Points of impact: observers get a break.Points of impact: Observers get a break
When the roughly 20 fragments of Comet comet [Gr.,=longhaired], a small celestial body consisting mostly of dust and gases that moves in an elongated elliptical or nearly parabolic orbit around the sun. Comets visible from the earth can be seen for periods ranging from a few days to several months. Shoemaker-Levy 9 plunge one by one into Jupiter next July, each will hit the planet's backside BACKSIDE, estates. In England this term was formerly used in conveyances and even in pleadings, and is still, adhered to with reference to ancient descriptions in deeds, in continuing the transfer of the same. property. : None of the explosive impacts will be visible from Earth. But new calculations, based on additional observations of the train of fragments, indicate that the pieces will strike closer to the limb, or outer edge, of Jupiter than originally thought.
Each impact site will thus take less time to rotate into view, giving astronomers Famous astronomers and astrophysicists include:
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Paul Chodas and Donald K. Yeomans of NASA's Jet Propulsion Laboratory “JPL” redirects here. For other uses, see JPL (disambiguation).
Jet Propulsion Laboratory (JPL) is a NASA research center located in the cities of Pasadena and La Cañada Flintridge, near Los Angeles, California, USA. in Pasadena, Calif., had previously calculated that the collisions would all occur about 30 degrees behind the limb. At that location, it would take the points of impact roughly 75 minutes to rotate past the limb and another 16 minutes to become clearly visible from Earth. In contrast, the revised calculations show that the collisions will occur only 6 degrees behind the limb. Thus each impact site will cross the limb in just 18 minutes and come into full view 16 minutes later.
Data collected since December, when the fragments moved far enough from the sun's glare that ground-based telescopes could once again detect them, helped improve the accuracy of the calculations, Chodas says. For the Galileo spacecraft, which will be the closest craft to Jupiter in July, the revised location means the difference between just barely observing the impacts and detecting them clearly.
"lt's now clear that Galileo will have a direct view of the impact sites," says Clark R. Chapman of the Planetary Science planetary science or planetology, study of planets and planetary systems as a whole. Planetary science applies the theories and methods of traditional disciplines such as astronomy, geology, physics, chemistry, and mathematics to the study of Institute in Tucson, Ariz. He notes, however, that astronomers will have to plan observations with Galileo carefully, since its crippled crip·ple
1. A person or animal that is partially disabled or unable to use a limb or limbs: cannot race a horse that is a cripple.
2. A damaged or defective object or device.
tr.v. high-gain antenna The high-gain antenna (HGA) is an antenna with a focused, narrow radiowave beam width. This narrow beam width allows more precise targeting of the radio signal - also known as a directional antenna. will make it difficult to send images.
Though excited about the prospect of viewing the aftermath of the collisions sooner, Heidi B. Hammel of the Massachusetts Institute of Technology Massachusetts Institute of Technology, at Cambridge; coeducational; chartered 1861, opened 1865 in Boston, moved 1916. It has long been recognized as an outstanding technological institute and its Sloan School of Management has notable programs in business, notes one disadvantage of the newly calculated location. Astronomers are hoping to indirectly observe the fireballs expected to erupt seconds after each impact by recording the flashes of light reflected off the surface of three of Jupiter's moons - Io, Europa, and Callinto. In the revised location, the collisions will still be reflected, but they won't appear as bright as previous calculations had indicated, Hammel says.