A small asteroid hit Earth and burned up over Siberia

An asteroid about 70 centimeters in diameter was spotted by astronomers hours before it burned up harmlessly but spectacularly in the atmosphere over Siberia.

The European Space Agency (ESA) issued an alert at 9:27 GMT and warned that the space rock would light up the sky around 23:15 local time (16:15 GMT) over northern Siberia.

Speaking before the event, Alan Fitzsimmons at Queen’s University Belfast in the UK says an object of this size poses no risk to those on Earth, but the early warning is a positive sign that our ability to detect these entities before they impact Earth is growing.

“It’s a small one, but it’s still going to be pretty spectacular,” says Fitzsimmons. “It will be dark over the impact site, and for hundreds of kilometers around there will be a very impressive, very bright fireball in the sky.”

Several objects of this size hit Earth every year, and we are now increasingly able to detect them early. The first was discovered in 2008. The next was six years later, but the pace of observations is increasing: C0WEPC5, as today’s asteroid has been named, is the fourth predicted strike on Earth this year.

Early warning of small asteroids allows astronomers to observe them and collect data or even try to collect small fragments that survive. Fitzsimmons says the first such predicted impact in 2008 led to the recovery of small sections of the rock and generated important science. “The beauty of it was that the reflectivity of the meteorites exactly matched the reflectivity as measured by telescopes before it hit, which shows you the really nice direct connection between what we saw out there in space and what we later found on the ground,” says he.

If we detect larger and more dangerous objects heading towards Earth, it may provide an opportunity to deflect them or at least evacuate areas at risk.

Both NASA and ESA now have dedicated programs to spot and track asteroids, which involve a large network of dedicated observatories, as well as amateur astronomers reading the positions of known objects so that their orbits can be better understood and predicted.

This latest asteroid was discovered by NASA’s Asteroid Terrestrial-impact Last Alert System (ATLAS), which has four telescopes operating around the world and is designed to provide up to a week’s warning of impact.

“It’s a win for science and (for) anyone who happens to be in Siberia this evening, something to take your mind off the admittedly pretty chilly temperatures,” says Fitzsimmons.