MidTerm Answers: Part II

Question 1

Layers of the sun: inner to outer

Answer 1

core > radiative zone > convection zone > photosphere > chromosphere > corona

Question 2

What is granulation?

Answer 2

individual convection cells: regions where hot gas bubbles up from the surface and takes cooler gas back down

Question 3

Limb darkening is caused by what two things?

Answer 3

we can only see a certain depth into the photosphere; upper layers of the photosphere are cooler than lower layers

Question 4

What is a sunspot?

Answer 4

regions with very high magnetic fields with closely separated poles of North and South, they inhibit convection and prevents cool gas from going back into photosphere

Question 5

Where do sunspots form?

Answer 5

Sunspots appear where the concentrated magnetic field “breaks” through the Solar Surface.

Question 6

How does the Sun get its energy?

Answer 6

creates energy from matter, smashes 4 hydrogen atoms together to form the heavier helium; 4 hydrogen atoms weigh more than helium, extra mass goes to making energy

Question 7

Temperature of chromosphere?

Answer 7

~6K-20K Celsius

Question 8

Where do most Dwarf Planets reside in the Solar System?

Answer 8

Kuiper Belt

Question 9

What is the main criterion for classifying Pluto and other large asteroids?

Answer 9

Dwarf Planets are large enough to be round, but too small to clear the neighborhood around their orbits

Question 10

Why is Neptune so deep blue in colour?

Answer 10

Neptune’s atmosphere is dominated by hydrogen and helium. Methane makes up a small fraction of the atmosphere, it absorbs the red sunlight leaving only the blue-green component.

Question 11

What is found in the Oort Cloud, how far does it extend from the Sun?

Answer 11

Contains trillions of comets with random tilts and eccentricities; about 50K AU away

Question 12

What is the largest Dwarf Planet in our Solar System?

Answer 12

Eris: twice as far away from the Sun as Pluto and 5% larger than Pluto

Question 13

What is the Great Red Spot in Jupiter, and what is mysterious about it?

Answer 13

A relatively stable storm in the atmosphere. It spins counterclockwise while the winds to the north and south both spin in opposite directions (caught in the middle)

Question 14

Jovian moon Io

Answer 14

Closest to Jupiter; geologically active; constantly “flexed” by Jupiter’s gravity

Question 15

Jovian moon Europa

Answer 15

Uncratered surface, solid water ice, lots of cracks

Question 16

Jovian moon Ganymede

Answer 16

Largest moon in the solar system, larger than Mercury; large amounts of water-ice in ice-layer under a salty ocean; has magnetic field/ high and low terrain

Question 17

Jovian moon Callisto

Answer 17

Many craters; oldest surface of all the Jovian moons; surface covered in water-ice mixed with rock (dirty glaciers)

Question 18

Why is Uranus an aquamarine colour?

Answer 18

Methane is a principle gas here, which absorbs the orange and red wavelengths of sunlight

Question 19

What makes Uranus strange?

Answer 19

It’s poles directly face the sun at different times of the year!

Question 20

How were Uranus’ rings discovered?

Answer 20

Just before & just after Uranus passes in front of a star the star’s light flickers! That occultation happened in 1977

Question 21

What makes Uranus’ rings so historically significant?

Answer 21

It meant that the theory of shepherding moons turned out to be correct!

Question 22

What is the Great Dark Spot on Neptune?

Answer 22

A cyclone as large as Earth

Question 23

What do we know about Neptune’s atmosphere?

Answer 23

High clouds made of methane ice and another layer of methane-ice and hydrogen-sulfide ice particles

Question 24

What makes Neptune’s moon Triton so different?

Answer 24

Very cold (-236 Celsius) which makes nitrogen and oxygen freeze! Even though nitrogen is dominant on the surface there is also a high proportion of water-ice

Question 25

What is an ice-volcano?

Answer 25

a volcano that erupts volatiles such as water, ammonia or methane, instead of molten rock.