NASA has confirmed there is at least one lake of liquid ethane and other hydrocarbons on Saturn's largest moon, Titan. Analysis of data from the Cassini probe led to the discovery.
Titan was already a fascinating world. Comparable in size to the planet Mercury, Titan is the only moon in the Solar System that has an atmosphere-- and its atmosphere is denser than Earth's. Hydrocarbons, the building blocks of life, seem to be everywhere, making Titan a possible home for life despite its deep freeze temperatures.
The confirmed liquid lake is near Titan's south pole, and is larger than Lake Ontario. Earlier images of the surface taken by Cassini revealed lake-like structures dotting the moon. If they are all liquid, the possibility of life on Titan probably improves.
Thursday, July 31, 2008
Wednesday, July 30, 2008
Watching Mars Change
When the Phoenix Mars Lander was in its final descent to the surface, the exhaust from its rocket engines blew away some nearby dirt, exposing what seemed to be a layer of ice that was beneath the surface before the landing.
Using cameras on Phoenix, scientists have kept watch on the area immediately around the Lander, and they have documented changes. The exposed ice layer, for example, was smooth on its surface at first, but now the surface is rough, cracks may be developing, and pebbles are where none were before. Scientists cannot yet explain exactly what is happening.
This is the first time humans have been able to watch change occurring on another world in something close to real time. Cool stuff.
Using cameras on Phoenix, scientists have kept watch on the area immediately around the Lander, and they have documented changes. The exposed ice layer, for example, was smooth on its surface at first, but now the surface is rough, cracks may be developing, and pebbles are where none were before. Scientists cannot yet explain exactly what is happening.
This is the first time humans have been able to watch change occurring on another world in something close to real time. Cool stuff.
Tuesday, July 29, 2008
Happy 50th, NASA
Today is the fiftieth anniversary of the creation of NASA. Born out of the American reaction to Sputnik, the agency was created during the Eisenhower administration. Perhaps the major force behind the creation, however, was the then Senate Majority Leader, Lyndon B. Johnson of Texas.
NASA came into being under Eisenhower, but President Kennedy gave the agency its historic mission-- to land a man on the Moon and return him safely to the Earth. Implicit in Kennedy's challenge was completing the task before the Soviets did it. In fact, to this day, the only humans who have ventured beyond low Earth orbit have been NASA astronauts fulfilling Kennedy's directive.
After Apollo, NASA's manned space program has drifted for lack of leadership by presidents and Congress, but the unmanned program has produced spectacular results on many fronts, completely transforming our understanding of the universe. What the next fifty years will see is unclear, but among the milestones could be a thriving lunar settlement, bases on Mars, the discovery of Earthlike planets orbiting other stars, and the discovery of life beyond Earth. NASA would likely have a strong hand in all that.
NASA came into being under Eisenhower, but President Kennedy gave the agency its historic mission-- to land a man on the Moon and return him safely to the Earth. Implicit in Kennedy's challenge was completing the task before the Soviets did it. In fact, to this day, the only humans who have ventured beyond low Earth orbit have been NASA astronauts fulfilling Kennedy's directive.
After Apollo, NASA's manned space program has drifted for lack of leadership by presidents and Congress, but the unmanned program has produced spectacular results on many fronts, completely transforming our understanding of the universe. What the next fifty years will see is unclear, but among the milestones could be a thriving lunar settlement, bases on Mars, the discovery of Earthlike planets orbiting other stars, and the discovery of life beyond Earth. NASA would likely have a strong hand in all that.
Monday, July 28, 2008
WhiteKnightTwo Rolls Out
Virgin Galactic takes its next step towards space operations today as its mother ship, WhiteKnightTwo, makes its public debut in Mojave, California. Ground tests of the plane's various systems will be conducted over the next several weeks, and test flights will begin after that. No firm schedule has been set.
WhiteKnightTwo is a huge plane, with its double fuselage and 140-foot wingspan. Not only will it be used to carry SpaceShipTwo up 40,000 feet for its launch on a suborbital arc, but it can also be used as a launch platform for unmanned satellites and a platform for short duration microgravity experiments, among other things. VG is developing plans to fully exploit the plane's capabilities.
WhiteKnightTwo is a huge plane, with its double fuselage and 140-foot wingspan. Not only will it be used to carry SpaceShipTwo up 40,000 feet for its launch on a suborbital arc, but it can also be used as a launch platform for unmanned satellites and a platform for short duration microgravity experiments, among other things. VG is developing plans to fully exploit the plane's capabilities.
Sunday, July 27, 2008
Preserving Lunar History
Plans to return to the Moon's surface, both by various nations and by private efforts, has brought up the question of how and whether to preserve the landing sites associated with the first era of lunar exploration some forty years ago.
It's an interesting subject. Virtually everyone involved in the debate agrees that the landing site of Apollo 11 should not be disturbed in any way, but the other Apollo sites might not merit such protection. Apollo 17, for example, left some items on the Moon specifically for future explorers to retrieve in order to study the affects of long term exposure to the lunar environment. Bringing those items back would seem justifiable-- finally ending the Apollo 17 mission, in a sense. Beyond the Apollo sites, there are also the unmanned sites-- from the American Ranger and Surveyor probes, and the Soviet Luna and Lunakhod vehicles.
The idea is to preserve certain areas of the Moon much as we preserve parts of Earth in national parks and heritage sites. The first such project in the world was Yellowstone National Park in 1872. At that time, the American West was still a frontier. Custer and his command died four years later. So, maybe it's not too soon to protect some areas of the lunar frontier.
It's an interesting subject. Virtually everyone involved in the debate agrees that the landing site of Apollo 11 should not be disturbed in any way, but the other Apollo sites might not merit such protection. Apollo 17, for example, left some items on the Moon specifically for future explorers to retrieve in order to study the affects of long term exposure to the lunar environment. Bringing those items back would seem justifiable-- finally ending the Apollo 17 mission, in a sense. Beyond the Apollo sites, there are also the unmanned sites-- from the American Ranger and Surveyor probes, and the Soviet Luna and Lunakhod vehicles.
The idea is to preserve certain areas of the Moon much as we preserve parts of Earth in national parks and heritage sites. The first such project in the world was Yellowstone National Park in 1872. At that time, the American West was still a frontier. Custer and his command died four years later. So, maybe it's not too soon to protect some areas of the lunar frontier.
Friday, July 25, 2008
Transiting Exoplanet
A team of European researchers has recently discovered a new planet orbitug another star by noting the planet's transit across the disk of its sun. The exoplanet is another "hot Jupiter," orbiting its star in 9.2 days, which happens to equal the rotation rate of the star about its axis-- its "day." The star is slightly larger than our Sun.
Observing transits to detect planets around other stars would seem to be a technique of limited value since it depends upon the planet's orbit being well enough aligned with Earth that our instruments can note the transit. Such alignment is a random occurrence, unless we postulate some deep connection between the Sun and the star in question, which nobody is doing. Still, several exoplanets have been discovered using the technique.
Observing transits to detect planets around other stars would seem to be a technique of limited value since it depends upon the planet's orbit being well enough aligned with Earth that our instruments can note the transit. Such alignment is a random occurrence, unless we postulate some deep connection between the Sun and the star in question, which nobody is doing. Still, several exoplanets have been discovered using the technique.
Thursday, July 24, 2008
More Time For Phoenix?
The science team operating the Phoenix Mars Lander is asking NASA to extend the mission beyond the planned 90 days, which would end in late August. The team wants at least another 30 days.
After doing all the work to get Phoenix where it is, shutting down the mission while the Lander is still producing good science woukd seem foolish. There would likely be only one extension, however. Pjoenix is above Mars' Arctic Circle, and winter is closing in. Just as in Earth's polar regions, the Sun will stay below the horizon through winter. As Phoenix operates on solar power, it will not function in the long night. The intense cold will also destroy the systems of Phoenix before the Martian spring arrives.
After doing all the work to get Phoenix where it is, shutting down the mission while the Lander is still producing good science woukd seem foolish. There would likely be only one extension, however. Pjoenix is above Mars' Arctic Circle, and winter is closing in. Just as in Earth's polar regions, the Sun will stay below the horizon through winter. As Phoenix operates on solar power, it will not function in the long night. The intense cold will also destroy the systems of Phoenix before the Martian spring arrives.
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