PASADENA — An asteroid more than a mile across could strike the Earth in 2019 but further observations will likely show it will turn out to provide no more than a close shave, astronomers said Wednesday .
There is a slight chance the asteroid, dubbed 2002 NT7, could smack the Earth on Feb. 1, 2019, causing a global catastrophe, astronomers said.
However, they stress the odds of such an encounter are about 1-in-250,000 — and shrinking.
“One way or another, this thing is coming off the risk page,” said Donald Yeomans, manager of NASA’s near-Earth object program office at the Jet Propulsion Laboratory.
Astronomers with the Lincoln Near Earth Asteroid Research Project used a New Mexico telescope to discover the space rock on July 9, when it was about 84 million miles from Earth.
More than 100 follow-up observations have allowed astronomers to calculate six other potential impact dates in 2044, 2053, 2060 and 2078.
The asteroid will remain in the sights of astronomers for another year at least, allowing them to further refine their estimates of its trajectory on its 837-day orbit around the sun.
“At that point, if it’s still a threat, I’d start to get a little concerned, but not before then,” said Gareth Williams, associate director of the Minor Planet Center in Cambridge, Mass.
In other cases where potentially Earth-crossing asteroids have been discovered, it has typically taken just days or weeks to determine they pose no threat. This asteroid, however, is larger than most and has attracted more interest.
Were the paths of 2002 NT7 and the Earth to cross, the object would cause widespread devastation. It would enter the atmosphere at nearly 64,000 mph and strike with the explosive energy of 1.2 million megatons of TNT, according to JPL estimates.
“We really wouldn’t want this object to fall on us,” Williams said.
The odds of the asteroid doing so remain slim. The 2019 date ranks a one on the zero-to-10 Torino scale, meaning the chances of a collision are about the same as a random object of the same size hitting the Earth in the next few decades.
Last month, an asteroid the size of a soccer field missed the Earth by 75,000 miles — less than one-third of the distance to the moon in one of the closest known approaches by objects of its size.