Diagram courtesy NASA, ESA, M. H. Wong, H. B. Hammel, I. de Pater, and the Jupiter Impact Team
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Hubble pictures show an impact scar on Jupiter last July (left) and a series of images as the scar fades.

Diagram courtesy NASA, ESA, M. H. Wong, H. B. Hammel, I. de Pater, and the Jupiter Impact Team

Bright Fireball Slams Into Jupiter

Flash from new impact caught on film.

Hot on the heels of last year's asteroid impact on Jupiter, the gas giant planet has been smacked once again.

In 2009 backyard astronomers saw a dark blemish on Jupiter that marked the spot where a space rock had slammed into the Jovian atmosphere.

This time, Anthony Wesley in Australia and Christopher Go in the Philippines both saw the actual moment of impact.

Photos and video show the bright flash as an Earth-size fireball rises above Jupiter's atmosphere on June 3 at 4:31 p.m. ET.

"The data—independently confirmed by two well-respected amateurs—seem robust, and the flare certainly bears all the characteristics of a Jovian 'bolide,' or impact," said Heidi Hammel of the Space Science Institute in Boulder, Colorado.

Race to See Jupiter's New Impact Scar

The recent impact happened the same day Hammel and her team released new photos and analysis of the 2009 Jupiter collision. According to the study, the previous impact was caused by a 1,640-foot-wide (500-meter-wide) asteroid.

Scientists are now racing to get professional and amateur astronomers to train their telescopes on the gas giant to see what kind of scar will be left behind by this latest impact and hopefully what kind of object hit the giant planet.

Experts believe the collision should produce a dark debris field in Jupiter's clouds—similar to the previous impact site—which may become visible over the next few days. (Related: "Jupiter Loses Big Belt; Great Spot Left Hanging.")

"We don't know if there is a dark site yet, since this appears be a small impact," Hammel said. "We are working on getting telescopes around the world in gear for followup work, including the world's largest telescopes and" the Hubble Space Telescope.

Second Jupiter Impact "Unbelievable"

Meanwhile, the odd coincidence of two Jovian smashes so close together has astronomers scratching their heads, since impacts on Jupiter have long been thought to be relatively rare.

Until the 2009 collision, the last known impact event on Jupiter was the famous "death" of Comet Shoemaker-Levy 9 in 1994.

"'Unbelievable' has been the word in many of the first emails about this one just seen," Hammel said. "It's back to the drawing board on our understanding of the statistics of impacting bodies."