In 2008, a group of researchers thought they had directly imaged the first exoplanet. Since then, that remarkable feat has been accomplished a few times, but now the 2008 imaging has been confirmed. At that time, there was a possibility the two objects, the star and the exoplanet, were only coincidentally related as seen from Earth. Continued observation, however, has confirmed the two travel through space together.
The star is Sun-like, with about 85 percent the mass of the Sun, while its planet is about eight times Jupiter's mass and orbits the star about once every 300 Earth years, if the orbit is close to circular. That's somewhere around the same distance Neptune is from the Sun. The exoplanet is extremely hot, however-- which is what allowed it to be detected in the first place. Astronomers think it's a young system, and the planet is still gravitationally contracting, which generates a huge amount of waste heat.
The whole shebang is about 500 light years away.
Wednesday, June 30, 2010
Tuesday, June 29, 2010
China and ISS
Russia appears ready to have China join the ISS project. A report in the Russian media has Russia talking to China about joining the 16-nation consortium that owns and operates ISS, but a NASA spokesman denies any offer has been made.
China is an interesting case. It's clearly a major nation. The Chinese economy has become a key factor in the world economy and continues to grow. China, of course, already has a manned space program, too. When the space shuttle is retired, Russia's Soyuz will be the only spacecraft able to ferry crews between Earth and ISS, but China's Shengzhou capsule, which is based on the Soyuz, might serve as a back up. On the other hand, China's human rights record is abysmal. The country is still a police state when the Communist Party decides to crack down. There is no rule of law in the Western sense, and no individual rights. The Chinese leadership is trying to build a modern economy, complete with a huge middle class, without giving the rising wealthy a real say in the governance of the nation-- and their own lives. If that doesn't work, China could be in for a period of instability, which, among other things, would make China's value as a partner in long term space projects questionable.
China is an interesting case. It's clearly a major nation. The Chinese economy has become a key factor in the world economy and continues to grow. China, of course, already has a manned space program, too. When the space shuttle is retired, Russia's Soyuz will be the only spacecraft able to ferry crews between Earth and ISS, but China's Shengzhou capsule, which is based on the Soyuz, might serve as a back up. On the other hand, China's human rights record is abysmal. The country is still a police state when the Communist Party decides to crack down. There is no rule of law in the Western sense, and no individual rights. The Chinese leadership is trying to build a modern economy, complete with a huge middle class, without giving the rising wealthy a real say in the governance of the nation-- and their own lives. If that doesn't work, China could be in for a period of instability, which, among other things, would make China's value as a partner in long term space projects questionable.
Monday, June 28, 2010
Explaining The Plan
Ever since its announcement, President Obama's new approach to space policy has been controversial. Today, the White House plans to make public a paper that attempts to further explain the new policy by putting it in a broader context.
The paper will reaffirm the traditional U. S. position that space should be open to all nations, while at the same time maintaining American leadership in space. Doing the second, as usual, is seen as a way of guaranteeing the first. American leadership will be pursued differently, however. U. S. policy will be to encourage the development of a commercial sector that will be able to make a profit from space operations. U. S. policy will also be to seek international cooperation in space.
The obvious next big step in manned spaceflight that could reasonably be done as an international project would be the establishment of a lunar base. Whether the Obama administration would participate in such an effort while maintaining its thrust of having NASA develop technologies that will support a sustainable manned space exploration effort remains to be seen.
The paper will reaffirm the traditional U. S. position that space should be open to all nations, while at the same time maintaining American leadership in space. Doing the second, as usual, is seen as a way of guaranteeing the first. American leadership will be pursued differently, however. U. S. policy will be to encourage the development of a commercial sector that will be able to make a profit from space operations. U. S. policy will also be to seek international cooperation in space.
The obvious next big step in manned spaceflight that could reasonably be done as an international project would be the establishment of a lunar base. Whether the Obama administration would participate in such an effort while maintaining its thrust of having NASA develop technologies that will support a sustainable manned space exploration effort remains to be seen.
Sunday, June 27, 2010
CST-100
With the retirement of the space shuttle looming, aerospace giant Boeing is joining several NewSpace companies in developing new man-rated spacecraft. Dubbed, for now, the CST-100, the ship will be a capsule, slightly larger than Apollo, but smaller than the projected Orion. CST-100 would be capable of carrying a crew of seven, but it would be designed for only short trips to and from low Earth orbit.
Partnering with Boeing to develop the craft is Bigelow Aerospace. The two companies are hoping to pair Boeing's expertise and experience with BA's entrepreneurial techniques to develop a new, safer spacecraft quickly and less expensively. Such a spacecraft would also fill a hole in BA's program. The company has been working to develop inflatable module technology that could be used to build space stations or bases on other worlds. So far, however, BA lacks a way to get people into space. The CST-100 project might change that.
NASA wants the spacecraft to be ready by 2016, but Boeing is working to have it flying before that.
Partnering with Boeing to develop the craft is Bigelow Aerospace. The two companies are hoping to pair Boeing's expertise and experience with BA's entrepreneurial techniques to develop a new, safer spacecraft quickly and less expensively. Such a spacecraft would also fill a hole in BA's program. The company has been working to develop inflatable module technology that could be used to build space stations or bases on other worlds. So far, however, BA lacks a way to get people into space. The CST-100 project might change that.
NASA wants the spacecraft to be ready by 2016, but Boeing is working to have it flying before that.
Friday, June 25, 2010
Arguing For Heavy Lift
In a letter to President Obama this week, 62 U. S. Representatives urged Mr. Obama to proceed immediately with the development of a heavy lift capability that could launch astronauts on deep space missions.
The Obama plan for NASA does support eventual deep space missions, including a manned mission to an asteroid in 2025, but puts off a decision on a heavy lift rocket for five years, to see what kind of technology is available at that time. The letter argues that we already know what kind of technology will be available in five years-- no breakthroughs are on the horizon-- we've already spent $10 billion on heavy lift under the Constellation program, and that money and progress shouldn't simply be thrown away, and that a skilled, experienced workforce already exists in this area, and that workforce should be maintained.
Of course, the nature of breakthroughs is that we don't necessarily see them coming until they break through. Critics also have said the Ares heavy lift rocket of the Constellation effort has some fairly serious flaws, though its supporters disagree. Any flaws that may exist could presumably be engineered away in five more years, but starting over has its advantages.
Seeing how this issue plays out this year should be interesting.
The Obama plan for NASA does support eventual deep space missions, including a manned mission to an asteroid in 2025, but puts off a decision on a heavy lift rocket for five years, to see what kind of technology is available at that time. The letter argues that we already know what kind of technology will be available in five years-- no breakthroughs are on the horizon-- we've already spent $10 billion on heavy lift under the Constellation program, and that money and progress shouldn't simply be thrown away, and that a skilled, experienced workforce already exists in this area, and that workforce should be maintained.
Of course, the nature of breakthroughs is that we don't necessarily see them coming until they break through. Critics also have said the Ares heavy lift rocket of the Constellation effort has some fairly serious flaws, though its supporters disagree. Any flaws that may exist could presumably be engineered away in five more years, but starting over has its advantages.
Seeing how this issue plays out this year should be interesting.
Thursday, June 24, 2010
Early Venus Habitable?
A new study using data from the European Space Agency's Venus Express spacecraft now orbiting Venus suggests that extremely early in its history Venus may have had a substantial amounr of water-- perhaps even an ocean. If an ocean did indeed exist, it's also possible that life may have begun there.
Other scientists suggest that if water did ever exist in quantity on Venus, it likely existed in the atmosphere, not on the ground. That may not preclude life starting out, but an aerial genesis would be quite different from the liquid water-based event most scientists think happened on early Earth.
The study bases its suggestion on the Venus Express data that sees two hydrogen atoms escaping into space from Venus for every one oxygen atom. That ratio, of course, suggests water is the source of the atoms. While water molecules are likely too heavy and too slow to escape into space from Venus, radiation would break water down into its constituent parts, and those lighter elements do escape.
Other scientists suggest that if water did ever exist in quantity on Venus, it likely existed in the atmosphere, not on the ground. That may not preclude life starting out, but an aerial genesis would be quite different from the liquid water-based event most scientists think happened on early Earth.
The study bases its suggestion on the Venus Express data that sees two hydrogen atoms escaping into space from Venus for every one oxygen atom. That ratio, of course, suggests water is the source of the atoms. While water molecules are likely too heavy and too slow to escape into space from Venus, radiation would break water down into its constituent parts, and those lighter elements do escape.
Wednesday, June 23, 2010
Lunar Uranium Setback
As reported in this blog, Japan's Kaguya lunar probe found uranium on the Moon. A new lunar map based on Kaguya data, however, shows there is not enough uranium to be commercially exploitable.
Scientists will still be able to use the uranium and other radioactive elements found to learn more about the formation of the Moon.
Space advocates had jumped on the announcement of lunar uranium as a boon to lunar colonization, especially as it came soon after the announcement of lunar water. (The lunar water story is still holding up.) The promise of a large uranium industry to anchor some part of an early lunar economy may be gone, but the obvious power source for a lunar civilization has always been the Sun. The first lunar outposts will almost certainly be located in the south polar region, where water is available and a continuous supply of solar energy can be arranged. Once we have the capacity to store huge amounts of energy through the long lunar night, perhaps by using ultracapacitor technology, or we build out the lunar energy infrastructure to the point where we can constantly access solar energy, powering a lunar civilization will not be a concern.
Scientists will still be able to use the uranium and other radioactive elements found to learn more about the formation of the Moon.
Space advocates had jumped on the announcement of lunar uranium as a boon to lunar colonization, especially as it came soon after the announcement of lunar water. (The lunar water story is still holding up.) The promise of a large uranium industry to anchor some part of an early lunar economy may be gone, but the obvious power source for a lunar civilization has always been the Sun. The first lunar outposts will almost certainly be located in the south polar region, where water is available and a continuous supply of solar energy can be arranged. Once we have the capacity to store huge amounts of energy through the long lunar night, perhaps by using ultracapacitor technology, or we build out the lunar energy infrastructure to the point where we can constantly access solar energy, powering a lunar civilization will not be a concern.
Tuesday, June 22, 2010
Mars Cave
A seventh grade class in Cottonwood, California, has discovered what could be a cave on Mars. Working under a program run by Arizona State University that allows classes across the country to formulate questions about Mars, then book time on one of the probes now orbiting the Red Planet to take images that might answer the questions, the Cottonwood kids found something interesting.
Their question involved searching for lava tubes, and they decided to look in a volcanically active area that hadn't been intensively studied before. They in fact found what looked like lava tube formations, but they found something more. Atop one lava tube was a big hole-- an entrance to the tube. Essentially, they found a cave. Scientists referred to the hole as a "skylight" formed when a weak part of the ceiling of the tube collasped.
Lava tubes are interesting places to look for life on Mars because they could shield that life from the radiation that constantly bathes the surface. For the same reason, they might make good locations for early human bases. Placing a base inside a lava tube but near a skylight could be interesting.
Will any of the kids have a chance to go to Mars and see the cave up close? If President Obama is right that the first human mission to Mars will happen in the 2030s, the kids might well be the right age to be among the first human explorers.
Their question involved searching for lava tubes, and they decided to look in a volcanically active area that hadn't been intensively studied before. They in fact found what looked like lava tube formations, but they found something more. Atop one lava tube was a big hole-- an entrance to the tube. Essentially, they found a cave. Scientists referred to the hole as a "skylight" formed when a weak part of the ceiling of the tube collasped.
Lava tubes are interesting places to look for life on Mars because they could shield that life from the radiation that constantly bathes the surface. For the same reason, they might make good locations for early human bases. Placing a base inside a lava tube but near a skylight could be interesting.
Will any of the kids have a chance to go to Mars and see the cave up close? If President Obama is right that the first human mission to Mars will happen in the 2030s, the kids might well be the right age to be among the first human explorers.
Monday, June 21, 2010
SpaceShipOne
Six years ago today, Burt Rutan's SpaceShipOne became the first privately funded and developed manned craft to reach space. At that time, hopes were high that Rutan was ushering in a new age of commercial spaceflight that would revolutionize human society.
In fact, no commercial, manned flights have yet even been firmly scheduled, and some people are beginning to think Rutan pulled off more a stunt than a start. Those people probably need more patience, a quality seemingly in ever shorter supply in today's world. There has been progress made in opening space to commercial activity and private human spaceflight. Bigelow Aerospace, for example, has two satellites in Earth orbit right now that have proven BA's inflatable module technology. That technology could be used to quickly establish space hotels, research labs or factories in orbit, and even bases on other worlds. Interorbital Systems plans its first manned orbital flight next year and a large lunar base by the end of the decade. Virgin Galactic is working steadily with Rutan to develop a safe flight system for paying customers. Those are a few of several projects in the early stages.
If a decade from now manned spaceflight is still the sole sphere of governments, we can say SpaceShipOne represented a stillborn promise. If even some of the projects now in the planning stages work out, however, the coming decade will be among the most exciting and decisive in human history. If that happens, Rutan's bold little effort can rightly take its place as an important moment.
In fact, no commercial, manned flights have yet even been firmly scheduled, and some people are beginning to think Rutan pulled off more a stunt than a start. Those people probably need more patience, a quality seemingly in ever shorter supply in today's world. There has been progress made in opening space to commercial activity and private human spaceflight. Bigelow Aerospace, for example, has two satellites in Earth orbit right now that have proven BA's inflatable module technology. That technology could be used to quickly establish space hotels, research labs or factories in orbit, and even bases on other worlds. Interorbital Systems plans its first manned orbital flight next year and a large lunar base by the end of the decade. Virgin Galactic is working steadily with Rutan to develop a safe flight system for paying customers. Those are a few of several projects in the early stages.
If a decade from now manned spaceflight is still the sole sphere of governments, we can say SpaceShipOne represented a stillborn promise. If even some of the projects now in the planning stages work out, however, the coming decade will be among the most exciting and decisive in human history. If that happens, Rutan's bold little effort can rightly take its place as an important moment.
Sunday, June 20, 2010
Kepler Exceeding Expectations
After only 43 days on the job, NASA's planet-hunting Kepler spacecraft has already found 706 possible candidates. So far, about 400 exoplanets have been discovered since 1994.
Kepler operates by looking for dips in starlight that could be caused by a planet moving across the disk of the star. Once Kepler finds a candidate. the possibility will be followed up by ground-based observatories, or by Hubble.
Kepler's goal is to find worlds similar to Earth. If all goes well, Kepler will be looking until November 2012. If the beginning is any indication, thousands of exoplanets might be identified. Whether any of them will be Earth-like, orbiting their parent star at a distance that would allow life to flourish, is another matter, but thousands of possibilities would argue strongly the planets are common in the universe.
Kepler operates by looking for dips in starlight that could be caused by a planet moving across the disk of the star. Once Kepler finds a candidate. the possibility will be followed up by ground-based observatories, or by Hubble.
Kepler's goal is to find worlds similar to Earth. If all goes well, Kepler will be looking until November 2012. If the beginning is any indication, thousands of exoplanets might be identified. Whether any of them will be Earth-like, orbiting their parent star at a distance that would allow life to flourish, is another matter, but thousands of possibilities would argue strongly the planets are common in the universe.
Friday, June 18, 2010
Meteor At Jupiter
After putting the Hubble Space Telescope on the case, astronomers have decided the object that smacked into Jupiter June 3 was a meteor, not a comet or asteroid. For the collision to be visible from Earth, it was likely a huge meteor, but finally not more than that.
Astronomers base their conclusion on images of Jupiter taken by Hubble on June 7. The images showed no dark areas in the Jovian atmosphere, as were seen after the string of impacts of pieces of Comet Shoemaker-Levy 9 in 1994, and after the impact of an asteroid last July. Astronomers conclude, therefore, that the June 3 object burned up high in the atmosphere, much as most meteors do on Earth.
The new bit of science is the result of work by two amateur astronomers. Andrew Wesley of Australia first reported a flash of light at Jupiter, and his observation was confirmed by another amateur, Chris Go, in The Philippines.
Astronomers base their conclusion on images of Jupiter taken by Hubble on June 7. The images showed no dark areas in the Jovian atmosphere, as were seen after the string of impacts of pieces of Comet Shoemaker-Levy 9 in 1994, and after the impact of an asteroid last July. Astronomers conclude, therefore, that the June 3 object burned up high in the atmosphere, much as most meteors do on Earth.
The new bit of science is the result of work by two amateur astronomers. Andrew Wesley of Australia first reported a flash of light at Jupiter, and his observation was confirmed by another amateur, Chris Go, in The Philippines.
Thursday, June 17, 2010
Looking For Life On Europa
Many scientists think life might exist on Jupiter's ice-covered moon, Europa. They think Europa has an ocean rich in oxygen under the ice-- an ocean that could be one hundred miles deep. To look for life in that ocean, NASA and others are studying landing a probe on the surface and somehow drilling through the ice, or possibly melting the ice, to reach the ocean below.
There might be a cheaper, faster way, however. Richard Greenberg, of the University of Arizona's Lunar and Planetary Institute, argues rovers should be sent. He points out there are few craters on Europa, which likely means the surface is regularly refreshed with water and ice coming up from below. Running a rover across newly created surface, therefore, could possibly allow us to come upon evidence of life below that was thrown to the surface with the water. That evidence could be as dramatic as the body of an unfortunate creature deposited on the surface to die in the powerful radiation that pounds the icy shell.
Of course, a rover mission would depend to some large degree on sheer luck to find evidence of life, but it could be done relatively cheaply, sooner than a larger, more complex effort aimed at actually reaching the ocean below, and could return valuable science even if it didn't bag proof of life beyond Earth.
There might be a cheaper, faster way, however. Richard Greenberg, of the University of Arizona's Lunar and Planetary Institute, argues rovers should be sent. He points out there are few craters on Europa, which likely means the surface is regularly refreshed with water and ice coming up from below. Running a rover across newly created surface, therefore, could possibly allow us to come upon evidence of life below that was thrown to the surface with the water. That evidence could be as dramatic as the body of an unfortunate creature deposited on the surface to die in the powerful radiation that pounds the icy shell.
Of course, a rover mission would depend to some large degree on sheer luck to find evidence of life, but it could be done relatively cheaply, sooner than a larger, more complex effort aimed at actually reaching the ocean below, and could return valuable science even if it didn't bag proof of life beyond Earth.
Wednesday, June 16, 2010
Falcon 9 Payoff
The successful test of its Falcon 9 launcher is already paying off for SpaceX. The company has a new contract with Iridium to launch its Iridium NEXT satellite constellation on the Falcon 9 in the 2015-2017 period. The contract is said to be worth $492 million. Add that to the $1.6 billion dollar contract the company already has with NASA to deliver cargo to ISS. and SpaceX would seem to be finding its financial footing.
Of course, all that is dependent upon execution. The Falcon 9 is to be the workhorse in both the Iridium and the NASA deals, and it has flown precisely once. Production rates for the rocket will also have to pick up to meet obligations, which will mean quality control and efficiency in the production process will become more important. SpaceX obviously knows that, but knowing and executing are two different things in business.
Of course, all that is dependent upon execution. The Falcon 9 is to be the workhorse in both the Iridium and the NASA deals, and it has flown precisely once. Production rates for the rocket will also have to pick up to meet obligations, which will mean quality control and efficiency in the production process will become more important. SpaceX obviously knows that, but knowing and executing are two different things in business.
Tuesday, June 15, 2010
More Lunar Water, Part Two
Before Apollo, mainstream science held that there was no water on the Moon. Rock samples brought back by Apollo astronauts hinted at water, but on the whole they were remarkably dry, so mainstream science ignored the hint. There the matter stood for a couple decades. A new generation of lunar probes, however, has shown not only hints of water, but significant amounts.
Now, a new study, based partly on a reexamination of Apollo samples, suggests there may be 100 times more water on the Moon than previously thought. Further, the study argues the water did not arrive in comets that crashed into the surface, but rather was present at the formation of the Moon; it is, therefore, spread over the Moon, under the surface or bound up in rocks, rather than being localized. Water ice on or just below the surface, on the other hand, would likely be a more localized phenomenon.
This is clearly extremely encouraging news for advocates of lunar settlement. The Moon has never been more attractive as a base for mankind. Perhaps NASA and the Obama administration, which still seems to need to find a manned space program more acceptable to Congress, may yet lead an international effort to establish a permanent base on the Moon. Failing that, or perhaps in addition to that, private companies like Bigelow Aerospace and Interorbital Systems are ready to found lunar bases that would hopefully grow into full-blown communities. A substantial amount of lunar water makes their task substantially simpler.
Now, a new study, based partly on a reexamination of Apollo samples, suggests there may be 100 times more water on the Moon than previously thought. Further, the study argues the water did not arrive in comets that crashed into the surface, but rather was present at the formation of the Moon; it is, therefore, spread over the Moon, under the surface or bound up in rocks, rather than being localized. Water ice on or just below the surface, on the other hand, would likely be a more localized phenomenon.
This is clearly extremely encouraging news for advocates of lunar settlement. The Moon has never been more attractive as a base for mankind. Perhaps NASA and the Obama administration, which still seems to need to find a manned space program more acceptable to Congress, may yet lead an international effort to establish a permanent base on the Moon. Failing that, or perhaps in addition to that, private companies like Bigelow Aerospace and Interorbital Systems are ready to found lunar bases that would hopefully grow into full-blown communities. A substantial amount of lunar water makes their task substantially simpler.
Monday, June 14, 2010
A Martian Ocean?
A new study bringing together data from various platforms suggests ancient Mars had a huge ocean. That idea has been around for years, but such proposals had been based on smaller projects. The new study takes a broader perspective and suggests that over three billion years ago an ocean of water existed in Mars' northern hemisphere. Researchers say the ocean covered more than a third of the planet's surface, and that the water cycle on early Mars seems to have been basically the same as the one that still exists on Earth.
The question, of course, becomes: What happened to all the water? There seems to be a substantial amount of water under the surface, and more frozen in the polar ice caps, especially in the northern cap, so all the water didn't go away. Still, the climate radically changed on Mars, whereas the basic natural systems on Earth either maintained or reasserted themselves. One factor involved may be simple size. Earth has enough mass, and therefore gravity, to keep its atmosphere and water from leaking away into space while Mars does not.
Of course, the presence of a large ocean of water on early Mars for any length of time inevitably leads to the possibility that life may have developed there. If it did, and if the Martian climate changed slowly enough to allow biological evolution to do its thing, life may still exist in niche environments on Mars.
The question, of course, becomes: What happened to all the water? There seems to be a substantial amount of water under the surface, and more frozen in the polar ice caps, especially in the northern cap, so all the water didn't go away. Still, the climate radically changed on Mars, whereas the basic natural systems on Earth either maintained or reasserted themselves. One factor involved may be simple size. Earth has enough mass, and therefore gravity, to keep its atmosphere and water from leaking away into space while Mars does not.
Of course, the presence of a large ocean of water on early Mars for any length of time inevitably leads to the possibility that life may have developed there. If it did, and if the Martian climate changed slowly enough to allow biological evolution to do its thing, life may still exist in niche environments on Mars.
Sunday, June 13, 2010
Hayabusa Capsule Returns
Japan's seven-year mission to collect samples from an asteroid and return them to Earth ended a successful flight as the sample capsule of the Hayabusa spacecraft blazed down through the atmosphere over Australia. The rest of the spacecraft will burn up in the atmosphere, but the capsule had a parachute and heat shield designed to allow for recovery.
When that is recovered, we will see if it contains asteroid samples. If so, they could tell a lot about asteroids and the early Solar System. Even if no samples are inside, the fact that Japan was able to fly the mission, overcome several problems along the way, and bring the probe and the capsule back to Earth as planned establishes Japan as a nation capable of being a major factor in space exploration.
When that is recovered, we will see if it contains asteroid samples. If so, they could tell a lot about asteroids and the early Solar System. Even if no samples are inside, the fact that Japan was able to fly the mission, overcome several problems along the way, and bring the probe and the capsule back to Earth as planned establishes Japan as a nation capable of being a major factor in space exploration.
Friday, June 11, 2010
Accounting For Comets
A new study suggests that long-period comets like Hale-Bopp and Halley's may have originated in another star system.
Current theory holds that the Oort Cloud, home to many comets that occasionally blaze into the inner Solar System, was created when Jupiter ejected comets orbiting near it to the very edge of the Sun's influence. There seems to be two problems with that theory. First, the projected number of objects in the Oort Cloud seems much larger than any Jupiter ejection theory could produce. Second, gravity weakens substantially at huge distances from the primary, and it's unclear how so many bodies flung so far by Jupiter could simply stop rather than continuing into interstellar space.
The new study, which uses computer simulations, suggests the Sun was born in a star cluster, as most stars are. As the stars in the cluster went their own ways in space, comets born around one star were carried away under the gravitational influence of another.
Some astronomers, of course, question the new explanation. For one thing, they argue, we don't yet know how many bodies are in the Oort Cloud, so we can't say that number doesn't match current theory. Still, the new explanation is intriguing. We might be able to physically sample another solar system far sooner than scientists think.
Current theory holds that the Oort Cloud, home to many comets that occasionally blaze into the inner Solar System, was created when Jupiter ejected comets orbiting near it to the very edge of the Sun's influence. There seems to be two problems with that theory. First, the projected number of objects in the Oort Cloud seems much larger than any Jupiter ejection theory could produce. Second, gravity weakens substantially at huge distances from the primary, and it's unclear how so many bodies flung so far by Jupiter could simply stop rather than continuing into interstellar space.
The new study, which uses computer simulations, suggests the Sun was born in a star cluster, as most stars are. As the stars in the cluster went their own ways in space, comets born around one star were carried away under the gravitational influence of another.
Some astronomers, of course, question the new explanation. For one thing, they argue, we don't yet know how many bodies are in the Oort Cloud, so we can't say that number doesn't match current theory. Still, the new explanation is intriguing. We might be able to physically sample another solar system far sooner than scientists think.
Thursday, June 10, 2010
Life On Io?
At first glance, Jupiter's moon Io would seem to be among the most unlikely places to find life. At second glance, too. Even after a long, hard stare. Io is the most volcanically active body in the Solar System; its surface is regularly re-sculpted by flowing lava. But, according to Washington State University astrobiologist Dirk Schulze-Makuch, Io shouldn't be dismissed so quickly.
He points out that Io presumably formed in the same region of space as Europa and Ganymede. Since they both have substantial water components, it's fair to assume early Io did, too. Heat plus water plus some fancy organic chemistry could produce life. Obviously, the surface of Io today couldn't be home to any life we can easily imagine, but he argues subsurface life might be possible. Specifically, he says, lava tubes might provide a stable, mild environment that is protected from the lethal radiation outside. Lava tubes support bacteria colonies on Earth, and they are among the best places to search for life on Mars. Features Io likely has in abundance are lava tubes.
He points out that Io presumably formed in the same region of space as Europa and Ganymede. Since they both have substantial water components, it's fair to assume early Io did, too. Heat plus water plus some fancy organic chemistry could produce life. Obviously, the surface of Io today couldn't be home to any life we can easily imagine, but he argues subsurface life might be possible. Specifically, he says, lava tubes might provide a stable, mild environment that is protected from the lethal radiation outside. Lava tubes support bacteria colonies on Earth, and they are among the best places to search for life on Mars. Features Io likely has in abundance are lava tubes.
Wednesday, June 9, 2010
Origins Of Saturn's Moonlets
A new study indicates that the tiny moons that orbit just inside and just outside Saturn's ring system were likely "born" in the rings not too long ago. The tiny moons are sometimes called "shepherding" moons because their gravity helps the rings maintain their shape, but the connection may be even deeper. According to computer simulations, the moons may have slowly built up within the rings, acquiring new material from the rings, until at some point the gravitational interplay with Saturn and the mass of the ring system pushed them into their present orbits.
That point may not have been terribly long ago, either. Judging by the lack of cratering on their bright, icy surfaces, they could have been formed as few as 10 million years ago. That would suggest the ring system is a dynamic place, still evolving. That view, in turn, would mesh with the theory that the ring system itself is in fact transitory. We just happen to be around at the right time to be able to see the glorious sight of Saturn ringed.
That point may not have been terribly long ago, either. Judging by the lack of cratering on their bright, icy surfaces, they could have been formed as few as 10 million years ago. That would suggest the ring system is a dynamic place, still evolving. That view, in turn, would mesh with the theory that the ring system itself is in fact transitory. We just happen to be around at the right time to be able to see the glorious sight of Saturn ringed.
Tuesday, June 8, 2010
Extreme Life
Researchers looking for niche environments on Earth that might be similar to such places on Mars have found one on an Arctic island in Canada. In fact, they say, Lost Hammer Spring is even more inhospitable to life than some places on Mars. And yet-- Lost Hammer is home to a thriving microbial ecosystem. The existence of such extreme life on Earth, scientists say, makes it more likely life could be found elsewhere.
Indeed, they say, the Lost Hammer microbes could survive on Mars. That's interesting, but may be beside the point. Science already knows of some Earthly life forms that could survive on Mars. Evolution takes extraordinary twists and turns and avenues once life is established. The central question, surely, is whether life ever arose on Mars. If it did arise early on, the Martian environment may have been stable enough long enough for evolution to begin. After that, the question is whether the climate on Mars changed slowly enough for that life to adapt.
The only way to determine whether life arose on Mars is to go there and look around.
Indeed, they say, the Lost Hammer microbes could survive on Mars. That's interesting, but may be beside the point. Science already knows of some Earthly life forms that could survive on Mars. Evolution takes extraordinary twists and turns and avenues once life is established. The central question, surely, is whether life ever arose on Mars. If it did arise early on, the Martian environment may have been stable enough long enough for evolution to begin. After that, the question is whether the climate on Mars changed slowly enough for that life to adapt.
The only way to determine whether life arose on Mars is to go there and look around.
Monday, June 7, 2010
Life On Titan?
New studies of Saturn's huge moon Titan, using Cassini data, suggest to some scientists, including NASA's Chris MacKay, that methane-based life might exist there. The studies document the absence of hydrogen and acetylene on Titan's surface. Those elements do exist in the atmosphere, so one explanation of their disappearance near the surface is that they are being consumed in some way by living things. Indeed, scientists believe that methane-based life in Titan's frigid environment would in fact use hydrogen and acetylene.
Of course, other scientists aren't jumping on the bandwagon. They say there are non-biological processes that could explain the situation, and embracing the biological explanation-- which, after all, would rank with the greatest discoveries in human history-- should only be done after all other possibilities have been ruled out. MacKay agrees. Still, the vanishing hydrogen and acetylene constitute two more tantalyzing mysteries of the intriguing world of Titan.
Of course, other scientists aren't jumping on the bandwagon. They say there are non-biological processes that could explain the situation, and embracing the biological explanation-- which, after all, would rank with the greatest discoveries in human history-- should only be done after all other possibilities have been ruled out. MacKay agrees. Still, the vanishing hydrogen and acetylene constitute two more tantalyzing mysteries of the intriguing world of Titan.
Sunday, June 6, 2010
The Spin Begins
In the warm afterglow of the successful test launch of the Falcon 9, individuals and organizations have already begun spinning that success to support previously held positions. Those who support President Obama's approach to NASA say the launch is a good step in that direction, while those who oppose the Obama plan continue to question it. Such is politics.
SpaceX is beginning to establish a good record with its Falcon series of rockets, of which Falcon 9 is the largest and the projected workhorse. That's good news for SpaceX, and it's also good news for other companies in the NewSpace industry. They may now have less pressure from government regulators early on as they move towards their first test launches.
The elemental task remains, however. Whether private enterprise can provide regular, rapid, relatively safe access to low Earth orbit at a profit anytime soon is still an open question. The Falcon 9 test flight maintains the hope, but dozens of such flights by several different companies are needed before we can begin to say we might have the key to the future in our hands.
SpaceX is beginning to establish a good record with its Falcon series of rockets, of which Falcon 9 is the largest and the projected workhorse. That's good news for SpaceX, and it's also good news for other companies in the NewSpace industry. They may now have less pressure from government regulators early on as they move towards their first test launches.
The elemental task remains, however. Whether private enterprise can provide regular, rapid, relatively safe access to low Earth orbit at a profit anytime soon is still an open question. The Falcon 9 test flight maintains the hope, but dozens of such flights by several different companies are needed before we can begin to say we might have the key to the future in our hands.
Friday, June 4, 2010
Falcon 9 Launches
After some delays, including one because a boat drifted into waters that would be under the flight path, SpaceX's Falcon 9 rocket lifted off on its first test launch from Cape Kennedy. Early on, the launch seems to have been a success.
If that turns out to be the case, it will be a major achievement for SpaceX, a boost for the NewSpace industry, and a political plus for the Obama administration, which plans to rely on commercial boosters, including the Falcon 9, to supply ISS after the shuttle retires, and, eventually, to put humans into low Earth orbit.
Of course, one successful launch is simply that. Developing a new rocket generally involves multiple failures-- and those failures often teach engineers more about the various components of the system than they learn from successes. So, a first success on a first test flight is terrific, but Falcon 9 may yet suffer setbacks before it becomes a reliable, operational launcher. If that happens, we should remember that we know the thing works. It worked today.
If that turns out to be the case, it will be a major achievement for SpaceX, a boost for the NewSpace industry, and a political plus for the Obama administration, which plans to rely on commercial boosters, including the Falcon 9, to supply ISS after the shuttle retires, and, eventually, to put humans into low Earth orbit.
Of course, one successful launch is simply that. Developing a new rocket generally involves multiple failures-- and those failures often teach engineers more about the various components of the system than they learn from successes. So, a first success on a first test flight is terrific, but Falcon 9 may yet suffer setbacks before it becomes a reliable, operational launcher. If that happens, we should remember that we know the thing works. It worked today.
Jupiter Rocked Again
For at least the second time in less than a year, Jupiter has been hit by a body, probably an asteroid. Amateur astronomer Andrew Wesley of Australia alerted the world to both collisions.
Two events in less than a year could well mean that Jupiter is hit more often than astronomers assume. Given the giant planet's huge, powerful gravitational field, a number of strikes is understandable; Jupiter sucks up bodies that come too close at the wrong angle, or with insufficient speed to break free.
The strikes are also a cautionary tale, however. Earth is also in danger of being hit. Earth's gravity is not nearly as strong as Jupiter's, but it is the strongest in the inner Solar System, which means it, too, could funnel bodies that come too close directly into the surface of the planet.
Two events in less than a year could well mean that Jupiter is hit more often than astronomers assume. Given the giant planet's huge, powerful gravitational field, a number of strikes is understandable; Jupiter sucks up bodies that come too close at the wrong angle, or with insufficient speed to break free.
The strikes are also a cautionary tale, however. Earth is also in danger of being hit. Earth's gravity is not nearly as strong as Jupiter's, but it is the strongest in the inner Solar System, which means it, too, could funnel bodies that come too close directly into the surface of the planet.
Thursday, June 3, 2010
Mars500
A simulated manned mission to Mars is underway in Russia. Six volunteers-- three Russians, two Europeans, and a Chinese-- are scheduled to remain in a mock up of a Mars ship for 549 days, the time required to reach Mars, spend 30 days there, and come home. During the experiment, the volunteers will follow a schedule based on the work schedule a Mars crew would have.
The main point of the mock mission is to study the psychological and interpersonal relationship issues that might present themselves when a small group of people are isolated in a small living space for that long.
The main point of the mock mission is to study the psychological and interpersonal relationship issues that might present themselves when a small group of people are isolated in a small living space for that long.
Wednesday, June 2, 2010
Retrograde Black Holes
A new study finds that black holes that spin in the opposite direction of the spin of the accretion disks that surround them-- retrograde black holes-- eject more powerful jets of energy and matter than do prograde black holes, which spin in the same direction as their accretion disks.
The reason seems to be that retrograde black holes have more room between them and the inner edge of their accretion disks, which gives the black holes' magnetic fields more room to develop and strengthen. It is the magnetic field of a black hole that sustains and directs the jets.
This finding is important in understanding star formations in galaxies, and, therefore, the development of galaxies. A monster black hole sitting at the center of a galaxy affects the development of that galaxy in various ways. One way is the jet sweeping through matter, clearing some areas and concentrating matter in others. Stars eventually form in knots of matter where the density becomes high enough to ignite the nuclear cycle.
The reason seems to be that retrograde black holes have more room between them and the inner edge of their accretion disks, which gives the black holes' magnetic fields more room to develop and strengthen. It is the magnetic field of a black hole that sustains and directs the jets.
This finding is important in understanding star formations in galaxies, and, therefore, the development of galaxies. A monster black hole sitting at the center of a galaxy affects the development of that galaxy in various ways. One way is the jet sweeping through matter, clearing some areas and concentrating matter in others. Stars eventually form in knots of matter where the density becomes high enough to ignite the nuclear cycle.
Tuesday, June 1, 2010
Unidentified Object
A small unidentified object whipped past Earth just outside the orbit of the Moon on May 21. It had been discovered on May 16.
Astronomers have determined the object is only a few meters long, is metallic on the exterior, and orbits the Sun in the same orbit Earth does. They speculate, therefore, that it's the upper stage of a rocket that launched an interplanetary probe on its way sometime in the past few decades. An enterprising grad student might come up with a pretty good paper if he or she could work out exactly which part of which rocket from which mission this object might be.
The object is also a reminder that although space junk may only be a real problem in Earth orbit, we have stuff scattered across the Solar System.
Astronomers have determined the object is only a few meters long, is metallic on the exterior, and orbits the Sun in the same orbit Earth does. They speculate, therefore, that it's the upper stage of a rocket that launched an interplanetary probe on its way sometime in the past few decades. An enterprising grad student might come up with a pretty good paper if he or she could work out exactly which part of which rocket from which mission this object might be.
The object is also a reminder that although space junk may only be a real problem in Earth orbit, we have stuff scattered across the Solar System.
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