On Monday morning, amateur astronomer Dan Petersen was staring at Jupiter through his backyard telescope from Racine, Wisconsin, when he saw something incredible: A bright white flash on the planet's surface.
The unexpected explosion lasted for about two seconds and appeared to be about 100-miles wide, Petersen wrote on the community blog CloudyNights.com.
"My best guess is that it was a small undetected comet that is now history," he added.
Over in Dallas, Texas, another amateur astronomer George Hall happened to capture the flash on video, allowing for further review.
So what do the professionals think?
"Although we don't yet know the size or exact nature of the impactor, based on the flash brightness we expect it is slightly bigger and energetic than the one seen in 2010, which was estimated to be on the order of 10 meters [33 feet] in size," NASA's Amy Simon Miller told National Geographic.
The possible crash adds to the theory that Jupiter acts as an impact shield for Earth, NBC News' Alan Boyle explains:
Astronomers suspect that giant Jupiter's gravitational pull serves as a cosmic shield, sweeping up incoming objects that would have a deadlier effect if they were to slam into our planet. Some scientists say that without Jupiter, life on Earth wouldn't have had much of a chance.
The next step will be to look for black soot marks on Jupiter's cloud tops, which would appear if the planet was hit by an asteroid or meteor.
Watch the video below: