how often is the earth hit with a meteorite one mile wide or larger?
- Tom SLv 711 months ago
First, something that big would be an asteroid, or comet , and it certainly has not happened in recorded history, so exact statistics would be hard to derive.
- Anonymous11 months ago
It only happens once every few million years. However, billions of years ago, when Earth was a very young planet, impacts of this sort were far more common.
- Anonymous11 months ago
Very rarely. A meteor that big would not be called a meteorite but a meteor and it would cause a big mass extinction. The one that wiped out the dinosaurs and caused one of the 5 worst mass extinctions in history was about 6 miles wide and it hit the earth 65 (actually about 65.9 according to new radioactive dating, but some people like to round it up to 66) million years ago. The one that created the Arizona Meteor Crater was much smaller, about 30-50 meters in diameter. That is about 1/35 of a mile or half a football field wide. If a meteor that small can create such a large crater, then ones that are a mile wide would create much larger craters, and yet we don't see lots of meteor craters around the world that are much larger than the one in Arizona.
Paleontologists David M. Raup and Jack Sepkoski have suggested that there is a mass extinction about every 26 million years, but many of them are pretty minor. Even if all of these extinction events are caused by meteor impacts, that would mean that the earth is only hit by a meteor big enough to cause mass extinctions once every 26 million years or so on average and those meteors are definitely much smaller than 6 miles. The one in Arizona 50,000 year ago seem to coincide with the mass extinction of large marsupials in Australia, but that hypothesis would require more evidence. It certainly did not cause any mass extinction of large mammals in North America at that time.
Some astronomers think that Jupiter's gravity may cause a meteor in the Asteroid Belt (located between Jupiter and Mars) to be redirected towards the Sun, and occasionally one of these may hit the earth, but it is still rather rare.
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- MorningfoxLv 711 months ago
About every 1.5 million years, on average. Sometimes 15 million years, sometimes two in the same year. Most of the hits were 4 billion years ago. There was an impact nearly that big about 52 thousand years ago, in India. Then 2 thousand years later, another big one in China. A thousand years of peace, and then we got hit in Arizona by a small one (160 feet diameter). So that was three hits in three thousand years.Source(s): https://en.wikipedia.org/wiki/Meteor_Crater
- WillLv 711 months ago
Rarely. One mile is still catastrophic. However Earth is hit every day by small meteoroids ranging in size from a pebble to a softball, but these never make it to the surface. They usually burn up completely during their journey through the atmosphere.