Russia May Attack Asteroid That’s Virtually No Threat

by Tariq Malik, Managing Editor Date: 30 December 2009 Time: 01:03 PM ET

The asteroid Apophis was discovered on June 19, 2004. It will fly within 18,300 miles of Earth on April 13, 2029, but poses little risk of impact. CREDIT: UH/IA

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.

via Russia May Attack Asteroid That’s Virtually No Threat | Space.com.

North Magnetic Pole Moving Due to Core Flux

Blue lines show Earth’s northern magnetic field and the magnetic north pole in an artist’s rendering. Picture courtesy Stefan Maus, NOAA NGDC

Richard A. Lovett in San Francisco for National Geographic News

December 24, 2009

Earth’s north magnetic pole is racing toward Russia at almost 40 miles (64 kilometers) a year due to magnetic changes in the planet’s core, new research says.

The core is too deep for scientists to directly detect its magnetic field. But researchers can infer the field’s movements by tracking how Earth’s magnetic field has been changing at the surface and in space.

Now, newly analyzed data suggest that there’s a region of rapidly changing magnetism on the core’s surface, possibly being created by a mysterious "plume" of magnetism arising from deeper in the core.

And it’s this region that could be pulling the magnetic pole away from its long-time location in northern Canada, said Arnaud Chulliat, a geophysicist at the Institut de Physique du Globe de Paris in France.

Finding North

Magnetic north, which is the place where compass needles actually point, is near but not exactly in the same place as the geographic North Pole. Right now, magnetic north is close to Canada’s Ellesmere Island.

Navigators have used magnetic north for centuries to orient themselves when they’re far from recognizable landmarks.

Although global positioning systems have largely replaced such traditional techniques, many people still find compasses useful for getting around underwater and underground where GPS satellites can’t communicate.

The magnetic north pole had moved little from the time scientists first located it in 1831. Then in 1904, the pole began shifting northeastward at a steady pace of about 9 miles (15 kilometers) a year.

In 1989 it sped up again, and in 2007 scientists confirmed that the pole is now galloping toward Siberia at 34 to 37 miles (55 to 60 kilometers) a year.

A rapidly shifting magnetic pole means that magnetic-field maps need to be updated more often to allow compass users to make the crucial adjustment from magnetic north to true North.

Wandering Pole

Geologists think Earth has a magnetic field because the core is made up of a solid iron center surrounded by rapidly spinning liquid metal. This creates a “dynamo” that drives our magnetic field.

Scientists had long suspected that, since the molten core is constantly moving, changes in its magnetism might be affecting the surface location of magnetic north.

Although the new research seems to back up this idea, Chulliat is not ready to say whether magnetic north will eventually cross into Russia.

“It’s too difficult to forecast,” Chulliat said.

Also, nobody knows when another change in the core might pop up elsewhere, sending magnetic north wandering in a new direction.

Chulliat presented his work this week at a meeting of the American Geophysical Union in San Francisco.

via North Magnetic Pole Moving Due to Core Flux.