Comets and Asteroids By Derek Smith & Noah Duncan Asteroids: General Information Size: couple kilometers-1,000 kilometers Location: Asteroid belt (mainly) Distance from sun: 1-5 au (149,588,000747,940,000 kilometers) Asteroids: In Depth • Asteroids are basically small bodies of rocks that orbit the Sun. They are left over from the time that the universe was formed that some scientists call the Big Bang. Asteroids range in size, some as big as 1,000 kilometers. Although some asteroids are rather big, all of the universe’s asteroids put together would create a body less than that Earth’s moon. Asteroid Belt • Most of the Universe’s asteroids are contained in an area called the Asteroid Belt. The Asteroid Belt is located between the planets of Mars and Jupiter. Even though asteroids are stuck in those planets’ orbits, they orbit the Sun. To be exact, 99% of the Universe’s asteroids are contained in the Asteroid Belt. Asteroid Classification • Many people don’t know what to call asteroids when they see them. Rocks in space are called asteroids. When an asteroid enters the atmosphere, it is called a meteoroid. When a meteoroid burns up and hits the Earth, it is called a meteorite. Other Info/Fun Facts • The word “asteroid” comes from a Greek word meaning “star-like.” Asteroids have axi and spin very slow on them, although it only takes a few hours to complete a rotation. Asteroids can be called a planetesimal, which is a piece of planets from long ago. Comets: General Information • Location: Varies…. • Size: 1-10 kilometers • Distance from Sun: couple au-8 trillion kilometers • Orbital period: most take around 20 Earth years, but some as much as 2,000 years Comets: In Depth • Comets are balls of ice, rocks, and gas that orbit the Sun in an elliptical path. The most famous part of a comet is the tail, which will be gone into depth in the next slide. There are two different types of comets, long-period and short-period. Short- period comets have as short a orbit as 20 years, while long-period comets can be have an orbit as long as 2,000 years!!!!!! Comet Tails • The most famous thing that comes to mind for comets is definitely the tail. They are very thin,even though it may look huge. A comet’s tail is actually 2 tails, and can even be three! These tails can stretch out as much as millions of miles into space. Explanation Behind Comet Tails • When a comet in it’s orbit comes within a few au of the Sun, its nucleus starts to burn and substances melt off and carries some particles with it. These particles form the comas, or tails. Other Info/Fun Facts • There is a long-period comet that you probably have heard of called Halley’s Comet. It was discovered by Professor Halley in 1986. That is the last time it was seen, and is not expected to be seen again until 2061, 86 years later. Computer Sources Nine planets-nineplanets.org NASA’s worldbook-nasa.gov/topics NASA Solar System-solarsystem.nasa.gov Harvard Astrophysics Research Websiteadsabs.harvard.edu Book Sources Earth and Space Science: Exploring Our Universe Dr. Gustavo Loret de Mola---Copyright 2009 Astronomy DeMYSTiFieD Stan Gibilisco---Copyright 2003