Comets, Asteroids and Meteors

The Asteroid Belt Small, rocky bodies that revolve around the sun Made of leftovers from the formation of the universe Range in size from a few meters to greater than 900 km in diameter Irregular shapes, but larger ones are spherical Most orbit the sun in the asteroid belt—a region of space b/w Mars & Jupiter Asteroids vary in color depending on their location in the asteroid belt Outermost region = reddish brown to black (organic composition) Innermost region = gray (carbon); light gray = stony/metallic

Famous Asteroids Hektor Ida and Dactyl http://neo.jpl.nasa.gov/images/ida.html

Ceres: the largest of the asteroids Observations of 1 Ceres, the largest known asteroid, have revealed that the object may be a "mini planet," and may contain large amounts of pure water ice beneath its surface. http://www.spaceflightnow.com/news/n0509/07ceres/

Meteoroids: “cousins” to asteroids; shooting stars Much smaller than asteroids but very similar Meteoroids are small, rocky bodies that revolve around the sun. Once it enters Earth’s atmosphere it becomes a meteor & stays a meteor if it burns up in the atmosphere. If it strikes the ground it is a meteorite.

Meteoroids continued 3 types: Stony(Rocky)—rocky material Metallic—iron & nickel Stony-iron—rocky, iron & nickel

Stony (Rocky) Meteorites: most primitive; contain water http://meteorites.asu.edu/images/new-concord-big.jpg

Metallic Meteorites http://www.astro.virginia.edu/class/oconnell/astr121/im/iron-meteorite.jpg

Stony-iron Meteorites http://www.gpc.edu/~pgore/myphotos/rocks/stonyironmeteor.jpg

Meteorite Crater In Canyon Diablo in Arizona, USA, you can visit the best preserved meteorite crater on earth. It was formed about 22,000 years ago by the impact of a giant metallic nickel-iron meteorite, which arrived from space at a speed of about 50,000 kilometers per hour, and weighed many hundreds of tons. Friction with the atmosphere does not really slow such a mighty mass, which smashed into the solid earth, punching away 300 million tons of rock in a mighty blast which left a crater which even today is still 1.5 kilometers in diameter and 170 meters deep. (http://www.rocksonfire.com/About-Meteorites.htm)

Stars Fell On Alabama, November 12, 1833, Leonid Meteor Shower New car license plate introduced in January, 2002, commemorating this. The new slogan on these plates is "Stars Fell on Alabama," in reference to the 1934 song written by Mitchell Parish and Frank Perkins and made famous by Ella Fitzgerald and Louis Armstrong, Frank Sinatra, and other artists over the years. The top of the plate contains a field of stars and musical notes around the slogan. http://www.15q.net/al.html

Comets http://www.nineplanets.org/comets.html

Comets http://www.nineplanets.org/comets.html Comets are sometimes called dirty snowballs or "icy mud balls". They are a mixture of ices (both water and frozen gases) and dust that for some reason didn't get incorporated into planets when the solar system was formed. This makes them very interesting as samples of the early history of the solar system. http://www.nineplanets.org/comets.html

Dust