Astronomy Class Web Page

October 27, 2017

Question 1

Asteroids and Meteoroids

Definitions: Asteroid, Meteroid, Meteor, Meteorite
Where are asteroids and meteoroids?
Pictures of some named asteroids
- Ceres
- Vesta
- Gaspra
- pictures of Ida and its moon, Dactyl
Sizes
Dawn Mission
- mission webpage
- launched 2007
- arrived at Vesta July 2011, then Ceres March 2015
- first mission to visit a dwarf planet
- first mission to orbit 2 different objects
- used an ion propulsion system.
  - how does it work?
  - Fun interactive game about ion propulsion
- still in orbit around Ceres. 360 flyover video
meteor showers
Impacts on earth?
- February 15, 2013 Russian meteor impact event
  - wikipedia page for Russian meteor event 2013
  - Stats:
    entered atmosphere at 40x speed of sound (41,000 miles/hr),
    exploded 14.5 miles above city of Chelyabinsk with a force 20x stronger than the 1945 Hiroshima atomic bomb,
    blast damaged multiple buildings and injured approx. 1600 people,
    original meteoroid estimated at 17 meters (54 ft) diameter and 10,000 metric tons.
  - incoming:
  - shockwave:
  - Russian meteor landed on icy lake
  - Recovery:
  - Russian meteorite fragment recovered
- impact craters
  - map of craters
  - Barringer crater
    - Barringer picture 2
    - My visit in summer 2015: picture 1, picture 2
    - Tunguska impact site
    - Tunguska pic #2
    - New impact crater found buried in Australia. Impact happened over 300 million years ago. Australian impact crater story
- Collecting meteorites
  - Meteorite types
    - chrondite
    - iron meteorite
  - Hunting meteorites movie (4 minutes)
  - buying/selling meteorites
Question 3

Reading: Chapter 8 sections 6-9 (comets)