An Ancient Universe: How Astronomers Know the Vast Scale of Cosmic Time . ... a) Changes in the Solar System - Continued . The Cratered Face of the Moon Impact craters on the Earth, Moon, and other worlds are formed by the bombardment of chunks of rock and ice from space. ... So we conclude that the solar system experienced many more impacts in the distant past than today. ... The Changing Universe - Changes in the Solar System - Changes in Stars - Changes in the Universe | ...

... 2011 November 8 . Jumping Sundogs Over Thunderclouds . ... In sum, this hypothesis holds that a lightning discharge in a thundercloud can temporarily change the electric field above the cloud where charged ice crystals were reflecting sunlight. The new electric field quickly re-orients the geometric crystals to a new orientation that reflects sunlight differently. ... Soon, the old electric field may be restored, causing the ice crystals to return to their original orientation. ...

... Saturns Moon Dione in Slight Color . ... Credit Copyright: NASA , JPL , SSI , ESA ; Post Processing: Marc Canale Explanation: Why does one half of Dione have more craters than the other? Start with the fact that Saturn 's moon Dione has one side that always faces Saturn, and one side that always faces away. ... This tidal locking means that one side of Dione always leads as the moon progresses in its orbit, while the other side always trails. ... Saturns Hyperion: A Moon with Odd Craters . ...

... Tonight's Sky . ... The Magazine . News . Observing . ... Magazine . ... Gravitational wave search provides insights into galaxy evolution and mergers . ... The double star 54 Leonis, spiral galaxy NGC 3198, and emission nebula NGC 3199 . ... Open cluster NGC 2818, spiral galaxy NGC 2964, and spiral galaxy NGC 2976 . ... Astronomy for Kids . ... November 2005 . ... Receive news, sky-event information, observing tips, and more from Astronomy's weekly email newsletter. ... Astronomy Magazine . ...

... Site . ... Main.Group . ... March 12, 2015, at 11:42 AM by ?: ... November 16, 2011, at 01:43 PM by ankur ? ... February 06, 2011, at 04:21 PM by JKhoo ? Changed to in the awk command. ... December 16, 2010, at 10:40 AM by ankur ? ... October 13, 2010, at 11:45 AM by ankur ? ... August 24, 2010, at 06:02 PM by ankur ? ... July 26, 2010, at 03:58 PM by ankur ? ... November 26, 2009, at 11:54 AM by ankur ? ... March 17, 2009, at 06:01 PM by jkhoo ? ... Pulsar Surveys . ... Pulsar Groups . ...

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... I am still trying to determine the cause of a difference between the results for the new and old code with the other kernels. ... I then returned to trying to figure out the difference between the old and new drizzlepac coordinate mapping. It turns out the old drizzlepac was using its internal mapping code, so I forced it to use the wcs mapping code instead.But that did .. ... I did some more testing and code reading in drizzlepac in search of the discrepancy between the old an new version. ...