News briefs: June 21
Posted: Sat, Jun 22, 2002, 9:26 AM ET (1326 GMT)
- Planetary scientists believe that a massive flood on ancient Mars carved a canyon the size of the Grand Canyon in a matter of months. In a paper published in the latest issue of Science, researchers at the National Air and Space Museum used Mars Global Surveyor images to find that a lake the size of Texas and California combined released its water 3.5 billion years ago, carving a canyon named Ma'adim Vallis, 2 kilometers deep nearly 1,000 km long, in just months.
- Astronomers have discovered an aging star that is spouting streams of water molecules. The jets of water streaming from star W43A were found by astronomers using the Very Large Baseline Array. Astronomers don't know what is producing the jets, but say that the jets could explain why planetary nebulae, formed by stars like W43A late in their lives, are not spherical.
- Most comets ejected from the Oort Cloud disintegrate before entering the inner solar system, according to a recent study. Astronomers writing in the latest issue of Science said that far fewer comets have been discovered than expected based on models of the Oort Cloud. Researchers believe that up to 99 percent of objects ejected from the Oort Cloud simply disintegrate before reaching the inner solar system. Kuiper Belt objects, in contrast, break apart far less frequently, implying a difference in structure or composition.
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