Huge asteroids and comets don’t collide with our planet very often, so scientists can’t easily observe the effects of a major impact.
But 20 years ago this month, in July of 1994, researchers got a glimpse of what can happen when a sizeable comet crashes into a planet—in this case, Jupiter. The fiery results offered clues to how devastating the ancient impact on Earth might have been.
The comet named Shoemaker-Levy 9, already shattered into many pieces, slammed into Jupiter in a series of impacts. Many of the fragments were between one and three kilometers (0.6 and 1.9 miles) across in size. The multiple impacts sent fireballs high above Jupiter’s atmosphere and left dark scars so large our own planet would have fit inside.
Learn more about planetary impacts in the Cullman Hall of the Universe.