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Jupiter: the "King" and His Moons
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Jupiter-02.jpgJupiter's Magnetic Fields53 visitenessun commento
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Jupiter-02.jpgInternal Heat Drives Jupiter's Giant Storm Eruption (IR + VL)54 visiteDetailed analysis of two continent-sized storms that erupted in Jupiter's Atmosphere in March 2007 shows that Jupiter's internal heat plays a significant role in generating atmospheric disturbances. Understanding this outbreak could be the key to unlock the mysteries buried in the deep Jovian Atmosphere, say astronomers.
Understanding these phenomena is important for Earth's meteorology where storms are present everywhere and jet streams dominate the atmospheric circulation. Jupiter is a natural laboratory where atmospheric scientists study the nature and interplay of the intense jets and severe atmospheric phenomena.
An international team coordinated by Agustin Sánchez-Lavega from the Universidad del País Vasco in Spain presents its findings about this event in the January 24 issue of the journal Nature.
The team monitored the new eruption of cloud activity and its evolution with an unprecedented resolution using NASA's HST, the NASA Infrared Telescope Facility in Hawaii, and telescopes in the Canary Islands (Spain).
A network of smaller telescopes around the world also supported these observations.
According to the analysis, the bright plumes were storm systems triggered in Jupiter's deep water clouds that moved upward in the atmosphere vigorously and injected a fresh mixture of ammonia ice and water about 20 miles (30 Km) above the visible clouds. The storms moved in the peak of a jet stream in Jupiter's Atmosphere at 375 mph (600 Km/hour). Models of the disturbance indicate that the jet stream extends deep in the buried atmosphere of Jupiter, more than 60 miles (approx. 100 Km) below the cloud tops where most sunlight is absorbed.MareKromium
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Jupiter-021307_JKdk3.jpgJupiter, from New Horizons54 visiteCaption NASA:"This image of Jupiter is produced from a 2x2 mosaic of photos taken by the New Horizons Long Range Reconnaissance Imager (LORRI), and assembled by the LORRI Team at the Johns Hopkins University Applied Physics Laboratory.
The telescopic camera snapped the images during a 3', 35" span on February 10, 2007, when the spacecraft was about 29 MKM (approx. 18 MMs) from Jupiter.
At this distance, Jupiter's diameter was 1015 LORRI pixels - nearly filling the imager's entire (1,024-by-1,024 pixel) field of view.
Features as small as 290 Km (about 180 miles) are visible.
Both the Great Red Spot and Little Red Spot are visible in the image, on the left and lower right, respectively. The apparent "storm" on the Planet's right limb is a section of the South Tropical Zone that has been detached from the Region to its West (or left) by a "disturbance" that scientists and amateur astronomers are watching closely.
At the time LORRI took these images, New Horizons was 820 million kilometers (510 million miles) from home - nearly 5½ times the distance between the Sun and Earth. This is the last full-disk image of Jupiter LORRI will produce, since Jupiter is appearing larger as New Horizons draws closer, and the imager will start to focus on specific areas of the planet for higher-resolution studies".MareKromium
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Jupiter-033007.jpgStorm Spectra54 visiteThese images, taken with the LEISA infrared camera on the New Horizons Ralph instrument, show fine details in Jupiter's turbulent atmosphere using light that can only be seen using infrared sensors. These are "false color" pictures made by assigning infrared wavelengths to the colors red, green and blue. LEISA (Linear Etalon Imaging Spectral Array) takes images across 250 IR wavelengths in the range from 1.25 to 2.5 microns, allowing scientists to obtain an infrared spectrum at every location on Jupiter. A micron is one millionth of a meter.
These pictures were taken at 05:58 UT on February 27, 2007, from a distance of 2.9 million kilometers (1.6 million miles). They are centered at 8 degrees south, 32 degrees east in Jupiter "System III" coordinates. The large oval-shaped feature is the well-known Great Red Spot. The resolution of each pixel in these images is about 175 kilometers (110 miles); Jupiter's diameter is approximately 145,000 kilometers (97,000 miles).
The image on the left is an altitude map made by assigning the color red to 1.60 microns, green to 1.89 microns and blue to 2.04 microns. Because Jupiter's atmosphere absorbs light strongly at 2.04 microns, only clouds at very high altitude will reflect light at this wavelength. Light at 1.89 microns can go deeper in the atmosphere and light at 1.6 microns can go deeper still. In this map, bluish colors indicate high clouds and reddish colors indicate lower clouds. This picture shows, for example, that the Great Red Spot extends far up into the atmosphere.
In the image at right, red equals 1.28 microns, green equals 1.30 microns and blue equals 1.36 microns, a range of wavelengths that similarly probes different altitudes in the atmosphere. This choice of wavelengths highlights Jupiter's high-altitude south polar hood of haze. The edge of Jupiter's disk at the bottom of the panel appears slightly non-circular because the left-hand portion is the true edge of the disk, while the right portion is defined by the day/night boundary (known as the terminator).
These two images illustrate only a small fraction of the information contained in a single LEISA scan, highlighting just one aspect of the power of infrared spectra for atmospheric studies.
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Jupiter-050107_11.jpgThe "Little Spot" of Jupiter54 visiteThis amazing color portrait of Jupiter’s “Little Red Spot” (LRS) combines high-resolution images from the New Horizons Long Range Reconnaissance Imager (LORRI), taken at 03:12 UT on February 27, 2007, with color images taken nearly simultaneously by the Wide Field Planetary Camera 2 (WFPC2) on the Hubble Space Telescope. The LORRI images provide details as fine as 9 miles across (15 Km), which is approx. 10 times better than Hubble can provide on its own.
The improved resolution is possible because New Horizons was only 1,9 MMs (about 3 MKM) away from Jupiter when LORRI snapped its pictures, while Hubble was more than 500 MMs (abou 800 MKM) away from the Gas Giant Planet.
The Little Red Spot is the second largest storm on Jupiter, roughly 70% the size of the Earth, and it started turning red in late-2005. The clouds in the Little Red Spot rotate counterclockwise, or in the anticyclonic direction, because it is a high-pressure region. In that sense, the Little Red Spot is the opposite of a hurricane on Earth, which is a low-pressure region – and, of course, the Little Red Spot is far larger than any hurricane on Earth.
Scientists don't know exactly how or why the Little Red Spot turned red, though they speculate that the change could stem from a surge of exotic compounds from deep within Jupiter, caused by an intensification of the storm system. In particular, sulfur-bearing cloud droplets might have been propelled about 50 kilometers into the upper level of ammonia clouds, where brighter sunlight bathing the cloud tops released the red-hued sulfur embedded in the droplets, causing the storm to turn red. A similar mechanism has been proposed for the Little Red Spot's "older brother," the Great Red Spot, a massive energetic storm system that has persisted for over a century.
New Horizons is providing an opportunity to examine an “infant” red storm system in detail, which may help scientists understand better how these giant weather patterns form and evolve.
MareKromium
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Jupiter-1994-33-a-full_jpg.jpgJupiter in natural colors, after being struck by Shoemaker-Levy 954 visiteThis image of the giant planet Jupiter, by NASA's HST, reveals the impact sites of fragments "D" and "G" from Comet Shoemaker-Levy 9.
The large feature was created by the impact of fragment "G" on July 18, 1994 at 3:28 a.m. EDT. It entered Jupiter's atmosphere from the south at a 45° angle and the resulting ejecta appears to have been thrown back along that direction. The smaller feature to the left of the fragment "G" impact site was created on July 17, 1994, at 7:45 a.m. EDT by the impact of fragment "D".
This image was taken 1h and 45' after fragment "G" impacted the Planet. The "G" impact has concentric rings around it, with a central dark spot that is about 2.500 Km in diameter. Such a dark spot is surrounded by a thin, dark, ring whose diameter is roughly 7.500 Km.
Last (but not least...), the dark, thick, outermost ring's inner edge has a diameter of approx. 12.000 Km (the size of Earth...).
The impact sites are located in Jupiter Southern Hemisphere at a latitude of about 44°.
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Jupiter-1994-35-a-web_print.jpgJupiter in ultraviolet light, after being struck by Shoemaker-Levy 953 visiteUltraviolet image of Jupiter taken by the Wide Field Camera of the HST. The image shows Jupiter's atmosphere at a wavelength of 2550 Angstroms after many impacts by fragments of comet Shoemaker-Levy 9. The most recent impactor is fragment R which is below the center of Jupiter (third dark spot from the right). This photo was taken 3:55 EDT on July 21, 1994, about 2,5 hours after R's impact. A large dark patch from the impact of fragment H is visible rising on the morning (left) side. Proceeding to the right, other dark spots were caused by impacts of fragments Ql, R, D and G (now one large spot) and L, with L covering the largest area of any seen thus far.
The spots are all very dark in ultraviolet light because - we think - a large amount of dust, right after the impacts, was being deposited on the upper layers of Jupiter stratosphere - and dust absorbs Sunlight.
The dark, round spot just above the center of Jupiter is the moon "Io".
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Jupiter-2006-19-b-full_jpg.jpgJupiter's Red Spot Jr. and the surrounding "swirls"53 visitenessun commento
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Jupiter-2006-19-d-xlarge_web.jpgFather and Son: Jupiter's Red Spots58 visitenessun commento
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Jupiter-20070323.gifWatch Jupiter and some of His Moons rotate! (GIF-Movie)53 visiteCaption NASA:"South is toward the top in this frame from a stunning movie featuring Jupiter and moons recorded last Thursday from the Central Coast of New South Wales, Australia. In fact, three Jovian Moons and two red spots are ultimately seen in the full video as they glide around the Solar System's ruling gas giant. In the early frame above, Ganymede, the largest moon in the Solar System, is off the lower right limb of the Planet, while intriguing Europa is visible against Jupiter's cloud tops, also near the lower right. Jupiter's new Red Spot junior is just above the broad white band in the Planet's Southern (upper) Hemisphere. In later frames, as Planet and moons rotate (right to left), red spot junior moves behind Jupiter's left edge while the Great Red Spot itself comes into view from the right. Also finally erupting into view at the right, is Jupiter's volcanic moon, Io (...)".
Note: click on the frame to see the movie
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Jupiter-CH-PIA02877_modest.jpgReal Colors and False Colors of Jupiter53 visiteCaption NASA originale:"These color composite frames of the mid-section of Jupiter were of narrow angle images acquired on December 31, 2000, a day after Cassini's closest approach to the planet. The smallest features in these frames are roughly ~ 60 kilometers. The left is natural color, composited to yield the color that Jupiter would have if seen by the naked eye. The right frame is composed of 3 images: two were taken through narrow band filters centered on regions of the spectrum where the gaseous methane in Jupiter's atmosphere absorbs light, and the third was taken in a red continuum region of the spectrum, where Jupiter has no absorptions".
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Jupiter-Clouds_NewHorizons_big.jpgJupiter's Clouds (from New Horizon) - HR54 visiteCaption NASA:"The New Horizons Spacecraft took some stunning images of Jupiter earlier this year while on the way out to Pluto. Famous for its Great Red Spot, Jupiter is also known for its regular, equatorial cloud bands, visible through even modest sized telescopes. The above image was taken near Jupiter's Terminator, and shows that the Jovian giant possibly has the widest diversity of cloud patterns in our Solar System. On the far left are clouds closest to Jupiter's South Pole.
Here turbulent whirlpools and swirls are seen in a dark region, dubbed a belt, that rings the Planet.
Even light colored regions, called zones, show tremendous structure, complete with complex wave patterns. The energy that drives these waves likely comes from below. New Horizons is the fastest space probe ever launched, and is zipping through the Solar System on track to reach Pluto in 2015".MareKromium
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