Universe Today - 10 new stories for 2016/04/26



10 new stories for 2016/04/26 Spaceflight Will Give You The Body Of An Elderly Alcoholic Shut In At least, that was what the results of a recent study conducted by the University of Colorado's Anschutz Medical Campus suggest. After examining a group of test mice that spent two weeks in space aboard STS-135 - the final mission of NASA's space shuttle program - they concluded that spending prolonged periods of time in space could in fact result liver damage.For some time now, scientists have understood that exposure to zero-gravity or micro-gravity environments comes with its share of health effects. But so far, the research has been largely confined to other areas of the human body. Understanding the effects it has on internal organs and other aspects of one's health are of extreme importance as NASA begins preparations for a crewed mission to Mars.While the effects of long-term stays in space has been the subject of much scientific and medical study, the focus thus far has been on the effects to bone density and muscle mass. A good example of this was a 2001 study conducted by NASA's Human Research Program (HRP), which researched the effects on an astronaut Scott Kelly's body after he spent a year aboard the International Space Station.The study reported that, "without gravity working on your body,  your bones lose minerals, with density dropping at over 1% per month." Similarly, a report by the Johnson Space Center - titled "Muscle Atrophy" - stated that "astronauts experience up to a 20 percent loss of muscle mass on spaceflights lasting five to 11 days."These and other studies have shown that exposure to zero-gravity or micro-gravity environments can take a toll on an astronaut's body, their senses (i.e. visual acuity and hearing), as well as their vestibular (sense of balance and orientation) and cardiovascular systems. However, this most recent study was the first to examine the effect of spaceflight on the liver.As Prof. Karen Jonscher - an associate professor of anesthesiology and a physicist at CU Anschutz, and the study's lead author - explained in a university press release: "Prior to this study we really didn't have much information on the impact of spaceflight on the liver. We knew that astronauts often returned with diabetes-like symptoms but they usually resolved quickly."Though temporary, these diabetes-like symptoms showed that there is a link between micro-gravity and metabolism. As the major organ of metabolism, it had been theorized that the liver could be a possible target of the space environment as well. However, until now, the question of whether or not the liver itself was effected remained an open one.But after Jonscher studies liver samples that were taken from the rats, they found that the time they spent in space appeared to activate specialized liver cells that may go on to induce scarring and cause long-term damage to the organ. All told, the rats only spent thirteen and a half days in space during the final flight of Space Shuttle Atlantis (in July of 2011). As such, the results were quite startling.Essentially, Jonscher's team found that spaceflight resulted in increased fat storage in the liver, which was accompanied by a loss of retinol (an animal form of Vitamin A) and changes to levels of genes responsible for breaking down fats. As a result, the mice showed signs of nonalcoholic fatty liver disease (NAFLD) and potential early indicators for the beginnings of fibrosis, which can be one of the more progressive consequences of NAFLD.Naturally, these findings raise concerns about the effects space travel would have on astronauts. "The question is," said Jonscher, "how does that affect your liver? It generally takes a long time, months to years, to induce fibrosis in mice, even when eating an unhealthy diet. If a mouse is showing nascent signs of fibrosis without a change in diet after 13 ½ days, what is happening to the humans?"Another interesting aspect of the research is the parallels it shows with health problems here on Earth. As the name would suggest, NAFLD can be caused by subsisting on a diet that is overly-rich in saturated fats. The abuse of alcohol has similar effects, damaging the liver to the point that it is no longer able to maintain regular metabolic and regulatory processes. In addition, there is a correlation between these results and the results of inactivity and aging.In fact, as was also indicated by NASA's 2001 HRP study, the rate of bone loss for elderly men and women on Earth is from 1% to 1.5% per year, consistent with what astronauts in space experience. And the CU Anschutz study noted similarities between the muscle atrophy the mice experienced and humans who experienced prolonged periods of bedrest (i.e. patients recovering in hospital).So really, it would seem that the effects of prolonged time spent in space, and/or space travel, will result in the same kinds of physical changes that come from a life of inactivity, alcoholism, and aging - possibly all rolled into one. But before anyone starts thinking that this should deter us from space travel and exploration, Prof. Jonscher admits that the study does leave some room for doubt."Whether or not this is a problem is an open question," she said. "We need to look at mice involved in longer duration space flight to see if there are compensatory mechanisms that come into play that might protect them from serious damage. Further study in this area is merited and analysis of tissues harvested in space from mice flown aboard the International Space Station for several months may help determine whether long-term spaceflight might lead to more advanced hepatic injury and whether damage can be prevented."In addition, NASA ensured that its astronauts maintain a physical and nutritional regimen to minimize the health effects of space travel. Whether or not they will be sufficient for long term missions remains to be seen. In any case, the research conducted by CU Anschutz and other institutions on the effects of time spent away from Earth is of great importance, especially when one considering NASA and other space agencies long term exploration plans for the future.Whether it is a mission to Mars, which will involve a year spent in space, or missions back to the Moon, knowing the long-term effects of zero-gravity or reduced gravity are paramount!http://www.asc-csa.gc.ca/videos/recherche/1_nvajj8o6/1_ywdhisww.webmFurther Reading: University of Colorado The post Spaceflight Will Give You The Body Of An Elderly Alcoholic Shut In appeared first on Universe Today.        • Email to a friend • View comments • Track comments •   Stunning Auroras From the Space Station in Ultra HD – Videos Stunning high definition views of Earth's auroras and dancing lights as seen from space like never before have just been released by NASA in the form of ultra-high definition videos (4K) captured from the International Space Station (ISS).Whether seen from the Earth or space, auroras are endlessly fascinating and appreciated by everyone young and old and from all walks of life.The spectacular video compilation, shown below, was created from time-lapses shot from ultra-high definition cameras mounted at several locations on the ISS.It includes HD view of both the Aurora Borealis and Aurora Australis phenomena seen over the northern and southern hemispheres.The video begins with an incredible time lapse sequence of an astronaut cranking open the covers off the domed cupola - everyone's favorite locale. Along the way it also shows views taken from inside the cupola.The cupola also houses the robotics works station for capturing visiting vehicles like the recently arrived unmanned SpaceX Dragon and Orbital ATK Cygnus cargo freighters carrying science experiments and crew supplies.The video was produced by Harmonic exclusively for NASA TV UHD;https://youtu.be/PBJAR3-UvSQVideo caption: Ultra-high definition (4K) time-lapses of both the Aurora Borealis and Aurora Australis phenomena shot from the International Space Station (ISS). Credit: NASA The video segue ways into multi hued auroral views including Russian Soyuz and Progress capsules, the stations spinning solar panels, truss and robotic arm, flying over Europe, North America, Africa, the Middle East, star fields, the setting sun and moon, and much more.Auroral phenomena occur when electrically charged electrons and protons in the Earth's magnetic field collide with neutral atoms in the upper atmosphere."The dancing lights of the aurora provide a spectacular show for those on the ground, but also capture the imaginations of scientists who study the aurora and the complex processes that create them," as described by NASA.Here's another musical version to enjoy:https://youtu.be/fVMgnmi2D1wThe ISS orbits some 250 miles (400 kilometers) overhead with a multinational crew of six astronauts and cosmonauts living and working aboard.The current Expedition 47 crew is comprised of Jeff Williams and Tim Kopra of NASA, Tim Peake of ESA (European Space Agency) and cosmonauts Yuri Malenchenko, Alexey Ovchinin and Oleg Skripochka of Roscosmos.Some of the imagery was shot by recent prior space station crew members.Here is a recent aurora image taken by flight engineer Tim Peake of ESA as the ISS passed through on Feb. 23, 2016."The @Space_Station just passed straight through a thick green fog of #aurora…eerie but very beautiful," Peake wrote on social media.A new room was just added to the ISS last weekend when the BEAM experimental expandable habitat was attached to a port on the Tranquility module using the robotic arm.BEAM was carried to the ISS inside the unpressurized trunk section of the recently arrived SpaceX Dragon cargo ship.Stay tuned here for Ken's continuing Earth and planetary science and human spaceflight news.Ken Kremer The post Stunning Auroras From the Space Station in Ultra HD – Videos appeared first on Universe Today.        • Email to a friend • View comments • Track comments •   How Do We Terraform Jupiter's Moons? Fans of Arthur C. Clarke may recall how in his novel, 2010: Odyssey Two (or the movie adaptation called 2010: The Year We Make Contact), an alien species turned Jupiter into a new star. In so doing, Jupiter's moon Europa was permanently terraformed, as its icy surface melted, an atmosphere formed, and all the life living in the moon's oceans began to emerge and thrive on the surface.As we explained in a previous video ("Could Jupiter Become a Star") turning Jupiter into a star is not exactly doable (not yet, anyway). However, there are several proposals on how we could go about transforming some of Jupiter's moons in order to make them habitable by human beings. In short, it is possible that humans could terraform one of more of the Jovians to make it suitable for full-scale human settlement someday. The Jovian Moons: Within the Jupiter system, there are 67 confirmed moons of varying size, shape and composition. In honor of Jupiter's namesake, they are sometimes collectively referred to as the Jovians. Of these, the four largest - Io, Europa, Ganymede and Callisto - are known as the Galileans (in honor of their founder, Galileo Galilei). These four moons are among the largest in the Solar System, with Ganymede being the largest of them all, and even larger than the planet Mercury.In addition, three of these moons - Europa, Ganymede and Callisto - are all believed or known to have interior oceans at or near their core-mantle boundary. The presence of warm water oceans is not only considered an indication of potential life on these moons, but is also cited as a reason for possible human habitation.https://youtu.be/ZErO1MCTj_kOf the Galilean Moons, Io, Europa and Ganymede are all in orbital resonance with each other. Io has a 2:1 mean-motion orbital resonance with Europa and a 4:1 resonance with Ganymede, which means that it completes two orbits of Jupiter for every one orbit of Europa, and four orbits for every orbit Ganymede. This resonance helps maintain these moons' orbital eccentricities, which in turn triggers tidal flexing their interiors.Naturally, each moon presents its own share of advantages and disadvantages when it comes to exploration, settlement, and terraforming. Ultimately, these come down to the particular moon's structure and composition, its proximity to Jupiter, the availability of water, and whether or not the moon in question is dominated by Jupiter's powerful magnetic field. Possible Methods: The process of converting Jupiter's Galilean moons is really quite simple. Basically, its all about leveraging the indigenous resources and the moons' own interactions with Jupiter's magnetic field to create a breathable atmosphere. The process would begin by heating the surface in order to sublimate the ice, a process which could involve orbital mirrors to focus sunlight onto the surface, nuclear detonators, or crashing comets/meteors into the surface.Once the surface ice begins to melt, it would form dense clouds of water vapor and gaseous volatiles (such as carbon dioxide, methane and ammonia). These would in turn create a greenhouse effect, warming the surface even more, and triggering a process known as radiolysis (the dissociation of molecules through exposure to nuclear radiation). Basically, the exposure of water vapor to Jupiter's radiation would result in the creation of hydrogen and oxygen gas, the former of which would escape into space while the latter remained closer to the surface. This process already takes place around Europa, Ganymede and Callisto, and is responsible for their tenuous atmospheres (which contain oxygen gas).And since ammonia is predominantly composed of nitrogen, it could be converted into nitrogen gas (N²) through the introduction of certain strains of bacteria. These would include members of the Nitrosomonas, Pseudomonas and Clostridium species, which would convert ammonia gas into nitrites (NO²-), and then nitrites into nitrogen gas. With nitrogen acting as a buffer gas, a nitrogen-oxygen atmosphere with sufficient air pressure to sustain humans could be created.Another option falls under the heading of "paraterraforming" - a process where a world is enclosed (in whole or in part) in an artificial shell in order to transform its environment. In the case of the Jovians, this would involve building large "Shell Worlds" to encase them, keeping the atmospheres inside long enough to effect long-term changes.Within this shell, Europa, Ganymede and Callisto could have their temperatures slowly raised, the water-vapor atmospheres could be exposed to ultra-violet radiation from internal UV lights, bacteria could then be introduced, and other elements added as needed. Such a shell would ensure that the process of creating of an atmosphere could be carefully controlled and none would be lost before the process was complete. Io: With a mean radius of 1821.6 ± 0.5 km, and an average distance (semi-major axis) of 421,700 km from Jupiter, Io is the innermost of the Galileans. Because of this, Io is completely enveloped by Jupiter's powerful magnetic field, which also why the surface is exposed to significant amounts of harmful radiation. In fact, Io receives an estimated 3,600 rem (36 Sv) of ionizing radiation per day, whereas living organisms here on Earth experience an average of 24 rem per year! The moon has the shortest orbital period of any of the Galileans, taking roughly 42.5 hours to complete a single orbit around the gas giant. The moon's 2:1 and 4:1 orbital resonance with Europa and Ganymede (see below) also contributes to its orbital eccentricity of 0.0041, which is the primary reason for Io's geologic activity.With a mean density of 3.528 ± 0.006 g/cm3, Io has the highest density of any moon in the Solar System, and is significantly denser than the other Galilean Moons. Composed primarily of silicate rock and iron, it is closer in bulk composition to the terrestrial planets than to other satellites in the outer Solar System, which are mostly composed of a mix of water ice and silicates.Unlike its Jovian cousins, Io has no warm-water ocean beneath its surface. In fact, based on magnetic measurements and heat-flow observations, a magma ocean is believed to exist some 50 km below the surface, which itself is about 50 km thick and makes up 10% of the mantle.  It is estimated that the temperature in the magma ocean reaches 1473 K (1200 °C/2192 °F).The main source of internal heat that allows for this comes from tidal flexing, which is the result of Io's orbital resonance with Europa and Ganymede. The friction or dissipation produced in Io's interior due to this varying tidal pull creates significant tidal heating within Io's interior, melting a significant amount of Io's mantle and core.https://youtu.be/08X9tET-d2kThis heat is also responsible for Io's volcanic activity and its observed heat flow, and periodically causes lava to erupt up to 500 km (300 mi) into space. Consistently, the surface of is covered in smooth plains dotted with tall mountains, pits of various shapes and sizes, and volcanic lava flows. It's colorful appearance (a combination of orange, yellow, green, white/grey, etc.) is also indicative of volcanic activity which has covered the surface in sulfuric and silicate compounds and leads to surface renewal.Io contains little to no water, though small pockets of water ice or hydrated minerals have been tentatively identified, most notably on the northwest flank of the mountain Gish Bar Mons. In fact, Io has the least amount of water of any known body in the Solar System, which is likely due to Jupiter being hot enough early in the evolution of the Solar System to drive volatile materials like water off its surface.Taken together, all of this adds up to Io being a total non-starter when it comes to terraforming or settlement. The planet is far too hostile, far too dry, and far too volcanically active to ever be turned into something habitable! Europa: Europa, by contrast, has a lot of appeal for proponents of terraforming. If Io could be characterized as hellish, lava-spewing place (and it certainly can!), then Europa would be calm, icy and watery by comparison. With a mean radius of about 1560 km and a mass of 4.7998 ×1022 kg, Europa is also slightly smaller than Earth's Moon, which makes it the sixth-largest moon and fifteenth largest object in the Solar System.https://youtu.be/m25i1edwiKsIt's orbit is nearly circular, with a eccentricity of 0.09, and lies at an average distance of 670 900 km from Jupiter. The moon takes 3.55 Earth days to complete a single orbit around Jupiter, and is tidally locked with the planet (though some theories say that this may not be absolute). At this distance from Jupiter, Europa still experiences quite a bit of radiation, averaging about 540 rem per day. Europa is significantly more dense than the other Galilean Moons (except for Io), which indicates that its interior is differentiated between a rock interior composed of silicate rock and a possible iron core. Above this rocky interior is layer of water ice that is estimated to be around 100 km (62 mi) thick, likely differentiated between a frozen upper crust and  a liquid water ocean beneath.If present, this ocean is likely a warm-water, salty ocean that contains organic molecules, is oxygenated, and heated by Europa's geologically-active core. Given the combination of these factors, it is considered a strong possibility that organic life also exists in this ocean, possibly in microbial or even multi-celled form, most likely in environments similar to Earth's deep-ocean hydrothermal vents.Because of its abundant water, which comes in both liquid and solid form, Europa is a popular candidate for proponents of colonization and terraforming. Using nuclear devices, cometary impacts, or some other means to increase the surface temperature, Europa's surface ice could be sublimated and form a massive atmosphere of water vapor.https://youtu.be/GqTaDCt_F1YThis vapor would then undergo radiolysis due to exposure to Jupiter's magnetic field, converting it into oxygen gas (which would stay close to the planet) and hydrogen that would escape into space. The resulting planet would be an ocean world, where floating settlements could be built that floated across the surface (due to oceans depths of ~100 km, they could not be anchored). Because Europa is tidally-locked, these colonies could move from the day-side to the night-side in order to create the illusion of a diurnal cycle. Ganymede: Ganymede's is the third most distant moon from Jupiter, and orbits at an average distance (semi-major axis) of 1,070,400 km – varying from 1,069,200 km at periapsis to at 1,071,600 km apoapsis. At this distance, it takes seven days and three hours to completes a single revolution. Like most known moons, Ganymede is tidally locked, with one side always facing toward the planet.With a mean radius of 2634.1 ± 0.3 kilometers (the equivalent of 0.413 Earths), Ganymede is the largest moon in the Solar System, even larger than the planet Mercury. However, with a mass of 1.4819 x 10²³ kg (the equivalent of 0.025 Earths), it is only half as massive, which is due to its composition, which consists of water ice and silicate rock.Ganymede is considered another possible candidate for human settlement - and even terraforming - for several reasons. For one, as Jupiter's largest moon, Ganymede has a gravitational force of 1.428 m/s2 (the equivalent of 0.146 g) which is comparable to Earth's Moon. Sufficient enough to limit the effects of muscle and bone degeneration, this lower gravity also means that the moon has a lower escape velocity - which means it would take considerably less fuel for rockets to take off from the surface.What's more, the presence of a magnetosphere means that colonists would be better shielded from cosmic radiation than on other bodies, and more shielded from Jupiter's radiation than Europa or Io. All told, Ganymede receives about 8 rem of radiation per day - a significant reduction from Europa and Io, but still well above human tolerances. The prevalence of water ice means that colonists could also produce breathable oxygen, their own drinking water, and would be able to synthesize rocket fuel. Like Europa, this could be done by heating up the surface through various means, sublimating the water ice, and allowing radiolysis to convert it into oxygen. Again, the result would be an ocean world, but one with significantly deeper oceans (~800 km).And then there is the distinct possibility that Ganymede, like Europa, has an interior ocean due to the heat created by tidal flexing in its mantle. This heat could be transferred into the water via hydrothermal vents, which could provide the necessary heat and energy to sustain life. Combined with oxygenated water, life forms could exist at the core-mantle boundary in the form of extremophiles, much like on Europa. Callisto: Callisto is the outermost of the Galileans, orbiting Jupiter at an average distance (semi-major axis) of 1,882,700 km. With a mean radius of 2410.3 ± 1.5 km (0.378 Earths) and a mass of 1.0759 × 1023 kg (0.018 Earths), Callisto is the second largest of  Jupiter's moons (after Ganymede) and the third largest satellite in the solar system. It is similarly comparable in size to Mercury – being 99% as large – but due to its mixed composition, it has less than one-third of Mercury mass.Compared to the other Galileans, Callisto presents numerous advantages as far as colonization is concerned. Much like the others, the moon has an abundant supply of water in the form of surface ice (but also possibly liquid water beneath the surface). But unlike the others, Callisto's distance from Jupiter means that colonists would have far less to worry about in terms of radiation. In fact, with a surface exposure of about  0.01 rem a day, Callisto is well within human tolerances.Much like Europa and Ganymede, and Saturn's moons of Enceladus, Mimas, Dione, Titan, the possible existence of a subsurface ocean on Callisto has led many scientists to speculate about the possibility of life. This is particularly likely if the interior ocean is made up of salt-water, since halophiles (which thrive in high salt concentrations) could live there.However, the environmental conditions necessary for life to appear (which include the presence of sufficient heat due to tidal flexing) are more likely on Europa and Ganymede. The main difference is the lack of contact between the rocky material and the interior ocean, as well as the lower heat flux in Callisto's interior. In essence, while Callisto possesses the necessary pre-biotic chemistry to host life, it lacks the necessary energy.Like Europa and Ganymede, the process of terraforming Callisto would involve heating up the surface in order to sublimate the surface ice and create an atmosphere, one which produces oxygen through radiolysis. The resulting world would be an ocean planet, but with oceans that reached to depths of between 130 and 350 km.https://youtu.be/NGjK_UQbkLI Potential Challenges: Okay, we've covered the potential methods and targets, which means its time for the bad news. To break it down, converting one or more of the Galileans into something habitable to humans presents many difficulties, some of which may prove to be insurmountable. These include, but are are not limited to: Distance Resources/Infrastructure Natural Hazards Sustainability Ethical Considerations Basically, the Jovian system is pretty far from Earth. On average, the distance between Jupiter and Earth is 628,411,977 million km (4.2 AU), roughly four times the distance between the Earth and the Sun. To put that into perspective, it took the Voyager probes between 18 months and two years to reach Jupiter from Earth. Ships designed to haul human passengers (with enough supplies and equipment to sustain them) would be much larger and heavier, which would make the travel time even longer.In addition, depending on the method used, transforming the surfaces of Europa, Ganymede, and/or Callisto could require harvesting comets and iceteroids from the edge of the Solar System, which is significantly farther. To put that in perspective, it took the New Horizons mission over eight years to reach Pluto and the Kuiper Belt. And since any mission to this region of space would need to haul back several tons of icy cargo, the wait time involved would be on the order of decades.Ergo, any vessels transporting human crews to the Jovian system would likely have to rely on cryogenics or hibernation-related technology in order to be smaller, faster and more cost-effective. While this sort of technology is being investigated for crewed missions to Mars, it is still very much in the research and development phase.As for transport missions to and from the Kuiper Belt, these ships could be automated, but would have to come equipped with advanced propulsion systems in order to make the trips in a decent amount of time. This could take the form of Nuclear-Thermal Propulsion (NTP), Fusion-drive systems, or some other advanced concept. So far, no such drive systems exist, with some being decades or more away from feasibility.An alternative to this last item could be to harvest asteroids from near Earth, the Asteroid Belt, or Jupiter's Trojans. However, this brings up the second aspect of this challenge, which is the problem of infrastructure. In order to mount multiple crewed missions to the Jovian system, as well as asteroid/iceteroid retrieval missions, a considerable amount of infrastructure would be needed that either does not exist or is severely lacking.This includes having lots of spaceships, which would also need advanced propulsion systems. Just as important is the need for refueling and supply stations between Earth and the Jovian System - like an outpost on the Moon, a permanent base on Mars, and bases on Ceres and in the Asteroid Belt. Harvesting resources from the Kuiper Belt would require more outposts between Jupiter and most likely Pluto.Where "Shell Worlds" are concerned, the challenge remains the same. Building an enveloping structure big enough for an entire moon - which range from 3121.6 km to 5262.4 km in diameter - would require massive amounts of material. While these could be harvested from the nearby Asteroid Belt, it would require thousands of ships and robot workers to mine, haul, and assemble the minerals into large enough shells.Third, radiation would be a significant issue for humans living on Europa or Ganymede. As noted already, Earth organisms are exposed to an average of 24 rem per year, which works out to 0.0657 rem per day. An exposure of approximately 75 rems over a period of a few days is enough to cause radiation poisoning, while about 500 rems over a few days would be fatal. Of all the Galileans, only Callisto falls beneath this terminal limit.As a result, any settlements established on Europa or Ganymede would require radiation shielding, even after the creation of viable atmospheres. This in turn would require large shields to be built in orbit of the moons (requiring another massive investment in resources), or would dictate that all settlements built on the surfaces include heavy radiation shielding.On top of that, as the surfaces of Europa, Ganymede and Callisto (especially Callisto!) will attest, the Jovian system is frequented by space rocks. In fact, most of Jupiter's satellites are asteroids it picked up as they sailed through the system. These satellites are lost on a regular basis, and new ones are added all the time. So colonists would naturally have to worry about space rocks slamming into their ocean world, causing massive waves and blotting out the sky with thick clouds of water vapor.Fourth, the issue of sustainability, has to do with the fact that all of the Jovian moons either do not have a magnetosphere or, in the case of Ganymede, are not powerful enough to block the effects of Jupiter's magnetic field. Because of this, any atmosphere created would be slowly stripped away, much as Mars' atmosphere was slowly stripped away after it lost its magnetosphere about 4.3 billion years ago. In order to maintain the effects of terraforming, colonists would need to replenish the atmosphere over time.Another aspect of sustainability, one which is often overlooked, has to do with the kinds of planets that would result from terraforming. While estimates vary, transforming Europa, Ganymede and Callisto would result in oceans that varied in depth - from 100 km (in the cae of Europa) to extreme depths of up to 800 km (in the case of Ganymede). In contrast, the greatest depth ever measured here on Earth was only about 10 km (6 miles) deep, in the Pacific's Mariana Trench.With oceans this deep, all settlements would have to take the form of floating cities that could not be anchored to solid ground. And in the case of Ganymede, the oceans would account for a considerable portion of the planet. What the physicals effects of this would be are hard to imagine. But it is a safe bet that they would result in tremendously high tides (at best) to water being lost to space.And finally, there is the issue of the ethics of terraforming. If, as scientists currently suspect, there is in fact indigenous life on one or more of the Jovian moons, then the effects of terraforming could have severe consequences or them. For instance, if bacterial life forms exist on the underside of Europa's icy surface, then melting it would mean death for these organisms, since it would remove their only source of protection from radiation.Life forms that exist close to the core-mantle boundary, most likely around hydrothermal vents, would be less effected by the presence of humans on the surface. However, any changes to the ec0logical balance could lead to a chain reaction that would destroy the natural life cycle. And the presence of organisms introduced by humans (i.e. germs), could have a similarly devastating effect.So basically, if we choose to alter the natural environment of one or more of the Jovian moons, we will effectively be risking the annihilation of any indigenous life forms. Such an act would be tantamount to genocide (or xenocide, as the case may be), and exposure to alien organisms would surely pose health risks for human colonists as well. Conclusions: All in all, it appears that terraforming the outer Solar System might be a bit of a non-starter. While the prospect of doing it is certainly exciting, and presents many interesting opportunities, the challenges involved do seem to add up. For starters, it doesn't seem likely or practical for us to contemplate doing this until we've established a presence on the Moon, Mars, and in the Asteroid Belt.Second, terraforming any of Jupiter's moons would involve a considerable amount of time, energy and resources. And given that a lot of these moon's resources could be harvested for terraforming other worlds (such as Mars and Venus), would it not make sense to terraform these worlds first and circle back to the outer Solar System later?Third, a terraformed Europa, Ganymede and Callisto would all be water worlds with extremely deep oceans. Would it even be possible to build floating cities on such a world? Or would they be swallowed up by massive tidal waves; or worse, swept off into space by waves so high, they slipped the bonds of the planet's gravity? And how often would the atmosphere need to be replenished in order to ensure it didn't get stripped away?https://youtu.be/kKeenzOsB8UAnd last, but not least, any act of terraforming these moons would invariably threaten any life that already exists there. And the threat caused by exposure wouldn't exactly be one-way. Under all of these circumstances, would it not be better to simply establish outposts on the surface, or perhaps within or directly underneath the ice? All valid questions, and ones which we will no doubt begin to explore once we start mounting research missions to Europa and the other Jovian moons in the future. And depending on what we find there, we might just choose to put down some roots. And in time, we might even begin thinking about renovating the places so more of our kin can drop by. Before we do any of that, we had better make sure we know what we're doing, and be sure we aren't doing any harm in the process! We have written many interesting articles about Jupiter's Moons here at Universe Today. Here's What Are Jupiter's Moons?, Io, Jupiter's Volcanic Moon, Jupiter's Moon Europa, Jupiter's Moon Ganymede, and Jupiter's Moon Callisto.To learn more about terraforming, check out The Definitive Guide To Terraforming, How Do We Terraform Mars?, How Do We Terraform Venus?, and How Do We Terraform the Moon? and Could We Terraform Jupiter?For more information, check out NASA's Solar System Exploration page on Jupiter's Moons. The post How Do We Terraform Jupiter’s Moons? appeared first on Universe Today.        • Email to a friend • View comments • Track comments •   Chinese Space Baby Research Lands In Mongolia We've solved many of the problems associated with space travel. Humans can spend months in the zero-gravity of space, they can perform zero-gravity space-walks and repair spacecraft, they can walk on the surface of the Moon, and they can even manage, ahem, personal hygiene in space. We're even making progress in understanding how to grow food in space. But one thing remains uncertain: can we make baby humans in space?According to a recent successful Chinese experiment, the answer is a tentative yes. Sort of.The Chinese performed a 96-hour experiment to test the viability of mammal embryos in space. They placed 6,000 mouse embryos in a micro-wave sized chamber aboard a satellite, to see if they would develop into blastocysts. The development of embryos into blastocysts is a crucial step in reproduction. Once the blastocysts have developed, they attach themselves to the wall of the uterus. Cameras on the inside of the chamber allowed Chinese scientists on Earth to monitor the experiment.Duan Enkui, from the Chinese Academy of Sciences, who is the principal researcher for this experiment, told China Daily "The human race may still have a long way to go before we can colonise space, but before that we have to figure out whether it is possible for us to survive and reproduce in the outer space environment like we do on Earth."The Chinese say some of the embryos became blastocysts, and are claiming success in an endeavour that others have tried and failed at. NASA has performed similar experiments on Earth, where the micro-gravity conditions in space were duplicated. A study from 2009 showed that fertilization occurred normally in micro-gravity environments, but the eventual birth rate for the micro-gravity subjects was lower than for a 1G control group. The results from this study concluded that normal Earth gravity might be necessary for the blastocysts to successfully attach themselves to the uterus.It's important to note that at this point that China has proclaimed success by saying "some" of the embryos developed. But how many? There were 6,000 of them. Until they attach numbers to their claim, the word "some" doesn't tell us much in terms of humans colonizing space. It also doesn't tell us whether or not the crucial blastocyst to uterus attachment is inhibited by micro-gravity. Call us pedantic here at Universe Today, but it's kind of important to know the numbers.On the other hand, an increase in scientific curiosity related to procreating in space is a healthy development. The ideas and plans for missions to Mars and an eventual long-term presence in space are heating up. Making babies in space might not that relevant right now, but issues have a way of sneaking up on us.The full results of this Chinese experiment will be interesting, if and when they're made public. They may help clarify one aspect of the whole "making babies in space" problem. But in the bigger picture, things are still a little cloudy.On shuttle mission STS-80, 2-cell mouse embryos were taken into space micro-gravity for 4 days. None of them developed into blastocysts, while a control group on the ground did. Another experiment in 1979, aboard Cosmos 1129, had male and female rats aboard. Though post-experiment results showed that some of the female rats had indeed ovulated, none of them gave birth. Two of the females even got pregnant, but the fetuses were reportedly r-absorbed.Still, we have to give credit where its due. And the Chinese study has shown that mammal blastocysts can develop from embryos in micro-gravity. Still, there's more to the space environment than low gravity. The radiation environment is much different. One study called the Space Pup study, led by principal investigator Teruhiko Wakayama, from the Riken Center for Developmental Biology, Japan, hopes to shed some light on that aspect of reproduction in space.Space Pup will take sample of freeze-dried mouse sperm to the ISS for periods of 1, 12, and 24 months. Then, the samples will be returned to Earth and be used to fertilize mouse eggs.There's a lot more to learn in the area of reproduction in space. The next steps will involve keeping live mammals in space to monitor their reproduction. It's not like ISS astronauts need more work to do, but maybe they'll like having some animals along for company.Maybe we'll need to think outside the box when it comes to procreation in space. Maybe some type of in-vitro procedure will help humans spread the love in space. Or maybe, we'll need to look to science fiction for inspiration. After all, countless alien species seem to be able to reproduce effectively, given the right circumstances. The post Chinese Space Baby Research Lands In Mongolia appeared first on Universe Today.        • Email to a friend • View comments • Track comments •   Weekly Space Hangout – Apr. 22, 2016: Mike Simmons highlights Global Astronomy Month Host: Fraser Cain (@fcain) Special Guest: Mike Simmons, Founder and President of Astronomers without Borders (http://astronomerswithoutborders.org), will be joining us to discuss the 2016 Global Astronomy Month (GAM)! GAM is organized each April by Astronomers Without Borders and is the world’s largest global celebration of astronomy. Find out about the amazing GAM events going on all over the world and how YOU can get involved. Guests: Kimberly Cartier (@AstroKimCartier ) Dave Dickinson (www.astroguyz.com / @astroguyz) Morgan Rehnberg (MorganRehnberg.com / @MorganRehnberg ) Their stories this week: China studies making babies in space Autopsying Hitomi Lone Planetary-Mass Object Found in Family of Stars Ultra-cool polar regions of Venus’s atmosphere We’ve had an abundance of news stories for the past few months, and not enough time to get to them all. So we’ve started a new system. Instead of adding all of the stories to the spreadsheet each week, we are now using a tool called Trello to submit and vote on stories we would like to see covered each week, and then Fraser will be selecting the stories from there. Here is the link to the Trello WSH page (http://bit.ly/WSHVote), which you can see without logging in. If you’d like to vote, just create a login and help us decide what to cover! We record the Weekly Space Hangout every Friday at 12:00 pm Pacific / 3:00 pm Eastern. You can watch us live on Google+, Universe Today, or the Universe Today YouTube page. You can also join in the discussion between episodes over at our Weekly Space Hangout Crew group in G+! The post Weekly Space Hangout – Apr. 22, 2016: Mike Simmons highlights Global Astronomy Month appeared first on Universe Today.        • Email to a friend • View comments • Track comments •   How Do We Know There's a Planet 9? At this point, I think the astronomy textbook publishers should just give up. They'd like to tell you how many planets there are in the Solar System, they really would. But astronomers just can't stop discovering new worlds, and messing up the numbers. Things were simple when there were only 6 planets. The 5 visible with the unaided eye, and the Earth, of course. Then Uranus was discovered in 1781 by William Herschel, which made it 7. Then a bunch of asteroids, like Ceres, Vesta and Pallas pushed the number into the teens until astronomers realized these were probably a whole new class of objects. Back to 7. Then Neptune in 1846 by Urbain Le Verrier and Johann Galle, which makes 8. Then Pluto in 1930 and we have our familiar 9. But astronomy marches onward. Eris was discovered in 2005, which caused astronomers to create a whole new classification of dwarf planet, and ultimately downgrading Pluto. Back to 8. It seriously looked like 8 was going to be the final number, and the textbook writers could return to their computers for one last update. A predicted consequence of Planet Nine is that a second set of confined objects should also exist. These objects are forced into positions at right angles to Planet Nine and into orbits that are perpendicular to the plane of the solar system. Five known objects (blue) fit this prediction precisely. Credit: Caltech/R. Hurt (IPAC) [Diagram was created using WorldWide Telescope.] Astronomers, however, had other plans. In 2014, Chad Trujillo and Scott Shepard were studying the motions of large objects in the Kuiper Belt and realized that a large planet in the outer Solar System must be messing with orbits in the region. This was confirmed and fine tuned by other astronomers, which drew the attention of Mike Brown and Konstantin Batygin. The name Mike Brown might be familiar to you. Perhaps the name, Mike "Pluto Killer" Brown? Mike and his team were the ones who originally discovered Eris, leading to the demotion of Pluto. Brown and Batygin were looking to find flaws in the research of Trujillo and Shepard, and they painstakingly analyzed the movement of various Kuiper Belt Objects. They found that six different objects all seem to follow a very similar elliptical orbit that points back to the same region in space. All these worlds are inclined at a plane of about 30-degrees from pretty much everything else in the Solar System. In the words of Mike Brown, the odds of these orbits all occurring like this are about 1 in 100. Animated diagram showing the spacing of the Solar Systems planet's, the unusually closely spaced orbits of six of the most distant KBOs, and the possible "Planet 9". Credit: Caltech/nagualdesign Instead of a random coincidence, Brown and Batygin think there's a massive planet way out beyond the orbit of Pluto, about 200 times further than the distance from the Sun to the Earth. This planet would be Neptune-sized, roughly 10 times more massive than Earth. But why haven't they actually observed it yet? Based on their calculations, this planet should be bright enough to be visible in mid-range observatories, and definitely within the capabilities of the world's largest telescopes, like Keck, Palomar, Gemini, and Hubble, of course. The trick is to know precisely where to look. All of these telescopes can resolve incredibly faint objects, as long as they focus in one tiny spot. But which spot. The entire sky has a lot of tiny spots to look at. Artist’s impression of Planet Nine, blocking out the Milky Way. The Sun is in the distance, with the orbit of Neptune shown as a ring. Credit: ESO/Tomruen/nagualdesign Based on the calculations, it appears that Planet 9 is hiding in the plane of the Milky Way, camouflaged by the dense stars of the galaxy. But astronomers will be scanning the skies, and hope a survey will pick it up, anytime now. But wait a second, does this mean that we're all going to die? Because I read on the internet and saw some YouTube videos that this is the planet that's going to crash into the Earth, or flip our poles, or something. Nope, we're safe. Like I just said, the best astronomers with the most powerful telescopes in the world and space haven't been able to turn anything up. While the conspiracy theorists have been threatening up with certain death from Planet X for decades now – supposedly, it'll arrive any day now. But it won't. Assuming it does exist, Planet 9 has been orbiting the Sun for billions of years, way way out beyond the orbit of Pluto. It's not coming towards us, it's not throwing objects at us, and it's definitely not going to usher in the Age of Aquarius. Once again, we get to watch science in the making. Astronomers are gathering evidence that Planet 9 exists based on its gravitational influence. And if we're lucky, the actual planet will turn up in the next few years. Then we'll have 9 planets in the Solar System again. The post How Do We Know There's a Planet 9? appeared first on Universe Today.        • Email to a friend • View comments • Track comments •   Dawn Just Wants To Make All The Other Probes Look Bad The Dawn spacecraft, NASA's asteroid hopping probe, may not be going gently into that good night as planned. Dawn has visited Vesta and Ceres, and for now remains in orbit around Ceres. The Dawn mission was supposed to end after its rendezvous with Ceres, but now, reports say that the Dawn team has asked NASA to extend the mission to visit a third asteroid.[embed]https://www.youtube.com/watch?v=YYxPw_T8Vlk[/embed]Dawn was launched in 2007, and in 2011 and 2012 spent 14 months at Vesta. After Vesta, it reached Ceres in March 2015, and is still in orbit there. The mission was supposed to end, but according to a report at New Scientist, the team would like to extend that mission.[embed]https://www.youtube.com/watch?v=nJiw2NxqoBU[/embed]Dawn is still is fully operational, and still has some xenon propellant remaining for its ion drive, so why not see what else can be achieved? There's only a small amount of propellant left, so there's only a limited selection of possible destinations for Dawn at this point. A journey to a far-flung destination is out of the question.Chris Russell, of the University of California, Los Angeles, is the principal investigator for the Dawn mission. He told New Scientist, "As long as the mission extension has not been approved by NASA, I'm not going to tell you which asteroid we plan to visit," he says. "I hope a decision won't take months."If the Dawn mission is not extended, then its end won't be very fitting for a mission that has accomplished so much. It will share the fate of some other spacecraft at the end of their lives; forever parked in a harmless orbit in an out of the way place, forgotten and left to its fate. The only other option is to crash it into a planet or other body to destroy it, like the Messenger spacecraft was crashed into Mercury at the end of its mission.The crash and burn option isn't available to Dawn though. The spacecraft hasn't been sterilized. If it hasn't been sterilized of all possible Earthly microbial life, then it is strictly forbidden to crash it into Ceres, or another body like it. Planetary protection rules are in place to avoid the possible contamination of other worlds with Earthly microbial life. It's not likely that any microbes that may have hitched a ride aboard Dawn would have survived Dawn's journey so far, nor is it likely that they would survive on the surface of Ceres, but rules are rules.The secret of Dawn's long-life and success is not only due to the excellent work by the teams responsible for the mission, it's also due to Dawn's ion-drive propulsion system. Ion drives, long dreamed of in science and science fiction, are making longer voyages into deep space possible.Ion drives start very slow, but gain speed incrementally, continuing to generate thrust over long distances and long periods of time. They do all this with minimal propellant, and are ideal for long space voyages like Dawn's.The success of the Dawn mission is key to NASA's plans for further deep space exploration. NASA continues to work on improving ion drives, and their latest project is the Advanced Electric Propulsion System (AEPS.) This project is meant to further develop the Hall Thruster, a type of ion-drive that NASA hopes will extend spacecraft mission capabilities, allow longer and deeper space exploration, and benefit commercial space activities as well.The AEPS has the potential to double the thrust of current ion-drives like the one on Dawn. It's a key component of NASA's Journey to Mars. NASA also has plans for a robotic asteroid capture mission called Asteroid Redirect Mission, which will use the AEPS. That mission will visit an asteroid, retrieve a boulder- sized asteroid from the surface, and place it in orbit around the Moon. Eventually, astronauts will visit it and return samples to Earth for study. Very ambitious.As far as the Dawn mission goes, it's unclear what its next destination might be. Vesta and Ceres were chosen because they are thought be surviving protoplanets, formed at the same time as the other planets. But they stopped growing, and they remain largely undisturbed, so in that sense they are kind of locked in time, and are intriguing objects of study. There are other objects in the vicinity, but it would be pure guesswork to name any.We are prone to looking at the past nostalgically, and thinking of prior decades as the golden age of space exploration. But as Dawn, and dozens of other current missions and scientific endeavours in space show us, we may well be in a golden age right now. The post Dawn Just Wants To Make All The Other Probes Look Bad appeared first on Universe Today.        • Email to a friend • View comments • Track comments •   Landslides and Bright Craters on Ceres Revealed in Marvelous New Images from Dawn Now in orbit for just over a year at dwarf planet Ceres, NASA's Dawn spacecraft continues to astound us with new discoveries gleaned from spectral and imagery data captured at ever decreasing orbits as well as since the probe arrived last December at the lowest altitude it will ever reach during the mission.Mission scientists have just released marvelous new images of Haulani and Oxo craters revealing landslides and mysterious slumps at several of the mysterious bright craters on Ceres - the largest asteroid in the main Asteroid Belt between Mars and Jupiter.The newly released image of oddly shaped Haulani crater above, shows the crater in enhanced color and reveals evidence of landslides emanating from its crater rim."Rays of bluish ejected material are prominent in this image. The color blue in such views has been associated with young features on Ceres," according to the Dawn science team."Enhanced color allows scientists to gain insight into materials and how they relate to surface morphology." Look at the image closely and you'll see its actually polygonal in nature - meaning it resembles a shape made of straight lines - unlike most craters in our solar system which are nearly circular."The straight edges of some Cerean craters, including Haulani, result from pre-existing stress patterns and faults beneath the surface," says the science team.Haulani Crater has a diameter of 21 miles (34 kilometers) and apparently was formed by an impacting object relatively recently in geologic time and is also one of the brightest areas on Ceres."Haulani perfectly displays the properties we would expect from a fresh impact into the surface of Ceres. The crater floor is largely free of impacts, and it contrasts sharply in color from older parts of the surface," said Martin Hoffmann, co-investigator on the Dawn framing camera team, based at the Max Planck Institute for Solar System Research, Göttingen, Germany, in a statement.The enhanced color image was created from data gathered at Dawn's High Altitude Mapping Orbit (HAMO), while orbiting at an altitude of 915 miles (1,470 kilometers) from Ceres.Data from Dawn's VIR instrument shows that Haulani's surface is comprised of different materials than its surroundings."False-color images of Haulani show that material excavated by an impact is different than the general surface composition of Ceres. The diversity of materials implies either that there is a mixed layer underneath, or that the impact itself changed the properties of the materials," said Maria Cristina de Sanctis, the VIR instrument lead scientist, based at the National Institute of Astrophysics, Rome.Since mid-December, Dawn has been orbiting Ceres in its Low Altitude Mapping Orbit (LAMO), at a distance of 240 miles (385 kilometers) from Ceres, resulting in the most stunning images ever of the dwarf planet.By way of comparison the much higher resolution image of Haulani crater below, is a mosaic of views assembled from multiple images taken from LAMO at less than a third of the HAMO image distance - at only 240 miles (385 kilometers) above Ceres.Dawn has also been busy imaging Oxo Crater, which despite its small size of merely 6-mile-wide (10-kilometer-wide) actually counts as a "hidden treasure" on Ceres - because it's the second-brightest feature on Ceres!Only the mysterious bright region comprising a multitude of spots inside Occator Crater shine more brightly on Ceres.Most importantly, Oxo Crater is the only place on Ceres where Dawn has detected water at the surface so far. Via VIR, Dawn data indicate that the water exists either in the form of ice or hydrated minerals. Scientists speculate that the water was exposed either during a landslide or an impact."Little Oxo may be poised to make a big contribution to understanding the upper crust of Ceres," said Chris Russell, principal investigator of the mission, based at the University of California, Los Angeles.The signatures of minerals detected on the floor of Oxo crater appears to be different from the rest of Ceres.Furthermore Oxo is "also unique because of the relatively large "slump" in its crater rim, where a mass of material has dropped below the surface."Dawn is Earth's first probe in human history to explore any dwarf planet, the first to explore Ceres up close and the first to orbit two celestial bodies.The asteroid Vesta was Dawn's first orbital target where it conducted extensive observations of the bizarre world for over a year in 2011 and 2012.The mission is expected to last until at least later into 2016, and possibly longer, depending upon fuel reserves.Dawn will remain at its current altitude at LAMO for the rest of its mission, and indefinitely afterward, even when no further communications are possible.Stay tuned here for Ken's continuing Earth and planetary science and human spaceflight news.Ken Kremer The post Landslides and Bright Craters on Ceres Revealed in Marvelous New Images from Dawn appeared first on Universe Today.        • Email to a friend • View comments • Track comments •   Recovered SpaceX Falcon 9 Booster Moves Back to KSC for Eventual Reflight The recovered SpaceX Falcon 9 first stage booster that successfully carried out history's first upright touchdown from a just flown rocket onto a droneship at sea, has just been moved back to the firms processing hanger at the Kennedy Space Center (KSC) for testing and eventual reflight.Space photographers and some lucky tourists coincidentally touring through Cape Canaveral Air Force Station in the right place at the right time on a tour bus, managed to capture exquisite up close images and videos (shown above and below) of the rockets ground transport on Tuesday, April 19, along the route from its initial staging point at Port Canaveral to a secure area on KSC.It was quite a sight to the delight of all who experienced this remarkable moment in space history - that could one day revolutionize space flight by radically slashing launch costs via recycled rockets. The boosters nine first stage Merlin 1 D engines were wrapped in a protective sheath during the move as seen in the up close imagery.The SpaceX Falcon 9 had successfully conducted a dramatic propulsive descent and soft landing on a barge some 200 miles offshore in the Atlantic Ocean on April 8, about 9 minutes after blasting off from Cape Canaveral Air Force Station at 4:43 p.m. EDT on the Dragon CRS-8 cargo mission for NASA to the International Space Station (ISS). The used Falcon 9 booster then arrived back into Port Canaveral, Florida four days later, overnight April 12, after being towed atop the ocean going platform that SpaceX dubs an 'Autonomous Spaceport Drone Ship' or ASDS.The spent 15 story tall Falcon 9 booster was transported to KSC by Beyel Bros. Crane and Rigging, starting around 9:30 a.m.After initial cleaning and clearing of hazards and processing to remove its four landing legs at the Port facility, the booster was carefully lowered by crane horizontally into a retention cradle on a multiwheel combination Goldhofer/KMAG vehicle and hauled by Beyel to KSC with a Peterbilt Prime Mover truck.The Falcon 9 was moved to historic Launch Complex 39A at KSC for processing inside SpaceX's newly built humongous hanger located at the pad perimeter.Indeed this Falcon 9 first stage is now residing inside the pad 39A hanger side by side with the only other flown rocket to be recovered; the Falcon 9 first stage that accomplished a land landing back at the Cape in December 2015 - as shown in this image from SpaceX CEO Elon Musk titled "By land and sea".Watch this video of the move taken from a tour bus:https://youtu.be/uC3Szb5raXESpaceX engineers plan to conduct a series of some 12 test firings of the first stage Merlin 1 D engines to ensure all is well operationally in order to validate that the booster can be re-launched. It may be moved back to Space Launch Complex-40 for the series of painstakingly inspections, tests and refurbishment.SpaceX hopes to refly the recovered booster in a few months, perhaps as early as this summer.The vision of SpaceX's billionaire founder and CEO Elon Musk is to dramatically slash the cost of access to space by recovering the firms rockets and recycling them for reuse - so that launching rockets will one day be nearly as routine and cost effective as flying on an airplane.The essential next step after recovery is recycling. Musk said he hopes to re-launch the booster this year.Whenever it happens, it will count as the first relaunch of a used rocket in history.SpaceX has leased Pad 39A from NASA and is renovating the facilities for future launches of the existing upgraded Falcon 9 as well as the Falcon Heavy currently under development.Landing on the barge was a secondary goal of SpaceX and not part of the primary mission sending science experiments and cargo to the ISS crew under a resupply contract with for NASA.Watch this SpaceX Falcon 9/Dragon CRS-8 launch video from my video camera placed at the pad:https://youtu.be/DDzRWoz_xFMVideo Caption: Spectacular blastoff of SpaceX Falcon 9 rocket carrying Dragon CRS-8 cargo freighter bound for the International Space Station (ISS) from Space Launch Complex 40 on Cape Canaveral Air Force Station, FL at 4:43 p.m. EST on April 8, 2016. Up close movie captured by Mobius remote video camera placed at launch pad. Credit: Ken Kremer/kenkremer.comStay tuned here for Ken's continuing Earth and planetary science and human spaceflight news.Ken Kremer The post Recovered SpaceX Falcon 9 Booster Moves Back to KSC for Eventual Reflight appeared first on Universe Today.        • Email to a friend • View comments • Track comments •   An Earth-like Planet Only 16 Light Years Away? Earth may have a new neighbour, in the form of an Earth-like planet in a solar system only 16 light years away. The planet orbits a star named Gliese 832, and that solar system already hosts two other known exoplanets: Gliese 832B and Gliese 832C. The findings were reported in a new paper by Suman Satyal at the University of Texas, and colleagues J. Gri?th, and Z. E. Musielak.Gliese 832B is a gas giant similar to Jupiter, at 0.64 the mass of Jupiter, and it orbits its star at 3.5 AU. G832B probably plays a role similar to Jupiter in our Solar System, by setting gravitational equilibrium. Gliese 832C is a Super-Earth about 5 times as massive as Earth, and it orbits the star at a very close 0.16 AU. G832C is a rocky planet on the inner edge of the habitable zone, but is likely too close to its star for habitability. Gliese 832, the star at the center of it all, is a red dwarf about half the size of our Sun, in both mass and radius.The newly discovered planet is still hypothetical at this point, and the researchers put its mass at between 1 and 15 Earth masses, and its orbit at between 0.25 to 2.0 AU from Gliese 582, its host star.The two previously discovered planets in Gliese 832 were discovered using the radial velocity technique. Radial velocity detects planets by looking for wobbles in the host star, as it responds to the gravitational tug exerted on it by planets in orbit. These wobbles are observable through the Doppler effect, as the light of the affected star is red-shifted and blue-shifted as it moves.[embed]https://www.youtube.com/watch?v=t2xTlv_I6ac[/embed]The team behind this study re-analyzed the data from the Gliese 832 system, based on the idea that the vast distance between the two already-detected planets would be home to another planet. According to other solar systems studied by Kepler, it would be highly unusual for such a gap to exist.As they say in their paper, the main thrust of the study is to explore the gravitational effect that the large outer planet has on the smaller inner planet, and also on the hypothetical Super-Earth that may inhabit the system. The team conducted numerical simulations and created models constrained by what's known about the Gliese 832 system to conclude that an Earth-like planet may orbit Gliese 832.This can all sound like some hocus-pocus in a way, as my non-science-minded friends like to point out. Just punch in some numbers until it shows an Earth-like planet, then publish and get attention. But it's not. This kind of modelling and simulation is very rigorous.Putting in all the data that's known about the Gliese 832 system, including radial velocity data, orbital inclinations, and gravitational relationships between the planets and the star, and between the planets themselves, yields bands of probability where previously undetected planets might exist. This result tells planet hunters where to start looking for planets.In the case of this paper, the result indicates that "there is a slim window of about 0.03 AU where an Earth-like planet could be stable as well as remain in the HZ." The authors are quick to point out that the existence of this planet is not proven, only possible.[embed]https://www.youtube.com/watch?v=y6g7c00v_nY[/embed]The other planets were found using the radial velocity method, which is pretty reliable. But radial velocity only provides clues to the existence of planets, it doesn't prove that they're there. Yet. The authors acknowledge that a larger number of radial velocity observations are needed to confirm the existence of this new planet. Barring that, either the transit method employed by the Kepler spacecraft, or direct observation with powerful telescopes, may also provide positive proof.So far, the Kepler spacecraft has confirmed the existence of 1,041 planets. But Kepler can't look everywhere for planets. Studies like these are crucial in giving Kepler starting points in its search for exoplanets. If an exoplanet can be confirmed in the Gliese 832 system, then it also confirms the accuracy of the simulation that the team behind this paper performed.If confirmed, G832 C would join a growing list of exoplanets. It wasn't long ago that we knew almost nothing about other solar systems. We only had knowledge of our own. And even though it was always unlikely that our Solar System would for some reason be special, we had no certain knowledge of the population of exoplanets in other solar systems.Studies like this one point to our growing understanding of the dynamics of other solar systems, and the population of exoplanets in the Milky Way, and most likely throughout the cosmos. The post An Earth-like Planet Only 16 Light Years Away? appeared first on Universe Today.        • Email to a friend • View comments • Track comments •         You Might Like Click here to safely unsubscribe from "Universe Today." Click here to view mailing archives, here to change your preferences, or here to subscribe • Privacy Email subscriptions powered by FeedBlitz, LLC, 365 Boston Post Rd, Suite 123, Sudbury, MA 01776, USA.