Galileo at Jupiter: the goodbye tour. (Astronomy).Hampered by a communications antenna that never unfurled, the Galileo spacecraft became known as the plucky mission that overcame major obstacles. During more than 6 years of touring Jupiter and its four largest moons, the spacecraft managed to radio some 5 gigabytes of data to Earth, including more than 14,000 images. It has recorded towering volcanic plumes above Jupiter's moon Io, gathered evidence that Europa Europa, in astronomyEuropa (y rō`pə), in astronomy, one of the 39 known moons, or natural satellites, of Jupiter. might have an ocean beneath its icy carapace carapace (kâr`əpās), shield, or shell covering, found over all or part of the anterior dorsal portion of an animal. In lobsters, shrimps, crayfish, and crabs, the carapace is the part of the exoskeleton that covers the head and thorax and protects the dorsal and lateral surfaces., and investigated the intense radiation environment near Jupiter. Now, 13 years after its launch, the mission is winding down. During several flybys of Io, Galileo has received nearly 4 times the radiation dose it was designed to endure. On Jan. 17, a half-hour before the craft took its last swing past Io's rarely glimpsed Jupiter-facing side, radiation damage caused Galileo to temporarily shut down To quit all applications and turn off the computer.. As a result, the craft never took close-up images as it passed just 102 kilometers from the moon's surface. In addition, the spacecraft has nearly run out of the hydrazine hydrazine /hy·dra·zine/ (hi´drah-zen) a toxic, irritant, carcinogenic, gaseous diamine, H2N·NH2, or any of its substitution derivatives. fuel needed to keep its only working antenna pointed toward Earth. NASA decided last month to permanently shut down the craft's two cameras, a visible-light detector, and a near-infrared mapping spectrometer. Another light-sensing device, a combination photopolarimeter and radiometer 1. A device that measures the intensity of radiant energy, consisting of a partially evacuated glass bulb containing lightweight vertical vanes, each blackened on one side, suspended radially about a central vertical axis to permit their revolution about the axis as a result of incident radiation. 2. An instrument that detects electromagnetic radiation. 3. , has also been switched off. Those moves will save NASA some $750 thousand, but they mean that when Galileo flies within 500 km of the inner Jovian Jovian (Flavius Claudius Jovianus) (jō`vēən), c.331–364, Roman emperor (363–64). The commander of the imperial guard under Julian the Apostate in his Persian campaign, Jovian was proclaimed emperor by the soldiers when Julian was killed. He made a humiliating peace with Shapur II of Persia. moon Amalthea Amalthea (ăm'əlthē`ə), in astronomy, one of the 39 known moons, or natural satellites, of Jupiter. in November, it will be blind. Only a magnetic field sensor and a high-energy-particle detector particle detector, in physics, device for detecting, measuring, and analyzing particles and other forms of radiation entering it. Such devices play an important role not only in basic research, as in the study of elementary particles, but also in numerous applications of physics, from uses of radioactive tracers in medicine and biology to prospecting for natural ores that exhibit radioactivity. will continue to operate. Scientists also hope to generate a detailed gravity map of Amalthea by studying small changes in the speed of the craft as it passes by. The Galileo team will officially disband next January, 9 months before the craft is set to plow into Jupiter. The huge planet was chosen for Galileo's demise to ensure the craft would not crash into Europa and destroy any life that might exist below its surface. --R.C. |
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