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RE: Jupiter
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A dark spot on Jupiter's south polar region, resembling a medium-sized impact from the 1994 crash of the Comet Shoemaker-Levy onto the planet, has been seen by Anthony Wesley of Australia on 19th July 2009 at 15:54 UTC. Calar Alto is monitoring this event and has already collected optical data last night (July 20th) with the LAICA camera on the 3.5m telescope and plans to collect near infrared data tonight (July 21st) with the Omega 2000 camera on the 3.5m telescope of the newly discovered dark spot.

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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.

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Great Red Spot
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New high-resolution maps of Jupiter have provided evidence that the Great Red Spot -- the biggest storm in the Solar System -- is shrinking. 
Scientists at Berkeley have collected data over a number of years from space probes such as Galileo and Cassini and have used them to create detailed maps of wind speeds in the Great Red Spot.
From 1996 to 2006, the spot's diameter shrank at an average rate of a kilometre a day. 

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Planetary scientists detected that an anticyclone on Jupiter called the Little Red Spot produces winds up to 384 miles per hour, far exceeding the 156 mph mark that would make it a category five storm on Earth. Scientists measured wind speeds and directions by tracking the motion of cloud features from two image mosaics from a telescopic Long Range Reconnaissance Imager (LORRI), taken 30 minutes apart. They combined the LORRI maps with visible-colour images from Hubble, and mid-infrared images from the European Southern Observatory's Very Large Telescope allowing scientists to "see" thermal structure and dynamics beneath the visible cloud layers.

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Jupiter radiation belts
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It's dangerous to remain too long inside the radiation belts of Jupiter. The high-energy particles can damage space probes, and they also can destroy biological molecules or other signatures of life that might exist on inner moons like Europa. A new study plans to determine just how hazardous an impact the radiation belts have on the Jovian system.

"Our goal is to find some areas that might be interesting for a future mission to explore" - Wes Patterson of Johns Hopkins University's Applied Physics Laboratory.

Patterson and his colleagues are building a detailed map of the surface of Europa and another map of its sister moon Ganymede. The project - led by Louise Prockter of John Hopkins University as part of NASA's Exobiology and Evolutionary Biology program - will identify dead zones where radiation would likely fry any interesting chemical compounds, as well as possible safe havens that might harbour material expelled from the ocean below.
The work should provide targets for follow-up characterisation by the next mission to Europa, which will probably be an orbiter. However, Patterson says it will be hard to directly address the question of life from orbit, so he and his colleagues envision their radiation maps guiding subsequent missions that will presumably land on the surface.

Source Astrobiology Magazine

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Jupiter's rocky core bigger and icier, model predicts
Jupiter has a rocky core that is more than twice as large as previously thought, according to computer calculations by a University of California, Berkeley, geophysicist who simulated conditions inside the planet on the scale of individual hydrogen and helium atoms.
The simulation predict the properties of hydrogen-helium mixtures at the extreme pressures and temperatures that occur in Jupiter's interior, which cannot yet be studied with laboratory experiments. Applying techniques originally developed to study semiconductors, UC Berkeley's Burkhard Militzer, an assistant professor of earth and planetary science and astronomy, calculated the properties of hydrogen and helium for temperature, density and pressure at the surface all the way to the planet's center.

Coauthor William B. Hubbard, professor of planetary sciences at the University of Arizona's Lunar and Planetary Laboratory in Tucson, used the theoretical data to build a new model for Jupiter's interior. The results were published Nov. 20 in Astrophysical Journal Letters.

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Title: A shift in Jupiter's equatorial haze distribution imaged with the Multi-Conjugate Adaptive Optics Demonstrator at the VLT
Authors: Michael H. Wong (1), Franck Marchis (1 and 2), Enrico Marchetti (3), Paola Amico (3), Sebastien Tordo (3), Herve Bouy (4), Imke de Pater (1) ((1) UC Berkeley, (2) SETI Institute, (3) ESO, (4) IAC)

Jupiter was imaged during the Science Demonstration of the MCAO Demonstrator (MAD) at the European Southern Observatory's UT3 Very Large Telescope unit. Io and Europa were used as natural guide stars on either side of Jupiter, separated from each other by about 1.6 arcmin from 23:41 to 01:32 UT (2008 Aug 16/17). The corrected angular resolution was 0.090 arcsec across the entire field of view, as measured on background stars.
The observations at 2.02, 2.14, and 2.16 micrometers were sensitive to portions of the Jovian spectrum with strong methane absorption. The data probe the upper troposphere, which is populated with a fine (~0.5 micrometer) haze. Two haze sources have been proposed: lofting of fine cloud particles into the stable upper troposphere, and condensation of hydrazine produced via ammonia photochemistry. The upper tropospheric haze is enhanced over Jupiter's equatorial region.
Dramatic changes in the underlying cloud cover--part of the 2006/2007 "global upheaval"--may be associated with changes in the equatorial haze distribution now evident in the 2008 MAD images. Haze reflectivity peaked at 5 degrees N in HST/NICMOS data from 2005, but it now peaks at the equator. The observations suggest that haze variation is controlled by particle size, cloud source variation, diffusion, and horizontal transport.

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According to a popular model of planetary interactions, Jupiter plays an entirely protective role in our solar system, shielding Earth and the other inner planets from space debris.
The long-accepted model indicates that the gravity and location of the giant body in the outer solar system deflects comets and other planetesimals rubble left over from the planet-making process -- that might otherwise bombard Earth.
But a new set of more detailed simulations suggests that Jupiter can sometimes act like a sniper instead of a shield, hurling material toward Earth.

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Sharpening Up Jupiter
New image-correction technique delivers sharpest whole-planet ground-based picture ever
A record two-hour observation of Jupiter using a superior technique to remove atmospheric blur has produced the sharpest whole-planet picture ever taken from the ground. The series of 265 snapshots obtained with the Multi-Conjugate Adaptive Optics Demonstrator (MAD) prototype instrument mounted on ESO's Very Large Telescope (VLT) reveal changes in Jupiter's smog-like haze, probably in response to a planet-wide upheaval more than a year ago.

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Jupiter and Saturn full of liquid metal helium
A strange, metal brew lies buried deep within Jupiter and Saturn, according to a new study by researchers at the University of California, Berkeley, and in London.
The study, published in this week's online edition of the journal Proceedings of the National Academy of Sciences, demonstrates that metallic helium is less rare than was previously thought and is produced under the kinds of conditions present at the centers of giant, gaseous planets, mixing with metal hydrogen and forming a liquid metal alloy.

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