Category Archives: Moon Colonization

Have you ever wondered what it would be like to live in space or on another world? One day it may be possible to do so, but whenever and wherever we colonize, we take with us our microbiota. Would they affect our ability to live beyond Earth? New research published today indicates that the health of space travelers could be negatively impacted by fungi in our microbiota.

Srimathy Sriskantharajah 11 Jul 2017

pixabay - public domain image

Long before the first living creature was sent into space, humans have looked up at the night sky and wondered what it would like to live in space. Space agencies and commercial companies are researching longer term habitation in space and on other worlds. We all assume that, one day, we will establish colonies on other planets and celestial bodies (e.g moons), but not many people have considered whether there are other Earthlings better adapted to space colonization than us microorganisms. The microorganisms that make up our microbiota will also come with us if and when we colonize another world. How they adapt could also influence our own ability to colonize other planets.

In 2015, AleksandraChecinska and colleagues published a study of the International Space Station that showed microbes from the human skin form a substantial part of the ISS microbiota. The results indicate better cleaning regimes are required on the ISS and that these microorganisms could affect the health of astronauts.

A recently published article by the same group looked at the mycobiome (fungal microbiota) of a prototype lunar modules during a 30-day occupation period by a group of humans. Fungi can live in extreme environments on Earth, so should be relatively amenable to living in space and on extra-terrestrial bodies. The study showed human presence influenced fungal presence and diversity within the lunar module, and consequently could affect human health in space. Furthermore, the presence of fungi in the module could affect its structural integrity, impacting the safety of the occupants.

These two studies show how our microbiota can cause health or safety issues in space when they leave our bodies and enter the surrounding environment, but what about the impact of space travel on our microbiota when it is still inside us? NASA recently investigated these effects on two ISS missions between 2013 and 2016, collecting swab samples (saliva, blood, sweat and fecal) from astronauts over the course of their missions. The results have yet to be published, but the fact that the investigation occurred indicates a belief that the impact of space travel on our microbiota is a serious concern.

Considering how closely our microbiota affect our lives here on Earth, it is not surprising that they could impact our ability to colonize the moon or any other celestial body. Even the journey to these new homes could be hampered or helped by our microbiota. Could certain microorganisms within our microbiota enable us to adapt better to space travel? Would our microbiota colonize other worlds successfully before we do? Or would deep space travel send our microbiota into meltdown? It would be interesting to see whether our microbiota, rather than technology, were to be the limiting factor in space exploration.

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Titan is the largest moon of Saturn. It is the only moon known to have a dense atmosphere, and the only object in space other than Earth where clear evidence of stable bodies of surface liquid has been found.

Titan is the sixth ellipsoidal moon from Saturn. Frequently described as a planet-like moon, Titan is 50% larger than Earth's Moon, and it is 80% more massive. It is the second-largest moon in the Solar System, after Jupiter's moon Ganymede, and is larger than the smallest planet, Mercury, but only 40% as massive. Discovered in 1655 by the Dutch astronomer Christiaan Huygens, Titan was the first known moon of Saturn, and the sixth known planetary satellite (after Earth's Moon and the four Galilean moons of Jupiter). Titan orbits Saturn at 20 Saturn radii. From Titan's surface, Saturn subtends an arc of 5.09 degrees and would appear 11.4 times larger in the sky than the Moon from Earth.

Titan is primarily composed of water ice and rocky material. Much as with Venus before the Space Age, the dense opaque atmosphere prevented understanding of Titan's surface until new information from the CassiniHuygens mission in 2004, including the discovery of liquid hydrocarbon lakes in Titan's polar regions. The geologically young surface is generally smooth, with few impact craters, although mountains and several possible cryovolcanoes have been found.

The atmosphere of Titan is largely nitrogen; minor components lead to the formation of methane and ethane clouds and nitrogen-rich organic smog. The climateincluding wind and raincreates surface features similar to those of Earth, such as dunes, rivers, lakes, seas (probably of liquid methane and ethane), and deltas, and is dominated by seasonal weather patterns as on Earth. With its liquids (both surface and subsurface) and robust nitrogen atmosphere, Titan's methane cycle is analogous to Earth's water cycle, at the much lower temperature of about 94K (179.2C).

Titan was discovered on March 25, 1655 by the Dutch astronomer Christiaan Huygens.[10][11] Huygens was inspired by Galileo's discovery of Jupiter's four largest moons in 1610 and his improvements in telescope technology. Christiaan, with the help of his brother Constantijn Huygens, Jr., began building telescopes around 1650 and discovered the first observed moon orbiting Saturn with one of the telescopes they built.[12] It was the sixth moon to be discovered.[13]

He named it Saturni Luna (or Luna Saturni, Latin for "Saturn's moon"), publishing in the 1655 tract De Saturni Luna Observatio Nova (A New Observation of Saturn's Moon). After Giovanni Domenico Cassini published his discoveries of four more moons of Saturn between 1673 and 1686, astronomers fell into the habit of referring to these and Titan as Saturn I through V (with Titan then in fourth position). Other early epithets for Titan include "Saturn's ordinary satellite".[14] Titan is officially numbered Saturn VI because after the 1789 discoveries the numbering scheme was frozen to avoid causing any more confusion (Titan having borne the numbers II and IV as well as VI). Numerous small moons have been discovered closer to Saturn since then.

The name Titan, and the names of all seven satellites of Saturn then known, came from John Herschel (son of William Herschel, discoverer of Mimas and Enceladus) in his 1847 publication Results of Astronomical Observations Made during the Years 1834, 5, 6, 7, 8, at the Cape of Good Hope.[15][16] He suggested the names of the mythological Titans (AncientGreek: ), brothers and sisters of Cronus, the Greek Saturn. In Greek mythology, the Titans were a race of powerful deities, descendants of Gaia and Uranus, that ruled during the legendary Golden Age.

Titan orbits Saturn once every 15 days and 22 hours. Like the Moon and many of the satellites of the giant planets, its rotational period (its day) is identical to its orbital period; Titan is tidally locked in synchronous rotation with Saturn, and permanently shows one face to the planet, so Titan's "day" is equal to its orbit period. Because of this, there is a sub-Saturnian point on its surface, from which the planet would always appear to hang directly overhead. Longitudes on Titan are measured westward, starting from the meridian passing through this point.[17] Its orbital eccentricity is 0.0288, and the orbital plane is inclined 0.348 degrees relative to the Saturnian equator.[2] Viewed from Earth, Titan reaches an angular distance of about 20 Saturn radii (just over 1,200,000 kilometers (750,000mi)) from Saturn and subtends a disk 0.8 arcseconds in diameter.

The small, irregularly shaped satellite Hyperion is locked in a 3:4 orbital resonance with Titan. A "slow and smooth" evolution of the resonancein which Hyperion migrated from a chaotic orbitis considered unlikely, based on models. Hyperion probably formed in a stable orbital island, whereas the massive Titan absorbed or ejected bodies that made close approaches.[18]

Size comparison: Titan (lower left) with the Moon and Earth (top and right)

A model of Titan's internal structure

Titan is 5,151 kilometers (3,201mi) in diameter,[3] 1.06 times that of the planet Mercury, 1.48 that of the Moon, and 0.40 that of Earth. Before the arrival of Voyager 1 in 1980, Titan was thought to be slightly larger than Ganymede (diameter 5,262 kilometers (3,270mi)) and thus the largest moon in the Solar System; this was an overestimation caused by Titan's dense, opaque atmosphere, which extends many kilometres above its surface and increases its apparent diameter.[19] Titan's diameter and mass (and thus its density) are similar to those of the Jovian moons Ganymede and Callisto.[20] Based on its bulk density of 1.88g/cm3, Titan's composition is half water ice and half rocky material. Though similar in composition to Dione and Enceladus, it is denser due to gravitational compression. It has a mass 1/4226 that of Saturn, making it the largest moon of the gas giants relative to the mass of its primary, with Titan being 1/22.609 of Saturn's diameter, Triton is larger in diameter relative to Neptune at 1/18.092.

Titan is likely differentiated into several layers with a 3,400-kilometer (2,100mi) rocky center surrounded by several layers composed of different crystalline forms of ice.[21] Its interior may still be hot enough for a liquid layer consisting of a "magma" composed of water and ammonia between the ice Ih crust and deeper ice layers made of high-pressure forms of ice. The presence of ammonia allows water to remain liquid even at a temperature as low as 176K (97C) (for eutectic mixture with water).[22] The Cassini probe discovered the evidence for the layered structure in the form of natural extremely-low-frequency radio waves in Titan's atmosphere. Titan's surface is thought to be a poor reflector of extremely-low-frequency radio waves, so they may instead be reflecting off the liquidice boundary of a subsurface ocean.[23] Surface features were observed by the Cassini spacecraft to systematically shift by up to 30 kilometers (19mi) between October 2005 and May 2007, which suggests that the crust is decoupled from the interior, and provides additional evidence for an interior liquid layer.[24] Further supporting evidence for a liquid layer and ice shell decoupled from the solid core comes from the way the gravity field varies as Titan orbits Saturn.[25] Comparison of the gravity field with the RADAR-based topography observations[26] also suggests that the ice shell may be substantially rigid.[27][28]

The moons of Jupiter and Saturn are thought to have formed through co-accretion, a similar process to that believed to have formed the planets in the Solar System. As the young gas giants formed, they were surrounded by discs of material that gradually coalesced into moons. Whereas Jupiter possesses four large satellites in highly regular, planet-like orbits, Titan overwhelmingly dominates Saturn's system and possesses a high orbital eccentricity not immediately explained by co-accretion alone. A proposed model for the formation of Titan is that Saturn's system began with a group of moons similar to Jupiter's Galilean satellites, but that they were disrupted by a series of giant impacts, which would go on to form Titan. Saturn's mid-sized moons, such as Iapetus and Rhea, were formed from the debris of these collisions. Such a violent beginning would also explain Titan's orbital eccentricity.[29]

In 2014, analysis of Titan's atmospheric nitrogen suggested that it has possibly been sourced from material similar to that found in the Oort cloud and not from sources present during co-accretion of materials around Saturn.[30]

Titan is the only known moon with a significant atmosphere,[31] and its atmosphere is the only nitrogen-rich dense atmosphere in the Solar System aside from Earth's. Observations of it made in 2004 by Cassini suggest that Titan is a "super rotator", like Venus, with an atmosphere that rotates much faster than its surface.[32] Observations from the Voyager space probes have shown that Titan's atmosphere is denser than Earth's, with a surface pressure about 1.45 atm. It is also about 1.19 times as massive as Earth's overall,[33] or about 7.3 times more massive on a per surface area basis. Opaque haze layers block most visible light from the Sun and other sources and obscures Titan's surface features.[34] Titan's lower gravity means that its atmosphere is far more extended than Earth's.[35] The atmosphere of Titan is opaque at many wavelengths and as a result, a complete reflectance spectrum of the surface is impossible to acquire from orbit.[36] It was not until the arrival of the CassiniHuygens spacecraft in 2004 that the first direct images of Titan's surface were obtained.[37]

Titan's atmospheric composition in the stratosphere is 98.4% nitrogen with the remaining 1.6% composed mostly of methane (1.4%) and hydrogen (0.10.2%).[9] There are trace amounts of other hydrocarbons, such as ethane, diacetylene, methylacetylene, acetylene and propane, and of other gases, such as cyanoacetylene, hydrogen cyanide, carbon dioxide, carbon monoxide, cyanogen, argon and helium.[8] The hydrocarbons are thought to form in Titan's upper atmosphere in reactions resulting from the breakup of methane by the Sun's ultraviolet light, producing a thick orange smog.[38] Titan spends 95% of its time within Saturn's magnetosphere, which may help shield it from the solar wind.[39]

Energy from the Sun should have converted all traces of methane in Titan's atmosphere into more complex hydrocarbons within 50 million yearsa short time compared to the age of the Solar System. This suggests that methane must be replenished by a reservoir on or within Titan itself.[40] The ultimate origin of the methane in its atmosphere may be its interior, released via eruptions from cryovolcanoes.[41][42][43][44][45]

On April 3, 2013, NASA reported that complex organic chemicals could arise on Titan, based on studies simulating the atmosphere of Titan.[46]

On June 6, 2013, scientists at the IAA-CSIC reported the detection of polycyclic aromatic hydrocarbons in the upper atmosphere of Titan.[47]

On September 30, 2013, propene was detected in the atmosphere of Titan by NASA's Cassini spacecraft, using its composite infrared spectrometer (CIRS).[48] This is the first time propene has been found on any moon or planet other than Earth and is the first chemical found by the CIRS. The detection of propene fills a mysterious gap in observations that date back to NASA's Voyager 1 spacecraft's first close flyby of Titan in 1980, during which it was discovered that many of the gases that make up Titan's brown haze were hydrocarbons, theoretically formed via the recombination of radicals created by the Sun's ultraviolet photolysis of methane.[38]

On October 24, 2014, methane was found in polar clouds on Titan.[49][50]

Titan's surface temperature is about 94K (179.2C). At this temperature, water ice has an extremely low vapor pressure, so the little water vapor present appears limited to the stratosphere.[51] Titan receives about 1% as much sunlight as Earth.[52] Before sunlight reaches the surface, about 90% has been absorbed by the thick atmosphere, leaving only 0.1% of the amount of light Earth receives.[53]

Atmospheric methane creates a greenhouse effect on Titan's surface, without which Titan would be far colder.[54] Conversely, haze in Titan's atmosphere contributes to an anti-greenhouse effect by reflecting sunlight back into space, cancelling a portion of the greenhouse effect and making its surface significantly colder than its upper atmosphere.[55]

Titan's clouds, probably composed of methane, ethane or other simple organics, are scattered and variable, punctuating the overall haze.[19] The findings of the Huygens probe indicate that Titan's atmosphere periodically rains liquid methane and other organic compounds onto its surface.[57]

Clouds typically cover 1% of Titan's disk, though outburst events have been observed in which the cloud cover rapidly expands to as much as 8%. One hypothesis asserts that the southern clouds are formed when heightened levels of sunlight during the southern summer generate uplift in the atmosphere, resulting in convection. This explanation is complicated by the fact that cloud formation has been observed not only after the southern summer solstice but also during mid-spring. Increased methane humidity at the south pole possibly contributes to the rapid increases in cloud size.[58] It was summer in Titan's southern hemisphere until 2010, when Saturn's orbit, which governs Titan's motion, moved Titan's northern hemisphere into the sunlight.[59] When the seasons switch, it is expected that ethane will begin to condense over the south pole.[60]

The surface of Titan has been described as "complex, fluid-processed, [and] geologically young".[61] Titan has been around since the Solar System's formation, but its surface is much younger, between 100 million and 1 billion years old. Geological processes may have reshaped Titan's surface.[62] Titan's atmosphere is twice as thick as Earth's, making it difficult for astronomical instruments to image its surface in the visible light spectrum.[63] The Cassini spacecraft is using infrared instruments, radar altimetry and synthetic aperture radar (SAR) imaging to map portions of Titan during its close fly-bys. The first images revealed a diverse geology, with both rough and smooth areas. There are features that may be volcanic in origin, disgorging water mixed with ammonia onto the surface. There is also evidence that Titan's ice shell may be substantially rigid,[27][28] which would suggest little geologic activity.[64]

There are also streaky features, some of them hundreds of kilometers in length, that appear to be caused by windblown particles.[65][66] Examination has also shown the surface to be relatively smooth; the few objects that seem to be impact craters appeared to have been filled in, perhaps by raining hydrocarbons or volcanoes. Radar altimetry suggests height variation is low, typically no more than 150meters. Occasional elevation changes of 500meters have been discovered and Titan has mountains that sometimes reach several hundred meters to more than 1 kilometer in height.[67]

Titan's surface is marked by broad regions of bright and dark terrain. These include Xanadu, a large, reflective equatorial area about the size of Australia. It was first identified in infrared images from the Hubble Space Telescope in 1994, and later viewed by the Cassini spacecraft. The convoluted region is filled with hills and cut by valleys and chasms.[68] It is criss-crossed in places by dark lineamentssinuous topographical features resembling ridges or crevices. These may represent tectonic activity, which would indicate that Xanadu is geologically young. Alternatively, the lineaments may be liquid-formed channels, suggesting old terrain that has been cut through by stream systems.[69] There are dark areas of similar size elsewhere on Titan, observed from the ground and by Cassini; at least one of these, Ligeia Mare, Titan's second-largest sea, is almost a pure methane sea.[70][71]

The possibility of hydrocarbon seas on Titan was first suggested based on Voyager 1 and 2 data that showed Titan to have a thick atmosphere of approximately the correct temperature and composition to support them, but direct evidence was not obtained until 1995 when data from Hubble and other observations suggested the existence of liquid methane on Titan, either in disconnected pockets or on the scale of satellite-wide oceans, similar to water on Earth.[72]

The Cassini mission confirmed the former hypothesis. When the probe arrived in the Saturnian system in 2004, it was hoped that hydrocarbon lakes or oceans would be detected from the sunlight reflected off their surface, but no specular reflections were initially observed.[73] Near Titan's south pole, an enigmatic dark feature named Ontario Lacus was identified[74] (and later confirmed to be a lake).[75] A possible shoreline was also identified near the pole via radar imagery.[76] Following a flyby on July 22, 2006, in which the Cassini spacecraft's radar imaged the northern latitudes (that were then in winter), several large, smooth (and thus dark to radar) patches were seen dotting the surface near the pole.[77] Based on the observations, scientists announced "definitive evidence of lakes filled with methane on Saturn's moon Titan" in January 2007.[78][79] The CassiniHuygens team concluded that the imaged features are almost certainly the long-sought hydrocarbon lakes, the first stable bodies of surface liquid found outside of Earth.[78] Some appear to have channels associated with liquid and lie in topographical depressions.[78] The liquid erosion features appear to be a very recent occurrence: channels in some regions have created surprisingly little erosion, suggesting erosion on Titan is extremely slow, or some other recent phenomena may have wiped out older riverbeds and landforms.[62] Overall, the Cassini radar observations have shown that lakes cover only a few percent of the surface, making Titan much drier than Earth.[80] Most of the lakes are concentrated near the poles (where the relative lack of sunlight prevents evaporation), but several long-standing hydrocarbon lakes in the equatorial desert regions have also been discovered, including one near the Huygens landing site in the Shangri-La region, which is about half the size of Utah's Great Salt Lake. The equatorial lakes are probably "oases", i.e. the likely supplier is underground aquifers.[81]

In June 2008, the Visual and Infrared Mapping Spectrometer on Cassini confirmed the presence of liquid ethane beyond doubt in Ontario Lacus.[82] On December 21, 2008, Cassini passed directly over Ontario Lacus and observed specular reflection in radar. The strength of the reflection saturated the probe's receiver, indicating that the lake level did not vary by more than 3mm (implying either that surface winds were minimal, or the lake's hydrocarbon fluid is viscous).[83][84]

Specular reflections are indicative of a smooth, mirror-like surface, so the observation corroborated the inference of the presence of a large liquid body drawn from radar imaging. The observation was made soon after the north polar region emerged from 15 years of winter darkness.

On July 8, 2009, Cassini's VIMS observed a specular reflection indicative of a smooth, mirror-like surface, off what today is called Jingpo Lacus, a lake in the north polar region shortly after the area emerged from 15 years of winter darkness.[85][86]

Early radar measurements made in July 2009 and January 2010 indicated that Ontario Lacus was extremely shallow, with an average depth of 0.43m, and a maximum depth of 3 to 7m (9.8 to 23.0ft).[87] In contrast, the northern hemisphere's Ligeia Mare was initially mapped to depths exceeding 8m, the maximum discernable by the radar instrument and the analysis techniques of the time.[87] Later science analysis, released in 2014, more fully mapped the depths of Titan's three methane seas and showed depths of more than 200 meters (660ft). Ligeia Mare averages from 20 to 40m (66 to 131ft) in depth, while other parts of Ligeia did not register any radar reflection at all, indicating a depth of more than 200m (660ft). While only the second largest of Titan's methane seas, Ligeia "contains enough liquid methane to fill three Lake Michigans."[88]

During a flyby on 26 September 2012, Cassini's radar detected in Titan's northern polar region what is likely a river with a length of more than 400 kilometers. It has been compared with the much larger Nile river on Earth. This feature is connected to Ligeia Mare.[75] Later, a paper ("Liquid-filled Canyons on Titan"[89]) published on Geophysical Research Letters on 9 August 2016 reported about the May 2013 Cassini RADAR altimeter observation of Vid Flumina channels, defined as a drainage network connected to Titan's second largest hydrocarbon sea, Ligeia Mare. Analysis of the received altimeter echoes showed that the channels are located in deep (up to ~570m), steep-sided, canyons and have strong specular surface reflections that indicate they are currently liquid filled. Elevations of the liquid in these channels are at the same level as Ligeia Mare to within a vertical precision of about 0.7m, consistent with the interpretation of drowned river valleys. Specular reflections are also observed in lower order tributaries elevated above the level of Ligeia Mare, consistent with drainage feeding into the main channel system. This is likely the first direct evidence of the presence of liquid channels on Titan and the first observation of hundred-meter deep canyons on Titan. Vid Flumina canyons are thus drowned by the sea but there are few isolated observations to attest to the presence of surface liquids standing at higher elevations.

During six flybys of Titan from 2006 to 2011, Cassini gathered radiometric tracking and optical navigation data from which investigators could roughly infer Titan's changing shape. The density of Titan is consistent with a body that is about 60% rock and 40% water. The team's analyses suggest that Titan's surface can rise and fall by up to 10 metres during each orbit. That degree of warping suggests that Titan's interior is relatively deformable, and that the most likely model of Titan is one in which an icy shell dozens of kilometres thick floats atop a global ocean.[90] The team's findings, together with the results of previous studies, hint that Titan's ocean may lie no more than 100 kilometers (62mi) below its surface.[90][91] On July 2, 2014, NASA reported the ocean inside Titan may be as salty as the Dead Sea.[92][93] On September 3, 2014, NASA reported studies suggesting methane rainfall on Titan may interact with a layer of icy materials underground, called an "alkanofer," to produce ethane and propane that may eventually feed into rivers and lakes.[94]

In 2016, Cassini found the first evidence of fluid-filled channels on Titan, in a series of deep, steep-sided canyons flowing into Ligeia Mare. This network of canyons, dubbed Vid Flumina, range in depth from 240 to 570m and have sides as steep as 40. They are believed to have formed either by crustal uplifting, like Earth's Grand Canyon, or a lowering of sea level, or perhaps a combination of the two. The depth of erosion suggests that liquid flows in this part of Titan are long-term features that persist for thousands of years.[95]

Radar, SAR and imaging data from Cassini have revealed few impact craters on Titan's surface.[62] These impacts appear to be relatively young, compared to Titan's age.[62] The few impact craters discovered include a 440-kilometer-wide (270mi) two-ring impact basin named Menrva seen by Cassini's ISS as a bright-dark concentric pattern.[97] A smaller, 60-kilometer-wide (37mi), flat-floored crater named Sinlap[98] and a 30km (19mi) crater with a central peak and dark floor named Ksa have also been observed.[99] Radar and Cassini imaging have also revealed "crateriforms", circular features on the surface of Titan that may be impact related, but lack certain features that would make identification certain. For example, a 90-kilometer-wide (56mi) ring of bright, rough material known as Guabonito has been observed by Cassini.[100] This feature is thought to be an impact crater filled in by dark, windblown sediment. Several other similar features have been observed in the dark Shangri-la and Aaru regions. Radar observed several circular features that may be craters in the bright region Xanadu during Cassini's April 30, 2006 flyby of Titan.[101]

Many of Titan's craters or probable craters display evidence of extensive erosion, and all show some indication of modification.[96] Most large craters have breached or incomplete rims, despite the fact that some craters on Titan have relatively more massive rims than those anywhere else in the Solar System. There is little evidence of formation of palimpsests through viscoelastic crustal relaxation, unlike on other large icy moons.[96] Most craters lack central peaks and have smooth floors, possibly due to impact-generation or later eruption of cryovolcanic lava. Infill from various geological processes is one reason for Titan's relative deficiency of craters; atmospheric shielding also plays a role. It is estimated that Titan's atmosphere reduces the number of craters on its surface by a factor of two.[103]

The limited high-resolution radar coverage of Titan obtained through 2007 (22%) suggested the existence of nonuniformities in its crater distribution. Xanadu has 29 times more craters than elsewhere. The leading hemisphere has a 30% higher density than the trailing hemisphere. There are lower crater densities in areas of equatorial dunes and in the north polar region (where hydrocarbon lakes and seas are most common).[96]

Pre-Cassini models of impact trajectories and angles suggest that where the impactor strikes the water ice crust, a small amount of ejecta remains as liquid water within the crater. It may persist as liquid for centuries or longer, sufficient for "the synthesis of simple precursor molecules to the origin of life".[104]

Scientists have long speculated that conditions on Titan resemble those of early Earth, though at a much lower temperature. The detection of argon-40 in the atmosphere in 2004 indicated that volcanoes had spawned plumes of "lava" composed of water and ammonia.[105] Global maps of the lake distribution on Titan's surface revealed that there is not enough surface methane to account for its continued presence in its atmosphere, and thus that a significant portion must be added through volcanic processes.[106]

Still, there is a paucity of surface features that can be unambiguously interpreted as cryovolcanoes.[107] One of the first of such features revealed by Cassini radar observations in 2004, called Ganesa Macula, resembles the geographic features called "pancake domes" found on Venus, and was thus initially thought to be cryovolcanic in origin, until Kirk et al. refuted this hypothesis at the American Geophysical Union annual meeting in December 2008. The feature was found to be not a dome at all, but appeared to result from accidental combination of light and dark patches.[108][109] In 2004 Cassini also detected an unusually bright feature (called Tortola Facula), which was interpreted as a cryovolcanic dome.[110] No similar features have been identified as of 2010.[111] In December 2008, astronomers announced the discovery of two transient but unusually long-lived "bright spots" in Titan's atmosphere, which appear too persistent to be explained by mere weather patterns, suggesting they were the result of extended cryovolcanic episodes.[22]

In March 2009, structures resembling lava flows were announced in a region of Titan called Hotei Arcus, which appears to fluctuate in brightness over several months. Though many phenomena were suggested to explain this fluctuation, the lava flows were found to rise 200 meters (660ft) above Titan's surface, consistent with it having been erupted from beneath the surface.[112]

A mountain range measuring 150 kilometers (93mi) long, 30 kilometers (19mi) wide and 1.5 kilometers (0.93mi) high was also discovered by Cassini in 2006. This range lies in the southern hemisphere and is thought to be composed of icy material and covered in methane snow. The movement of tectonic plates, perhaps influenced by a nearby impact basin, could have opened a gap through which the mountain's material upwelled.[113] Prior to Cassini, scientists assumed that most of the topography on Titan would be impact structures, yet these findings reveal that similar to Earth, the mountains were formed through geological processes.[114] In December 2010, the Cassini mission team announced the most compelling possible cryovolcano yet found. Named Sotra Patera, it is one in a chain of at least three mountains, each between 1000 and 1500m in height, several of which are topped by large craters. The ground around their bases appears to be overlaid by frozen lava flows.[115]

Most of Titan's highest peaks occur near its equator in so-called "ridge belts". They are believed to be analogous to Earth's fold mountains such as the Rockies or the Himalayas, formed by the collision and buckling of tectonic plates, or to subduction zones like the Andes, where upwelling lava (or cryolava) from a melting descending plate rises to the surface. One possible mechanism for their formation is tidal forces from Saturn. Because Titan's icy mantle is less viscous than Earth's magma mantle, and because its icy bedrock is softer than Earth's granite bedrock, mountains are unlikely to reach heights as great as those on Earth. In 2016, the Cassini team announced what they believe to be the tallest mountain on Titan. Located in the Mithrim Montes range, it is 3,337 m tall.[116]

If volcanism on Titan really exists, the hypothesis is that it is driven by energy released from the decay of radioactive elements within the mantle, as it is on Earth.[22] Magma on Earth is made of liquid rock, which is less dense than the solid rocky crust through which it erupts. Because ice is less dense than water, Titan's watery magma would be denser than its solid icy crust. This means that cryovolcanism on Titan would require a large amount of additional energy to operate, possibly via tidal flexing from nearby Saturn.[22] The low-pressure ice, overlaying a liquid layer of ammonium sulfate, ascends buoyantly, and the unstable system can produce dramatic plume events. Titan is resurfaced through the process by grain-sized ice and ammonium sulfate ash, which helps produce a wind-shaped landscape and sand dune features.[117]

In 2008 Jeffrey Moore (planetary geologist of Ames Research Center) proposed an alternate view of Titan's geology. Noting that no volcanic features had been unambiguously identified on Titan so far, he asserted that Titan is a geologically dead world, whose surface is shaped only by impact cratering, fluvial and eolian erosion, mass wasting and other exogenic processes. According to this hypothesis, methane is not emitted by volcanoes but slowly diffuses out of Titan's cold and stiff interior. Ganesa Macula may be an eroded impact crater with a dark dune in the center. The mountainous ridges observed in some regions can be explained as heavily degraded scarps of large multi-ring impact structures or as a result of the global contraction due to the slow cooling of the interior. Even in this case, Titan may still have an internal ocean made of the eutectic waterammonia mixture with a temperature of 176K (97C), which is low enough to be explained by the decay of radioactive elements in the core. The bright Xanadu terrain may be a degraded heavily cratered terrain similar to that observed on the surface of Callisto. Indeed, were it not for its lack of an atmosphere, Callisto could serve as a model for Titan's geology in this scenario. Jeffrey Moore even called Titan Callisto with weather.[107][118]

Many of the more prominent mountains and hills have been given official names by the International Astronomical Union. According to JPL, "By convention, mountains on Titan are named for mountains from Middle-earth, the fictional setting in fantasy novels by J.R.R. Tolkien." Colles (collections of hills) are named for characters from the same Tolkien works.[119]

In the first images of Titan's surface taken by Earth-based telescopes in the early 2000s, large regions of dark terrain were revealed straddling Titan's equator.[120] Prior to the arrival of Cassini, these regions were thought to be seas of liquid hydrocarbons.[121] Radar images captured by the Cassini spacecraft have instead revealed some of these regions to be extensive plains covered in longitudinal dunes, up to 330ft (100m) high[122] about a kilometer wide, and tens to hundreds of kilometers long.[123] Dunes of this type are always aligned with average wind direction. In the case of Titan, steady zonal (eastward) winds combine with variable tidal winds (approximately 0.5 meters per second).[124] The tidal winds are the result of tidal forces from Saturn on Titan's atmosphere, which are 400 times stronger than the tidal forces of the Moon on Earth and tend to drive wind toward the equator. This wind pattern, it was theorized, causes granular material on the surface to gradually build up in long parallel dunes aligned west-to-east. The dunes break up around mountains, where the wind direction shifts.

The longitudinal (or linear) dunes were initially presumed to be formed by moderately variable winds that either follow one mean direction or alternate between two different directions. Subsequent observations indicate that the dunes point to the east although climate simulations indicate Titan's surface winds blow toward the west. At less than 1 meter per second, they are not powerful enough to lift and transport surface material. Recent computer simulations indicate that the dunes may be the result of rare storm winds that happen only every fifteen years when Titan is in equinox.[125] These storms produce strong downdrafts, flowing eastward at up to 10 meters per second when they reach the surface.

The "sand" on Titan is likely not made up of small grains of silicates like the sand on Earth,[126] but rather might have formed when liquid methane rained and eroded the water-ice bedrock, possibly in the form of flash floods. Alternatively, the sand could also have come from organic solids produced by photochemical reactions in Titan's atmosphere.[122][124][127] Studies of dunes' composition in May 2008 revealed that they possessed less water than the rest of Titan, and are thus most likely derived from organic soot like hydrocarbon polymers clumping together after raining onto the surface.[128] Calculations indicate the sand on Titan has a density of one-third that of terrestrial sand.[129] The low density combined with the dryness of Titan's atmosphere might cause the grains to clump together because of static electricity buildup. The "stickiness" might make it difficult for the generally mild breeze close to Titan's surface to move the dunes although more powerful winds from seasonal storms could still blow them eastward.[130]

Titan is never visible to the naked eye, but can be observed through small telescopes or strong binoculars. Amateur observation is difficult because of the proximity of Titan to Saturn's brilliant globe and ring system; an occulting bar, covering part of the eyepiece and used to block the bright planet, greatly improves viewing.[131] Titan has a maximum apparent magnitude of +8.2,[7] and mean opposition magnitude 8.4.[132] This compares to +4.6[132] for the similarly sized Ganymede, in the Jovian system.

Observations of Titan prior to the space age were limited. In 1907 Spanish astronomer Josep Comas i Sol observed limb darkening of Titan, the first evidence that the body has an atmosphere. In 1944 Gerard P. Kuiper used a spectroscopic technique to detect an atmosphere of methane.[133]

The first probe to visit the Saturnian system was Pioneer 11 in 1979, which revealed that Titan was probably too cold to support life.[134] It took images of Titan, including Titan and Saturn together in mid to late 1979.[135] The quality was soon surpassed by the two Voyagers.

Titan was examined by both Voyager 1 and 2 in 1980 and 1981, respectively. Voyager 1's trajectory was designed to provide an optimized Titan flyby, during which the spacecraft was able to determine the density, composition, and temperature of the atmosphere, and obtain a precise measurement of Titan's mass.[136] Atmospheric haze prevented direct imaging of the surface, though in 2004 intensive digital processing of images taken through Voyager 1's orange filter did reveal hints of the light and dark features now known as Xanadu and Shangri-la,[137] which had been observed in the infrared by the Hubble Space Telescope. Voyager 2, which would have been diverted to perform the Titan flyby if Voyager 1 had been unable to, did not pass near Titan and continued on to Uranus and Neptune.[136]:94

Even with the data provided by the Voyagers, Titan remained a body of mysterya large satellite shrouded in an atmosphere that makes detailed observation difficult. The mystery that had surrounded Titan since the 17th-century observations of Christiaan Huygens and Giovanni Cassini was revealed by a spacecraft named in their honor.

The CassiniHuygens spacecraft reached Saturn on July 1, 2004, and began the process of mapping Titan's surface by radar. A joint project of the European Space Agency (ESA) and NASA, CassiniHuygens has proved a very successful mission. The Cassini probe flew by Titan on October 26, 2004, and took the highest-resolution images ever of Titan's surface, at only 1,200 kilometers (750mi), discerning patches of light and dark that would be invisible to the human eye.

On July 22, 2006, Cassini made its first targeted, close fly-by at 950 kilometers (590mi) from Titan; the closest flyby was at 880 kilometers (550mi) on June 21, 2010.[138] Liquid has been found in abundance on the surface in the north polar region, in the form of many lakes and seas discovered by Cassini.[77]

Same image with contrast enhanced

Huygens landed[139] on Titan on January 14, 2005, discovering that many of its surface features seem to have been formed by fluids at some point in the past.[140] Titan is the most distant body from Earth to have a space probe land on its surface.[141]

The Huygens probe landed just off the easternmost tip of a bright region now called Adiri. The probe photographed pale hills with dark "rivers" running down to a dark plain. Current understanding is that the hills (also referred to as highlands) are composed mainly of water ice. Dark organic compounds, created in the upper atmosphere by the ultraviolet radiation of the Sun, may rain from Titan's atmosphere. They are washed down the hills with the methane rain and are deposited on the plains over geological time scales.[142]

After landing, Huygens photographed a dark plain covered in small rocks and pebbles, which are composed of water ice.[142] The two rocks just below the middle of the image on the right are smaller than they may appear: the left-hand one is 15centimeters across, and the one in the center is 4centimeters across, at a distance of about 85centimeters from Huygens. There is evidence of erosion at the base of the rocks, indicating possible fluvial activity. The surface is darker than originally expected, consisting of a mixture of water and hydrocarbon ice. The "soil" visible in the images is interpreted to be precipitation from the hydrocarbon haze above.

In March 2007, NASA, ESA, and COSPAR decided to name the Huygens landing site the Hubert Curien Memorial Station in memory of the former president of the ESA.[143]

There have been several conceptual missions proposed in recent years for returning a robotic space probe to Titan. Initial conceptual work has been completed for such missions by NASA, the ESA and JPL. At present, none of these proposals have become funded missions.

The Titan Saturn System Mission (TSSM) was a joint NASA/ESA proposal for exploration of Saturn's moons.[144] It envisions a hot-air balloon floating in Titan's atmosphere for six months. It was competing against the Europa Jupiter System Mission (EJSM) proposal for funding. In February 2009 it was announced that ESA/NASA had given the EJSM mission priority ahead of the TSSM.[145]

The proposed Titan Mare Explorer (TiME) was a low-cost lander that would splash down in a lake in Titan's northern hemisphere and float on the surface of the lake for three to six months.[146][147][148] It was selected for a Phase-A design study in 2011 as a candidate mission for the 12th NASA Discovery Program opportunity,[149] but was not selected for flight.[150]

Another mission to Titan proposed in early 2012 by Jason Barnes, a scientist at the University of Idaho, is the Aerial Vehicle for In-situ and Airborne Titan Reconnaissance (AVIATR): an unmanned plane (or drone) that would fly through Titan's atmosphere and take high-definition images of the surface of Titan. NASA did not approve the requested $715 million, and the future of the project is uncertain.[151][152][153]

A conceptual design for another lake lander was proposed in late 2012 by the Spanish-based private engineering firm SENER and the Centro de Astrobiologa in Madrid. The concept probe is called Titan Lake In-situ Sampling Propelled Explorer (TALISE).[154][155] The major difference compared to the TiME probe would be that TALISE is envisioned with its own propulsion system and would therefore not be limited to simply drifting on the lake when it splashes down.

A Discovery Program contestant for its mission #13 is Journey to Enceladus and Titan (JET), an astrobiology Saturn orbiter that would assess the habitability potential of Enceladus and Titan.[156][157][158]

In 2015, the NASA Innovative Advanced Concepts program (NIAC) awarded a Phase II grant[159] to a design study of a submarine to explore the seas of Titan.[160][161][162]

Titan is thought to be a prebiotic environment rich in complex organic chemistry[46] with a possible subsurface liquid ocean serving as a biotic environment.[163][164][165]

The CassiniHuygens mission was not equipped to provide evidence for biosignatures or complex organic compounds; it showed an environment on Titan that is similar, in some ways, to ones theorized for the primordial Earth.[166] Scientists surmise that the atmosphere of early Earth was similar in composition to the current atmosphere on Titan, with the important exception of a lack of water vapor on Titan.[167]

The MillerUrey experiment and several following experiments have shown that with an atmosphere similar to that of Titan and the addition of UV radiation, complex molecules and polymer substances like tholins can be generated. The reaction starts with dissociation of nitrogen and methane, forming hydrogen cyanide and acetylene. Further reactions have been studied extensively.[168]

It has been reported that when energy was applied to a combination of gases like those in Titan's atmosphere, five nucleotide bases, the building blocks of DNA and RNA, were among the many compounds produced. In addition, amino acids, the building blocks of protein were found. It was the first time nucleotide bases and amino acids had been found in such an experiment without liquid water being present.[169]

On April 3, 2013, NASA reported that complex organic chemicals could arise on Titan based on studies simulating the atmosphere of Titan.[46]

Laboratory simulations have led to the suggestion that enough organic material exists on Titan to start a chemical evolution analogous to what is thought to have started life on Earth. The analogy assumes the presence of liquid water for longer periods than is currently observable; several theories suggest that liquid water from an impact could be preserved under a frozen isolation layer.[170] It has also been theorized that liquid-ammonia oceans could exist deep below the surface.[163][171] Another model suggests an ammoniawater solution as much as 200 kilometers (120mi) deep beneath a water-ice crust with conditions that, although extreme by terrestrial standards, are such that life could survive.[164]Heat transfer between the interior and upper layers would be critical in sustaining any subsurface oceanic life.[163] Detection of microbial life on Titan would depend on its biogenic effects. That the atmospheric methane and nitrogen might be of biological origin has been examined, for example.[164]

It has been suggested that life could exist in the lakes of liquid methane on Titan, just as organisms on Earth live in water.[172] Such organisms would inhale H2 in place of O2, metabolize it with acetylene instead of glucose, and exhale methane instead of carbon dioxide.[165][172]

All living things on Earth (including methanogens) use liquid water as a solvent; it is speculated that life on Titan might instead use a liquid hydrocarbon, such as methane or ethane.[173] Water is a stronger solvent than methane.[174] Water is also more chemically reactive, and can break down large organic molecules through hydrolysis.[173] A life-form whose solvent was a hydrocarbon would not face the risk of its biomolecules being destroyed in this way.[173]

In 2005, astrobiologist Chris McKay argued that if methanogenic life did exist on the surface of Titan, it would likely have a measurable effect on the mixing ratio in the Titan troposphere: levels of hydrogen and acetylene would be measurably lower than otherwise expected.[172]

In 2010, Darrell Strobel, from Johns Hopkins University, identified a greater abundance of molecular hydrogen in the upper atmospheric layers of Titan compared to the lower layers, arguing for a downward flow at a rate of roughly 1028 molecules per second and disappearance of hydrogen near Titan's surface; as Strobel noted, his findings were in line with the effects McKay had predicted if methanogenic life-forms were present.[172][174][175] The same year, another study showed low levels of acetylene on Titan's surface, which were interpreted by McKay as consistent with the hypothesis of organisms consuming hydrocarbons.[174] Although restating the biological hypothesis, he cautioned that other explanations for the hydrogen and acetylene findings are more likely: the possibilities of yet unidentified physical or chemical processes (e.g. a surface catalyst accepting hydrocarbons or hydrogen), or flaws in the current models of material flow.[165] Composition data and transport models need to be substantiated, etc. Even so, despite saying that a non-biological catalytic explanation would be less startling than a biological one, McKay noted that the discovery of a catalyst effective at 95K (180C) would still be significant.[165]

As NASA notes in its news article on the June 2010 findings: "To date, methane-based life forms are only hypothetical. Scientists have not yet detected this form of life anywhere."[174] As the NASA statement also says: "some scientists believe these chemical signatures bolster the argument for a primitive, exotic form of life or precursor to life on Titan's surface."[174]

In February 2015, a hypothetical cell membrane capable of functioning in liquid methane in Titan conditions was modeled. Composed of small molecules containing carbon, hydrogen, and nitrogen, it would have the same stability and flexibility as cell membranes on Earth, which are composed of phospholipids, compounds of carbon, hydrogen, oxygen, and phosphorus. This hypothetical cell membrane was termed an "azotosome", a combination of "azote", French for nitrogen, and "liposome".[176][177]

Despite these biological possibilities, there are formidable obstacles to life on Titan, and any analogy to Earth is inexact. At a vast distance from the Sun, Titan is frigid, and its atmosphere lacks CO2. At Titan's surface, water exists only in solid form. Because of these difficulties, scientists such as Jonathan Lunine have viewed Titan less as a likely habitat for life, than as an experiment for examining theories on the conditions that prevailed prior to the appearance of life on Earth.[178] Although life itself may not exist, the prebiotic conditions on Titan and the associated organic chemistry remain of great interest in understanding the early history of the terrestrial biosphere.[166] Using Titan as a prebiotic experiment involves not only observation through spacecraft, but laboratory experiments, and chemical and photochemical modeling on Earth.[168]

It is hypothesized that large asteroid and cometary impacts on Earth's surface may have caused fragments of microbe-laden rock to escape Earth's gravity, suggesting the possibility of transpermia. Calculations indicate that these would encounter many of the bodies in the Solar System, including Titan.[179][180] On the other hand, Jonathan Lunine has argued that any living things in Titan's cryogenic hydrocarbon lakes would need to be so different chemically from Earth life that it would not be possible for one to be the ancestor of the other.[181]

Conditions on Titan could become far more habitable in the far future. Five billion years from now, as the Sun becomes a red giant, its surface temperature could rise enough for Titan to support liquid water on its surface making it habitable.[182] As the Sun's ultraviolet output decreases, the haze in Titan's upper atmosphere will be depleted, lessening the anti-greenhouse effect on the surface and enabling the greenhouse created by atmospheric methane to play a far greater role. These conditions together could create a habitable environment, and could persist for several hundred million years. This was sufficient time for simple life to spawn on Earth; the presence of ammonia on Titan would cause chemical reactions to proceed more slowly.[183]

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Titan (moon) - Wikipedia

smithsonian.com July 6, 2017

The hope for Martian life took another blow today. AsIan Sample at The Guardian reports, a new study suggests that in the presence of ultraviolet light, perchlorates, a class of chemical compounds widespread on Mars' surface, turn deadly for bacteria.

The presence of perchlorates isn't new. Viking 1 and 2 spacecraft detected perchlorates when they landed on the Martian surface in 1976,JeffreyKlugerreportsfor Time. Since then, other spacecraft have confirmed the presence of the compounds. The 2009 Phoenix lander found that perchlorates make upbetween 0.4 and 0.6 percentof the soil sample it collected.

While perchlorates, which are composed of chlorine and oxygen, are toxic to humans, microbes typically love the stuff. Andresearchers have beenoptimistic that their presencecould support bacterial life on Mars. AsKluger reports,some bacteria on Earth use naturally occurring perchlorate as an energy source. The compound also lowers the melting point of water, which could improve the chance ofliquid water existing on the Red Planet.

But the latest study, published in the journalScientific Reports, suggests thatin the presence of ultraviolet lightperchlorate is not so microbe-friendly. Mars has a thin atmosphere, which often leaves its surface bathed in UV rays. And when heated, chlorine-based molecules like perchlorates cause heavy damage to living cells, reportsSarahFechtat Popular Science.

Researchers at the University of Edinburgh wanted to see just how much damage those perchlorates would cause to any Martian bacteria. So theyexposed test tubes of a common bacteria, Bacillus subtilis, to conditions similar to ones they might encounter on Mars. They started with low temperatures and low oxygen in the presence of perchlorate. Bacteriaunder these conditions survived for up to an hour, Fecht reports. But when the researchers addedUV light to the mix, the test tube was completely sterilized within 30 seconds. The researcher also found that two other common Martian soil components, iron oxide and hydrogen peroxide, reacted with irradiated perchlorate to make the soil hostile to bacteria.

We knew before that any life would have an incredibly hard time to survive on the surface, and this study experimentally confirms that, Dirk Schulze-Makuch, an astrobiologist at Washington State University not involved in the study, tells Fecht.

That doesnt completely rule out the possibility that bacteria may exist on Mars. I cant speak for life in the past, co-author Jennifer Wadsworth tells Sample. As far as present life, it doesnt rule it out but probably means we should look for life underground where its shielded from the harsh radiation environment on the surface.As Sample reports, the ExoMars rover, scheduled to launch in 2020, will test this idea, digging about 12 feet into the Martian soil to look for bacteria.

Therestill remains some hope for surface microbes. As Kluger reports, the researchers found that the colder temperatures offersome small protection for thebacteria. And the average temperature on Mars is -67 Fahrenheit. Also, the concentrations of perchlorate are not uniform, meaning there may be some pockets where life could exist.

It's also possible that hypothetical Martian bacteria could be much tougher than the commonBacillus subtilis.On Earth, researchers have found all types of extremophile organisms with the ability to survive under intense heat and pressure, in the presence of acid, without water and even inside rocks. Life can survive very extreme environments, Wadsworth tells Fecth. The bacterial model we tested wasnt an extremophile so its not out of the question that hardier life forms would find a way to survive.

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Mars Surface May Be Too Toxic for Microbial Life - Smithsonian

Feature Article of Tuesday, 4 July 2017

Columnist: King David Dzirasah

It cannot be said that Christianity is a colonial relic or symbolism of slavery

Jerusalem long lost or not, Christianity is Afro-orient, not European. Christianity was thriving in the horn of Africa in the 1st century before this religion had really taken root anywhere in Europe. Akinyi Princess of KOrinda Yimbo.

Most often both academic and non-intellectuals based on historical understanding conclude that Europeans brought or introduced Christianity to Africa. It is often said that missionaries from Europe during the colonial days came down from Europe to Africa in their quest of spreading Christianity on a dark continent that is heading towards hell. However, there is ample evidence suggesting that Christianity was already on the continent before the advent of colonization and the coming of European missionaries.

The Coptic orthodox church of Alexandria is an oriental orthodox Christian church in Egypt, northeast Africa and Middle East. The Egyptian church is traditionally believed to be founded by Saint Mark at around AD 42. Christianity spread throughout Egypt within half a century of Saint Marks arrival. Christianity being introduced to the horn of Africa clearly is not as a result of missionary work of Europeans. Even though Christianity was able to spread from the northern part of Africa to the eastern part (Ethiopia), the complete spread of the religion to all part of the continent was made impossible due to the advancement of Islam in the northern part of the continent.

It is recognizable that historically Christianity came to Sub-Sahara Africa in the 15th century but that cannot over shadow the fact that Christianity was already on the continent before the coming of colonial imperialist. As of the 7th to 8th century, African warriors were fighting in Europe under the banner of the lion and the half-moon in order to bring the truth faith, Christianity or Islam, to Europe.

Europeans at the time were in the majority heathen and did everything in their power to remain heathen. Because Christ came from their corner of the world, Africans had embraced Christianity at a time when the religion was struggling to take root in Greece and Rome. Princess of Korinda-Yimbo. Historically Jesus was actually taken to the northern part of Africa (Egypt) as a child. With that link to that part of the continent, the people were accommodating to the missionary work of Saint Mark.

The biblical Ark of the Covenant is now believed to be kept in St Mary of Zions Church in Axum, Ethiopia. With the knowledge in mind that Africans actually play a crucial role in the expansion of the religion in Europe, one cannot make the assertion that Europeans actually introduced Africans to the religion. It cannot be said that Christianity is a colonial relic or symbolism of slavery since evidentially the existence of the religion precede colonization.

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Startling revelation of how Christianity was in already in Africa before colonization - GhanaWeb

NASA assured the public on Thursday that there was no child slave colony on the planet Mars, refuting a claim recently made by a guest on the popular The Alex Jones Show.

There are no humans on Mars, NASA spokesperson Guy Webster told The Daily Beastin a statement. There are active rovers on Mars. There was a rumor going around last week that there werent. There are.

But there are no humans, he added.

According toRobert David Steele, a former CIA officer who appeared on Alex Jones show this week, NASA had been shuttling children to the distant red planet for their blood, bone marrow and sexual exploitation.

We actually believe that there is a colony on Mars that is populated by children who were kidnapped and sent into space on a 20-year ride, Steele said this week on Infowars. So that once they get to Mars they have no alternative but to be slaves on the Mars colony.

Look, I know that 90 percent of the NASA missions are secret and Ive been told by high level NASA engineers that you have no idea, Jones said in response to the outlandish allegation. There is so much stuff going on.

Accustomed to dealing with conspiracy theories (and the bunk claims of certain websites owned by certain Oscar Award-winning actors), NASA provided a statement Thursday clearly explaining to the American people that no human, let alone no child, had ever touched foot on the planet Mars.

Infowars listeners will likely disregard the denial. A child slave colony on Mars might not even be the most absurd conspiracy theory floated on The Alex Jones Show.

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NASA denies Infowars claim that the agency runs a child slave colony on Mars - Salon

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Astrophysicist Stephen Hawkings recently released documentary Expedition New Earth argues that humanity needs to develop ways to colonize the moon and Mars if it has any chance of surviving.Professor Stephen Hawking thinks the human species will have to populate a new planet within 100 years if it is to survive,thesaid in a statement. With climate change, overdue asteroid strikes, epidemics and population growth, our own planet is increasingly precarious.

In the past few years, several others have voiced their opinions that humanity is doomed and technology needs to rapidly progress to come to the rescue.

Elon Musk has sounded the alarm that life on Earth is inherently finite. Therefore, he says, colonization on different planets is a necessity to ensure the human race survives. I think there are really two fundamental paths. History is going to bifurcate along two directions. One path is we stay on Earth forever, and then there will be some eventual extinction event. I do not have an immediate doomsday prophecy, but eventually, history suggests, there will be some doomsday event, writes Musk on June 1. The alternative is to become a space-bearing civilization and a multiplanetary species, which I hope you would agree is the right way to go.

Amazon CEO Jeff Bezosarguedfor a slightly different approach at the Recode Conference earlier this month. Let me assure you, this is the best planet. We need to protect it, and the way we will is by going out into space. You dont want to live in a retrograde world where we have to freeze population growth, he said. Energy is limited here. In at least a few hundred yearsall of our heavy industry will be moved off-planet. Earth will be zoned residential and light industrial. You shouldnt be doing heavy energy on earth. We can build gigantic chip factories in space.

Harvard Biologist Dr. E.O. Wilson outlined in a 2016booka Half-Earth theory in that 50 percent of the planet should be set aside in conservation to save the Earths biodiversity, not just humans. Now, this proposal doesnt mean moving anybody out. It means creating something equivalent to the U.N.s World Heritage sites that could be regarded as priceless assets of humanity, said Wilson in a March 2016interview, citing that interconnected wildlife corridors could be established to preserve the biodiversity currently suffering a mass extinction due to man. Do no further harm to the rest of life. If we can agree on that, everything else will follow.

While the tendency to speculate and grow technological capabilities is important and exciting, the apocalyptic foreshadowing this thinking generates needs to take into account what can be done currently to render solutions to the biodiversity and environmental crisis facing Earth today. No space colonies or infrastructure will be able to replace our planet.

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Stephen Hawking, Elon Musk and Jeff Bezos Think the Earth Is ... - Observer

SEOUL South Korean President Moon Jae-in is returning from an official visit to Washington with two ancient royal seals looted during the Korean War, reports said Saturday.

The repatriation of the Joseon Dynasty antiques, dating from the 16th and 17th centuries, comes after years of campaigning by the South Korean government, which said they were stolen during the turbulent 1950-53 war.

Moon received the seals at a ceremony in Washington on Friday and was to arrive in South Korea with them on Sunday, the Yonhap news agency said.

The Joseon Dynasty, which cultivated a ruling philosophy drawn from Confucianism, governed from 1392 to 1910, when Japan colonized the country.

One of the seals was made in 1547 to honor Queen Munjeong (1501-1565), the third wife of Joseon Dynastys 11th king, Jungjong.

The other is a jade block created in 1651 to commemorate the crown prince becoming King Hyojong.

They were seized by U.S. authorities in 2013 after Seoul clarified these were stolen items.

It marked the third time that Washington has returned South Korean treasures. In 2013 the United States sent back Koreas first money-printing block, made in late 19th century; the following year, it handed back nine royal seals.

Tens of thousands of old Korean cultural items were spirited abroad during Japans colonization of Korea from 1910 to 1945 and during the Korean War.

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US returns looted royal seals to South Korea - The Japan Times

Where once the space race meant which superpower would get to the moon first, now the countries of the world are racing to build the first lunar base. Already the European Space Agency, or the ESA, have an agreement with China to build a joint moon station. When you include intentions to partner with private corporations, these agencies obviously have a clear picture of the space exploration plans.

At the same time, NASA and the Trump administration are leaning towards private corporations like Space X and investment groups focusing on building communities on the moon.

Ultimately, the goal for all the agencies and the main driving force for establishing a moon base in the first place is to send a manned mission to Mars. From the NASA Scope and Subject Category Guide indicates what parts of the moon will be built up in their plans and the Space Technology Roadmap lists the many projects it will work on to get there. The Deep Space Gateway, an orbiting spaceport, looks promising for a first start. Plus the smart robots which will build on the moon while also producing electricity send back to Earth.

With plans for an inflatable greenhouse for sustainable farming on the moon in the works too, there will have plenty of activity during our days on the moon. Published in the journal New Space, a new paper from NASA states its full lunar station plans that rely heavily on the work already done for the International Space Station, or ISS. Specifically learning from the architecture of the station, the next steps will be developed in low-earth-orbit space, also called LEO.

As previously mentioned, the lunar station will be a stepping stone on the way to Mars and therefore will be a testing ground for new technologies that will help complete the journey to Mars, and perhaps spur settlements there too.

The authors of the paper Robert Bruce Pittman, Mark E. Newfield, Daniel J. Rasky, and Lynn D. Harper addressed this in their paper: It Lunar Station can provide a testing and prove ground for a variety of important advanced technologies and capabilities, including robotics, ISRU, resource depots, deep-space crew habitats, closed-loop life support, in-space propulsion, optical communication, and space-additive manufacturing [further elaborating that] the Lunar Station will give our space program a much-needed logical next step to strengthen its relevance to the US public, its leadership in the international community, and its technical cutting edge.

Initially expected to be fully operational in five years, Lunar Station will cost about $2 billion a year. Once constructed, the Station will crew up to 10 people much in the same way as ISS and allow a much wider cooperative effort to support scientific work as well as commercial ends.

The paper further states that: The Lunar Station community would jointly develop and share infrastructure as well as separately develop and own specific capabilities [] Activities would range from scientific research and technology development to resource mining and processing and human exploration of the Moon and even tourism.

Although this latest NASA releases may disappoint those excited about the possibility or Mars colonization occurring soon stations and experiments on the moon must be the first step. As a matter of course, space exploration and development is risky, and the moon offers a perfect opportunity safely test technology before we move on to deeper space.

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The Race for Space Colonization Starts with NASA's Lunar Station Plans - TrendinTech

Stephen Hawking is fed up. He thinks the world is doomed and that we should start preparing our exit strategy now. Easier said than done. Hawking recently spoke out at the Starmus Festival of arts and sciences in Norway. In his speech, the world famous physicist slammed President Donald Trump for taking the most serious, and wrong, decision on climate change this world has seen. When asked to comment further the famouscosmologist groaned:"The Earth is under threat from so many areas that it is difficult for me to be positive.

In two previous statements, Hawking has warned that wed better formulate a workable plan B in order to punch out in the next century or so, as Earth is caught in a downward spiral he believes we cant escape. As a result, the professor suggests we find a new home planet in the next two to five centuries. The only way we can do that is to start exploring space for a suitable planet sufficient to sustain life, or even perhaps more than one. Using advanced scientific instruments, weve been able to peer into the universe like never before, Hawking said.

"When we have reached similar crises in our history, there has usually been somewhere else to colonize, he said. Columbus did it in 1492 when he discovered the New World. But now there is no new world. No Utopia around the corner." The first logical places to start are the moon and Mars. According to the BBC, Hawking called on nations to colonize the moon by 2020 and Mars by 2025.

Hawking believes one of our first moves is colonizing Mars. Getty Images.

But each is subject to cosmic radiation, long-term exposure of which could cause cancer and Alzheimers. Well need to invent proper shielding. Whats more, no one knows how a child being born in such circumstances might fare. The gravity for instance, is way different in both places than on Earth. How would this affect skeletal development? Growing up on Mars might mean never being able to set foot on the Earth, as ones skeletal system wouldnt be able to withstand the gravity.

Planet Proxima b in the Proxima Centauri system, approximately 4.5 light-years from Earth, was one such candidate Hawking mentioned. Note that one light-year is around six trillion miles (10 million km). We dont even have the cryonic process down completely yet. We can freeze a person but we dont know how to revive them. Beyond that, the distances are just mind-blowing. Even with such technology tucked under our arm, is such a feat feasible?

The renowned cosmologist said, "To go faster would require a much higher exhaust speed than chemical rockets can providethat of light itself. He added, A powerful beam of light from the rear could drive the spaceship forward. Nuclear fusion could provide 1 percent of the spaceship's mass energy, which would accelerate it to a tenth of the speed of light." Such technology is theoretical. NASA has tested an EM or impossibility drive, and other types of next generation rocketsare on the horizon.

Of course, wed have to harness the power of antimatter to achieve the kind of technological feat Hawking is proposing. Antimatter particles are puzzlingly rare in the universe, even though equal parts of matter and antimatter were supposedly present at the Big Bang. Generating enough antimatter to power a rocket borders on the fantastical. Such an engine remains, for the time being, in the theoretical stages.

Model of an antimatter rocket. NASA.

Even so the moderator, taking Hawkings suggestion as granted, feared that we might become complacent or preoccupied in an era of such technology, having the ability to observe the unexplored corners of the universe and marvel at their wonders, as one watches television. But Hawking replied that the peril the Earth is in will motivate us to take action.

Hawking said in his speech:

Human colonization on other planets is no longer science fiction. It can be science fact. The human race has existed as a separate species for about 2 million years. Civilization began about 10,000 years ago, and the rate of development has been steadily increasing. If humanity is to continue for another million years, our future lies in boldly going where no one else has gone before.

Cheesy Stark Trek line aside, Russian billionaire Yuri Milner, Facebook founder Mark Zuckerberg, and Hawking have developed an initiative called Breakthrough Starshot, which plans to comb the universe for intelligent life and Earth-like planets. They plan on sending out hundreds or even thousands of tiny spacecraft, each weighing less than one ounce, to explore the Alpha Centauri star system and see whats out there. This will be 2,000 times farther than anything from Earth has ever traveled.

This animation depicts the Breakthrough Starshot:

These little spacecraft, called nanocrafts, will be propelled by an array of powerful lasers. The lasers will hit each nanocrafts solar sail, pushing it along. With such force behind it and at such a small size, they should travel at an unheard of velocity, one fifth the speed of light. Hawking said at the announcement, "With light beams, light sails and the lightest spacecraft ever built, we can launch a mission to Alpha Centauri within a generation." So far the project has raised $100 million to explore its viability. There will be other benefits besides saving humanitys collective skin.

At the Starmus festival, Hawking commented:

Spreading out into space will completely change the future of humanity. I hope it would unite competitive nations in a single goal, to face the common challenge for us all. A new and ambitious space program would excite (young people), and stimulate interest in other areas, such as astrophysics and cosmology.

Will the Earth really perish? To hear what physicist Michio Kaku thinks, click here:

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Stephen Hawking Believes We Will Abandon Earth via Light-Based Transportation - Big Think