Astronomers say that 2017 AG13, a 111-foot asteroid that flew by Earth at a close-shave distance of about 120,000 miles on Monday morning (January 9), was spotted for the first time only about two day before it passed. The latest incident has raised concern once again about our unpreparedness to ward off a potentially devastating asteroid impact which experts say is only a matter of time.
Astronomers at the University of Arizona's Catalina Sky Survey spotted asteroid 2017 AG13 on Saturday, two days before it zipped past Earth at about 7:47 a.m. EST (1247 GMT) on Monday, January 9. It passed at a dangerously close distance of 120,000 miles, about half of the distance of the Moon to Earth, according to Slooh.
The average distance of the Moon to Earth is about 239,000 miles (385, 000 kilometers).The asteroid, estimated at about 50 and 111 feet (15 to 34 meters) across -- about the size of a "10-story building" -- was traveling at a speed of about 9.9 miles per second (16 kilometers per second) when it was detected.
"This is moving very quickly, very nearby to us," said Slooh's Eric Feldman during a live broadcast of the event (see YouTube videos below). "It actually crosses the orbits of two planets, Venus and Earth."Astronomers at the Minor Planet Center in Cambridge, Massachusetts, said that 2017 AG13 was in the size range of the meteor that exploded over Russia's Chelyabinsk Oblast in February 2013, injuring more than 1,500 people, according to Space.com.
The Chelyabinsk meteor was estimated at about 65 feet (20 meters) across.Using an asteroid impact simulator called "Impact Earth!" experts at Purdue University said that an impact at a 45 degree-angle by a space rock in the size range of 2017 AG13 would cause a powerful air burst releasing energy equivalent to about 700 kilotons.
For perspective, the Hiroshima bomb exploded with energy of about 15 kilotons, while the Chelyabinsk meteor exploded with energy of about 500 kilotons.
But due to the fact that the meteor air burst will occur at an altitude of about 10 miles, the power of the explosion will not have full impact on the ground. But if the air burst occurs over a major population center it could cause damage similar to the Chelyabinsk meteor, according to Slooh.
The Chelyabinsk meteor entered the Earth's atmosphere over the southern Ural region at 3:20 UTC on February 15, 2013, at 3:20 UTC. It manifested as a brilliant superbolide brighter than the Sun over several kilometers and exploded with energy of about 500 kilotons, causing panic in multiple urban communities.
About 1,500 people sought medical treatment due to injury caused mostly by flying glass after the superbolide explosion. About 7,200 buildings were damaged in six cities across the region.
Asteroid 2017 AG13 is expected to pass close to Earth once again on December 28, 2017. NASA's Near Earth Object (NEO) Program estimates that about 38 similar close approaches will occur in the month of January.
"It is not that uncommon of an event, which is one of the reasons it is interesting," Business Insider reports that Mark Sykes, director and CEO of the Planetary Science Institute, said.The latest incident has focused attention once again on the danger posed to Earth by Near Earth space objects (asteroids and comets) whose orbits bring then close to Earth's. According to astronomers, an asteroid much larger than 2017 AG13 could enter the Earth's atmosphere over a major urban area unexpectedly and wreak havoc. Even if we detect the approach of such an asteroid months before it impacts we would be unable to do anything to stop it, experts say.
The recently released "National Near-Earth Object Preparedness Strategy" highlighted our unpreparedness to defend Earth against a threatening asteroid despite recent efforts by scientists and advocacy groups to galvanize governments into action.
The White House document admitted that the world was unprepared to face an asteroid threat but said that efforts were ongoing to improve preparedness.Scientists have proposed that NASA launch a special asteroid-hunting space telescope called the Near-Earth Objects Camera (NEOCam). According to Sykes, NEOcam will detect small asteroids slightly larger -- about 460 feet (140 meters) -- than asteroids in the 2017 AG13 size range before they hit Earth. Such asteroids are capable of inflicting serious local damage if they enter the Earth's atmosphere over major population centers.
At the moment we know so little about smaller asteroids that could inflict serious local or regional damage that some experts compare the situation to a deadly game of Russian roulette.
Despite the risk, the authorities refused last week to approve the proposed $450 million funding of NEOcam, according to Business Insider. NASA authorities chose instead to fund programs Lucy and Psyche. Lucy will explore asteroids in Jupiter's orbit while Psyche will explore the metallic core of a long-dead protoplanet.But NASA authorities said they would consider funding NEOCam in the future. But some speculate that NASA's apparent reluctance to invest in NEOCam could be due to an assessment that the probability that a small object capable of causing serious local damage could hit the U.S. is extremely low. NASA authorities are apparently not convinced of the need to invest to develop space technology to deflect an asteroid that would more likely hit another country than the U.S. Meanwhile, astronomers continue to warn about the danger of delaying a coordinated response to the asteroid threat.
Last December, Dr. Joseph Nuth, at NASA's Goddard Space Flight Center in Maryland, warned at the annual meeting of the American Geophysical Union that we are unprepared for an asteroid strike.
Impacts by large asteroids capable of causing Earth-wide devastation are relatively rare. Scientists estimate that they occur once in about 50 to 60 million years.
"They are the extinction-level events, things like dinosaur killers, they're 50 to 60 million years apart, essentially," Nuth said, according to the Daily Mail.
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