Week 3

Question 1

What do elliptical orbits indicate?

Answer 1

An evolving solar system

Question 2

What do circular orbits indicate?

Answer 2

A stable solar system

Question 3

Mercury atmosphere and surface

Answer 3

No atmosphere, solid surface

Question 4

Jovian planet features

Answer 4

Larger, lower density, no solid surface, mostly made of H/He, colder, many rings and moons

Question 5

Terrestrial planet features

Answer 5

Smaller, higher density, solid surface, mostly made of metal and rocks, warmer, not many moons

Question 6

Mars atmosphere

Answer 6

thin so won’t protect from radiation, no oxygen

Question 7

Closest planet in size to earth

Answer 7

Venus

Question 8

Nebular theory

Answer 8

Solar system formed from the gravitational collapse of a gas cloud

Question 9

Nebular theory, Cloud rotation

Answer 9

as the cloud condensed in out solar system formation, it will spin faster (conservation of angular momentum)

Question 10

Nebular theory, Flattening

Answer 10

Gravity will act on all directions of cloud, but the shortest side will collapse faster causing a flattened disk shape to form

Question 11

How did planets form

Answer 11

Particle collisons casue objects to form, eventually causing planetesimals to form which gravity assembles into planets

Question 12

Why are the composition of jovian and terrestrial plannets different?

Answer 12

Further out in the solar system the temperature is cooler, which results in substances staying as ice instead of melting, causing a different composition of planetesimals and more of them

Question 13

Why is jupiter larger then saturn?

Answer 13

the further out you go in the solar system, the lower the density and hence the less effcient the process of planet formation

Question 14

What are comets?

Answer 14

Mainly icey parts, left over from parts of outer solar system

Question 15

What are asteroids?

Answer 15

Mainly rock parts, left over from parts of inner solar system

Question 16

Commet tails

Answer 16

1 - ion tail, pointing directly away from sun

2 - sunlight reflected from melting stuff from commet

Question 17

The planet closest to Earth in size is

Answer 17

venus

Question 18

Where did the elements heavier than Hydrogen and Helium come from?

Answer 18

they closest inside stars

Question 19

What are the main constituents of the jovian planets?

Answer 19

Hydrogen and helium

Question 20

Based on our current theory of the formation of the Earth, the water we drink came from

Answer 20

Comets that hit the earth

Question 21

Which of the following is NOT an observed motion of the planets in our Solar System?

• Most planets move at the same speed
• All planets orbit the Sun in the same direction
• Most planets lie in approximately the same plane
• Most planets rotate in the same direction that they orbit

Answer 21

Most planets move at the same speed

Question 22

Which planet has a ring system?
Jupiter
Saturn
Uranus
Neptune

Answer 22

all of them

Question 23

Which is these facts is NOT explained by the nebular theory?

• There are two main types of planets: terrestrial and jovian
• Planets orbit in the same direction and plane
• Existance of comets and asteroids
• Number of planets of each type (4 terrestrial and 4 jovian)

Answer 23

Number of planets of each type (4 terrestrial and 4 jovian)

Question 24

Which planet has the highest average surface temperature and why?

Answer 24

Venus because of its dense atmosphere of carbon dioxide

Question 25

Which of the following events can NOT be explained by a giant impact event?

• The formation of the Moon
• The large metallic core of Mercury
• The backwards rotation of Venus
• The exteme axis tilt of Uranus

Answer 25

The large metallic core of Mercury

Question 26

According to the nebular theory, what are comets and asteroids?

Answer 26

Leftover planetesimals that never accreted into planets