an impact site on Jupiter, formed after an asteroid struck Jupiter's southern hemisphere. Then this year, on June 3, astronomers Anthony Wesley and Christopher Go spotted a meteor impact the planet's upper atmosphere, burning up before it could leave its own mark on the solar system's largest planet. Well, it has happened again.
On Friday, August 20 at 18:22 UTC (Saturday morning in Japan), Japanese astronomer Masayuki Tachikawa detected an optical flash, likely from a meteor striking Jupiter's upper atmosphere using a Philips Toucam Pro2 USB camera attached to his telescope. The impact is the first to be seen over Jupiter's northern hemisphere, occurring on the northern edge of the North Equatorial Belt (south is up in the image above) just to the east of the Great Red Spot's longitude. A detailed report on the discovery can be found over at the ALPO-Japan website (scroll down to the bottom for an English description of the observation). A video of the optical flash can be found on that site as well, though I found it best to save the file first before playing it. A French description (the first link I saw with this news, posted by Eric Soucy, tip o' the hat to him for this news) can be found at Ciel et Espace.
The ALPO-Japan website also has images from after the impact, taken yesterday. So far there doesn't appear to be any evidence for an impact scar, like the June 3 fireball.
Anyways, soon, observations of meteors in Jupiter's atmosphere will be just statistics used to determine the current impact flux in the Jupiter system...
UPDATE: Nick Previsich found a great English language link describing how this discovery was made from the Sky and Telescope's website.
Another Update: Two more excellent blog posts from Daniel Fischer and Emily Lakdawalla (who has a Youtube version of the optical flash video up) I would remiss to point out.
UPDATE 08/23 2:38 am: Thanks to Kelly Beatty and Emily Lakdawalla for pointing out some independent confirmation that this optical flash is in fact an impact on Jupiter.
Link: Optical flash on the surface of the Jupiter by M.Tachikaw [alpo-j.asahikawa-med.ac.jp]
Link: Another Flash on Jupiter? [www.skyandtelescope.com]
Link: Offenbar schon wieder ein Impaktblitz auf Jupiter von Amateur gefilmt [skyweek.wordpress.com]
Link: Yet another Jupiter impact!? August 20, seen from Japan [www.planetary.org]