chapter 11: meteoroids, asteroids, and comets. the kuiper belt of comets spreads from neptune out...
TRANSCRIPT
Chapter 11: Meteoroids, Asteroids, and Comets
The Kuiper Belt of comets spreads from Neptune out 500 AU from the Sun
Kuiper Belt Objects
Oort Comet Cloud
A. icy dirtball?
B. dirty snowball?
or
Comets
Rosetta Mission
Rosetta Images
Composition of a Comet
Comets lack tails until they enter the inner solar system.
Composition of a Comet
Period of orbit is 75-76 yearspredicted by Edmond Halley
Nucleus very dark
Dirty snowball!
Halley’s Comet
“I came in with Halley’s comet in 1835.It is expecting to come again next year (1910), and I expect to go out with it.The Almighty has said no doubt: ‘ Nowhere are two unaccountable freaks; theycame in together, they must go outtogether.”
- Mark Twain, a Biography
Halley’s Comet and Mark Twain
Meteor Showers
Meteor Showers
The Great Leonid Storm of 1833
Meteor Showers
• meteoroids: chunks of matter in space orbiting in the Solar System ranging up to tens of meters across and sometimes larger
• meteors: when these chunks hit the Earth’s atmosphere and show up as streaks in the sky
• meteorite: when a fragment of a meteoroid survives its passage through the Earth’s atmosphere
Meteoroids
Meteorites
Meteorites
Gaspra
Ida and its moon Dactyl
Asteroids
Ceres was the largest Asteroid, now it’s a Dwarf Planet
Most asteroids orbit the Sun between Mars and Jupiter
Near Earth Asteroids cross the Earth’s orbit
Impact!
Tunguska Mystery, Siberia, 1908
Barringer Meteor Crater, Arizona 15000 years ago
Impact!
The Extinction of Dinosaurs
The Extinction of
Dinosaurs
Next Impact?