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.)
Asteroids:
-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”
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 2022.
Astronomers have been monitoring the path of the giant
space rock since it was spotted on January 28, 2000.
http://www.thehollywoodgossip.com/2013/03/cosmic-crash-2022-asteroid-to-go-boom/
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 → 500-1000 times more energy
Side note: velocity = SQRT(2 * 9.8 m/s2 * 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