General Astronomy Quiz 7

Question 1

Is it hard to get a sense of the scale of our solar system?

Answer 1

Yes

Question 2

What is the main star in our solar system?

Answer 2

The Sun (99.8% of the mass)

Question 3

How many planets are in our solar system?

Answer 3

Eight planets (four inner/outer)

Question 4

How many dwarf planets are in our solar system?

Answer 4

Five

Question 5

What are the names of the dwarf planets?

Answer 5

-Ceres (formerly an asteroid)
-Pluto (formerly a plent)
-Haumea
-Makemake
-Eris

Question 6

What are cosmic debris?

Answer 6

-Asteroids
-Comets
-Meteors

Question 7

What was the FIRST definition of a planet?

Answer 7

A planet is a celestial body that
1. has sufficient mass to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape, and
2. is in orbit around a star, and is neither a star nor a satellite of a planet.

Question 8

What would have been a planet based on the FIRST definition?

Answer 8

-The current eight
-Ceres
-Pluto
-Charon
-Eris

Question 9

What is the CURRENT definition of a planet?

Answer 9

A planet is a celestial body that
1. is in orbit around the Sun,
2. has sufficient mass to assume hydrostatic equilibrium
3. has “cleared the neighborhood” around its orbit

Question 10

Which planets fall under the CURRENT definition?

Answer 10

The current eight

Question 11

How do the eight planets orbit?

Answer 11

In the same, nearly circular plane

Question 12

How do dwarf planets orbit?

Answer 12

In tilted, elliptical orbits

Question 13

What are the inner planets?

Answer 13

-Mercury
-Venus
-Earth
-Mars

Question 14

What is another name for the inner planets?

Answer 14

Terrestrial planets

Question 15

What type of surface do inner planets have?

Answer 15

Solid and rocky

Question 16

What are the outer planets?

Answer 16

-Jupiter
-Saturn
-Uranus
-Neptune

Question 17

What is another name for the outer planets?

Answer 17

Jovian or giant planets

Question 18

What are the outer planets made out of?

Answer 18

Mostly gas and ices

Question 19

How do astronomers estimate surface age?

Answer 19

By counting craters, the more craters means the surface has been around for longer

Question 20

How do scientists estimate the age of complete objects?

Answer 20

Radioactive dating

Question 21

What is radioactive dating?

Answer 21

A method of dating rocks and minerals using radioactive isotopes

Question 22

What is a half-life?

Answer 22

The time required for half of the radioactive atoms to disintegrate

Question 23

How can you tell how much time has passed for a half-life?

Answer 23

By comparing the fractions of the elements from half of the original sample changes

Question 24

How old is Earth’s surface?

Answer 24

4.56 billion years old

Question 25

What does the age of Earth tell us?

Answer 25

The formation age of the solar system

Question 26

What is the solar nebula model?

Answer 26

All the evidence we have about our solar system and observations we have of other star systems

Question 27

What does the protoplanetary disk allow us to do?

Answer 27

Look at the formation of stars and the material that forms around those stars

Question 28

What is the Sun made of?

Answer 28

Mostly hydrogen and helium, less than 2% of other elements

Question 29

Is the extra material near the Sun solid?

Answer 29

No, it is not solid

Question 30

Where do inner planets form?

Answer 30

Where temperatures are high, which leads to them not having a lot of solids to build with

Question 31

What is the ice line?

Answer 31

The distance from a star where water and other compounds turn into ice

Question 32

Why are inner and outer planets separated?

Answer 32

The difference of temperature

Question 33

Which of the following types of planets would form in the early solar system at locations hot enough for water molecules to exist only as a gas? 1) Inner terrestrial planets 2) Outer giant planets 3) Both options above are possible 4) None of the above

Answer 33

1) Inner terrestrial planets