It hit the atmosphere at an estimated 31,000 miles (50,000 kilometers) per hour, and at that high velocity—many times the speed of sound—tremendous air pressure caused the meteor to explode about 18 miles (30 kilometers) in altitude. Eyewitness videos show a dramatic light and smoke trail followed by an enormous fireball and a deafening sonic boom which in turn appears to have caused the reported damages to building and shattered glass which has injured hundreds in the city below the air blast.
Once shattered the meteor fragments continued to traverse the skies and rain down on the ground. Reports are that a 20-foot-wide (6-meter-wide) crater may have been found along with many meteorite fragments.
These pieces of the space rock will be a boon to scientists because meteors are thought to be cosmic fossils from the earliest part of the solar system’s formation. Actually getting a meteorite in hand is a big deal for researchers, as it provides clues to not only what the parent object was composed of but possibly the part of the solar system from which it originated.
Astronomers are quite sure the two events are unrelated because the Russian meteor impacted the Northern Hemisphere, while DA14 is approaching the Earth from the far Southern Hemisphere. The two objects are therefore have completely different orbits and came from completely different parts of the solar system.
A stony meteor the size that exploded over Russia has an estimated power of an atomic bomb—at least several kilotons of TNT—and occurs about once or twice a decade. We don’t usually hear about them, however, because they occur mostly over remote, unpopulated areas. (See “Russian Meteorite Spotlights History’s Other Crashes.”)
After all two-thirds of our planet is covered by water, so it’s more than likely a meteor will strike over an ocean somewhere without anyone around to report it.
Astronomers were caught by surprise by today’s fiery interloper as much as the public because there are no telescopes powerful enough to detect such small rocks in space. Luckily for life on our planet, the truly devastating large objects, like the one that killed off the dinosaurs 65 million years ago, have mostly been surveyed. And thankfully none so far have been found on a collision course—at least for the foreseeable future.
Tracking the Big Ones
“We believe we have found the vast majority of asteroids in Earth-crossing orbits that are a kilometer or bigger in diameter,” said Tim Swindle, director of the Lunar and Planetary Lab at University of Arizona at Tucson. “We are [still] aiming to find the ones larger than a couple of hundred meters, which could have very large impacts for civilization.”
Teams of asteroid hunters scattered across the globe are using telescopes to track down any potentially hazardous objects. It’s tedious and time-consuming work—much like looking for a needle in a haystack—and involves combing through images of the sky night after night. But it’s invaluable to find out if an asteroid has Earth in its crosshairs. (Related video: “Predicting Meteorite Impacts.”)
“They take a picture of an area of the sky, an hour or two apart, and then compare the images and look to see something that has moved from one image to another, because the stars remain in the same location relative to one another and an asteroid will appear to move across the sky,” Swindle said.
According to Swindle, some estimates say there may be hundreds of thousands of meteors crossing Earth’s orbit regularly like the one the caused today’s event. The problem is that we haven’t found the vast majority of them yet.
“We are the first species to be able to see these coming,” Swindle said.