The asteroid came within 3.6 million miles of our planet. NBC's Brian Williams reports.
Asteroid 1998 QE2, a space rock big enough to wipe out civilization, sailed past our planet harmlessly on Friday — but not before stirring up attention at the White House and around the world.
There was never any chance that QE2 could hurt us. The closest it ever got was 3.6 million miles (5.8 million kilometers) at 4:59 p.m. ET. That's 15 times farther away than the distance between Earth and the moon. "Its next pass, on July 12, 2028, will be at a very safe 45 million miles (73 mil km)," NASA said in a Twitter tweet giving the all-clear.
Even though this particular asteroid posed no threat, the fact that it's big enough and close enough to see through backyard telescopes captured the world's interest.
QE2's diameter of 1.7 miles (2.7 kilometers) makes it nine times the length of the Queen Elizabeth 2 ocean liner (which it is not named after). That's big enough to create a civilization-ending catastrophe if it were to hit Earth.
Even its moon, discovered in radar imagery just this week, is formidable: It's 2,000 feet (600 meters) wide. In a worst-case scenario, a collision would devastate your typical statewide area and throw the world into chaos.
Gathering the geeks
The White House used Friday's flyby as a teachable moment to talk about the potential threat posed by asteroids, as well as the potential for scientific discovery and economic exploitation. White House spokesman Josh Earnest was even asked about 1998 QE2 during Friday's regular news briefing.
"Scientists have concluded that the asteroid poses no threat to planet Earth," Earnest told reporters. "I never really thought I'd be standing up here saying that — but I guess I am."
During a briefing, White House spokesman Josh Earnest was asked about a large asteroid making a close approach to Earth. He says scientists have concluded the asteroid "poses no threat to planet Earth."
Watch the "We the Geeks" Google Hangout on asteroids.
The White House's Office of Science and Technology Policy dwelled on the asteroid issue in greater depth during a "We the Geeks" webcast on Google+.
Among the geeks in attendance were NASA Deputy Administrator Lori Garver; Bill Nye the Science Guy, who's executive director of the Planetary Society; former NASA astronaut Ed Lu, who is chief executive officer of the B612 Foundation; Peter Diamandis, co-founder and co-chairman of Planetary Resources; and Jose Luis Galache, an astronomer at the International Astronomical Union's Minor Planet Center.
Garver pointed out that NASA has quintupled its budget for asteroid detection over the past few years, to an annual level of $20 million. And in the wake of February's spectacular asteroid blast over Russia, the Obama administration has proposed boosting that figure to more than $40 million.
Meanwhile, the B612 Foundation is working to get its Sentinel Space Telescope launched as early as 2017. Lu said the infrared-sensitive telescope could spot as many as 200,000 near-Earth asteroids in the first year of operation. That will make it easier to spot potentially hazardous asteroids in time to turn them aside. "We are turning science fiction into science fact," Lu said.
Diamandis stressed that there's a bright side as well as a dark side to asteroids. Planetary Resources is developing its own fleet of space telescopes to scout out asteroids with the potential of yielding trillions of dollars' worth of resources. "We're having a blast — that's not a good term — we're having fun, and hopefully becoming part of the economy between NASA, B612 and others to help humanity explore, and exploit, and protect."
Seeing it online
Slooh Space Camera shared real-time images of 1998 QE2 from a telescope in the Canary Islands, via its website as well as its iPad app. The Virtual Telescope Project 2.0, based in Italy, also offered a flyby webcast.
If you have a respectable telescope, you can see the asteroid yourself on Friday night. For viewing tips, consult David Dickinson's guide on Universe Today.
NASA's Deep Space Antenna at Goldstone, Calif., is watching the asteroid on Friday night as well. "We will manage to get a little bit better resolution," said Marina Brozovic, an astronomer at NASA's Jet Propulsion Laboratory who is leading the radar observation campaign. The Arecibo Observatory in Puerto Rico will join the campaign on June 6, when 1998 QE2 comes into its field of view.
Brozovic told NBC News that the discovery of 1998 QE2's moon was a surprise — but a welcome surprise, because close observation of the sizes and orbital movements of the two bodies will allow astronomers to calculate their masses and densities. Based on previous asteroid obervations, experts assume that "these objects are rubble piles," Brozovic said. The current radar campaign could determine that with greater certainty.
Will more revelations turn up over the next couple of weeks? Stay tuned ... and in the meantime, take a look at this hourlong program about 1998 QE2 that aired on NASA TV on Thursday:
Franklin Institute astronomer Derrick Pitts discusses the flyby of asteroid 1998 QE2.
More about asteroids:
- TODAY video: Asteroid (with moon) is flying by
- Radar reveals that 1998 QE2 has a moon
- QE2 generates wave of attention
- Cosmic Log archive on asteroids
Alan Boyle is NBCNews.com's science editor. Connect with the Cosmic Log community by "liking" the NBC News Science Facebook page, following @b0yle on Twitter and adding the Cosmic Log page to your Google+ presence. To keep up with NBCNews.com's stories about science and space, sign up for the Tech & Science newsletter, delivered to your email in-box every weekday. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for new worlds.
This story was originally published on Fri May 31, 2013 1:51 PM EDT