NASA needs more cash in order to meet its goal of finding nearby space rocks that could hit Earth in a devastating impact, a new report says.
Congress ordered NASA in 2005 to find and track 90 percent of the large asteroids near Earth by 2020, but did not set aside the necessary funds required to do the job, according to a report released Wednesday by the National Academy of Sciences.
Without that funding, NASA will not be able to build the new facilities and telescopes required to track potentially threatening asteroids down to the size of about 460 feet (140 meters) across, according to the interim report.
?I think they?re pretty much right on,? said Lindley Johnson, NASA?s manager of the Near-Earth Objects program at the agency?s headquarters in Washington.
Johnson told SPACE.com Wednesday that NASA has estimated it needs between $800 million and $1 billion over the course of 12 to 15 years to build and support the more sensitive telescopes required to meet its goal of tracking most of the near-Earth objects.
Astronomer Donald Yeomans, manager of NASA's Near-Earth Object program office at the Jet Propulsion Laboratory in Pasadena, Calif., has said that about 15 percent of the objects 460 feet wide and larger have been found, and only 5 percent of objects down to about 164 feet (50 meters) in size.
One of the top space rocks under observation is 2007 VK184, a 425-foot-wide (130 meters) asteroid that has a 1-in-2,940 chance of hitting Earth sometime between 2048 and 2057. An impact, if it occurred, would cause an explosion roughly equivalent to 150 million tons of TNT, or more than 10,000 times that of the atom bomb dropped on Hiroshima.
NASA is just about 85 percent complete with tracking asteroids about a half-mile (1 km) in size, Johnson said.
Hunting asteroids near Earth
Scientists estimate there are about 100,000 asteroids and comets near Earth, but only about 20,000 are expected to pose any risk of impact. As of Monday, NASA has found 6,330 of those objects, 1,000 of them flying in orbits that could potentially threaten the Earth in the future, Johnson said.
Aside from efforts to launch space-based missions to track incoming asteroids by Germany and Canada, the United States is carrying the bulk of the asteroid watch work, the new report stated. NASA currently has three separate search teams running five different telescopes to hunt for potentially threatening objects near Earth.
The recent impact on Jupiter last month of a previously unknown object has brought Earth?s risk of a similar hit back to the forefront. If such an impact occurred on Earth, the results would be catastrophic, scientists have said.
?It caught us a little bit by surprise,? Johnson said of the Jupiter impact, which scientists believe was caused by an asteroid or comet.
Johnson said that scientists plan to use data from NASA?s new Wide-field Infrared Survey Explorer spacecraft, which is slated to launch in late 2009 to map the night sky in more detail than ever before, to expand their search for near-Earth objects. He and his team are looking forward to the final version of the National Academy of Sciences report.
A final version of the report is slated to be completed by the end of the year.
In the meantime, NASA recently launched a new ?Asteroid Watch? Web site (http://www.jpl.nasa.gov/asteroidwatch/) to keep the public current on its work to track near-Earth objects. The Web site launched July 29 to post updates and alert the public to new research and findings via updates, Twitter and an asteroid tracking widget.
Johnson said the Web site was in development long before the Jupiter impact, which occurred just over a week earlier.
?We had actually started work to bring up that Web site a couple of months ago,? Johnson said. ?That was just another event out of the blue.?
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