SOLAR SYSTEM

Question 1

Definition of asteroid, comets, meteor and meteorite

Answer 1

asteroid - rocky body that orbits sun.
comet - ice and dust
meteorite - asteroid that collides with Earth
meteor - asteroid that burns in Earth’s atmosphere

Question 2

Meteorites

Answer 2

• remnants of terrestrial planet that failed to form
• 4.6Ga

Question 3

Types of meteorites

Answer 3

stony - 93% of meteorites, similar to Earths mantle
iron - 6% of meteorites, similar to Earth’s core
carbonaceous chondrites - <1% of meteorites, water + organic compounds

Question 4

Impact craters

Answer 4

• created by bolides (extraterrestrial impact object)
• small = common, large = rare

Question 5

Characteristics of an impact crater

Answer 5

• ejecta (radial pattern)
• inverted strata (older sediment on top)
• shocked quartz (shock waves cause quartz to crumble)
• iridium (not often found on earth, indicate iron meteorite)

Question 6

Solar nebula disc theory

Answer 6

1. Cloud (nebula) of hydrogen gas
2. Nebula starts to collapse and spin (“protoplanetary disc”)
3. Nuclear fusion begins in middle - forms a sun
4. Heavier elements accrete to rocky lump + gas (“planetismal”)
5. Planetismals accrete to form planet

Question 7

Solar system age

Answer 7

Solar system - 4.6Ga
Earth - 4.6Ga
Universe - 14Ga