Space News Archive - March 09, 2005
How dust specks in the early solar systems came together to become planets has vexed astronomers for years. Gravity, always an attractive candidate to explain how celestial matter pulls together, was no match for stellar winds. Now, scientists offer a cool answer to the planet-formation riddle.
Recent discoveries on Mars such as methane in the atmosphere, a subterranean ice pack near the equator, and evidence of flowing water in the planet's past brings new speculation to the most frequently asked questions about the Red Planet: Is there, or was there ever life on Mars?
Arizona's Jonathan Lunine presented a lecture entitled "Titan: A Personal View after Cassini's first six months in Saturn orbit" at a NASA Director's Seminar on January 24, 2005. Lunine discusses the question of missing methane in an edited transcript of Part 2.
The iron meteorite that blasted out Meteor Crater almost 50,000 years ago was traveling much slower than has been assumed, University of Arizona Regents' Professor H. Jay Melosh and Gareth Collins of the Imperial College London report in the cover article of Nature (March 10).
Saturn's largest and hazy moon, Titan, has a surface shaped largely by Earth-like processes of tectonics, erosion, winds, and perhaps volcanism. Titan, long held to be a frozen analog of early Earth, has liquid methane on its cold surface, unlike the water found on our home planet.
Astronomers have taken an important step toward establishing a weight limit for stars. Studying the densest known cluster of stars in our galaxy, the Arches cluster, astronomers determined that stars are not created any larger than about 150 times the mass of our Sun, or 150 solar masses.