by Tariq Malik, Managing Editor Date: 30 December 2009 Time: 01:03 PM ET
This story was updated at 4:55 p.m. ET.
Russia is considering a plan to launch a spacecraft capable of moving a huge asteroid in a bid to protect Earth from an impact, but the target space rock poses virtually no threat to our planet and moving it could actually make matters worse, experts say.
American astronomer Paul Chodas, part of NASA’s Near-Earth Object (NEO) Program Office, said Wednesday that claims by a top Russian space official that the asteroid Apophis would definitely crash into Earth around 2036 are inaccurate.
“That’s not right,” Chodas told SPACE.com. “The probability of an impact is going down.”
Anatoly Perminov, chief of Russia’s Federal Space Agency, said today that his agency will soon hold a special meeting to discuss a potential mission to Apophis, according to Russian wire reports. Perminov spoke on the Voice of Russia radio and said experts from the United States and other nations and space agencies would be able to join the project once the details are set.
Perminov said he had heard of Apophis’ threat to Earth from a scientist who had calculated that the asteroid was getting closer and would “surely collide with Earth in the 2030s,” according to Russia’s RIA Novosti news service.
Apophis is actually expected to fly harmlessly by Earth on April 13, 2036 and come within 18,300 miles (29,450 km) of the planet at its closest approach.
In October, Chodas and NEO office colleagues at NASA’s Jet Propulsion Laboratory in Pasadena, Calif., announced that the odds of Apophis slamming into Earth when it swings by had dropped to a low, 1-in-250,000 chance. Those odds improved on earlier studies that predicted a 1-in-45,000 chance of an impact.
The asteroid’s second near pass by Earth comes in 2068, when it has a three-in-a-million chance (or about 1-in-333,000) of endangering the planet.
Chodas told SPACE.com that Apophis will remain a top impact risk for Earth over the long term, say over the next million years. But sending a spacecraft to intentionally tweak the asteroid’s orbit in the short term, when it poses little risk, carries its own dangers.
“You have the potential of increasing the impact probability with failures in the mission,” Chodas said. “You could make matters worse.”
An exploratory mission to study Apophis, and perhaps return a sample, could be a vital resource for any future deflection efforts, he added. Knowing the composition of an asteroid would likely play a large part in deciding exactly how to attempt to deflect its course.
Perminov did not mention the recent Apophis impact risk estimates or elaborate on exactly how a Russian spacecraft may try to move the asteroid, though he did say nuclear weapons would not play a role.
“No nuclear explosions [will be carried out], everything [will be done] on the basis of the laws of physics,” RIA Novosti quoted Perminov as saying. Past studies have weighed using everything from nuclear weapons and spacecraft’s gravity to rocket engines, robotic swarms and old-fashioned paint to protect Earth from space rocks.
Don Yeomans, head of NASA’s Near-Earth Object Program Office, told SPACE.com that Russia’s interest in tackling potentially threatening asteroids in general is a good sign.
“While Apophis is almost certainly not a problem, I am encouraged that the Russian science community is willing to study the various deflection options that would be available in the event of a future Earth threatening encounter by an asteroid,” Yeoman’s said in an e-mail. “We haven’t found one yet but it does make sense to study deflection options in advance.”
Apophis has been a poster child of sorts for the risk near-Earth objects pose to life on our planet because of the back-and-forth over when it could strike.
“Its orbit nearly intersects the Earth’s orbit,” Chodas said.
At one time, early projections gave Apophis an alarming 1-in-37 chance of crashing into Earth, sparking public fears of an imminent disaster. That’s about a 2.7 percent chance of an impact somewhere on Earth. Better observations of Apophis since then have allowed astronomers to refine their projections of its trajectory and quell hysteria over its hazard to Earth.
Apophis is about 900 feet (270 meters) long and larger than two football fields overall. The asteroid is massive enough to create significant devastation to a region if it ever did strike Earth. But it is not large enough to create a global catastrophe, NASA scientists have said.
Tracking Apophis has been challenging because of its orbit, which lies within the orbit of Earth with the space rock hard to spot at times. The asteroid is expected to come back within observation range of Earth (about 9 million miles) in late 2012 and early 2013.
“The additional optical and radar data taken then will almost certainly remove any possibility of an Earth collision in April 2036,” Yeomans said. “To my mind it would make sense to wait until 2013, refine the orbit and in the very unlikely event that the impact probability increases, then begin planning possible deflection options.”
Still, Russian space officials apparently consider Apophis a significant threat to life on Earth despite the low odds of an impact.
“People’s lives are at stake. We should pay several hundred million dollars and design a system that would prevent a collision, rather than sit and wait for it to happen and kill hundreds of thousands of people,” Perminov said, according to RIA Novosti.