If you’ve been watching the news, listening to the radio, reading newspapers, checking the Internet or just talking to people, you’re probably aware that a meteorite struck Russia this morning and caused a bit of damage — from the sonic boom it created — and also excited a few people.
It’s interesting that people were prepared for a near-miss “fly-by” of another asteroid today. Just to set your mind at ease, the asteroid 2012 DA14 has already passed as close to Earth as it’s going to get and is moving away from Earth now. That asteroid was (is) a 150-foot rock. It was the closest known flyby for an asteroid of its size — it passed within 17,000 miles of Earth. That’s closer than the satellites that bring us Dish and Direct TV.
I’ve heard several terms used to describe what happened earlier today. As I understand it, asteroids — like the fly-by today are small solar system bodies that orbit the Sun. They are similar to comets but don’t have a visible coma (“tail”) like a comet has. A meteoroid is an even smaller piece of debris or a particle that goes around the Sun. A meteor is the light phenomenon we wee when a meteoroid burns up as it flies through the atmosphere (we often call these shooting stars.) A meteorite is a meteoroid that survives its fall through the atmosphere and lands on Earth.
I read that today’s meteorite probably weighed about 10 metric tons and may have been made of iron. It entered Earth’s atmosphere and broke apart somewhere between 19 and 31 miles above the ground. The energy released when it entered the atmosphere was equivalent to a few kilotons — the power of a small atomic explosion.
In order for a meteorite to reach the Earth’s surface, it has to be just the right size. Meteors that are too small will disintegrate in the atmosphere before ever reaching the surface. Meteors that are too big tend to explode before reaching the Earth’s surface.
Well anyhow, it’s been an interesting day — all this stuff falling from the sky. I would imagine the Congressional investigation should start early next week.
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