Tag Archives: Chelyabinsk

Origin of Chelyabinsk meteorite remains unknown

The uncertainty of science: The origin of the Chelyabinsk meteorite that crashed over that Russian city two years ago remains murky to scientists.

Originally, astronomers thought that the Chelyabinsk meteor came from a 1.24-mile-wide (2 kilometers) near-Earth asteroid called 1999 NC43. But a closer look at the asteroid’s orbit and likely mineral composition, gained from spectroscopy, suggests few similarities between it and the Russian meteor.

The scientists noted in their paper that you really can’t use the similarity of orbits to link different asteroids, as their orbits are chaotic and change too much.

According to a new study, Chelyabinsk-scale meteorite impacts happen more often than we have been aware.

According to a new study, Chelyabinsk-scale meteorite impacts happen more often than we have been aware.

The bright flare of the Russian meteor was hard to miss, and left 1,200 people injured in February 2013. What the human eye missed was two separate high-altitude explosions that occurred over Argentina and the North Atlantic Ocean just months later. That’s according to data from an infrasound network used to track nuke tests, released Tuesday by the B612 Foundation.

The data shows that there were 26 comparable events since 2000.

The accumulated evidence from the Chelyabinsk meteorite now suggests the risk of large asteroid impacts might be ten times greater than previously estimated.

The accumulated evidence from the Chelyabinsk meteorite now suggests the risk of large asteroid impacts might be ten times greater than previously estimated.

The Chelyabinsk asteroid had approached Earth from a region of the sky that is inaccessible to ground-based telescopes. In the 6 weeks before the impact, it would have been visible above the horizon only during the daytime, when the sky is too bright to see objects of its size, says Borovička.

“The residual impact risk — from asteroids with yet-unknown orbits — is shifting to small-sized objects,” says Peter Brown, a planetary scientist at the University of Western Ontario in London, Canada, and an author on the Nature papers.

Of the millions of estimated near-Earth asteroids 10–20 metres in diameter, only about 500 have been catalogued. Models suggest that an object the size of the Chelyabinsk asteroid hits Earth once every 150 years on average, Brown says. But the number of observed impacts exceeding 1 kiloton of TNT over the past 20 years alone hints at an actual impact risk that may be an order of magnitude larger than previously assumed,

The data also now suggests that the Chelyabinsk asteroid was twice as big as previously thought, and that it had an almost identical orbit to a much larger already known asteroid.

Divers have pulled fragments from the February 15 Chelyabinsk meteorite impact out of nearby Chebarkul Lake.

Divers have pulled fragments from the February 15 Chelyabinsk meteorite impact out of nearby Chebarkul Lake.

Posted from Gaitlinburg, Tennessee, the Coney Island of the Smoky Mountains. The drive today was sadly a lot longer than planned, as we hit bad traffic in Nashville.