Chapter 14, 15 & 16 : Terrestrial planets - Mercury, the Moon, Venus, Earth & Mars

Rhea is one of Saturn’s moons. Based on where it was formed, its composition is probably

Mostly ice, but also rock and metal

Craters

A crater is a bowl-shaped depression, or hollowed-out area, produced by the impact of a meteorite, volcanic activity, or an explosion. Mercury and the Moon are covered in craters

Why are planet interiors hot?

The heat from when the planet formed, The heat from the decay of radioactive elements

Imagine that planet and its much smaller moon start at the same temperature. After 1 billion years, which will be cooler?

The Moon, because it has a greater surface area to volume ratio

Which planet, Venus or Mars, would you expect to have more on going volcanism?

Venus

The largest volcano in the solar system

Olympus Mons on Mars

Small terrestrial planets

Intoor cools rapidly

Erosion happens on earth due to

-Flowing Water

-Glaciers
-Wind

What does the existence of craters in this
dried river delta on Mars tell us?

The river must have dried up a very long time ago

high-speed strikes

Creates Craters

Volcansim

Molten rock makes mountains, and covers old surfaces

Erosion

Wind, Ice, and Water cut into the surface, and moves material around

Internal stresses

Causes mountain ranges and some types of canyons

Earth’s moon

Lots of craters remaining

Mars

Some craters remaining

Venus

Very few craters remaining

Earth

Very few craters remaining

Low mass planet

-Escape velocity lower

-Easier to escape

Low mass gas

-Moves faster
-Easier to escape

Hot Gas

-Moves faster
-Easier to escape

Why does Venus have so much more CO2
than Earth?

Earth kept is Oceans, where dissolved CO2
could form rock, while Venus didn’t