Amateur astronomers Gerrit Kernbauer and John McKeon were gazing at Jupiter on March 17 when they noticed something slam into the side of the gas giant:
"I was observing and filming Jupiter with my Skywatcher Newton 200/1000 Telescope," Kernbauer wrote as the YouTube video description. "The seeing was not the best, so I hesitated to process the videos. Nevertheless, 10 days later I looked through the videos and I found this strange light spot that appeared for less than one second on the edge of the planetary disc. Thinking back to Shoemaker-Levy 9, my only explanation for this is an asteroid or comet that enters Jupiter's high atmosphere and burned up/exploded very fast."
What the hell was it? What Kernbauer and McKeon saw is probably another comet or asteroid slamming into the planet.
Phil Plait from Slate reported that the object must have been moving incredibly fast for us to be able to see the crash from Earth:
On average (and ignoring orbital velocity), an object will hit Jupiter with roughly five times the velocity it hits Earth, so the impact energy is 25 times as high. The asteroid that burned up over Chelyabinsk, Russia, in 2013 was 19 meters across, and it exploded with the energy of 500,000 tons of TNT. Now multiply that by 25, and you can see how it doesn't take all that big a rock to hit Jupiter for us to be able to see it from Earth.
Plait said Jupiter gets hit by something big enough to see from Earth almost every year. Normally we don't have anyone filming the impact, though.
This is not the first time we've seen something crash into Jupiter. In 1994, the planet was hit with pieces from a comet called Shoemaker-Levy 9, and then again in 2010 and 2012.
You can see Kernbauer's and McKeon's videos below: