Russian Meteorite Provides Reminder About Larger Dangers In Space

Last week's Russian meteorite impact was a reminder of how powerful stuff falling from space can be. But the hundreds of injuries and thousands of broken windows are nothing compared with what might happen if a much larger asteroid made hit Earth.

Q: When was the last event like this?

A: In 2008, astronomers spotted a meteor similar to the one in Russia heading toward Earth about 20 hours before it entered the atmosphere. It exploded over the vast African nation of Sudan, causing no known injuries.

The largest known meteor in recent times caused the "Tunguska event" - flattening thousands of square miles of forest in remote Siberia in 1908. Nobody was injured by the meteor blast, or by the Sikhote-Alin meteorite that fell in eastern Siberia in 1947.

Scientists believe that a far larger meteorite strike on what today is Mexico's Yucatan Peninsula may have been responsible for the extinction of the dinosaurs about 66 million years ago. According to that theory, the impact would have thrown up vast amounts of dust that blanketed the sky for decades and altered the climate on Earth.

Q: What can scientists learn from Friday's strike?

A: Bischoff says scientists and treasure hunters are probably already racing to find pieces of the space rock. Some meteorites can be very valuable, selling for up to $670 per gram, depending on their origin and composition. Because meteors have remained largely unchanged for billions of years - unlike rocks on Earth affected by erosion and volcanic outbreaks - scientists will study the fragments to learn more about the early universe.

Alan Harris, a senior scientist at the German Aerospace Center in Berlin, says some meteorites are also believed to carry organic material and may have influenced the development of life on Earth.

Q: What would happen if a sizable meteorite hit a city?

A: A blast at low altitude or on the surface would result in many casualties and cause serious damage to buildings. The exact extent would depend on many factors, including the mass of the meteorite, its speed and composition, said Harris.

Scientists have been discussing for several years how to prepare for such an event - however remote. European Space Agency spokesman Bernhard von Weyhe says experts from Europe, the U.S. and Russia are working on way to spot potential threats sooner and avert them. But don't expect a Hollywood-style mission to fly a nuclear bomb into space and blow up the asteroid, like the movie "Armageddon."

"It's a global challenge and we need to find a solution together," he said. "But one thing's for sure, the Bruce Willis 'Armageddon' method won't work."