Apr 16 1998
From The Space Library
James K. Yungel, a NASA scientist studying Earth remote sensing, discussed a joint project underway at Monterey Peninsula Airport, involving NASA, the U.S. Geological Survey, and the National Oceanic and Atmospheric Administration. The researchers had parked at the airport a Twin Otter airplane, with a scanning laser system and a global-positioning-satellite receiver, to make precise measurements of the West Coast, mapping the changes El Nino had caused along the coastline. The goal of the survey was to create "the most highly detailed map yet of the West Coast," increasing scientists' ability to predict erosion over the next decade.
Jeremy Lin of Taiwan's Academia Sinica Institute and colleagues at the National Radio Astronomy Observatory in Socorro, New Mexico, reported in the journal Nature that measurements taken with the world's largest radio telescopes-the Very Large Array (VLA)-had detected "peculiar bulges in the atmosphere of a giant star." Huge plumes of gas thrust from beneath the surface of the red supergiant star, Betelgeuse, had likely caused the bulges. Betelgeuse is located in the shoulder of the constellation Orion, about 430 light-years from Earth. The research team used the Y-shaped, 22-mile-wide (35-kilometer-wide) cluster of 27 huge antennas of the VLA telescopes to capture the most detailed radio image ever taken of a star other than the Sun. The team discovered that some of the gas in the star's atmosphere was much cooler than previously believed-about 5,750°F (3,200°C). The discovery of the lower temperatures enabled astronomers to understand "how huge amounts of dust are constantly blown away from the star." Before the lower temperatures were identified, scientists had not been able to explain how the stellar dust formed, because at "higher temperatures the dust could not condense from the hot gas expelled from the star's interior." Astronomers believe that dust created and expelled by stars like Betelgeuse "is distributed throughout the universe and provide[s] the raw materials that gave rise to life on Earth.
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