Earth structure: direct and indirect evidence

Question 1

Name the four terrestrial planets.

Answer 1

Mercury, Venus, Earth and Mars.

Question 2

Name the four gas giants.

Answer 2

Jupiter, Saturn, Uranus and Neptune.

Question 3

What is an asteroid?

Answer 3

A rocky object which failed to form a planet.

Question 4

What is a meteorite?

Answer 4

Rock fragments which fall to the Earth from space.

Question 5

What is a comet?

Answer 5

Composed of ice and dust. The outer layer melts into water vapor as it gets closer to the sun.

Question 6

Name the eight planets in the solar system.

Answer 6

Mercury, Venus, Mars, Earth, Jupiter, Saturn, Uranus and Neptune.

Question 7

What did the Apollo missions discover and bring back?

Answer 7

• 20 kg of rock and soil which were much older than expected, up to 4400 Ma.
• The moon has a solid crust, mantle and core.

Question 8

What is the moons surface made up of?

Answer 8

• Maria: dark areas composed of basalt lava flows, generated by meteorite impacts.
• Highlands: light coloured areas composed of the plagioclase-rich rock anorthosite.