Nearly 200 tons of dust, ice, and rock bombard our planet each day. Lucky for us, Earth’s atmosphere acts as a protective shield. The upper air vaporizes most of this space junk before it can do any harm.

But not always. In 1908, an asteroid, which is a piece of rock or metal from space, that was the size of a skyscraper entered the atmosphere over central Russia.

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Earth Versus Asteroids!By Ron Fridell

This 220-million-pound space rock was about five miles above Earth when it blew apart and vaporized.

Super hot gases from the explosion turned the air into a fireball. Shockwaves generated hurricane-force winds that toppled 80 million trees in an area the size of New York City. No people were hurt, but hundreds of reindeer were killed.

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Several times a year small chunks of space rock hit Earth. On October 7, 2008, an asteroid fell on Sudan, northern Africa. The asteroid was not big enough to be a threat to life, but its fall was a history-making event.

Scientists tracked the asteroid as it approached Earth and then watched as it exploded in the sky. This was the first time scientists had tracked an asteroid from space all the way to its landing place. An expedition trekked into Sudan’s Nubian Desert to search for the debris.

The expedition recovered 280 pieces of space rock in all. The biggest was the size of an egg. Some contained tiny diamonds.

These bits of space rock are older than anything humans have ever found. Scientists hope the rocks will help them learn more about how the planets were formed when the solar system began.

History in a Rock

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Have you looked at the Moon lately? Take a good look and notice all the craters. That is how the Earth’s surface would look if we did not have the atmosphere to protect us from flying space rocks.

The 1908 asteroid explosion blew down trees for hundreds of miles.

An artist’s drawing of an asteroid approaching Earth

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This piece of asteroid was found in Sudan.

much of the life on this planet. And that is a threat we should not ignore.

On March 2, 2009, an asteroid about the same size missed the earth by only 45,000 miles. To astronomers that is not a great distance. That’s why scientists are tracking asteroids and comets. They have identified more than 1,000 that could cause trouble in the future.

Some asteroids are miles wide. Luckily, the one in 1908 hit in a rural area. But, if one of those gets on a collision course with one of Earth’s cities, what could we do? One plan is to use a very long rope to attach a very heavy weight to the asteroid, which might throw it off course. Or we could send up a spacecraft with a missile that might send it off course.

Scientists admit these are pretty far-out ideas. No one in recorded history has been killed by an asteroid. Scientists warn that if a miles-wide asteroid were to hit the earth it could destroy

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Write About This!

The 1908 asteroid explosion in Russia was a natural disaster. Think of other kinds of natural disasters. List as many as you can. Then pick one and write a TV news story, a live report from the scene of the disaster as it happens.

Spaceship JunkyardsSpace rocks are not the only things that fall from the sky. People have sent thousands of satellites into space. Rockets headed for space drop spare parts, such as empty fuel tanks, which fall back to Earth. People living under their flight paths worry that fallen parts will crash through their roofs. Others value these rocket parts falling from the sky. They collect them, store them in junkyards, and make money selling them for scrap metal or souvenirs.

About 65 million years ago, a massive asteroid crashed near eastern Mexico. Some scientists believe this crash is what caused the dinosaurs to become extinct.

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Scientists have several plans for moving asteroids, including changing their paths.