbles sharp images now suggest the blob might be as least as many as seven galaxies in incredibly close proximity to one another. In fact, the galaxies are so close to one another that they could all fit inside our own Milky Way.

There are some signs that the group members are interacting, Fong said. In other words, they could be trading materials or possibly on a path to merging. These groups of galaxies (called compact groups) are incredibly rare environments in the universe and are the densest galaxy-scale structures we know of.

This interaction could trigger bursts of star formation, Gordon said. That might indicate that the progenitor of FRB 20220610A is associated with a fairly recent population of stars which matches what weve learned from other FRBs.

Despite hundreds of FRB events discovered to date, only a fraction of those have been pinpointed to their host galaxies, said study co-author Yuxin (Vic) Dong, an NSF Graduate Research Fellow, astronomy Ph.D. student in Fongs lab and member of CIERA. Within that small fraction, only a few came from a dense galactic environment, but none have ever been seen in such a compact group. So, its birthplace is truly rare.

Although astronomers have uncovered up to 1,000 FRBs since first discovering them in 2007, the sources behind the blinding flashes remain stubbornly uncertain. While astronomers have yet to reach a consensus on the possible mechanisms behind FRBs, they generally agree that FRBs must involve a compact object, such as a black hole or neutron star.

By revealing the true nature of FRBs, astronomers not only could learn about the mysterious phenomena but also about the true nature of the universe itself. When radio waves from FRBs finally meet our telescopes, they have traveled for billions of years from the distant, early universe. During this cross-universe odyssey, they interact with material along the way.

Radio waves, in particular, are sensitive to any intervening material along the line of sight from the FRB location to us, Fong said. That means the waves have to travel through any cloud of material around the FRB site, through its host galaxy, across the universe and finally through the Milky Way. From a time delay in the FRB signal itself, we can measure the sum of all of these contributions.

To continue to probe FRBs and their origins, astronomers need to detect and study more of them. And with technology continually becoming more sensitive, Gordon says more detections potentially even capturing incredibly faint FRBs are right around the corner.

With a larger sample of distant FRBs, we can begin to study the evolution of FRBs and their host properties by connecting them to more nearby ones and perhaps even start to identify more strange populations, Dong said.

In the near future, FRB experiments will increase their sensitivity, leading to an unprecedented rate in the number of FRBs detected at these distances, Gordon said. Astronomers will soon learn just how special the environment of this FRB was.

The study, A fast radio burst in a compact galaxy group at z ~ 1, was supported by the National Science Foundation (award numbers AST-1909358, AST-2047919 and AST-2308182), the David and Lucile Packard Foundation, the Alfred P. Sloan Foundation, the Research Corporation for Science Advancement and NASA (award number GO-17277). Astronomers first detected FRB 20220610A with the Australian Square Kilometer Array Pathfinder radio telescope in Western Australia and then confirmed its origin with the European Southern Observatorys Very Large Telescope in Chile.

Read more:

'Blob-like' home of farthest-known fast radio burst is collection of seven galaxies - Northwestern Now

Typically, new stars form when diffuse atomic gas condenses into concentrations of molecular gas, forming molecular clouds. The high-density cores within these molecular clouds act as triggers for star formation. While this process is common in the inner regions of galaxies, it becomes less common toward the outer edges of galaxies.

A team of astronomers has discovered unusual star formation at the outer edge of the galaxy M83. The study utilized various instruments, including ALMA, VLA, GBT from NRAO, Subaru Telescope from NAOJ, and GALEX from NASA.

The team identified 23 molecular clouds exhibiting a distinct type of star formation at the outer edges of the galaxy M83. Unlike typical molecular clouds, only the star-forming dense cores of these clouds were observed. This discovery provides valuable insights into the physical processes involved in star formation at the far edges of galaxies.

Astronomer Jin Koda of Stony Brook University, who led this research, said,The star formation at galaxy edges has been a nagging mystery since their discovery by the NASA GALEX satellite 18 years ago.

David Thilker of Johns Hopkins University commented,Previous searches for molecular clouds in this environment were unsuccessful. Seeing the search for dense clouds associated with the outer disk finally come to fruition has been gratifying, revealing a characteristically different observational fingerprint for the molecular clouds.

The discovery of these molecular clouds has revealed a connection to a vast reservoir of diffuse atomic gas. While it is common for atomic gas to condense into dense molecular clouds, where even denser cores lead to star formation, the conversion of atomic gas to molecular clouds at the edges of galaxies was not previously evident and still needs to be solved.

Its remarkable that an undergraduate student, Amanda Lee, played a significant role in processing data from the Green Bank Telescope (GBT) and Very Large Array (VLA) for these findings. Her work led to the discovery of the atomic gas reservoir at the edge of the galaxy M83.

She said,We still do not understand why this atomic gas does not efficiently become dense molecular clouds and form stars. As is often the case in astronomy, pursuing answers to one mystery can lead to another. Thats why research in astronomy is exciting.

This research was presented in a press conference at the 243rd American Astronomical Society (AAS) meeting in New Orleans, Louisiana.

Here is the original post:

Astronomers revealed mysterious star formation by hearts of molecular clouds - Tech Explorist

Mathis, J. S., Rumpl, W. & Nordsieck, K. H. The size distribution of interstellar grains. Astrophys. J. 217, 425433 (1977).

Article ADS Google Scholar

McClure, M. Observational 5-20 m interstellar extinction curves toward star-forming regions derived from Spitzer IRS spectra. Astrophys. J. 693, L81L85 (2009).

Article ADS Google Scholar

Flaherty, K. M. et al. Infrared extinction toward nearby star-forming regions. Astrophys. J. 663, 10691082 (2007).

Article ADS Google Scholar

Chapman, N. L., Mundy, L. G., Lai, S.-P., Evans, I. & Neal, J. The mid-infrared extinction law in the Ophiuchus, Perseus, and Serpens molecular clouds. Astrophys. J. 690, 496511 (2009).

Article ADS Google Scholar

Jones, A. P. et al. Mantle formation, coagulation, and the origin of cloud/core shine. I. Modelling dust scattering and absorption in the infrared. Astron. Astrophys. 588, A43 (2016).

Article Google Scholar

Weingartner, J. C. & Draine, B. T. Dust grain-size distributions and extinction in the Milky Way, Large Magellanic Cloud, and Small Magellanic Cloud. Astrophys. J. 548, 296309 (2001).

Article ADS Google Scholar

Madden, M. C. L. et al. Infrared spectroscopic survey of the quiescent medium of nearby clouds. II. Ice formation and grain growth in Perseus and Serpens. Astrophys. J. 930, 2 (2022).

Article ADS Google Scholar

Ysard, N., Koehler, M., Jimenez-Serra, I., Jones, A. P. & Verstraete, L. From grains to pebbles: The influence of size distribution and chemical composition on dust emission properties. Astron. Astrophys. 631, A88 (2019).

Article ADS Google Scholar

Boogert, A. C. A. et al. Infrared spectroscopic survey of the quiescent medium of nearby clouds. I. Ice formation and grain growth in Lupus. Astrophys. J. 777, 73 (2013).

Article ADS Google Scholar

van Breemen, J. M. et al. The 9.7 and 18 m silicate absorption profiles towards diffuse and molecular cloud lines-of-sight. Astron. Astrophys. 526, A152 (2011).

Article Google Scholar

Chiar, J. E. et al. The relationship between the optical depth of the 9.7 m silicate absorption feature and infrared differential extinction in dense clouds. Astrophys. J. Lett. 666, L73L76 (2007).

Article ADS Google Scholar

Ysard, N. et al. Mantle formation, coagulation, and the origin of cloud/core shine. II. Comparison with observations. Astron. Astrophys. 588, A44 (2016).

Article Google Scholar

Saajasto, M., Juvela, M. & Malinen, J. Near-infrared scattering as a dust diagnostic. Astron. Astrophys. 614, A95 (2018).

Article ADS Google Scholar

Steinacker, J. et al. Grain size limits derived from 3.6 m and 4.5 m coreshine. Astron. Astrophys. 582, A70 (2015).

Article Google Scholar

Marchand, P., Guillet, V., Lebreuilly, U. & Mac Low, M. M. Fast methods for tracking grain coagulation and ionization. II. Extension to thermal ionization. Astron. Astrophys. 666, A27 (2022).

Article ADS Google Scholar

Silsbee, K., Ivlev, A. V., Sipil, O., Caselli, P. & Zhao, B. Rapid elimination of small dust grains in molecular clouds. Astron. Astrophys. 641, A39 (2020).

Article ADS Google Scholar

Lebreuilly, U., Commeron, B. & Laibe, G. Small dust grain dynamics on adaptive mesh refinement grids. I. Methods. Astron. Astrophys. 626, A96 (2019).

Article ADS Google Scholar

Paruta, P., Hendrix, T. & Keppens, R. Dust grain coagulation modelling: From discrete to continuous. Astronomy and Computing 16, 155165 (2016).

Article ADS Google Scholar

Ormel, C. W. An atmospheric structure equation for grain growth. Astrophys. J. Lett. 789, L18 (2014).

Article ADS Google Scholar

Smith, R. G., Sellgren, K. & Tokunaga, A. T. Absorption features in the 3 micron spectra of protostars. Astrophys. J. 344, 413 (1989).

Article ADS Google Scholar

Dartois, E., dHendecourt, L., Thi, W., Pontoppidan, K. M. & van Dishoeck, E. F. Combined VLT ISAAC/ISO SWS spectroscopy of two protostellar sources. The importance of minor solid state features. Astron. Astrophys. 394, 10571068 (2002).

Article ADS Google Scholar

Noble, J. A., Fraser, H. J., Aikawa, Y., Pontoppidan, K. M. & Sakon, I. A survey of H2O, CO2, and CO ice features toward background stars and low-mass young stellar objects using Akari. Astrophys. J. 775, 85 (2013).

Article ADS Google Scholar

McClure, M. K. et al. An Ice Age JWST inventory of dense molecular cloud ices. Nat. Astron. 7, 431443 (2023).

Article ADS Google Scholar

Gibb, E. L., Whittet, D. C. B., Boogert, A. C. A. & Tielens, A. G. G. M. Interstellar ice: The infrared space observatory legacy. Astrophys. J. Suppl. Ser. 151, 3573 (2004).

Article ADS Google Scholar

Dartois, E. The ice survey opportunity of ISO. Space Sci. Rev. 119, 293310 (2005).

Article ADS Google Scholar

Boogert, A. C. A., Gerakines, P. A. & Whittet, D. C. B. Observations of the icy universe. Annu. Rev. Astron. Astrophys. 53, 541581 (2015).

Article ADS Google Scholar

Dartois, E., Noble, J. A., Ysard, N., Demyk, K. & Chabot, M. Influence of grain growth on CO2 ice spectroscopic profiles. Modelling for dense cores and disks. Astron. Astrophys. 666, A153 (2022).

Article ADS Google Scholar

Ehrenfreund, P., Boogert, A., Gerakines, P. & Tielens, A. Apolar ices. Faraday Discussions 109, 463 (1998).

Article ADS Google Scholar

Dartois, E. & Bauerecker, S. Infrared analysis of CO ice particles in the aerosol phase. J. Chem. Phys. 128, 154715 (2008).

Article ADS Google Scholar

Dartois, E. Spectroscopic evidence of grain ice mantle growth in YSOs. I. CO ice modeling and limiting cases. Astron. Astrophys. 445, 959970 (2006).

Article ADS Google Scholar

Dartois, E. & dHendecourt, L. Search for NH3 ice in cold dust envelopes around YSOs. Astron. Astrophys. 365, 144156 (2001).

Article ADS Google Scholar

van Broekhuizen, F. A., Pontoppidan, K. M., Fraser, H. J. & van Dishoeck, E. F. A 35 m VLT spectroscopic survey of embedded young low mass stars II: Solid OCN. Astron. Astrophys. 441, 249260 (2005).

Article ADS Google Scholar

Boogert, A. C. A., Brewer, K., Brittain, A. & Emerson, K. S. Survey of ices toward massive young stellar objects. I. OCS, CO, OCN, and CH3OH. Astrophys. J. 941, 32 (2022).

Article ADS Google Scholar

Ormel, C. W., Paszun, D., Dominik, C. & Tielens, A. G. G. M. Dust coagulation and fragmentation in molecular clouds. I. How collisions between dust aggregates alter the dust size distribution. Astron. Astrophys. 502, 845869 (2009).

Article ADS Google Scholar

Husser, T. O. et al. A new extensive library of PHOENIX stellar atmospheres and synthetic spectra. Astron. Astrophys. 553, A6 (2013).

Article Google Scholar

Palacios, A. et al. POLLUX: a database of synthetic stellar spectra. Astron. Astrophys. 516, A13 (2010).

Article Google Scholar

Draine, B. T. & Flatau, P. J. User guide for the discrete dipole approximation code DDSCAT 7.3. Preprint at https://arxiv.org/abs/1305.6497 (2013).

Khler, M., Jones, A. & Ysard, N. A hidden reservoir of Fe/FeS in interstellar silicates? Astron. Astrophys. 565, L9 (2014).

Article ADS Google Scholar

Jones, A. P. Variations on a themethe evolution of hydrocarbon solids. II. Optical property modellingthe optEC(s) model. Astron. Astrophys. 540, A2 (2012).

Article ADS Google Scholar

Godard, M., Geballe, T. R., Dartois, E. & Muoz Caro, G. M. The deep 3.4 m interstellar absorption feature toward the IRAS 18511+0146 cluster. Astron. Astrophys. 537, A27 (2012).

Article ADS Google Scholar

Pendleton, Y. J., Sandford, S. A., Allamandola, L. J., Tielens, A. G. G. M. & Sellgren, K. Near-infrared absorption spectroscopy of interstellar hydrocarbon grains. Astrophys. J. 437, 683 (1994).

Article ADS Google Scholar

Zhu, H., Tian, W., Li, A. & Zhang, M. The gas-to-extinction ratio and the gas distribution in the Galaxy. Mon. Not. R. Astron. Soc. 471, 34943528 (2017).

Article ADS Google Scholar

Palumbo, M. E., Baratta, G. A., Collings, M. P. & McCoustra, M. R. S. The profile of the 2140 cm-1 solid CO band on different substrates. Phys. Chem. Chem. Phys. 8, 279284 (2006).

Article Google Scholar

Dartois, E. et al. Cosmic ray sputtering yield of interstellar ice mantles. CO and CO2 ice thickness dependence. Astron. Astrophys. 647, A177 (2021).

Article Google Scholar

Rocha, W. R. M. et al. LIDA: The Leiden Ice Database for Astrochemistry. Astron. Astrophys. 668, A63 (2022).

Article Google Scholar

Ehrenfreund, P. et al. Laboratory studies of thermally processed H2O-CH3OH-CO2 ice mixtures and their astrophysical implications. Astron. Astrophys. 350, 240253 (1999).

ADS Google Scholar

Dartois, E. Les glaces interstellaires: interpretation par simulations en laboratoire des observations du satellite ISO. PhD thesis, Paris-VI (1998).

Dullemond, C. P. et al. RADMC-3D: A multi-purpose radiative transfer tool. Astrophysics Source Code Library, record ascl 1202, 015 (2012).

Google Scholar

Bouilloud, M. et al. Bibliographic review and new measurements of the infrared band strengths of pure molecules at 25 K: H2O, CO2, CO, CH4, NH3, CH3OH, HCOOH and H2CO. Mon. Not. R. Astron. Soc. 451, 21452160 (2015).

Article ADS Google Scholar

Luna, R. et al. Densities, infrared band strengths, and optical constants of solid methanol. Astron. Astrophys. 617, A116 (2018).

Article Google Scholar

Bottinelli, S. et al. The c2d Spitzer spectroscopic survey of ices around low-mass young stellar objects. IV. NH3 and CH3OH. Astrophys. J. 718, 11001117 (2010).

Article ADS Google Scholar

Continue reading here:

Spectroscopic sizing of interstellar icy grains with JWST - Nature.com

Kip Thorne works at a blackboard in a screenshot taken from a promotional video for Interstellar. Credit: Warner Brothers.

Astronomy enthusiasts are my kinda people. Like me, they love all sorts of science, and science fiction, too particularly films that lead us into a dystopian, mysterious, explorative future we cant experience in our everyday lives. One of the most intriguing recent films of this type is the 2014 effort Interstellar, which I am willing to wager theres a pretty good chance youve seen.

Nominated for five Academy Awards, the movie performed extremely well and became an instant favorite for many science nerds. The New York Times declared that Interstellar investigates the relationships between science and faith and science and the humanities and that it illustrates the symbiosis between the fields.

The film featured a cast including Matthew McConaughey, Anne Hathaway, Jessica Chastain, Bill Irwin, Ellen Burstyn, Michael Caine, and Matt Damon. Its cowriter, director, and producer was Christopher Nolan, and an executive producer was none other than Kip Thorne, the celebrated Caltech astronomer. Kip also acted as the films science consultant and wrote a tie-in book, The Science of Interstellar. He is very well known as the worlds leading expert on black holes, and is celebrated for his long body of astronomical work and collaboration with many important associates, including his good friends Stephen Hawking and Carl Sagan.

In 2017 Kip won the Nobel Prize along with his collaborators Rainer Weiss and Barry Barish for their major contributions to the LIGO gravitational wave detectors and the breakthrough discovery of gravitational waves from colliding black holes. In recent years Ive had to pleasure to get to know Kip, as he is an active and frequent speaker and collaborator at the Starmus Festival, the science gatherings for which I serve on the board. Without question, he is one of the most brilliant, kind, and straight-out funny people in the entire world of astronomy and astrophysics.

Born in Logan, Utah, Kip studied at Caltech before earning masters and PhD degrees at Princeton, for the latter studying under the supervision of John Archibald Wheeler. Returning to Caltech in 1967, he soon thereafter became one of the youngest full professors in the history of the institution. He held some adjunct professorships, too, and after a long and storied career, resigned his professorship in 2009, went emeritus, and concentrated on writing and movie projects.

Aside from being one of the fathers of LIGO, Thorne is an expert on black hole cosmology, hypothetical wormhole and time travel research, relativistic stars, and assorted other astrophysical and cosmological pursuits. He is the author of a number of important books including Gravitation, the classic text coauthored with Charles Misner and John Wheeler, and the celebrated Black Holes and Time Warps.

Kips involvement in Interstellar arguably made it one of the most compelling sci-fi films not only of our time, but perhaps of all time. The story begins in 2067, when earthlings are facing a global famine. The plot moves quickly and is both hypothetical and smart enough to keep novices on their edges of their seats and to earn the respect of those who know science. McConaugheys character discovers a gravitational anomaly inside a bedroom, and the pattern leads to a NASA administrative facility. A NASA team, meanwhile, prepares to travels through a wormhole near Saturn. McConaugheys character leads a spacecraft crew on this dangerous mission.

Through the wormhole, the crew finds an ocean world complete with tidal waves, and return after experiencing time dilation, 23 years having passed on Earth and a few hours for the crew. They envision an exodus from Earth to find a habitable world. A second planet through the wormhole offers a possible habitat. During a complex set of problems, this doesnt work out, and they seek a third planet. Countless adventures follow, and allow the writers and filmmakers to explore all manner of dramatic and scientific subjects and possibilities.

Kip Thorne is unique among the world of astronomy. He has long been one of the worlds greatest experts on a panel of very important areas, those at the cutting edges of our curiosity. And yet his brilliant and groundbreaking knowledge has not limited his ability to communicate very smoothly and effectively with novices, and to entertain us all with inspiring stories.

Interstellar is a grand vision of just this mixture. If you have not seen the film, I encourage you to do so. If you have, perhaps you will sometime watch it again, and realize the story hides an advisor who made the script and the direction a little better, and a little more inspiring, toward the scientific wonder we all treasure.

David J. Eicher is Editor of Astronomy, author of 26 books on science and history, and a board member of the Starmus Festival and of Lowell Observatory.

Read the original:

Kip Thorne and the mind-bending science of Interstellar | Astronomy.com - Astronomy Magazine

Active supermassive black holes often produce powerful jets of ionized gas that stream away from their host galaxies. These jets can be seen by radio telescopes as radio lobes. Active galaxies can have one or two radio lobes, and when they have two they are known as Double-lobed Radio sources associated with Active Galactic Nuclei, or DRAGNs. The jets of most DRAGNs are symmetrical, but a few are not. These asymmetrical DRAGNs could tell us a great deal about galaxies and their surrounding environment, but identifying them can be a challenge.

University of the West Indies student Kavita Gosine Bissessar wanted to find these asymmetrical DRAGNs, so she started with a catalog of 17,724 DRAGNs captured by the Very Large Array Sky Survey (VLASS). She combined this with infrared data from the Wide-field Infrared Survey Explorer (WISE) to identify their host galaxies. From this Kavita found that 1,587 of them had confirmed galactic cores.

But to find out which of these were asymmetrical, Kavita had to comb through them by hand. She started by measuring the arm-core distance ratio since DRAGNs with larger ratios are more likely to be symmetrical. She found that 33 of them had ratios greater than 3.6. Interestingly, she found that those with the largest ratios appeared asymmetrical, but were actually false positives. Some were actually two separate galaxies, while others had bright radio cores misidentified as a lobe. Kavita found that DRAGNs with arm-core distance ratios between 3 and 8 had the greatest chance of being true asymmetrical DRAGNs.

This result can help astronomers find galaxies with asymmetric radio lobes more easily. In the future Kavita would like to study the environments of these galaxies to see how that might affect galactic lobe symmetry.

See the original post:

Here There Be DRAGNs National Radio Astronomy Observatory - National Radio Astronomy Observatory

French telescope company Unistellar has launched two new tech-infused models at CES 2024 promising to eliminate the tedious parts of backyard astronomy. The new Odyssey and Odyssey Pro smart telescopes use new technology to focus on both nearby objects like Jupiter and distant stars or nebulae. They also feature new Nikon optics and an updated smartphone app that helps you align and focus the telescope, while automatically finding targets to image.

Unistellar's current smart telescopes, the eVscope 2 and eQuinox 2, are primarily designed to image distant galaxies, stars, clusters and the like they can also image planets, but focus can be tricky. However, the Odyssey and Odyssey Pro use what the company calls Multi-Depth technology to focus equally well on both near and far objects, letting you switch instantly from viewing the Moon to a distant nebula.

It works by using the full sensor resolution to image close-in objects, which are bright but relatively small. For dim, larger objects it combines four pixels into one, much like many smartphone cameras, to boost the light gathering capability, at the cost of some detail. As the company told us at CES, it also "stacks multiple images of the same spot to render a clean output."

They even work in light-polluted areas, thanks to a high-sensitivity sensor and smart image processing. "With the Odyssey, Unistellar is offering a new generation of smart telescopes that are both ultra-powerful and capable of instantly transforming your stargazing evenings into adventures across the cosmos with family or friends, even in the middle of the city," said Laurent Marfisi, Unistellar co-founder and CEO.

The other big update is the Android/iOS app. As before, it automatically points the telescope toward the desired target at the right time, by recognizing groups of stars and calculating exactly where a target should be. However, it can now suggest items to look at on a particular evening, and provide extra context about the body in question.

Both telescopes have new optical tubes using Nikon optics and the company says they're the first that don't need manual adjustments something that can be difficult for amateur astronomers. That marries with a new autofocus system much like what you'd see on a digital camera to deliver consistently sharp images.

The new telescopes are cheaper than past models, though they do have smaller mirrors than the eVscope 2, at 320mm compared to 450mm focal length. The main difference between the two models is that the Odyssey Pro has slightly more resolution (4.1 megapixels compared to 3.4 megapixels), along with a Nikon-made eyepiece. The Odyssey is now shipping for $2,499, while the Odyssey Pro costs $3,999. The company also has a special edition Odyssey Pro Red Edition (above), that costs $4,499.

Engadget's Richard Lai contributed to this report.

We're reporting live from CES 2024 in Las Vegas from January 6-12. Keep up with all the latest news from the show here.

Read more from the original source:

Unistellar's latest smart telescopes take the hassle out of backyard astronomy - Engadget

The red spots at the top of the corona of the Sun during the total solar eclipse are called Bailey's beads. This image was taken during the Great American Eclipse of 2017. NASA Photo / Carla Thomas

The total solar eclipse set to occur April 8, 2024, will dazzle everyone who views it. However, potential observers might have some questions.

Where exactly in Mexico and the U.S. will totality be visible? Thats easy to answer with a detailed map, such as the one below. But which locations are the best spots to view the event? That answer is less straightforward.

Youll surely want to set up shop near the center line of the eclipse, where totality will last the longest. But what else makes for a good viewing site for a total solar eclipse? Below are 20 great locations you should consider for the 2024 Great North American Eclipse, starting in Mexico and working to the Northeast U.S.

Ill also offer one other suggestion when choosing a site: Carefully consider the population. All things being equal, a town of 10,000 is much more likely to have event-related problems than a city of 75,000. Traffic will be one of the primary issues; small communities with one main road may suffer hours of gridlock. If you opt to travel to such a location, get there early perhaps even a day or two ahead of the eclipse. (Remember: April 8, 2024, is a Monday, and most people will be free the entire weekend beforehand.)

Drive safe anddont forget your eclipse glasses. I wish you all clear skies!

The Moons umbra touches the coast of the United Mexican States at 12:07 p.m. Mexican Pacific Daylight Time less than 12 miles (19 km) southeast of Mazatln, which was one of the main destinations for travelers viewing the July 11, 1991 total solar eclipse. This city knows how to host a large influx of travelers, so its a good bet that it will be a prime destination.

Eclipse starts:9:51:28 a.m. MPDT Eclipse ends:12:32:11 p.m. MPDT Maximum eclipse:11:09:39 p.m. MPDT Suns altitude at maximum eclipse:69.1 Duration of totality:4 minutes 18 seconds Width of Moons shadow:123.7 miles (199.1 km)

At 1:15 p.m. Mexican Central Daylight Time, the umbra arrives at Nazas. This town of some 4,000 residents will surely see that number swell because it is the nearest location to the point of longest totality. The town itself will enjoy that duration, but the actual spot is about 3 miles (5 km) to the north, just east of Durango Paso Nacional, the road that connects Nazas to San Luis del Cordero. If youre headed here for the longest possible totality, get there at least a day early.

Eclipse starts:11:58:24 a.m. MCDT Eclipse end:2:39:42 p.m. MCDT Maximum eclipse:1:17:17 p.m. MCDT Suns altitude at maximum eclipse:69.8 Duration of totality:4 minutes 28 seconds Width of Moons shadow:122.6 miles (197.4 km)

Related: The best equipment to see an eclipse | How to make a pinhole camera out of a cardboard box

A large city that lies across the Rio Grande River from Eagle Pass, Texas, is Piedras Negras. Anyone from the U.S. who wants to experience the maximum duration of totality (4 minutes 28 seconds), will either cross the Eagle PassPiedras Negras International Bridge or the Camino Real International Bridge. Using Piedras Negras as a base is a good idea because its metro population is a quarter million, so it contains lots of amenities for travelers.

Eclipse starts:12:10:08 p.m. CDT Eclipse end:2:51:17 p.m. CDT Maximum eclipse:1:29:37 p.m. CDT Suns altitude at maximum eclipse:68.6 Duration of totality:4 minutes 25 seconds Width of Moons shadow:120.9 miles (194.5 km)

For eclipse chasers who want the greatest possible amount of totality without leaving the U.S., consider Radar Base, which lies right on the U.S.Mexico border. Its name, by the way, isnt that of a military base but instead a small town of several hundred residents. That number will balloon on eclipse day, so be sure to get there early.

Eclipse starts:12:10:26 p.m. CDT Eclipse end:2:51:30 p.m. CDT Maximum eclipse:1:29:53 p.m. CDT Suns altitude at maximum eclipse:68.5 Duration of totality:4 minutes 27 seconds Width of Moons shadow:120.9 miles (195.5 km)

While San Antonio certainly will be the base of operations for many eclipse chasers, most will not stay there, opting instead to head to the center line for an additional minute of umbral darkness. Several small towns lie centered in the path, the largest of which is Kerrville, with roughly 24,000 residents. Be sure to check in advance for any eclipse-related activities.

Eclipse starts:12:14:43 p.m. CDT Eclipse end:2:55:29 p.m. CDT Maximum eclipse:1:34:17 p.m. CDT Suns altitude at maximum eclipse:67.5 Duration of totality:4 minutes 25 seconds Width of Moons shadow:120.2 miles (193.4 km)

NASA/Bill Ingalls

Many travelers will choose to base in Austin, the state capital of Texas. Its a good choice because that city features lots of amenities, especially in the food and music realms. Unfortunately, it lies near the southern limit of the path of totality. So, a good choice on eclipse day would be to drive the 68 miles (109 km) north to Lampasas, which lies quite near the center line.

Eclipse starts:12:18:03 p.m. CDT Eclipse ends:2:58:23 p.m. CDT Maximum eclipse:1:37:35 p.m. CDT Suns altitude at maximum eclipse:66.5 Duration of totality:4 minutes 24 seconds Width of Moons shadow:119.7 miles (192.6 km)

Although not a huge city, Hillsboro is an easy destination, lying, as it does, on Interstate 35 where I-35E and I-35W split south of Dallas. It also lies right along the center line of totality, which will help maximize your time under the Moons umbra.

Eclipse starts:12:21:23 p.m. CDTEclipse ends:3:01:16 p.m. CDTMaximum eclipse:2:40:53 p.m. CDTSuns altitude at maximum eclipse:65.5 Duration of totality:4 minutes 23 seconds Width of Moons shadow:119.2 miles (191.8 km)

Another great location in the Lone Star State is Sulphur Springs. It lies along Interstate 30, so getting there wont be a problem. Although the city isnt huge (less than 20,000 residents), there are many open areas. One is Coleman Lake and Park, which offers 186 acres with trails and waterfalls. Cooper Lake State Park lies 15 miles (24 km) north. It has more than 2,500 acres of land and nearly 20,000 acres of lake. Observing from a boat would certainly be relaxing. And youll only lose 2 seconds of totality compared to Sulphur Springs.

Eclipse starts:12:25:38 p.m. CDT Eclipse ends:3:04:52 p.m. CDT Maximum eclipse:1:45:04 p.m. CDT Suns altitude at maximum eclipse:64 Duration of totality:4 minutes 21 seconds Width of Moons shadow:118.4 miles (190.6 km)

With a population near 30,000, Russellville has enough resources to host a moderate influx of visitors for the eclipse. Those eclipse chasers who prefer to observe the event outside the city could head for nearby Mount Nebo, a flat-topped mountain that rises 1,350 feet (410 meters) above the surrounding valley.

Eclipse starts:12:33:08 p.m. CDT Eclipse ends:3:10:46 p.m. CDT Maximum eclipse:1:52:10 p.m. CDT Suns altitude at maximum eclipse:49.0 Duration of totality:4 minutes 11 seconds Width of Moons shadow:117.2 miles (188.6 km)

The largest city in southeastern Missouri that will experience totality is Cape Girardeau, with its 80,000 residents. It lies on the bank of the Mississippi River and is easily accessible from Interstate 55. For an additional 4 seconds of totality, eclipseophiles can head 10 miles (16 km) west on State Route 72 to Jackson. Eclipse starts:12:41:51 p.m. CDT Eclipse ends:3:17:26 p.m. CDT Maximum eclipse:2:00:21 p.m. CDT Suns altitude at maximum eclipse:57.3 Duration of totality:4 minutes 6 seconds Width of Moons shadow:115.5 miles (185.9 km)

This small city of some 16,000 residents lies along U.S. Highway 50 (east-west) and U.S. Highway 150, which becomes U.S. Hwy. 41 (north-south). Its a quick hop from Interstate 69. More importantly, it sits squarely on the eclipses center line, so it will probably be a popular destination for inhabitants of the region. Eclipse starts:1:46:59 p.m. EDT Eclipse ends:4:20:57 p.m. EDT Maximum eclipse:3:04:55 p.m. EDT Suns altitude at maximum eclipse:54 Duration of totality:4 minutes, 5 seconds Width of Moons shadow:114.5 miles (184.3 km)

The umbra will cover a wide swath of Indiana, but most of the attention will focus on the states capital city. Downtown Indianapolis is a metropolis served by four interstate highways and will surely be one of the most sought-after destinations. It offers plentiful lodging, excellent cuisine, and many attractions for travelers.

Eclipse starts:1:50:31 p.m. EDT Eclipse ends:4:23:10 p.m. EDT Maximum eclipse:3:07:56 p.m. EDT Suns altitude at maximum eclipse:53 Duration of totality:3 minutes 49 seconds Width of Moons shadow:114 miles (183.4 km)

This small city of 36,000 is well positioned for viewing the eclipse and is just large enough to handle a moderate influx of visitors. For those who want the maximum possible length of totality, youll get 6 additional seconds if you drive south on Interstate 75 to Wapakoneta, and an extra second if you continue south to the center line.

Eclipse starts:1:54:51 p.m. EDT Eclipse ends:4:26:01 p.m. EDT Maximum eclipse:3:11:43 p.m. EDT Suns altitude at maximum eclipse:50.8 Duration of totality:3 minutes 51 seconds Width of Moons shadow:113 miles (181.9 km)

With a metro population of more than 2 million, this city will host a multitude of eclipse chasers. Get there a couple of days early, and fill the waiting time with visits to some of Clevelands highlights, including the Cleveland Museum of Arts and the Rock and Roll Hall of Fame.

Eclipse starts:1:59:20 p.m. EDT Eclipse ends:4:28:57 p.m. EDT Maximum eclipse:3:15:37 p.m. EDT Suns altitude at maximum eclipse:48.6 Duration of totality:3 minutes 49 seconds Width of Moons shadow:111.9 miles (180.1 km)

The only large city in the Commonwealth of Pennsylvania to be graced by the Moons umbra is Erie, which, with its 100,000 residents, sits on the shore of the Great Lake that bears its name. Its certain that many eclipse chasers from Pittsburgh, 130 miles to the south via Interstate 79, will visit for the event.

Eclipse starts:2:02:23 p.m. EDT Eclipse ends:4:30:48 p.m. EDT Maximum eclipse:3:18:12 p.m. EDT Suns altitude at maximum eclipse:47 Duration of totality:3 minutes 42 seconds Width of Moons shadow:111.2 miles (179 km)

If the Northeastern United States has good weather on eclipse day, the most picturesque images of the event might come from Niagara Falls. One of the best perspectives will come from the outlook called Terrapin Point, where the Sun will hang halfway up in the southwest directly over the Falls! Science buffs who observe or photograph the eclipse from this area surely will want to visit the Nikola Tesla Statue within Queen Victoria Park on the Canadian side of Niagara Falls. It lies only 0.3 mile (0.5 km) north of Terrapin Point.

Eclipse starts:2:04:50 p.m. EDT Eclipse ends:4:31:57 p.m. EDT Maximum eclipse:3:20:02 p.m. EDT Suns altitude at maximum eclipse:45.6 Duration of totality:3 minutes 31 seconds Width of Moons shadow:110.8 miles (178.4 km)

The largest city in New York that will experience the Moons umbra is Buffalo, with its metropolitan population of 1.1 million. The center line passes right through downtown, so expect all activity to come to a screeching halt in mid-afternoon. Travelers desiring information about the eclipse might want to check with the staff of Zygmunt Planetarium, which is part of the Buffalo Museum of Science.

Eclipse starts:2:04:54 p.m. EDT Eclipse ends:4:32:07 p.m. EDT Maximum eclipse:3:20:11 p.m. EDT Suns altitude at maximum eclipse:45.6 Duration of totality:3 minutes 45 seconds Width of Moons shadow:110.7 miles (178.2 km)

This small city of roughly 20,000 residents makes this list primarily because its a one-hour drive from Montral, Canadas second most populous city. Montral itself will enjoy nearly 2 minutes of totality, but all serious eclipse chasers will head south to the center line for that additional 90 seconds. Good choice.

Eclipse starts:2:14:02 p.m. EDT Eclipse ends:4:37:04 p.m. EDT Maximum eclipse:3:27:29 p.m. EDT Suns altitude at maximum eclipse:40.4 Duration of totality:3 minutes 33 seconds Width of Moons shadow:108.4 miles (174.5 km)

Those Canadians who may not wish to cross the border can opt for Sherbrooke, which is only a 100-mile (161 km) drive from Montral. With a metro population of nearly a quarter million, Sherbrooke offers plenty of lodging and other amenities. And a quick 10-mile (16 km) drive south will bring you to the center line and 5 additional seconds of totality.

Eclipse starts:2:16:35 p.m. EDT Eclipse ends:4:38:13 p.m. EDT Maximum eclipse:3:29:23 p.m. EDT Suns altitude at maximum eclipse:38.8 Duration of totality:3 minutes 25 seconds Width of Moons shadow:107.8 miles (173.5 km)

To be honest, Mars Hill is a small town of some 1,500 residents. But just think of it: an amateur astronomer watching the Moon cover the Sun from a place named Mars Hill? Terrific. This location also is one of the last spots in the U.S. to see totality. But if youre one of those serious types, just drive 20 miles (32 km) south for an additional 10 seconds of totality.

Eclipse starts:2:22:20 p.m. EDT Eclipse ends:4:40:52 p.m. EDT Maximum eclipse:3:33:41 p.m. EDT Suns altitude at maximum eclipse:35.2 Duration of totality:3 minutes 12 seconds Width of Moons shadow:106.2 miles (171 km)

See the original post here:

20 of the best places to view the 2024 total solar eclipse - Astronomy Magazine

Back to Article List

Simulations show it's possible for lunar material to achieve a quasi-satellite orbit like Kamo`oalewa.

By using the NASA's JPL Small-body Database Lookup, the orbit of 469219 Kamo'oalewa can be displayed alongside Earth's orbit. The orbits appear to be nearly identical but just shifted. In the bottom-left corner it provides the distance from Kamo'oalewa to Earth and to the Sun. Credit: NASA

Normally, near-Earth objects (NEOs) are either asteroids or comets that are gravitationally influenced enough by nearby planets to enter Earths neighborhood. However, in April 2016, a group of astronomers discovered a near-Earth asteroid named Kamooalewa (pronounced kamo-o-a-lewa) and provisionally designated (469219) 2016 HO3, that appeared to be an outlier compositionally.

Fast forward five years and a team of astronomers from the University of Arizona suggested that the object could have originated from the Moon, since it shared more similarities with our earth-bound satellite than any other known asteroid.

Two years and a second University of Arizona team later, this time led by a graduate student in the Department of Physics, Jose Daniel Castro-Cisneros, the 2016 study and a 2021 study pushed a step further to confirm their idea.

Several teams are dedicated to detecting NEOs because asteroids and comets close to Earth can reveal key details about the early days of the solar system. Many asteroids and comets are relatively pristine since their formation, offering a window to the distant past. So, when the results for Kamooalewa differed, the team knew something unusual was going on.

Kamooalewa stood out for several reasons. First, it is classified as a quasi-satellite, meaning that it seems to orbit Earth but is really orbiting the Sun in an earth-like orbit. Second, Kamooalewa displays loyalty to Earth through its longevity. Usually, objects with earth-like orbits are stable for only a few decades, but Kamooalewa is expected to have a dynamical lifetime of millions of years. Further, the objects spectrum offered clues to its unusual composition. Astonishingly, the spectrum matches lunar material and suggests the object is a small piece of the Moon.

We looked at Kamooalewas spectrum only because it was in an unusual orbit, says Regents Professor of Planetary Sciences and co-author Renu Malhotra of the University of Arizona. If it had been a typical near-Earth asteroid, no one would have thought to find its spectrum and we wouldnt have known Kamooalewa could be a lunar fragment.

The spectrum shows that Kamooalewa is silicate-rich, a typical find in lunar-like material. Its history is partially revealed through extensive space weathering and reddening, beyond what is seen in nearby asteroids. Given the findings, the team suggested that Kamooalewa could have been ejected from one of the many meteorite impacts that have struck the Moon.

An ejected piece of Moon entering a quasi-earth-satellite orbit was always considered an unlikely phenomenon. Normally, when objects impact the Moon, the ejecta can either fall back on the Moons surface or even Earths surface. In rare cases the right amount of kinetic energy exists to launch material out of the Earth-Moon system but too much to enter earth-like orbits. Kamooalewa is testing this idea and now, the Castro-Cisneros team is testing Kamooalewa.

The 2023 group is using numerical simulations to show that it is, indeed, feasible for lunar material to achieve a quasi-satellite orbit. We are now establishing that the Moon is a more likely source for Kamooalewa, says Malhotra.

Castro-Cisneros plans on developing a simulation that creates a free pathway for Kamooalewa to reach Earths co-orbital space, and to calculate its age. Numerical computations like these will improve the understanding of NEOs. Whats more, these studies can help our space forces combat asteroids that may pose dangers to Earth.

If youd like to know more, feel free to read University of Arizonas news release, or some of our articles on either tracking NEOs or about the Apollo 17 lunar samples that revealed secrets of the Moons violent origin.

Read the rest here:

Evidence builds that Kamo'oalewa is a chunk of the Moon accompanying Earth - Astronomy Magazine