Jupiter Adds a Feature (Forwarded)

W. M. Keck Observatory
65-1120 Mamalahoa Hwy.
Kamuela, Hawai'i

July 20, 2009

Jupiter Adds a Feature

Mauna Kea, Hawai'i -- Jupiter's got a brand new mark. Something slammed into
the gas giant leaving a dark bruise in the planet's atmosphere, scientists
at Keck Observatory confirmed early on the morning of July 20 Hawaiian
Standard Time.

The observation, made with the Keck II telescope, marks only the second time
astronomers have seen such an impact on the planet. The first collision
occurred 15 years ago, when more than 20 fragments of comet Shoemaker-Levy 9
(SL9) collided with Jupiter.

The SL9 impact events were well-studied in 1994, and many theories were
subsequently developed based on the observations. "Now we have a chance to
test these ideas on a brand new impact event," said Paul Kalas, one of the
University of California Berkeley (UCB) astronomers who helped observe the
latest impact.

Kalas, along with Michael Fitzgerald of Lawrence Livermore National Lab and
UCLA, happened to have observing time on the Keck II telescope early on the
morning of Monday July 20, 2009. The two were searching for the Jupiter-like
planet, Fomalhaut b, which orbits the star Fomalhaut. The star is located
roughly 25 light years from Earth in the direction of the constellation
Piscis Austrinus.

The astronomers decided to observe Jupiter after hearing of Australian
amateur astronomer Anthony Wesley's discovery of the planet's new feature,
which they read about on the blog of UCB and SETI Institute astronomer
Franck Marchis. Together, the group of UC astronomers collaborated on how
best to make the observations of the new feature. Fitzgerald then performed
the observations with the help of Keck Observatory astronomer Al Conrad.

"The fact that [the feature] shows up so clearly means that it's associated
with high-altitude aerosols as seen in the Shoemaker-Levy impacts," noted
James Graham of UCB, who also assisted with the new observations as well as
the observations taken during the SL9 event in 1994. According to the new
data, an impact must have created Jupiter's latest feature, the team of
astronomers said.

Astronomers plan to conduct further observations using the Keck II telescope
and its laser-guide-star adaptive optics system later this week.

IMAGE CAPTIONS:

[Image 1:
http://keckobservatory.org/images/ga...ges/jup_bb.jpg (219KB)]
This infrared image taken with Keck II shows the new feature observed on
Jupiter and its relative size compared to Earth. Credit: Paul Kalas (UCB),
Michael Fitzgerald (LLNL/UCB), Franck Marchis (SETI Institute/UCB), James
Graham (UCB)

[Image 2:
http://keckobservatory.org/images/ga.../Jupiter_1.jpg
(308KB)]
This infrared image taken with Keck II shows the new feature observed on
Jupiter. Credit: Paul Kalas (UCB), Michael Fitzgerald (LLNL/UCB), Franck
Marchis (SETI Institute/UCB), James Graham (UCB)