• Question: If a comet falls to eath, will parts of it be broken off by our atmosphere ?

    Asked by nav1 to Indi, Jarv, John, Ken, Vicky on 15 Mar 2012.
    • Photo: Vicky Young

      Vicky Young answered on 15 Mar 2012:

      It depends on the size of the comet, the angle which is is falling to earth and the speed it is traveling at. Sometimes they can burn up on entry to our atmosphere, sometimes they can break into pieces and other times large comets can fall onto the earth.

    • Photo: John Prytherch

      John Prytherch answered on 15 Mar 2012:

      Comets are mostly made up of ice and dust, so if they hit our atmosphere, they would likely disintergrate. This is because, realtive to the Earth, they would be travelling at thousands of miles per hour. At this speed, the friction from the comet hitting the air particles will generate lots of heat, which will likely destroy the comet while still high in the atmosphere.

      Asteroids are similar to comets, but are made up of rock rather than ice. Asteroids hit our atmosphere all the time. The small ones are burnt up high in the atmosphere for the same reason as comets. Bigger ones though can and do reach the Earth. Museums often have pieces of asteroid on display. Maybe we should all be wearing hard hats outside?

    • Photo: Jarvist Moore Frost

      Jarvist Moore Frost answered on 15 Mar 2012:

      Definitely!
      The outer layers of meteorites burning off like a heatshield are what makes ‘shooting stars’. Our atmosphere is thick enough and the modern solar system is quiet enough that very few rocks are big enough and tough enough to reach the surface of the earth and still cause much damage. Just over a hundred years ago, a meteorite penetrated the atmosphere and exploded over Siberia with the force of a large nuclear bomb (it was called the Tunguska event if you want to read more about it).

      Our moon also really helps keep the Earth’s surface a safe place to live – acting like a giant gravitational vacuum cleaner to pick up rocks that would otherwise hit us. You can see the scars and impact craters covering the moon from the last few billion years of protecting us, as there’s no weather on the moon to wash them away.

      Two days ago a fist-sized meteorite was found to have crashed through a someone’s house in Oslo, Norway. Bits of meteorites land somewhere on the earth every day!

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