Parts Explained• Nucleus – mass of ice and frozen gas• Coma – cloud of gas that surrounds thenucleus• Tail – formed when the comet travels nearthe sun; it’s the nucleus vaporizing
Comet Orbits• Comets have long, narrow elliptical orbits• Short period comets are found in the KuiperBelt• Long period comets are found in the OortCloud• Sometimes, comets get too close to the sun,and then…
Asteroids• Description: Rocky remains from theformation of the solar system• Notable Asteroids:– Ceres – now a dwarf planet, only one in theasteroid belt– Vesta – can be seen without a telescope
Asteroids• Composition:– Rocky, iron, or rocky-iron• Location/Orbit:– Asteroid Belt – between Mars and Jupiter– Trojans – orbit with a planet– Near Earth Asteroids – cross the Earth’s orbit
Asteroid BeltThe regionbetween the orbitsof Mars andJupiter, wheremany asteroids arefound.
Asteroids• Size: Varies from a few hundred feet to afew hundred miles• Jupiter’s relationship with asteroids:– Scientists believe the asteroid belt is theremains of a planet that never formed becauseof Jupiter’s gravity• Evidence asteroids have hit planets:– Impact craters like the one thought to havecaused the dinosaur extinction
Asteroids Summary• Not all asteroids are located in the asteroidsbelt and can pass near Earth• Jupiter’s gravity kept the asteroids fromforming a planet• Some asteroids orbit just before and afterJupiter• Largest asteroid, Ceres, is 580 mi across butmost are less than a few miles across
Asteroid Impacts Summary• Scientists think an asteroid impact nearMexico caused the dinosaur extinction.• Chicxulub Crater in Mexico• Video
http://www.mnh.si.edu/Asteroid Impact crater in Canada
Meteors• Description: Rocky or metal debris inspace; most no bigger than a pebble• Meteoroid: a small chunk of rock or dust inspace• Meteor: a streak of light in the skyproduced by the burning of a meteoroid inEarth’s atmosphere• Meteorite: a meteoroid that has hit Earth’ssurface
Meteoroids• Meteoroids are small chunks of rock anddust left over from asteroids and cometsthat pass by the Earth.• Composition: rocky, iron, or mixed• Location/orbit: Found within the path of theEarth’s orbit around the sun.
Meteors• 3 types:• Meteor: a streak of light in the skyproduced by the burning of a meteoroid inEarth’s atmosphere• Meteoroid: a chunk of rock or dust in space• Meteorite: a meteoroid that has hit Earth’ssurfaceMeteor Impact Crater inArizona.