Continuing it’s role as our solar system’s cosmic vacuum cleaner, the planet Jupiter swallowed up an object that was estimated to be similar in size to the meteorite that exploded over Chelyabinsk in Russia in 2013 — an incident that reportedly caused property damage and injuries to approximately 1,500 people. But, despite being 674.5 million km (419.1 million miles) away, the spectacular explosion the impact caused was recorded by modest-sized telescopes here on Earth.
The impact was recorded on March 17, at 00:18:33 UTC (5:18 PM PDT) by two telescopes: the first announcement was made by an amateur astronomer in Austria, Gerrit Kernbauer, who recorded the impact using his 20 cm (8-inch) telescope. The bright flash he recorded on Jupiter’s limb might very well have been a brief reflection within the device’s lenses, but confirmation came from another astronomer in Ireland, having recorded the same event with his 28 cm (11-inch) telescope.
Slate.com’s Phil Plait estimates that the object — no-one knows, and likely will never know, whether it was an asteroid or a comet — wasn’t terribly big, probably on the same scale as the Chelyabinsk meteorite, which was estimated to be 19 meters (62 ft) wide. However, due to Jupiter’s higher gravity, it likely impacted the upper atmosphere at five times the speed, meaning it would have released 25 times the energy of the half-megaton explosion experienced over Chelyabinsk, making for a 12.5 megaton release. To compare this with Earth-bound explosions, this is on-par with the 15 Mt detonation of the Castle Bravo nuclear test, the U.S.’s largest test detonation, or over 830 times the yield of the bomb used on Hiroshima.
Numerous impacts have been observed on Jupiter over the past few decades, with the most famous being the collision of the Shoemaker-Levy 9 comet in 1994, that left visible scars in Jupiter’s atmosphere for months after the event. Plait reminds us that Jupiter sees a major impact like this roughly once a year, although some of the strikes remain unseen, since they occur on the far side of the planet.