The unexpected
impact of some space object with Jupiter, creating a dark bruise in the gas
giant's atmosphere, proved a tempting enough target for scientists to put a
hold on testing out the revamped Hubble Space Telescope and use its new camera
to capture an image of the rare event.
The plan,
first reported by Spaceflight Now, was carried out yesterday so that
astronomers could use the 19-year-old Hubble's unique capabilities to get an
image of the spot, probably caused by a comet, before too many days had passed since the impact and
Jupiter's atmosphere distorted the shape.
The new
Hubble image, released today, shows a lumpiness to the debris plume caused by
turbulence in Jupiter's atmosphere. The image is a natural color image of Jupiter in visible light.
"It
was important for Hubble to get an early look," said Hubble spokesman Ray
Villard.
The dark
spot was first
noticed by chance by amateur astronomer Anthony Wesley in Australia on Sunday, July 19.
The bruise
is near Jupiter's southern pole and is about the size of the Pacific Ocean,
according to one astronomer's estimates.
The feature
is reminiscent of the 1994 impact of Comet Shoemaker-Levy 9.
While
astronomers don't know for sure what impacted Jupiter this time around,
"the best guess is that it's a comet," the reasoning being that
comets cross Jupiter's orbit while asteroids rarely do, Villard said.
While other
telescopes (including the Keck II
telescope and the Gemini Observatory, both in Hawaii) have trained their
eyes on the spot in recent days, it was important for Hubble to take a look
because "it's the sharpest at visible wavelengths," Villard told
SPACE.com. Hubble also has capabilities to look at ultraviolet wavelengths,
which can show details of the impact debris that has been tossed high into
Jupiter's atmosphere.
"It
really was incumbent upon us to join with the other telescopes," Villard
said.
Hubble was
in the middle of testing and calibration of its new instruments, installed by
astronauts during a service mission in May. Hubble managers decided that the
impact event was rare enough and important enough to pause testing to get a
look.
Recent glitches
have delayed the commissioning of some instruments, but the new Wide Field
Camera 3 is working fine.
"It's
not fully calibrated, but it doesn't mean we can't take pictures," Villard
said.
With the
Hubble images complementing other telescope's efforts, astronomers hope to
learn more about the dark spot and the impactor that caused it.
With the
data astronomers have from the Shoemaker-Levy 9 impact, they can guess at some
features of the likely comet. It is estimated to have been no bigger than half
a kilometer and likely had thousands of times the energy of the Tunguska impact
here on Earth, which generated a huge explosion over Siberia in 1908,
flattening an area as big as a large city.
Hubble is
slated to take more images of the new impact spot in the coming days, to help
astronomers track its progress. In between pictures, the Hubble team should be
able to resume testing and calibration of the camera.
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