Amateur astronomers are reporting a bright spot on the planet Jupiter, apparently an explosion in the planet’s upper atmosphere caused by an incoming piece of space debris that struck yesterday morning – September 10, 2012 at 6:35 a.m. CDT (11:35 UTC). Jupiter is the largest world in our solar system and a gas giant world. What we see of the planet – its red-and-white banded surface – is only the tops of the clouds in its exceedingly dense upper atmosphere. Comets and asteroids have been seen to strike Jupiter’s clouds in the past.
Yesterday’s apparent explosion occurred in the cloud tops of Jupiter’s North Equatorial Belt by American amateur astronomer Dan Petersen of Racine, Wisconsin. He was using a 12-inch telescope to observe the planet. He wrote on the Cloudy Nights forum that a “bright white two-second long explosion” happened just inside Jupiter’s eastern limb, or edge.
Another amateur astronomer, George Hall in Dallas, caught a video of the event. To see it, click here
Astronomers are waiting to see if a dark spot develops inside the southern regions of Jupiter’s North Equatorial Belt over the next day or two. As Dan Peterson said:
My best guess is that it was a small undetected comet that is now history. Hopefully, it will sign its name on Jupiter’s cloud tops.
Similar impacts were observed in June and August 2010. An analysis of those earlier events suggests that Jupiter is frequently struck by asteroids. After all, it orbits the sun just outside the asteroid belt, and its gravity is strong.
Comets are also seen to strike Jupiter. This apparent impact to Jupiter comes slightly more than 15 years after pieces of Comet Shoemaker-Levy 9 famously hit Jupiter in 1994. That was the first time astronomers had directly observed impacts between two bodies in our solar system – although such impacts were believed to be ubiquitous in the early history of the solar system and although we know they still happen fairly often today.
Since Shoemaker_Levy, amateur astronomers who watch Jupiter continuously with small telescopes have recorded a number of smaller apparent impacts.
In the coming days, astronomers across the globe will be monitoring Jupiter for signs of debris left by the September 10, 2012 impact. Some impacts do produce dark “bruises” on the planet’s clouds, but others don’t. According to the website spacweather.com:
Researchers aren’t sure why; perhaps this event will provide some clues.
Bottom line: On the morning of September 10, 2012, American amateur astronomers who were gazing at Jupiter spied a bright spot that suddenly appeared in the planet’s upper atmosphere. They believe it was a small comet or asteroid striking Jupiter. Astronomers in the coming days will be monitoring the planet for signs of “bruises” left by the impact.
Deborah Byrd created the EarthSky radio series in 1991 and founded EarthSky.org in 1994. Today, she serves as Editor-in-Chief of this website. She has won a galaxy of awards from the broadcasting and science communities, including having an asteroid named 3505 Byrd in her honor. A science communicator and educator since 1976, Byrd believes in science as a force for good in the world and a vital tool for the 21st century. "Being an EarthSky editor is like hosting a big global party for cool nature-lovers," she says.