Tuesday, September 11, 2012

Another Fireball Flash on Jupiter?

On September 10, Dan Petersen of Racine, Wisconsin, reported on Cloudy Nights forum the visual detection of a flash on Jupiter at 11:35 UT (of September 10 2012):

"This morning (9/10/2012) at 11:35:30 UT, I observed a bright white two second long explosion just inside Jupiter's eastern limb, located at about Longitude 1 = 335, and Latitude = + 12 degrees north, inside the southern edge of the NEB. I used my Meade 12" LX200 GPS telescope and a binoviewer working at 400X for the observation, seeing was very good at the time."

Another amateur astronomer, George Hall of Dallas, Texas, was video-recording Jupiter at the time, and he confirmed the fireball. The video was captured with a 12" LX200GPS, 3x Televue Barlow, and Point Grey Flea 3 camera. Click on the image below for a bigger version.

                                     (Credit: George Hall)

Hall also posted online a short clip of the impact video. 

It is possible that the flash was caused by a meteor or small asteroid/comet hitting Jupiter. This is the sixth time that we have seen something slam into Jupiter, beginning with a fireball recorded by Voyager 1 as it flew past in 1979 and the famous impact of Comet Shoemaker-Levy 9 in 1994. The more recent cases are that of July 19, 2009 (discovered by Anthony Wesley), of June 03, 2010 (discovered by Anthony Wesley and Christopher Go) and of August 20, 2010 (discovered by Masayuki Tachikawa & Aoki Kazuo).

The role of planet Jupiter as a shield protecting Earth from getting hit by such objects is still controversial and it has been discussed in depth in a series of articles by Jonathan Horner and Barrie Jones (Jupiter - friend or foe?):

"It has long been assumed that the giant planet Jupiter acts as a shield, significantly lowering the impact rate on the Earth from both cometary and asteroidal bodies. Such shielding, it is claimed, enabled the development and evolution of life in a collisional environment which is not overly hostile. The reduced frequency of impacts, and of related mass extinctions, would have allowed life the time to thrive, where it would otherwise have been suppressed. However, in the past, little work has been carried out to examine the validity of this idea. Our results show that the situation is far less clear cut that has previously been assumed - for example, the presence of a giant planet can act to enhance the impact rate of asteroids on the Earth significantly."

In this blog we reported about the 2009 & 2010 impact flashes on Jupiter:




Once again amateur astronomers have shown their ability in monitoring almost permanently the planet Jupiter.

For other info about this 2012 event please see also:

http://www.skyandtelescope.com/observing/home/Another-Flash-on-Jupiter-169263686.html

http://cosmicdiary.org/fmarchis/2012/09/10/another-fireball-on-jupiter/


UPDATE - September 14, 2012

On September 11, 2012 Astronomer Mike Wong was able to analyze the video data of the flash kindly provided by George Hall. According to his analysis he made the prediction that "this event is too small to create a visible impact scar".

Several observers have imaged the planet Jupiter on the second and third rotations after the fireball and nothing new has been detected at the impact site. So the total energy seems to have been low and "we can conclude that the flash was most likely a meteor due to a small (diameter < 10m assuming a density of 2 g/cc) meteoroid".

by Ernesto Guido

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