Asteroids Comets and Meteoroids Bodes Law In 1772

Asteroids, Comets, and Meteoroids

Bode’s Law • In 1772 Johann Bode, a German astronomer, created a mathematical formula now called Bode’s Law. • This formula determines the pattern that describes the distances between the planets. • His formula predicted that there should be a planet between Mars and Jupiter, but there wasn’t!

Bode’s Law • So why was there no planet? • What was there instead? • Correct! Scientists knew the asteroid belt was there even before they could see it!!!

The Asteroid Belt • The first asteroid found in 1801 was thought to be a tiny planet. • Ceres is actually an asteroid only 560 miles in diameter. • There are now thousands of these tiny “planets” that have been catalogued. • The total number may be more than one million!

Asteroids • Some asteroids are found outside the asteroid belt. • These are called Trojan Asteroids. • These asteroids orbit the sun with Jupiter. • Another group, called Apollo Asteroids, follow individual paths that lead them close to earth. • These are the ones that have the slim chance of hitting earth or our moon.

Asteroids In your notebook, answer the following: • Which asteroids travel before and behind the planet Jupiter? • When completed write your summary for this section of notes on Asteroids!

Comets • Comets are subject to the same laws of motion as the planets. • Edmund Halley in 1682 studied a comet that he predicted would return again in 1758. • This comet was named Halley’s comet in his honor.

Comet Components • The heart of the comet is the nucleus. • The nucleus is a frozen chunk of ice and dust. • The nucleus of Halley’s Comet is about the size of Manhattan Island.

Comet Components • As it approaches the sun, it melts and produces jets of steam and dust. • This cloud of gas and dust around the nucleus is called the coma.

Comet Components • As it approaches even closer to the sun, the solar winds causes the gases and dust to produce a tail. • A comet’s tail can be millions of miles long.

A Comet’s Course • Comets orbit the sun. • However, some of these orbits take the comet out past Pluto.

The amount of time it takes a comet to orbit the sun is called the comet’s period. Some periods may be a few years and some are several decades.

Meteoroids • Meteoroids are the smallest pieces of space debris that orbit the sun. • Most meteoroids are smaller than a man’s fist. • They range in size from microscopic specs of dust to boulders almost as large as asteroids.

Meteors • When meteoroids enter the earth’s atmosphere, they are called meteors. • Meteors are mistakenly called “falling stars”.

Meteor Showers • Sometimes the earth passes through a cluster of meteoroids. • When this happens, the earth experiences a meteor shower.

Meteor Showers • These clusters are usually debris left behind by a comet. • They are named after the constellation from which they “appear” to come from as they fall to the earth.

Meteor Showers • The most often watched “shower” is the Perseids. • The Perseid shower occurs on August 12 -13.

Meteorite • Not all meteors burn up in the atmosphere as they fall. • Some hit the earth!

Meteorites • When a meteor falls and hits the earth, it is called a meteorite. • Most are very tiny! • The largest ever found intact was one in Russia • It weighs 450 metric tons!!!! • It was confirmed found in 2009!