Astronomers study 'gargantuan' Jupiter impact

An unseen comet or possibly an icy asteroid apparently crashed into Jupiter's atmosphere near the giant planet's south pole sometime during the last few days, creating a "gargantuan" blemish easily visible from Earth.

The presumed impact, discovered by Australian amateur astronomer Anthony Wesley July 19 and confirmed by NASA's Infrared Telescope Facility at Mauna Kea, Hawaii, came almost 15 years to the day after multiple fragments of Comet Shoemaker-Levy 9 crashed into Jupiter in 1994.
by William Harwood - http://news.cnet.com/8301-19514_3-10291824-239.html