Chapter 8

Question 1

What can the inner planets be described as

Answer 1

Solid and rocky

Question 2

What can the outer planets be described as

Answer 2

Gaseous and liquid

Question 3

How long ago did the solar system develop

Answer 3

4.5 billion years

Question 4

What are the suns main elements

Answer 4

Hydrogen (71%) and helium (27%)

Question 5

How large is the sun compared to the mass of the rest of the solar system combined

Answer 5

700 times

Question 6

What can the planets orbits be described as

Answer 6

Almost circular lying on nearly the same plane

Question 7

What planets travel counterclockwise

Answer 7

Six planets; mercury,earth,mars,Jupiter, Saturn and Neptune

Question 8

What planet travels clockwise

Answer 8

Venus

Question 9

What planet appears to rotate on its side

Answer 9

Uranus

Question 10

What are the inner planets

Answer 10

Mercury, Venus, earth, and mars. They are known as terrestrial planets

Question 11

What are the outer planets

Answer 11

Jupiter,Saturn,Uranus,Neptune. Also known as Jovian planets. They are gaseous, liquid, or icy

Question 12

How comparable is the size of Jovian planets next to terrestrial planets

Answer 12

They are much larger, and do not have a well defined surface

Question 13

What are dwarf planets

Answer 13

They are a group of planets such as Pluto that fail to fit in either family.

Question 14

What are asteroids

Answer 14

They are rocky or metallic bodies that range from a few km to 1000km across

Question 15

What are comets

Answer 15

They are icy bodies that are about 10km or less and have very long tails of gas and dust as they near the sun

Question 16

Where are most asteroids found

Answer 16

Within the asteroid belt between mars and Jupiter

Question 17

Where are most comets from

Answer 17

From a disc like swarm of icy object that lay beyond Neptune called the Kuiper belt

Question 18

Where do most comets orbit the sun from

Answer 18

From the Oort Cloud that is 40,000 to 100,000 AU from the sun

Question 19

How do we measure a planets mass

Answer 19

Keplers modified third law

Question 20

How do we measure a planets volume

Answer 20

We measure it’s radius

Question 21

What is a planets reflection spectrum

Answer 21

It is a way to reveal a planets atmospheric contents and the nature of surface rocks

Question 22

Do mercury and Venus have moons

Answer 22

No they are moonless

Question 23

What planet has the most moons

Answer 23

Jupiter then Saturn and then Uranus

Question 24

How did we determine the age of the solar system

Answer 24

Radioactive dating of rocks

Question 25

What is the theory on how the solar system formed

Answer 25

The solar nebula hypothesis

Question 26

What is the solar nebula hypothesis

Answer 26

It proposes that the solar system evolved from a rotating flat disc of gas and dust called an interstellar cloud

Question 27

How did the solar nebula form

Answer 27

A collision with another cloud of nearby exploding star

Question 28

How was the temperature of the solar nebula before planets formed

Answer 28

The inner part of the disc was hot, and the outer disk was colder than the freezing point of water

Question 29

What is condensation

Answer 29

It is when gas cools below a critical temperature

Question 30

What is the role of condensation in the solar nebula

Answer 30

The sun kept anything until Jupiter unable to condense and this helped the planets form

Question 31

What is accretion

Answer 31

Tiny particles sticking together by electrical forces into bigger pieces. If they don’t undergo too violent of impacts they become planetesimals

Question 32

What are planetesimals

Answer 32

They range from millimeters to kilometers in size, are mainly rocky iron composites in the inner solar nebula while the outer had more icy rocky iron composites

Question 33

How did planetesimals evolve

Answer 33

Different ones slowly merged together to form circular orbs that grew in size and began to develop planets

Question 34

Where was planetary growth the fastest

Answer 34

The outer solar nebula

Question 35

How were these planetesimals impacted

Answer 35

They received continuous bombardment and this he,led internal radioactivity melt the inside and lead to different interiors

Question 36

How did atmospheres form for inner planets

Answer 36

From the continuous bombardment by asteroids and comets craters and volcanos started to form on the surface of these planets and the volcanic activity together with their gravity helped form it

Question 37

How did atmospheres form for outer planets

Answer 37

They captured their atmosphere from the solar nebula gravitationally

Question 38

Why does mercury and the moon not have an atmosphere

Answer 38

Because they are too small and there is not enough gravity to retain gases on their surface

Question 39

What are exoplanets

Answer 39

Planets around other nearby stars

Question 40

How do we detect exoplanets

Answer 40

The Doppler shift method, gravitational lensing, or the transit method

Question 41

What is gravitational lensing

Answer 41

Gravity bends the path of light when it passes near a massive object, we detect this light

Question 42

What is the transit method

Answer 42

We detect if there is a dimming of light from the central star at any point