Ever since Newton showed light was made up of components that could be separated, as using a prism does, scientists have been trying to discover new ways to gain information from light. A basic tool of astronomers has long been the spectrograph, for example, which lays out light from a target across the visible light spectrum, allowing scientists to identify elements in that target by studying markers in that spectrum.
Simple light may also help us to find extrasolar Earths. Light from a home star glinting off the surface of a planetary ocean, for instance, could tell us that world may be Earthlike. That technique-- which has been tested by using ESA probes orbiting Mars and Venus to look at Earth-- works best when the target planet is in crescent phase, so the light will be coming from a dark background. Studying the"light curve"-- the nature of the light that is reflected away from a body-- can also tell us whether the light bounced off water, ice, or dry land, and perhaps give an indication of the planet's rate of rotation on its axis.
The planet finder probes scheduled for launch in the next decade could give us some wonderful surprises.
Friday, August 8, 2008
Thursday, August 7, 2008
UFOs and Civilized Behavior
SPACE.com has a feature it calls the "SETI Channel" that presents articles or essays concerned with some aspect of the search for extraterrestrial intelligence. It's a good feature. If I ran a cable science network, I'd make it a regular documentary series. Often, the writer of the articles is Dr. Seth Shostak, senior astronomer of the SETI Institute. This week, for example, Dr. Shostak discusses the abuse he regularly takes from UFO investigators and believers.
As noted in this blog, Larry King's talk show ran a series of programs focusing on UFOs in July. Dr. Shostak played the skeptic on at least two of the programs. In his SETI Channel article, he complains about how he and Bill Nye were treated on the show, and about how he gets abusive emails from the UFO community. He has a point. The King shows did degenerate into personal remarks against Shostak and Nye at times. However, that has become the nature of such shows. When several people are trying to be heard at once, you'll likely get frustrated people saying things they shouldn't. That's what passes for good television these days. That's why Mr. King didn't try too terribly hard to cut the potshots. TV people, seemingly, crave confluct as vampires need warm blood. If Shostak and Nye don't understand that, perhaps they should limit their appearances to more controlled situations.
Dr. Shostak also notes in his article that he can understand the frustrations of UFO investigators who feel their work is not taken seriously by reputable scientists. Mainstream science points out that sixty years after Roswell no physical evidence has ever been brought forward by ufologists. That is true, but it's also true that we don't know what might be turned up if more scientists put more time, energy, and resources into trying to settle this matter once and for all. Ufologists say they have some strong cases. Start there. See what happens.
As noted in this blog, Larry King's talk show ran a series of programs focusing on UFOs in July. Dr. Shostak played the skeptic on at least two of the programs. In his SETI Channel article, he complains about how he and Bill Nye were treated on the show, and about how he gets abusive emails from the UFO community. He has a point. The King shows did degenerate into personal remarks against Shostak and Nye at times. However, that has become the nature of such shows. When several people are trying to be heard at once, you'll likely get frustrated people saying things they shouldn't. That's what passes for good television these days. That's why Mr. King didn't try too terribly hard to cut the potshots. TV people, seemingly, crave confluct as vampires need warm blood. If Shostak and Nye don't understand that, perhaps they should limit their appearances to more controlled situations.
Dr. Shostak also notes in his article that he can understand the frustrations of UFO investigators who feel their work is not taken seriously by reputable scientists. Mainstream science points out that sixty years after Roswell no physical evidence has ever been brought forward by ufologists. That is true, but it's also true that we don't know what might be turned up if more scientists put more time, energy, and resources into trying to settle this matter once and for all. Ufologists say they have some strong cases. Start there. See what happens.
Wednesday, August 6, 2008
Obama's Space Plans
Speaking to voters along Florida's Space Coast recently, Sen. Barack Obama pledged to build the spacecraft and launcher of the new Constellation program and seek to narrow the time gap between the last shuttle flight and the first Constellation flight, even if that might mean additional shuttle flights. He also said he wanted to use ISS "intelligently" and give NASA a mission that would once again "inspire" the world.
Obama, however, declined to commit himself to returning humans to the Moon, let alone going on to Mars, saying he intended a thorough study of what NASA should do in the future. Fair enough. Likely, a review of NASA's direction is in store no matter who wins the presidency. The Constellation hardware, however, is being designed to support deep space manned missions. If that hardware is built, logic-- economic and otherwise-- would seem to drive a decision to use it for what it was intended.
Obama, however, declined to commit himself to returning humans to the Moon, let alone going on to Mars, saying he intended a thorough study of what NASA should do in the future. Fair enough. Likely, a review of NASA's direction is in store no matter who wins the presidency. The Constellation hardware, however, is being designed to support deep space manned missions. If that hardware is built, logic-- economic and otherwise-- would seem to drive a decision to use it for what it was intended.
Tuesday, August 5, 2008
More Planethood Debate
Is the New Horizon probe flying to a planet? The mission's target is Pluto, but in just the past two years Pluto has been defined by groups of astronomers as a planet, a dwarf planet, and a plutoid. No kidding.
Next week, another group of astronomers will meet in Laurel, Maryland, to try to come to a consensus on the definition of "planet." This bizarre little controversy really caught fire in 2006 when the International Astronomical Union decided Pluto would no longer have planet status. The IAU's case is based on the facts that Pluto is much smaller than any other planet-- indeed, smaller than some moons, including our own. The case can also be made that Pluto is simply the closest in a new class of objects orbiting in the Kuiper Belt beyond Neptune. We are beginning to find others, and New Horizon may visit one or more after its Pluto flyby.
On the other hand, many argue Pluto is a substantial, spherical body that orbits a star; it is, therefore, a planet. If that definition means a few more bodies in the Solar System get uograded to planets, they say, so be it.
Whatever the outcome at Laurel, the conference will look at extrasolar planets, as well, and try to find consensus that covers bodies everywhere. One further quirk in the IAU's decision is that its definition of planethood applied only to this solar system, leaving open the possibility that the definition in other solar systems could be different. Laurel, hopefully, will bring that position into the modern age.
Next week, another group of astronomers will meet in Laurel, Maryland, to try to come to a consensus on the definition of "planet." This bizarre little controversy really caught fire in 2006 when the International Astronomical Union decided Pluto would no longer have planet status. The IAU's case is based on the facts that Pluto is much smaller than any other planet-- indeed, smaller than some moons, including our own. The case can also be made that Pluto is simply the closest in a new class of objects orbiting in the Kuiper Belt beyond Neptune. We are beginning to find others, and New Horizon may visit one or more after its Pluto flyby.
On the other hand, many argue Pluto is a substantial, spherical body that orbits a star; it is, therefore, a planet. If that definition means a few more bodies in the Solar System get uograded to planets, they say, so be it.
Whatever the outcome at Laurel, the conference will look at extrasolar planets, as well, and try to find consensus that covers bodies everywhere. One further quirk in the IAU's decision is that its definition of planethood applied only to this solar system, leaving open the possibility that the definition in other solar systems could be different. Laurel, hopefully, will bring that position into the modern age.
Monday, August 4, 2008
More Evidence Supporting Dark Energy
Dark energy and its running mate, dark matter, constitute one of the biggest mysteries in modern day physics. Scientists don't understand exactly what they are or how they work. The role they seem to play in the universe, however, is profound. Estimates are that 74% of the universe is dark energy, 22% dark matter, and only 4% everything we see and touch and know. Dark energy seems to be responsible for the acceleration in the expansion of the universe scientists have recently discovered.
A recent study by a team of astronomers at the University of Hawaii buttresses the case for the existence of dark energy. The team studied microwave radiation before it entered a supercluster of galaxies, and microwave radiation leaving the supercluster. The team also studied microwaves before they entered a supervoid, and microwaves leaving it. Supervoids are exactly what you'd expect-- huge areas of space that contain little or no matter. The obsrved behavior of the microwave radiation fit precisely what it would be if dark energy exists.
We may not know what dark energy is, but it certainly seems to be around.
A recent study by a team of astronomers at the University of Hawaii buttresses the case for the existence of dark energy. The team studied microwave radiation before it entered a supercluster of galaxies, and microwave radiation leaving the supercluster. The team also studied microwaves before they entered a supervoid, and microwaves leaving it. Supervoids are exactly what you'd expect-- huge areas of space that contain little or no matter. The obsrved behavior of the microwave radiation fit precisely what it would be if dark energy exists.
We may not know what dark energy is, but it certainly seems to be around.
Sunday, August 3, 2008
SpaceX Ups and Downs
On Saturday, SpaceX's Falcon 1 rocket failed for the third time to put a payload into orbit. This time, the payload included a microsat built by SpaceDev. The flight went wrong when the second stage failed to separate a bit more than two minutes after launch.
Failures in the early days of developing a new rocket are not uncommon, and Elon Musk, chairman of SpaceX, has made it clear the company will continue the process.
Indeed, all was not gloom at SpaceX last week. On July 31, the company successfully carried out the first ground firing test of the main engine of its large Falcon 9 rocket. The Falcon 9 is slated to deliver cargo, and possibly a manned capsule, to ISS early in the next decade.
Failures in the early days of developing a new rocket are not uncommon, and Elon Musk, chairman of SpaceX, has made it clear the company will continue the process.
Indeed, all was not gloom at SpaceX last week. On July 31, the company successfully carried out the first ground firing test of the main engine of its large Falcon 9 rocket. The Falcon 9 is slated to deliver cargo, and possibly a manned capsule, to ISS early in the next decade.
Friday, August 1, 2008
Water Down, Organics To Go
NASA announced yesterday that it had confirmed the existence of water on Mars, at least in the form of subsurface ice. Scientists have had good evidence for several years of water on Mars, but the Phoenix Mars Lander was finally able to deliver a sample of the ice into its lab, heat it, and confirm it was made of water. If that ground truth can be used to validate evidence of water obtained from orbiting probes, there would seem to be more than enough water to support human exploration and settlement of the planet.
The next goal for Phoenix, however, is to look for organic compounds and molecules, starting with the ice sample. If organics are discovered, that wouldn't necessarily prove Mars has Martians, but it would confirm the building blocks of life are present. Mix water, organics, and a more hospitable climate in the past, and the case for life on Mars at some point becomes fairly strong.
If life arose independently on at least two worlds in the same solar system, that would strongly argue life is common throughout the universe. With any luck, we should be able to settle the question of how rare or abundant life actually is yet this century.
The next goal for Phoenix, however, is to look for organic compounds and molecules, starting with the ice sample. If organics are discovered, that wouldn't necessarily prove Mars has Martians, but it would confirm the building blocks of life are present. Mix water, organics, and a more hospitable climate in the past, and the case for life on Mars at some point becomes fairly strong.
If life arose independently on at least two worlds in the same solar system, that would strongly argue life is common throughout the universe. With any luck, we should be able to settle the question of how rare or abundant life actually is yet this century.
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