Flash on Jupiter – most likely a meteor

As I mentioned in this blog, yesterday two amateur astronomers reported the detection of a flash on Jupiter yesterday on September 10. Since then, various teams have been working around the clock to estimate if this event was a meteor or a large fireball. The results are coming…

Recombined image of Jupiter and the flash made by R. Hueso (University of Basque Country at Bilbao) based on the only known video recorded by George Hall (amateur astronomer located in Dallas, Texas) (Credit: R. Hueso & G. Hall)

Ricardo Hueso, a colleague from University of the Basque Country in Bilbao built a high quality image from the video recorded by George Hall. George from Dallas, Texas is the only amateur astronomer who recorded a video of the event. The final image attached above shows the atmospheric feature of Jupiter (the bands and belts). The flash location has been refined to Long= 345 deg, Lat = +2 deg in system I. The bolide fell into the Equatorial one of Jupiter (see this wikipedia page to learn about the names of the Jupiter bands and belts).

Ricardo Hueso also predicted the best time to observe the impact site from the ground  using the equatorial period of rotation of Jupiter (9h 50min 30 s). If a debris field is visible it will be at the central meridien for the following date and time:

•  11-September   08:50 UT
•  11-September   18:41
•  12-September   04:31
•  12-September   14:22
•  13-September   00:12
•  13-September   10:03
•  13-September   19:53
•  14-September   05:44
•  14-September   15:34
•  15-September   01:25
•  15-September   11:15
•  15-September   21:06
•  16-September   06:56
•  16-September   16:47
•  17-September   02:37
•  17-September   12:28
•  17-September   22:18
•  18-September   08:09
•  18-September   17:59
•  19-September   03:50
•  19-September   13:40
•  19-September   23:31

If you have access to a telescope, we strongly encourage you to observe Jupiter close to these dates and times using a methane filter at (0.89 micron) or in the near-infrared between 1.6um and 2.5 um. You may be able to detect a debris field on your observations.

Several images were taken before and after the flash by amateurs astronomers around the world. I am attaching below several observations collected by my colleague John Rogers coming from the Philippines (Tomio Akutsu), Georgia, USA (Gary Walker, Mike Hood), Pennsylvania, USA (Wayne Jaeschke) and Japan (Isao Miyazaki). The arrow indicates the located of the flash on the second and third rotations after the fireball event. There is nothing visible at the impact site on these images.

Observations of Jupiter collected before and after the event by amateur astronomers. The arrow indicates the position of the flash. No debris field can be seen (credit: J.H. Rogers, British Astronomical Association)

My colleague Mike Wong stayed awake all night to estimate the amount of energy  delivered by this fireball. He posted the result of the analysis on his blog shortly before finally going to bed (the life of a scientist…). Despite the large uncertainty on the generated light curve he predicted “that this event is too small to create a visible impact scar“. The total amount of energy that was derived for this impact is very close to the June 2010 event one which was analyzed and discussed by R. Hueso and his colleagues in arXiv:1009.1824.

At the present, since no debris field has been detected and the total energy seems to be low, 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. Even if the event may be 500 times less energetic than recent estimates of the Tunguska event, it is remarkable that an amateur astronomer equipped with a 12″ telescope and a webcam could record it at 730 million of km.

Several collisions of this size may happen on Jupiter on a yearly basis. Their observation gives us an opportunity to better estimate the meteorite flux on Jupiter which in return will provide a better age dating estimate for the surface of terrestrial planets and moons of giant planets. It may also help to better quantify the threat of impacting bodies to Earth.

Since these events last only a few seconds, a program like this one is doable only if we film almost continuously Jupiter (and Saturn) when they are visible in the sky. A well coordinated effort involving robotic small telescopes and amateur astronomers is needed, with a robust source of funding as well.

Clear skies,

Franck Marchis