Mar 10 2006
From The Space Library
A team of researchers reported in the journal Science that images from NASA’s ESA spacecraft revealed evidence of towering plumes of water vapor and ice particles erupting from the surface of Saturn’s moon Enceladus. ESA had conducted three flybys of the moon in 2005. According to Carolyn C. Porco, leader of the ESA Imaging Team at the Space Science Institute, Boulder, Colorado, the scientists surmised that Enceladus possessed water reservoirs under high pressure below its icy exterior. When the ice ruptured, the subsurface water shot out and froze into icy crystals. Porco stated that, if this assumption were correct, the discovery had “significantly broadened the diversity of solar system environments where we might possibly have conditions suitable for living organisms.” The Imaging Team reported that the discovery of water plumes on Enceladus was unique because the “pockets of liquid water may be no more than tens of meters below the surface,” whereas liquid-water oceans on other moons in Earth’s solar system are covered by kilometers of icy crust.
NASA, “NASA’s ESA Discovers Potential Liquid Water on Enceladus,” new release 06-088, 9 March 2006, http://www.nasa.gov/home/hqnews/2006/mar/HQ_06088_cassini_saturns_moon.html (accessed 14 September 2009).
After a seven-month, 310-mile (498.9-kilometer) journey, NASA’s Mars Reconnaissance Orbiter (MRO) completed the crucial step of entering orbit around Mars. To achieve initial capture by the planet’s gravity, the orbiter fired its main propulsion engines for 27 minutes, thereby reducing its speed by 3,540 kilometers per hour (2,200 miles per hour). This placed the US$720 million spacecraft in a highly elliptical orbit. The next phase of the orbiter’s mission would involve a seven-month “aerobraking” process. The spacecraft would dip into Mars’s atmosphere hundreds of times, using the friction of atmospheric drag to move from an approximately 35- hour orbit, extending almost 35,000 miles (56,000 kilometers) above the planet, to a 2-hour polar orbit that skims only 190 miles (300 kilometers) above Mars’s surface. A two-year phase of scientific study would follow the aerobraking phase. During those two years, the orbiter would use six instruments to study every level of Mars, from underground layers to the top of the atmosphere. The instruments would include the most powerful telescopic camera ever sent to another planet, an advanced mineral mapper to identify water-related areas, radar to probe beneath the surface for buried ice and water, and a weather camera that would monitor the planet daily. MRO Project Manager James Graf predicted, “this spacecraft will return more data than all previous Mars missions combined.”
NASA, “Mars Reconnaissance Orbiter Arrival,” press kit, March 2006, http://marsprogram.jpl.nasa.gov/mro/files/mro/mro-arrival.pdf (accessed 30 July 2010); Damian Carrington, “New Mars Probe Safely Enters Orbit,” New Scientist, 10 March 2006; Warren E. Leary, “U.S. Spacecraft Enters Orbit Around Mars,” New York Times, 11 March 2006.
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