Building a Comet! (An excuse to play with dry ice.)

What’s the difference between a comet and an asteroid?

Comets are “beautiful objects.”

“Ooooooooooh”

“Aaaaaaaaaaaaaah”

Asteroids are kind of ugly.

...and sometimes they hate us.

(Best movie EVER.)

-Chunks of rock that orbit the sun between Mars and Jupiter -Most are small pebbles; a few are larger than New Mexico -Can be seen as meteors, or “shooting stars” Asteroids:

NEWS FLASH ASTEROID TO HIT EARTH IN 2022! An asteroid was discovered that's on a near-collision course with the Earth - and could crash into us in Astronomers have been monitoring the path of the giant space rock since it was spotted on January 28,

Meteorite impact in Russia, February 2013

Shoemaker Levy 9 meets Jupiter July 1994

Crater chain on Callisto (One of Jupiter’s moons.)

Energy from impacts... - Speeds of ~65,000mph - Meteorite the size of a football field → 1000 atomic bombs - Dinosaur-killing meteorite: ~6 miles wide - A little bigger means a LOT more energy 10 times bigger → times more energy Side note: velocity = SQRT(2 * 9.8 m/s 2 * height)

Comets: -Dirty snowballs (rock and ice) -Long-period comets from the Oort cloud -Short-period comets from the Kuiper Belt -100,000 km in diameter with really long tails (2500 x Earth’s circumference)

Diagram of a Comet

Making a Comet! - Make craters in flour - ½ cup of water - 1 or 2 spoons of sand -- stir well - a little ammonia and a little organic material - crushed dry ice stir “vigorously” when adding the dry ice (but don’t tear the plastic bag) - a little more water – shape your comet