Shoemaker-Levy 9
Shoemaker-Levy 9 er navnet på en komet opdaget i 1993 af Eugene Shoemaker sammen med sin kone Carolyn Shoemaker og David Levy. På opdagelsestidspunktet var kometen blevet opdelt i 21 brudstykker.
Kometens brudstykker gav i 1994 en stor opvisning i hvilke kræfter der er i spil i Solsystemet. Ved en tidligere passage af Jupiter i 1992 havde kometen passeret så tæt på Jupiters tyngdefelt, at tidevandskræfterne havde sønderrevet kometen til mange stumper i størrelse af op til 2 km. Disse brudstykker slog ned på Jupiter mellem d. 16. og 22. juli 1994 med en hastighed af omkring 60 km/s svarende til 216.000 km/t. Nedslagene ramte den side af Jupiter, der ikke var synlig fra Jorden - men pga. Jupiters hurtige rotation kunne de tydeligt følges fra Jorden efter nogle få timer. Rumsonden Galileo var på vej til Jupiter, og havde fra en afstand af 1,6 AE direkte udsyn til nedslagene. Nedslagene kunne ses som enorme paddehatte, der efterlod store stabile mærker i Jupiters øverste atmosfære med en størrelse på op til 12.000 km. Man regner med at de tre største brudstykker hver frigjorde en energi på ikke mindre end 6.000.000 megaton TNT svarende til 120.000 x Tsar Bomba, den allerstørste brintbombe produceret.
Se også
Eksterne links
 | Wikimedia Commons har medier relateret til: |
- ^ Shoemaker-Levy 9 images University of Nevada
- Comet Shoemaker-Levy Collision with Jupiter. NASA
- Movies of Comet Shoemaker-Levy Impact on Jupiter July 16, 1994. SAAO Arkiveret 23. juli 2013 hos Wayback Machine
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A fireball appears over the limb of Jupiter after the impact of fragment A
A NASA Hubble Space Telescope (HST) image of comet Shoemaker-Levy 9, taken on May 17, 1994, with the Wide Field Planetary Camera 2 (WFPC2) in wide field mode.
When the comet was observed, its train of 21 icy fragments stretched across 1.1 million km (710 thousand miles) of space, or 3 times the distance between Earth and the Moon. This required 6 WFPC exposures spaced along the comet train to include all the nuclei. The image was taken in red light.
The comet was approximately 660 million km (410 million miles) from Earth when the picture was taken, on a mid-July collision course with the gas giant planet Jupiter.Image of Jupiter with NASA's Hubble Space Telescope's Planetary Camera. Eight impact sights are visible. From left to right are the E/F complex (barley visible on the edge of the planet), the star shaped H site, the impact sites for tiny N, Q1, small Q2, and R, and on the far right limb the D/G complex. The D/G complex also shows extended haze at the edge of the planet. The features are rapidly evolving on timescales of days. The smallest features in the this image are less than 200 kilometers across. This image is a color composite of three filters at 9530, 550, and 4100 Angstroms.
Ultraviolet image of Jupiter taken by the Wide Field Camera of the Hubble Space Telescope. 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, 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. Proceding to the right, other dark spots were caused by impacts of fragments Q1, R, D and G (now one large spot), and L, with L covering the largest area of any seen thus far. Small dark spots from B, N, and Q2 are visible with careful inspection of the image. The spots are very dark in the ultraviolet because a large quantity of dust is being deposited high in Jupiter's stratosphere, and the dust abosrbs sunlight. The dark circle on the upper half is the moon Io in front of Jupiter.