Welcome to Science 12/13/10

• Open your books to page 557-561 and use these pages to begin completing the outline you just received.

• Today’s Schedule

• 1. Schedule for the week

• 2. Science Folder/Notes Organized

• 3. Question of the Day

• 4. Discussion on Comets, Asteroids, & Meteors

Science Folder/Notes• These items should be in your Science Folder

and should be studied for Friday’s Test 5 Key Concepts Paper• Big Bang Theory/Solar System Flow Chart• Sun Packet• Planet Packet• Comets, Asteroids, & Meteoroids Packet• Life Beyond Earth Packet• Word Wall List

Question of the Day• What is most likely the object that hit Earth in

the picture below? A comet, asteroid, meteoroid, meteor, or meteorite?

• Most likely it was an asteroid

• Why study comets, asteroids, & meteoroids.

• Because they threaten the existence of life on Earth

• Ultra Science: Hitting Earth :

Comets• What is a comet?

• Small body of ice, dust, and small rocky particles packed together that orbit the sun. “dirty snowballs”

• Where do they come

from?

• Cold outer solar system.

• Oort Cloud & Kuiper Belt

Why are comets important?

• Comets are made of the “leftovers” from the process of planet formation.

• Each comet is a sample of the early solar system.

A Comet’s Tail When a comet passes close to the sun, the

heat from the sun evaporates the water in the comet creating a tail of gas and dust.

Comet Orbits• Like the planets, comets also orbit the sun in an

ellipse.

• A comet’s tail will point away from the sun as it gets closer to the sun.

• Interactive Comet Animation

Asteroids• Large rocky objects that orbit the sun between

Mars & Jupiter (asteroid belt)

• Like comets, asteroids are the leftovers from the formation of the solar system.

Meteoroids• Meteoroid- small chunk of rock or dust. Could

be a piece of a comet or asteroid

• Meteor- meteoroid that enters Earth’s atmosphere & creates a streak (shooting star)

• Meteorite- meteor that hits Earth’s surface

Impact of Asteroids & Meteoroids• The main theory on the extinction of the

dinosaurs is that it was caused by an asteroid strike.

• Could an asteroid hit again? • Yes• Will it happen again?• Yes • When will it happen?• 2014 & 2021 Possibly• Ultra Science: Hitting Earth : Bad Universe: Asteroid Impact SimulationWatch The Asteroid Threat: