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New measurements of Neptune's atmosphere by a European space telescope suggest that a comet may have crashed into the gas giant about 200 years ago.Scientists analyzed the composition of Neptune's atmosphere using data from the Herschel space observatory. They found a peculiar distribution of carbon monoxide in the gas giant's atmosphere, which could be an indication of an earlier comet impact...Other similar collisions between comets (or asteroids) and planets helped the astronomers detect the telltale signs of cometary impacts.When pieces of the comet Shoemaker-Levy 9 slammed into Jupiter in 1994, scientists were able to examine the trajectory and debris to...

Heavenly bodies stir up routine catastrophes March 18 2003 at 01:30PM By Graeme Addison Legend has it that when two people get together and er... bond, the Earth will move – at least in a metaphorical sense. Likewise, it takes two heavenly bodies, an impactor and a target, to come together with Earth-shattering force to form a crater. There’s nothing dreamlike about this: it happens, frequently, throughout the solar system. Impact catastrophes are routine. Just over two-billion years ago, a chunk of asteroid at least the size of Table Mountain struck the landmass that is now South Africa. It hurtled...

Jupiter already has an abundance of moons, but from 1949 to 1961 it had another, temporary satellite in the form of a comet trapped in the gas giant's gravitational grip. Comet 147P/Kushida-Muramatsu was captured as a temporary moon of Jupiter in the mid-20th century and remained trapped in an irregular orbit for about twelve years, astronomers announced today. There are only a handful of known comets where this phenomenon of temporary satellite capture has occurred and the capture duration in the case of Kushida-Muramatsu is the third longest... The team used recent observations tracking the comet over nine years to...

Astronomy Picture of the Day Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. 2002 May 25 A String Of Pearls Credit: H. Weaver (JHU), T. Smith (STScI), NASA Explanation: Comet Shoemaker-Levy 9, named after its co-discoverers, was often referred to as the "string of pearls" comet. It is famous for its suggestive appearance as well as its collision with the planet Jupiter! The comet's original single nucleus was torn to pieces by Jupiter's strong gravity during a close encounter with the...