Hold on to your hats: An asteroid is to zoom within spitting distance of Earth next week, in what NASA said on Thursday is the closest flyby ever predicted for an object this large.
The 2012 DA 14, discovered by chance by astronomers after passing nearby in February last year, will be just about 27,700km above Earth’s surface when it speeds by, the US space agency said.
That is outside the Earth’s atmosphere, but closer than the orbit of most weather and communications satellites.
However, despite the close shave, NASA said there was nothing to fear.
“This asteroid’s orbit is so well known that we can say with confidence that even considering it’s orbital uncertainties, it can pass no closer than 17,100 miles [27,700km] from the Earth’s surface. So no Earth impact is possible,” Donald Yeomans of NASA’s Jet Propulsion Laboratory said.
“At the same time, it will pass 5,000 miles [8,000km] inside the ring” of satellites, Yeomans said, adding that the asteroid’s path puts it right in the “sweet spot” to avoid having any damaging impact.
The asteroid is predicted to come closest to Earth on Friday next week, at about 7:24pm GMT, and will pass over the Indian Ocean off Sumatra.
It will be visible with a little help from a telescope in eastern Europe, Australia and Asia, astronomers said.
“What you would see through a small telescope would be something like a star, a small point of light ... that moved against a background of stars,” Tim Spahr of the Harvard-Smithsonian’s Minor Planet Center said.
The asteroid measures about 45m in diameter. That makes it relatively small by celestial standards.
“The object that ... took out the dinosaurs was about 10km,” Yeomans said.
If it were to hit the Earth, the impact would be roughly equivalent to a 2.4 megaton bomb — enough to flatten a large area, but not globally catastrophic, he said.
NASA estimates that a smallish asteroid like 2012 DA 14 flies close to the Earth every 40 years, on average, but only hits the Earth once every 1,200 years.
Statistically speaking, that means we are probably safe for quite a while, since a similar asteroid hit just more than 100 years ago.
“With an estimated size of the order of 50m, [2012 DA 14] is comparable in dimensions to the object that destroyed over 2,000 square kilometers of forest in Tunguska, Siberia, on 30th June 1908,” said Mark Bailey, director of the Armagh Observatory in Northern Ireland.