Giant Meteor Caused Jupiter Fireball

Astronomers around the world determined that an object must have whacked the gas giant in order to unleash a flash of energy that was bright enough to be seen 400 million miles (643.7 million km) away. But, with no visible scar or debris cloud from the impact, there was no telling how deep the object penetrated into the atmosphere.

The Hubble Space Telescope's sharp vision and ultraviolet sensitivity was called into action to seek out any traces of the aftermath of the cosmic collision.

Images taken on June 7 – a little over three days after the flash was discovered – showed no sign of debris above Jupiter's cloud tops. That suggests the object did not descend beneath the clouds and explode as a fireball, astronomers said.

"If it did, dark sooty blast debris would have been ejected and would have rained down onto the cloud tops, and the impact site would have appeared dark in the ultraviolet and visible images due to debris from an explosion," Hammel explained. "We see no feature that has those distinguishing characteristics in the known vicinity of the impact, suggesting there was no major explosion and fireball." Jupiter impacts of times past

Dark smudges marred Jupiter's atmosphere after pieces of the comet Shoemaker-Levy 9 slammed into the planet in 1994. A similar phenomenon occurred more recently in July 2009, when a suspected asteroid estimated to be about 1,600 feet (500 meters) wide collided with Jupiter.

This latest cosmic interloper is estimated to be only a fraction of the size of these previous impactors.

The two-second-long flash of light in the videos was created by the same physics that causes a meteor or "shooting star" on Earth. A shock wave is generated by ram pressure as the meteor speeds into the planet's atmosphere, heating the impacting body to a very high temperature.

As the hot object streaks through the atmosphere, it leaves behind a glowing trail of superheated atmospheric gases and vaporized meteor material that then rapidly cools and fades in the span of only a few seconds.

Though astronomers are still uncertain about the rate of such large meteoroid impacts on the planets in our solar system, it is estimated that the smallest detectable events may happen as frequently as every few weeks.

"It's difficult to even know what the current impact rates are throughout the solar system," said Amy Simon-Miller of NASA's Goddard Space Flight Center in Greenbelt, Md., the principal investigator on the Jupiter observation. "That's partly why we are so excited by the latest impact. It illustrates a new capability that can be exploited with increased monitoring of Jupiter and the other planets."