In Kathmandu sky suddenly a big smoke appears from nowhere. It is very Mysterious and no one what cause this smoke in tuesday morning Kathmandu sky. Watch this exclusive footage from Kathmandu, Nepal. According to Super Science, Dozens of these meteorites fall to Earth each week. Most fall harmlessly onto open land or into the ocean. Nobody's ever been killed by a meteorite. But now, some scientists are asking this question: What if a really big rock — even bigger than the one that made Meteor Crater — came our way tomorrow?
They know where such a big rock could come from. For one thing, an asteroid could break up and send huge meteoroids tumbling in our direction. So could a comet (a giant space chunk of mixed-up ice, rock, and frozen gases). And it's even possible for a whole asteroid or comet to be on a collision course with Earth.
How? Like planets, asteroids and comets each follow an orbit — an oval-shaped path around the Sun. Most of these orbits never meet. But some asteroids and comets move in paths that cross Earth's orbit. If the timing were right, on of these giant space rocks could collide with Earth.
In fact, asteroids bigger than jetliners streak past Earth every few years. Most don't even come as close to Earth as the Moon does. But some get too close.
