Washington: The Earth is surrounded by nearly 50 percent fewer potentially dangerous asteroids than thought previously, a new NASA study has found.
According to the US space agency, a space telescope that meticulously mapped the entire sky has found that about 19,500 medium-size, potentially dangerous asteroids are orbiting near the Earth.
The discovery significantly lowers their number by 50 percent, as their number was initially estimated at 35,000, LiveScience reported.
The study suggests that the threat to Earth by dangerous asteroids may be "somewhat less than previously thought," NASA officials said in a statement.
Still, there are thousands more of these asteroids, which can measure up to 3,300 feet wide, that remain to be found.
"Fewer does not mean none and there are still tens of thousands out there to find," said study leader Amy Mainzer, principal investigator for NASA`s NEOWISE project at the agency`s Jet Propulsion Laboratory (JPL) in Pasadena, Calif.
Additional research will also need to be conducted to determine if fewer medium-size asteroids also means fewer dangerous asteroids that could pass hazardously close to Earth, NASA officials said.
Scientists believe that asteroids measuring about 460 feet wide can cause widespread damage around their impact sites, but much larger space rocks would have to strike Earth to cause global devastation.