Asteroids, Meteors & Comets, Oh My!
Asteroids & the Asteroid Belt: An asteroid is a planetesimal left over from the beginning of the solar system. The majority of asteroids are found within the asteroid belt, between Jupiter and Mars. The gravitational pull of Jupiter is so big that a planet could not form there.
Meteors, Meteoroids, Meteorites Meteoroid: A chunk of iron and rock in space that is NOT part of the asteroid belt Meteor: A chunk of iron & rock that is in Earth’s atmosphere (usually burning up) Meteorites: A chunk of iron & rock that has hit the Earth’s surface Most are smaller than a grain of corn!
Meteorite: Meteorites are bits of the solar system that have fallen to the Earth. Most come from collisions of asteroids within the asteroid belt, few come from comets, or from the other planets
Impact Craters Throughout the Solar System
Meteor Showers: Happen the same time each year when Earth’s atmosphere intersects debris left by a comet. Comet debris burns in the Earth’s atmosphere. When meteors burn up in the atmosphere, they create a trail of light.
Tanguska Event June 30, 1908, a comet exploded at Tanguska There was no crater--it exploded above ground Explosion flattened hundreds of trees
Trees have been flattened, by the explosion.
Tanguska Event Dust found in Antarctic ice, showing global spreading of the dust One degree cooling in Northern Hemisphere in years following 1908 have been attributed to impact. Shows that even small events like Tanguska can cause global temperature change--causing global cooling.
Barringer Meteorite Crater, Arizona: One-mile wide, 570 feet deep 50,000 years old Meteorite 45 meters (~135 ft) in diameter Most of the meteorite vaporized on impact Small meteorite fragments found around crater
Chicxulub Crater Located near the port city of Progreso, Mexico Scientist believe that this may be the crater that wiped out the dinosaurs Formed 65 million years ago Meteorite 10 km in diameter Dates coincide with iridium layer on Cretaceous Called an astrobleme
Chicxulub Crater