Meteorites, Asteroids, and Comets!!!!

Comets will make you vomit and make your teeth turn green!! (this is to be sung)

Welcome to the AMAZING world of Meteorites, Asteroids, and Comets! Today we and I will be guiding your learning experience. We will talk about the characteristics and composition of Meteorites, Asteroids and Comets, we will even present famous examples of Meteorites, Asteroids and Comets to you! You are very lucky duckys today.

Description and Characteristics:

Meteorites: When a small meteoroid enters the earths atmosphere it produces a meteorite. Meteorites appear as a bright streak of light flashing across the sky, also know as a shooting star. Very rarely you will witness a fireball which is an especially bright and big meteor.
Asteroids: Asteroids are the remnants of when the earth was formed. They are the rocky leftovers and have been seen beyond Saturn's orbit and as near as inside the earths orbit. They are often referred to as "minor planets" and they can be as big as 1000 km and as small as pearls.
Comets: Comets have been visible since 240 BC and are made up of a mixture of frozen gases, water, and remaining dust that was not used to create the earth. (one way of thinking of it is like "icy mudballs") Comets are most easily seen when near the sun (sunrise or sunset) which makes them easy to spot, even by amateurs.

Composition:

Comets: Comets are split up into five different parts: Nucleus, Coma, Hydrogen cloud, Dust tail, and Ion tail.


Asteroids: There are four types of Asteroids: C-type which is made of carbon, S-type which is made of metallic iron mixed with iron-silicates and magnesium-silicates, M-type which is made of iron and nickel, D-type which is made of water, carbon monoxide and rock. The most common type of Asteroid is the C-type. Asteroids are observed after they fall to earth since they are easier to examine. The point at which they hit the earth, is when they become a meteorite.


Meteorites: Because Meteorites are formed in many different galaxies through many different processes, they can be composed of many different compounds. There are three general categories that meteorites fall under bases on their composition. These three groups are irons, stony-irons, and stones. Most Meteorites consist of a variety of sulfides and silicates, nickel-iron alloys. They are then classified by the ration of silicate to metal in the Meteorite.

Impact Craters:
Impact craters are the indentations left on planets as a result of falling meteorites, Asteroids, and Comets.
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EXAMPLES:
One of the oldest impact craters to hit earth fell 49,000 years ago, traveling at a speed of 40,000 miles per hour. Weighing several thousand tons it created a large indentation in Flagstaff Arizona. It's called the Barringer Crater.

In Kumasi, Ghana there is only one lake. It was created 1.3 million years ago by a falling meteorite that created a six mile hole. Over the years it filled with water, creating a lake. This lake is now considered sacred by the Ashanti people.

Famous examples:

Comet Halley is one of the most famous Comets. It was named after the astronomer who calculated its orbit, Edmund Halley. He discovered that the comet observed in 1531 and 1607 were the same Comet. Comet Halley will be visible from Earth again in 2061.

The famous asteroid named Hermes disappeared after is skimmed the Earth in 1937. It was found 65 years later by the International Astronomical Union (I.A.U.).

The Cape York Meteorite landed over 1,000 years ago in West Greenland. It is one of the largest meteorites over found. It was discovered in 1894 by Robert Peary.


Formation:

Meteorites:

Scientists have many theories as to how meteorites are formed. None of them are exact of proven. They suspect the tiny dust particles solidified from gas and formed rocks. They suspect that either electrical charges or gravitational pull allowed the rocks to be formed.

Asteroids:

Asteroids are made up of chemicals. Chemical arguments based on the S concentrations in the metallic magmas that formed magmatic iron meteorites and on the lack of pyroxene in pallasites tells us that the asteroid was caused by melting silicates. At least 40% melting of the silicate needs to happen to form an asteroid.

Comets:

Recently NASA has changed its views on Comet formation. They have new samples of comets and they have concluded that Comet's are a collection of substances from the Earth and Sun and other planets in the farther reaches of the Universe.

Asteroid Belts:

An Asteroid belt is the region where the majority of asteroids live. There are two main asteroid belts, one exists between Mars and Jupiter and the other is called the Kupin Belt. The asteroid belt formed from the primordial solar nebula which is a group of plant and animals.
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Orbits:

Asteroids:

Many Asteroids are orbiting the Sun in an Asteroid belt. Almost all of the Asteroids that are in our solar system are in a wide band, or Asteroid belt, that is over 19,400,000 miles wide between Jupiter and Mars.

Comets:

Comets orbit the Sun. They can spend thousands of years in deep space before they return to the sun. Comets follow a highly elliptical orbit. Like all other orbiting bodies in space, comets follow Kepler's Law. The closer they come to sun, the faster they move.

Meteorites:

Meteorites do not travel on any orbit in particular. They move in a straight line through space until their path of travel is changed by impact or a gravitational pull. This pattern makes them difficult to track, observe, or study.

Conclusion:

Thank you for reading our Wikki!! We hoped you learned lots about the amazing characteristics of asteroids, meteorites, and comets. As you can see from reading this, asteroids, meteorites, and comets are an amazing part of our universe and have helped shape the world as we know it. Of course, there is much more to learn about this topic and we hope that after reading this wikki you will continue to learn about meteorites, asteroids, and comets!

Bibliography:
Meteors, meteorites, and impacts:
http://www.nineplanets.org/meteorites.html
Asteroids:
http://www.nineplanets.org/asteroids.html
Impact Craters
http://geology.com/meteor-impact-craters.shtml

We also used our science teacher, as a source because she is VERY smart!