Lecture 11

Question 1

What is the role of planetary size?

Answer 1

• smaller worlds cool faster
• larger worlds remain warmer, promoting volcanism and tectonics
• larger worlds have more erosion because their gravity retains an atmosphere

Question 2

How does the distance from the Sun effect erosion?

Answer 2

• planets close to the sun are too hot for rain, snow and ice so erode less
  -hot planets have difficulty retaining an atmosphere
• planets far from the sun are too cold for rain and so erode less
• planets with liquid water have the most erosion

Question 3

What is the effect of rotation on erosion and magnetic field strength?

Answer 3

-Planets with slower rotation have less weather, less erosion and a weak magnetic field
-Planets with faster rotation have more weather, more erosion and a stronger magnetic field

Question 4

How can we use of the number of craters on a planet?

Answer 4

Craters can be used to approximate the age of a planet

Question 5

What is evidence of tectonics on Mercury?

Answer 5

Long cliffs indicate that Mercury shrank early in its history after the mantle shrank

Question 6

Why are some of the earlier craters on the moon smooth?

Answer 6

Some areas of the moon are heavily cratered. Younger regions were flooded by lava, which smoothed the surface.

Question 7

Where is water on the Moon and how did it arrive?

Answer 7

• water exists on the moon’s poles
• the water was delivered by comets

Question 8

What is a Lunar Maria?

Answer 8

Smooth, dark areas created by floods of runny lava

Question 9

What is the process of formation of Lunar Maria?

Answer 9

-early surface is covered with craters
-large impact craters weaken the crust
-heat build-up allows lava to well up to the surface
-cooled lava is smoother and darker than surroundings

Question 10

Why is the moon geographically dead?

Answer 10

The geological processes have virtually stopped

Question 11

How do we map Venus?

Answer 11

The thick atmosphere means that radar must be used to image the surface

Question 12

What did flowing lava do to the surface of Mercury?

Answer 12

Smoothed some of the surface

Question 13

What are some surface features on Venus?

Answer 13

-Venus has impact craters (but not as many as the Moon)
-Shield volcanoes
-Fractures on the surface indicate tectonic stress on Venus- but not recent stress

Question 14

How is continental motion measured on the Earth?

Answer 14

By GPS

Question 15

How did the Himalayas form?

Answer 15

Collision between tectonic plates

Question 16

How did the Red Sea form?

Answer 16

The red sea formed where plates pulled apart

Question 17

What is cratering like on Mars?

Answer 17

-Cratering differs greatly across the surface
-Many of the earlier craters have been erased

Question 18

What are volcanoes like on Mars?

Answer 18

Mars has many large volcanoes including the largest volcano in the solar system

Question 19

What was thought to have formed the Valles Marineris on Mars?

Answer 19

The Valles Marineris are thought to have originated from tectonics

Question 20

Was there liquid water on Mars?

Answer 20

Gullies and craters suggest liquid water may have existed less than one million years ago

Question 21

What does the erosion of Martian craters suggest?

Answer 21

Details found in some of the craters suggest that they were once filled with water

Question 22

What do Martian rocks show?

Answer 22

Mars rovers have found some rocks which look like they formed in water