Nasa scientist admits 'for an asteroid of this size, it's a close shave', but closest approach will be 3.6m miles from Earth
A large asteroid accompanied by its own small moon was approaching Earth on Friday, the latest in a string of celestial visitors drawing attention to the potential dangers of objects in space.
Asteroid 1998 QE2 is about 1.7 miles in diameter. At its closest approach, which will occur at 4.59 pm ET, it will be about 3.6m miles from Earth, which is roughly 15 times farther away than Earth's moon.
"For an asteroid of this size, it's a close shave," said Paul Chodas, a scientist with Nasa's Near Earth Object program office at the Jet Propulsion Laboratory in Pasadena, California.
The White House, which on Friday hosted a Google+ hangout on Friday about asteroids, stressed that QE2 was no danger to humanity. Asked about it during a briefing, spokesman Josh Earnest said scientists had concluded the asteroid "poses no threat to planet Earth."
To laughter, he added: "I never really thought I'd be standing up here saying that."
Nasa is tracking 95% of the large asteroids with orbits that come relatively close to Earth. The agency, as well as Russia, Europe and others, plans to beef up detection efforts to find smaller objects that could still do considerable damage if they hit a populated area.
On February 15, a small asteroid blasted through the skies over Chelyabinsk, Russia, leaving more than 1,500 people injured by flying glass and debris.
That same day another asteroid, about 150ft in diameter, passed about 17,200 miles from Earth – closer than the networks of communication satellites that ring the planet.
Scientists used radar to get a preview of the QE2 asteroid on Wednesday and discovered it had a small moon in tow.
"It was quite a surprise," Marina Brozovic, a radar scientist with the Jet Propulsion Laboratory, said in a Nasa TV interview.
After its pass around the sun, QE2 will head back toward the outer asteroid belt on an orbit that extends nearly to Jupiter.
Friday's fly-by is the closest this asteroid will come to Earth for at least the next 200 years, Chodas said. Astronomers are hoping to get images and data during the flyby that will be as good as what spacecraft visiting other asteroids have returned.