NASA predicts 2012-DA14 asteroid smaller than football field will pass close to earth
By Dr. Tony Phillips, NASA – On Feb. 15th an asteroid about half the size of a football field will fly past Earth closer than many man-made satellites, says NASA.
“Since regular sky surveys began in the 1990s, astronomers have never seen an object so big come so close to our planet.”
That’s a pretty close shave! Should be worry? Watch the video and find out.
The asteroid will only be 17,000 miles above the earth’s surface. That’s just above the International Space Station and below the geosynchronous satellites.
“This is a record-setting close approach,” says Don Yeomans of NASA’s Near Earth Object Program at JPL. “Since regular sky surveys began in the 1990s, we’ve never seen an object this big get so close to Earth.”
Earth’s neighborhood is littered with asteroids of all shapes and sizes, ranging from fragments smaller than beach balls to mountainous rocks many kilometers wide. Many of these objects hail from the asteroid belt, while others may be corpses of long-dead, burnt out comets. NASA’s Near-Earth Object Program helps find and keep track of them, especially the ones that come close to our planet.
2012 DA14 is a fairly typical near-Earth asteroid. It measures some 50 meters wide, neither very large nor very small, and is probably made of stone, as opposed to metal or ice. Yeomans estimates that an asteroid like 2012 DA14 flies past Earth, on average, every 40 years, yet actually strikes our planet only every 1200 years or so.
The impact of a 50-meter asteroid is not cataclysmic–unless you happen to be underneath it. Yeomans points out that a similar-sized object formed the mile wide Meteor Crater in Arizona when it struck about 50,000 years ago. “That asteroid was made of iron,” he says, “which made it an especially potent impactor.” Also, in 1908, something about the size of 2012 DA14 exploded in the atmosphere above Siberia, leveling hundreds of square miles of forest. Researchers are still studying the “Tunguska Event” for clues to the impacting object.
Even so, it will come interestingly close. NASA radars will be monitoring the space rock as it approaches Earth closer than many man-made satellites. Yeomans says the asteroid will thread the gap between low-Earth orbit, where the ISS and many Earth observation satellites are located, and the higher belt of geosynchronous satellites, which give weather data and telecommunications.
In this oblique view, the path of near-Earth asteroid 2012 DA14 is seen passing close to Earth on Feb. 15, 2013. (NASA)
“The odds of an impact with a satellite are extremely remote,” he says. Almost nothing orbits where DA14 will pass the Earth.
NASA’s Goldstone radar in the Mojave Desert is scheduled to ping 2012 DA14 almost every day from Feb. 16th through 20th. The echoes will not only pinpoint the orbit of the asteroid, allowing researchers to better predict future encounters, but also show physical characteristics such as size, spin, and reflectivity. A key outcome of the observing campaign will be a 3D radar map showing the space rock from all sides.
During the hours around closest approach, the asteroid will brighten until it resembles a star of 8th magnitude. Theoretically, that’s an easy target for backyard telescopes. The problem, points out Yeomans, is speed. “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.” Only the most experienced amateur astronomers are likely to succeed.
Those who do might experience a tiny chill when they look at their images. That really was a close shave.
For more information about 2012 DA and other asteroids of interest, visit NASA’s Near-Earth Object Program web site.
Story from NASA
Time to watch “Deep Impact” again, an almost great movie about asteroid impact.