Module 20

• Comet - chunk of ice and rock originating from the outer solar system
• Comet - often accompanied by a coma and tail
• Asteroid - rock in orbit generally between Mars & Jupiter
• Asteroid - sometimes get bounced towards Earth
• Meteoroid - space rock that's bigger than a dust grain but smaller than an asteroid
• Meteor - streak of light seen when a space rock enters the atmosphere and starts burning up (falling star)
• Meteorite - piece of space rock that lands on Earth
• If a meteor doesn't entirely burn up, it is a meteorite
• Silicate - responsible for the reflection of light from these celestial bodies
• Kuiper Belt - short-period comets
• Kuiper Belt - take less than 200 years to orbit the Sun
• Oort Cloud - long-period comets because they take much longer to orbit the Sun
• Comet Halley - most renowned short-period comet of the 20th century
• Ceres - 1st asteroid discovered in 1801
• Alvares Hypothesis - extinction of dinosaurs
• Asteroid belt - where asteroids originate
• Nucleus - specific part of a comet
• Nucleus - often referred to as a "dirty snowball," is primarily made of ice