Something big Just hit Jupiter!


In 1994, the Comet Shoemaker-Levy 9 (SL9) impacted Jupiter, which had captured the comet shortly before (and broken apart by its gravity). The event became a media circus as it was the first direct observation of an extraterrestrial collision of Solar System objects. The impact was so powerful that it left scars that endured for months and were more discernible than Jupiter’s Great Red Spot.

Since then, astronomers have observed multiple objects impacting Jupiter, and it is expected that such impacts happen all the time (though unobserved). On September 13th, 2021, at 22:39:30 UTC (06:39:30 PM EDT; 03:39 PM:30 PDT), another impact was observed by multiple astronomers across the world. Images and a video of the impact (shown below) were captured by members of Société Lorraine d’Astronomie (SLA) in France.

The impact was reported by Brazilian amateur astronomer Jose Luis Pereira and confirmed a day later by Harald Paleske from Langendorf, Germany. At the time, Paleske had been taking a video of the transit of Io’s shadow when the event occurred, which appeared as a two-second flash. Upon reviewing the footage, he ruled out the possibility that the event happened closer to Earth (with Jupiter merely being the backdrop).

Something big Just hit Jupiter!
Still image of the impact. Credit: H. Paleske

After a thorough examination, Paleske determined that the impact happened at Jovian latitude 106.9° (CM1), longitude +3.8°, and timed it to 22:39:27 UTC on Sept. 13th. The impact was independently observed by two teams of French amateur astronomers with the SLA. According to a statement issued by the SLA, the two teams consisted of:

“Jean-Paul Arnould from his observatory in Villey-le-sec with the C11 telescope of the SLA [and] a team made up of Thibaut Humbert, Stéphane Barré, Alexis Desmougin, and Didier Walliang at the Astroqueyras observatory in Saint-Véran, with the 62 cm diameter telescope Other people around the world have observed the same phenomenon. This is the first time that so many people (currently 9) have captured this type of event.”

Thanks to the DeTeCt software/project, the amateur and professional astronomical community was issued a wide alert that allowed for rapid responses. All across the world, instruments that were aimed at Jupiter were consulted to see if they also recorded the light flash on the Jovian gas giant. The SLA also sent the data to Marc Delcroix, a Senior Research Scientist at the NTT Communication Science Laboratories‘ Media Information Laboratory in Kyoto, Japan.

Based on the images and video provided observers, the object’s diameter is estimated at 20 meters (ft). Similar to what happened with SL-9, this object is believed to be the remnant of a larger comet or asteroid that was captured by Jupiter’s gravity that broke up shortly before the impact took place. This information and any updates on the event can be found at Delcroix’s website, who indicated that this impact could be the brightest ever observed by amateur astronomers (save for the SL-9 impact).

Light on at Jupiter! Anyone home? This bright impact flash was spotted yesterday on the giant planet by astronomer José Luis Pereira.Not a lot of info on the impacting object yet but its likely to be large and/or fast!

Thanks Jupiter for taking the hit??#PlanetaryDefence pic.twitter.com/XLFzXjW4KQ