1. Asteroids,, Comets, and Meteoroids Chapter 5

2. 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!

3. 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!!!

4. 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!

5. 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.

6. 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!

7. 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.

8. 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.

9. 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.

10. 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.

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

12. 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.

13. 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.

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

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

16. 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.

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

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

19. 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!

20. Meteorites This meteorite was found in Africa. Until scientist discovered the Russia one, this was the world’s largest at 66 tons!

21. Meteorites The largest found in the United States is this one found in Oregon. It weighs 15.5 tons.

22. Scientists only recently found the crater left by the meteor that caused a huge explosion that flattened a forest in 1908!

23. Meteor Craters Largest meteor crater in United States! In Arizona!

24. The End!!!!