Aug 30 2004
From The Space Library
Astronomers announced the discovery of three planets, comparable in size to Earth, orbiting stars outside the solar system, a finding they considered an important step in the search for life elsewhere in the universe. Although the planets have orbits too close to their stars to enable the planets to support life, all have relatively small mass, indicating that planets vary significantly in size. This discovery led the astronomers to hope that researchers might eventually discover planets as small as Earth. The three planets' masses ranged from 14 to 20 times greater than that of Earth, far smaller than planets that scientists had previously observed orbiting living stars, which have been around 50 times the mass of Earth. Three groups of astronomers had made the discoveries separately: the teams of R. Paul Butler of the Carnegie Institution, Michael Endl of the University of Texas at Austin, and Michel Mayor of the Geneva Observatory in Switzerland. (Dennis Overbye, “3 Planets Are Found Close in Size to Earth, Making Scientists Think 'Life',” New York Times, 1 September 2004; R. Paul Butler et al., “A Neptune Mass Planet Orbiting the Nearby M Dwarf GJ 436,” Astrophysical Journal 617, no. 1 (10 December 2004): 580-588; Michael Endl et al., “HD 137510: An Oasis in the Brown Dwarf Desert,” Astrophysical Journal 611, no. 2 (20 August 2004): 1121-1124.
Astronomer Fred Lawrence Whipple, a pioneering comet researcher, died at the age of 97. Whipple, born on 5 November 1906 in Red Oak, Iowa, had begun his research at Harvard University in 1931, studying meteors and Earth's atmosphere. During his career, Whipple had contributed to many significant scientific achievements, including a meteor bumper known as the Whipple shield ~ a device that protects spacecraft from meteor collisions. However, Whipple was best known for research defying conventional scientific theories about comets: whereas many scientists had suspected that comets were composed of sand and rock bound by gravity, Whipple had theorized that comets are discrete bodies with a frozen nucleus that heats up and emits propulsive jets of gas and dust. Later spacecraft missions to comets had proven his theory correct. (Adam Bernstein, “Fred L. Whipple, 97, Dies; Comet Research Pioneer,” Washington Post, 1 September 2004.
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