A close call for Earth.
On February 15, an asteroid is expected to race past Earth, according to NASA.
The asteroid will pass at a distance of 27,000 kilometers (17,000 miles), coming closer to Earth’s surface than the satellites used to record weather data. According to NASA, an object this size has never been recorded passing so close to Earth before, making it a historic opportunity for stargazers.
If the asteroid were to collide with Earth (astronomers say there is not a chance of impact), estimates suggest it could produce the equivalent of 2.4 megatons of TNT, enough to flatten a city. But given that 70 percent of Earth’s surface is covered by water, it is highly unlikely an impact would result in too much destuction.
The good news, however, is that 2012 DA14 (as the asteroid is known) will not impact Earth, according to NASA. The space agency noted that the asteroid will zip across the night sky, leaving a small window to observe it.
“The asteroid will travel rapidly from the southern evening sky into the northern morning sky with its closest Earth approach occurring about 19:26 UTC … About 4 minutes after its Earth close approach, there is a good chance it will pass into the Earth’s shadow for about 18 minutes or so before reappearing from the eclipse,” the agency noted in a statement released on Wednesday. “When traveling rapidly into the northern morning sky, 2012 DA14 will quickly fade in brightness.”
2012 DA14, which was discovered last February, weighs approximately 130,000 metric tons and has an estimated diameter of 45 meters (148 feet), according to NASA’s Near Earth Object Program. It has an orbit similar to that of Earth. The asteroid approaches Earth about every six months, though usually at much greater distances. When it passed on February 16 of last year, it did so at a distance of 2.5 million kilometers (1.5 million miles), about six times the distance to the moon, says astronomer and science writer Phil Plait.
After its discovery early last year, a handful of news reports claimed the asteroid could very likely hit Earth at some point; Some projections note the possibility of an impact in 2020, although many astronomers say there is a small likelihood. The longer astronomers observe 2012 DA14, the more accurately they can predict its path, though there will always be uncertainties about the measurements.
Plait estimated last year that after its close pass this year, we won’t see the asteroid again until February 2020, and placed the likelihood of an impact with earth at a very low 1 in 100,000. Other experts have since ruled out even that unlikely possibility of a collision.
Astronomers say asteroids the size of 2012 DA14 pass Earth roughly every 40 years. They make impact once every 1,200 years. A comparably-sized asteroid may have exploded over Siberia in 1908, known as the Tunguska event.