NEAT computer tracks asteroids
- By Bob Brewin
- Jun 07, 1998
NASA astronomers soon will begin using a new computer and data analysis hardware to double their efforts to find and track asteroids that may have orbits that come close to Earth.
Scientists at NASA's Jet Propulsion Laboratory will use the new system, which features four 300 MHz Sun Microsystems Inc. processors, to double the amount of sky that a camera and telescope sweep in search of comets and asteroids. The new system is part of the Near-Earth Asteroid Tracking project and will be devoted solely to processing and analyzing the massive amount of data collected from the monthly sweeps of the sky.
Steven Pravdo, NEAT project manager at JPL, said the new system will allow scientists to perform real-time analysis of the data obtained from the fully auto-mated camera and telescope located almost 2 miles above the Pacific Ocean on Mount Hale-akala, Maui, Hawaii. Before the upgrade, it took scientists all day to process data obtained from the night before, he said.
"It's no good to have unanalyzed data because we need to clear our disks and start again," he said. The old system is "barely able to keep up."
Installed in 1995, the NEAT telescope detects asteroids and comets by observing the same part of the sky three times during an interval of about one hour and comparing the three images to determine the location of objects moving across the sky. This fully automated system has detected more than 25,000 objects, including 30 near-Earth asteroids. Recently, the NEAT team discovered two new near-Earth asteroids that are classified as potentially hazardous because the asteroids' orbits come within 3 million miles of Earth— about 20 times the distance between the Earth and the moon. Such an asteroid was the subject of the movie "Deep Impact," in which an asteroid hits Earth.
The NEAT program has been the most active asteroid-tracking effort in the world, finding 90 percent of the known asteroids, but NEAT has mapped only 10 percent of the total number of asteroids scientists believe to exist, Pravdo said.
The last large asteroid to strike the Earth—- one the size of a football field—- smashed into Siberia in 1908, leveling 800 square miles of trees with an explosive energy that was equal to 1,000 times the nuclear blast at Hiroshima, Japan.
"We expect something like that to happen every 100 years," Pravdo said. "There's no question that asteroids and comets hit the Earth. We don't know when the next catastrophic event will happen. There's always fear...that an object is headed our way, and we won't have enough time to do anything about it."
Paul Thomas, a physics and astronomy professor at the University of Wisconsin-Eau Claire, was one of three scientists to report that the Siberian blast was caused by an asteroid and not a comet. Thomas estimated that an asteroid with the magnitude of the Siberia impact will hit land every 300 years.
"At current rates of progress, it's likely that we might know all the objects that would hits us...by 2020 or so," Thomas said. "Obviously, there would be an interest in accelerating that pace. Presumably, the odds are that we'll pick up one...passing close to the Earth but not hitting it."
Lack of funding and time prevent the NEAT team from tracking more than 10 percent of asteroids, Pravdo said, because NEAT shares the telescope with the Air Force. The team scans 500 square degrees of the sky six days a month, but officials hope to increase tracking time to 18 nights each month.
The United States last year spent $1 million on tracking near-Earth asteroids; that amount was increased to $3 million this year. NEAT was able to purchase the new computer equipment with an additional $800,000 that was allocated this fiscal year, he said.