January 29, 2013
Large Asteroid Will Make Earth Flyby Around Valentine’s Day
[Watch Video: Record-Setting Asteroid Flyby]
Lee Rannals for redOrbit.com — Your Universe Online
An asteroid similar in size of 2012 DA14 flies past Earth on average about once every 40 years, and one actually strikes Earth every 1,200 years or so, Yeomans said.
An impact of a 164-foot asteroid is not cataclysmic, and a similar-sized object formed the mile wide Meteor Crater in Arizona about 500,000 years ago.
"That asteroid was made of iron," Yeoman said, "which made it an especially potent impactor."
In 1908, another similar-in-size asteroid exploded in the atmosphere above Siberia, and leveled hundreds of square miles of forest. NASA said researchers are still studying this event for clues to the impacting object.
"2012 DA14 will definitely not hit Earth," Yeomans assured. "The orbit of the asteroid is known well enough to rule out an impact."
NASA radars will be monitoring the space rock as it approaches Earth closer than many man-made satellites. Yeomans said the asteroid will thread the gap between low-Earth orbit, where the International Space Station is, and the higher belt of geosynchronous satellites.
"The odds of an impact with a satellite are extremely remote," Yeomans said, because almost nothing orbits where DA14 will pass the Earth.
The U.S. space agency said that its Goldstone radar in the Mojave Desert is scheduled to ping 2012 DA14 nearly every day from February 16th through the 20th. This will help NASA pinpoint the orbit of the asteroid, and allow researchers to better predict future encounters.
As the asteroid makes its closest approach, DA14 will brighten until it resembles a star of 8th magnitude. Although the brightness will be easily picked up by backyard astronomers, its speed will make it hard to track.
“The asteroid will be racing across the sky, moving almost a full degree (or twice the width of a full Moon) every minute. That´s going to be hard to track," Yeomans noted.