July 24, 2009

Jupiter Collision Captured By Gemini Telescope

A team of astronomers using the Gemini North telescope on Mauna Kea in Hawai'i obtained a new infrared image of Jupiter on Wednesday night, July 22, showing its new scar still glowing in mid-infrared wavelengths.

The image complements earlier infrared images, including two taken July 20, shortly after the bruise was noticed, with the Keck II telescope and NASA's Infrared Telescope Facility "” both a stone's throw from the Gemini telescope on Mauna Kea.

Jupiter's new glowing bruise, some 8,000 kilometers across, is the result of the planet getting unexpectedly whacked less than a week ago by a small solar system object, perhaps a small comet or asteroid. Using the 1994 Shoemaker-Levy 9 (SL9) impacts as a guide, University of California, Berkeley, astronomer Imke de Pater and Space Science Institute astronomer Heidi B. Hammel estimate that the impacting object was probably just a few hundred meters in diameter.

Such small bodies are nearly impossible to detect near or beyond Jupiter unless they reveal cometary activity, or, as in this case, make their presence known by impacting a giant planet. The impact site is dark in visible-wavelength images.

"The structure of the impact site is eerily reminiscent of the larger Shoemaker-Levy 9 sites 15 years ago," said Hammel, who was part of the team that supported the effort at Gemini. In 1994, Hammel led the Hubble Space Telescope team that imaged Jupiter when it was pummeled by a shattered comet.

"The morphology is suggestive of an arc-like structure in the feature's debris field," she noted.

With the superb angular resolution of the Gemini observations, the data show the impact site in remarkable detail.

"We utilized the powerful mid-infrared capabilities of the Gemini telescope to record the impact's effect on Jupiter's upper atmosphere," said Pater, a UC Berkeley professor of astronomy. "At these wavelengths, we receive thermal radiation (heat) from the planet's upper atmosphere. The impact site is clearly much warmer than its surroundings, as shown by our image taken at an infrared wavelength of 18 microns."

By Robert Sanders, UC Berkeley Media Relations, and Peter Michaud, Gemini Observatory


Image Caption: This mid-infrared composite image was obtained with the Gemini North telescope on Mauna Kea, Hawai'i, on 22 July at ~13:30 UT with the MICHELLE mid-infrared spectrograph/imager. The impact site is the bright yellow spot at the center bottom of Jupiter's disk. The image was constructed from two images: one at 8.7 micron (blue) and one at 9.7 micron (yellow). The excellent quality of the Gemini images reveals that the morphology of this new impact bears a striking resemblance to that of the larger impact sites seen after the comet Shoemaker-Levy 9 crashed into Jupiter in 1994.  (Imke de Pater, UC Berkeley; Heidi B. Hammel, Space Science Institute; Travis Rector, University of Alaska Anchorage; Gemini Observatory/AURA)


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