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What happened when pieces of Comet Shoemaker-Levy 9 struck Jupiter?
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Comet
Comet McNaught with filamentary tail and the Moon over the Pacific Ocean, photographed from Paranal Observatory, Chile, January 2007.
Between July 16 and 22, 1994, 21 fragments of Comet Shoemaker-Levy 9 collided with Jupiter. Traveling at 221,000 km per hour, the fragments plunged into the Jovian atmosphere, creating massive, super-hot "fireballs" as they exploded.12
The impacts resulted in several notable effects:
- Dark Ejecta Clouds: As the fireballs rose, they deposited dark clouds of organic cometary dust and debris onto the planet's cloud layers. These black smudges were visible from Earth as the planet’s rotation brought the impact sites into view.12
- Immense Energy: The largest fragment, Fragment G, released energy equivalent to at least 48 billion tons of TNT, creating a multiringed black cloud larger than Earth’s diameter.1
- Chemical Changes: Spectroscopic studies showed the impacts delivered or produced chemicals such as water, hydrogen cyanide, and carbon monoxide. Some of these substances remained detectable in the upper atmosphere for years.2
This event was the first collision between two solar system bodies ever predicted and observed, providing critical data for studying Earth impact hazards.12