"It could only be an impact."
Astronomers watching Jupiter got a surprise on Monday when a large unknown object appeared to smash into the gas giant.
At the time, many amateur astronomers were watching an ongoing transit of the shadow of Io, one of Jupiter’s moons, according to SpaceWeather.com. Suddenly a "bright flash of light" appeared, German astrophotographer Harald Paleske told the site.
"It could only be an impact," he said.
Other astronomers across the world witnessed and captured images of the event as well, which was corroborated by professional astronomers as well.
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!
— ESA Operations (@esaoperations) September 14, 2021
Impact Flash on Jupiter confirmed by at least 2 amateur astronomers: H. Paleske in Germany & by J.P. Arnould in France. See attached images & for more info about past Jupiter impact events: https://t.co/VIpSt2TQfn #astronomy #jupiter #impact pic.twitter.com/0kMP7iRMao
— Ernesto Guido (@comets77) September 14, 2021
Paleske told SpaceWeather.com that the fireball was located at 106.9 degrees latitude, and +3.8 degrees longitude. His images indicate that the flash was visible for about two seconds.
The exact origin of the flash and the nature of the object that caused it is still somewhat of a mystery. However, it can be safely assumed that the fireball originated from an asteroid.
Astronomers are now on the lookout for a dark mark or other signs of disruption on the gas giant's surface — telltale signs that an asteroid did indeed collide with Jupiter.
Astronomers are no strangers to witnessing objects colliding with Jupiter in real time. In fact, NASA data analyzed in 2019 suggests that earlier in the solar system's history, Jupiter may have absorbed an entire planet.
One notable example occurred when Comet Shoemaker-Levy 9 smashed into Jupiter in July 1994, according to NASA. When that happened, it left a massive trail of debris and dark marks — and bolstered a theory that life has been able to thrive on Earth because Jupiter sucks up so many harmful asteroids that would otherwise decimate its surface.
READ MORE: Impact On Jupiter Surprises Skywatchers [EarthSky]
More on Jupiter: Watch the Rare “Triple Transit” From Jupiter’s Moons