New NASA Images Indicate Object Hits Jupiter

IMAGE ADVISORY: 2009-112 July 20, 2009

New NASA Images Indicate Object Hits Jupiter

Scientists have found evidence that another object has bombarded Jupiter, exactly 15 years after
the first impacts by the comet Shoemaker-Levy 9.

Following up on a tip by an amateur astronomer that a new dark "scar" had suddenly appeared
on Jupiter, this morning between 3 and 9 a.m. PDT (6 a.m. and noon EDT) scientists at NASA's
Jet Propulsion Laboratory in Pasadena, Calif., using NASA's Infrared Telescope Facility at the
summit of Mauna Kea, Hawaii, gathered evidence indicating an impact.

New infrared images show the likely impact point was near the south polar region, with a visibly
dark "scar" and bright upwelling particles in the upper atmosphere detected in near-infrared
wavelengths, and a warming of the upper troposphere with possible extra emission from
ammonia gas detected at mid-infrared wavelengths.

"We were extremely lucky to be seeing Jupiter at exactly the right time, the right hour, the right
side of Jupiter to witness the event. We couldn't have planned it better," said Glenn Orton, a
scientist at JPL.

The new Jupiter images are online at: http://www.jpl.nasa.gov/news/news.cfm?release=2009-112 .

Orton and his team of astronomers kicked into gear early in the morning and haven't stopped
tracking the planet. They are downloading data now and are working to get additional observing
time on this and other telescopes.

This image was taken at 1.65 microns, a wavelength sensitive to sunlight reflected from high in
Jupiter's atmosphere, and it shows both the bright center of the scar (bottom left) and the debris
to its northwest (upper left).

"It could be the impact of a comet, but we don't know for sure yet," said Orton. "It's been a
whirlwind of a day, and this on the anniversary of the Shoemaker-Levy 9 and Apollo
anniversaries is amazing."

Shoemaker-Levy 9 was a comet that had been seen to break into many pieces before the pieces
hit Jupiter in 1994.

Leigh Fletcher, a NASA postdoctoral student at JPL who worked with Orton during these latest
observations said, "Given the rarity of these events, it's extremely exciting to be involved in
these observations. These are the most exciting observations I've seen in my five years of
observing the outer planets!"

The observations were made possible in large measure by the extraordinary efforts of the
Infrared Telescope Facility staff, including telescope operator William Golisch, who adroitly
moved three instruments in and out of the field during the short time the scar was visible on the
planet, providing the wide wavelength coverage.

JPL is managed for NASA by the California Institute of Technology in Pasadena.

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