A Russian astrophysicist says his team has located a huge, mountain-sized asteroid whose orbit crosses the Earth's every three years.
Even though experts say the giant object, known as 2014 UR116, poses no immediate threat of collision, its unexpected discovery underscores how little is still known about asteroids and their unpredictable orbits.
Vladimir Lipunov, a professor at Moscow State University, announced the find in a short documentary, "Asteroid Attack," posted on the website of the Russian Space Agency on Sunday. Mr. Lipunov says the asteroid, which he calculates is 370 meters in diameter, could hit the Earth with an explosion 1,000 times greater than the surprise 2013 impact of a bus-sized meteor in Russia. That object entered Earth’s atmosphere over the city of Chelyabinsk, resulting in a series of ferocious blasts that blew out windows and damaged buildings for miles around.
In the film, Lipunov says it's difficult to calculate the orbit of big objects like 2014 UR116 because, as they hurtle through the solar system, their trajectories are constantly being altered by the gravitational pull of nearby planets. "We need to permanently track this asteroid, because even a small mistake in calculations could have serious consequences," he said.