Exam 2 Flashcards
Why is the core of a planet made of metal and not rock?
Metal is denser and sank to the core
What property of a planet determines if it will cool off quickly or slowly?
Size of the planet
Two basic types of planets
Terrestrial and Jovian
Jovian planets have more internal energy than terrestrials because jovians
Are much larger
Jupiter and Saturn have liquid metallic hydrogen but Uranus and Neptune don’t because of the ice giants:
Lower mass
What information do you need to know to calculate how long it takes a planet to go around the sun?
Semi-major axis
Saturn is almost 10x further from the sun than the earth is, so Saturn has a long orbital period and probabaly
Rotation rate has nothing to do w orbital period
Which best describes the spacing of the planets in our solar system?
Uneven, planets bunched together close to the sun and spread out farther from the sun
Which planet is halfway between the sun and Pluto
Uranus
Description of the distances in our solar system
The distances between planets are large compared to their sizes
What causes a planet to have volcanoes
Having a liquid, molten interior
If a planet has volcanoes and a strong global magnetic field it must have
Lots of internal energy and is probably large like the earth
What characteristic of a planet creates powerful winds
Fast rotation rate
What characteristic of a planet determines the length of year
Orbit size (semi major axis)
What characteristic of a planet determines the strength of seasons
Tilt of the rotation axis
What characteristic of a planet determines the length of day
Rotation rate
What characteristic of a planet determines the rate at which is cools
Planet size
What characteristic of a planet determines its surface gravity
Mass and size
Planets in order of size from SMALLEST to LARGEST
Mercury Mars Venus Earth Neptune Uranus Saturn Jupiter
Planets in order of semi-major axis from SMALLEST to LARGEST
Mercury Venus Earth Mars Jupiter Saturn Uranus Neptune
What information do you need to know to calculate how long it takes a planet to go ground the sun if you already know the suns mass?
Semi major axis
What trait of a planet determines its length of day
Rotation rate
What trait of a planet determines whether or not it has seasons?
Tilt of the rotation axis
Mars and Seasons
Mars has seasons because it’s rotation axis is tilted, but it’s orbital eccentricity affects the strength and duration of the seasons
We blue world with swirling white clouds
Earth
Frat, barren rocky world covered by craters
Mercury
Dusty red world with faint wisps of clouds and a polar ice cap
Mars
A world whose rocky surface is permanently hidden by swirling clouds
Venus
Earth and mars rotate at about the same rate, but earth has a global magnetic field while mars does not. Why is this?
Mars’ metal core is mostly solid
Which planet has the hottest surface temperature and why?
Venus due to a powerful greenhouse effect
Why is venus’ greenhouse effect so much stronger than mars’?
Venus’ atmosphere is thicker
What is a good analogy for the greenhouse effect?
Greenhouse gases delay the escape of infrared light, so they act like an insulation blanket
Why does the surface of the moon have so many craters but the earth doesn’t?
The moon has no atmosphere so the craters are not eroded like they are on earth
I had oceans in my distant past, but now all my water hides under the surface under my polar caps
Mars
Natural satellite (moon) is absurdly large considering my size
Earth
I have an absurdly large metal core covered in craters
Mercury
I am mug hotter than I should be, since my greenhouse gasses trap so much of the heat I radiate
Venus
I have a lot of volcanoes but I never had any plate tectonics
Venus
I am both very hot and very cold and my sky is black during both day and night
Mercury
Two basic categories of planets
Terrestrial (rock and metal)
Jovian (hydrogen and helium)
Bland mint green cue ball, but infrared light shows us the activity beneath the haze
Uranus
Banded with light an dark red clouds with many storms
Jupiter
Blue world that is far from bland, with powerful storms and high speed winds
Neptune
Bland yellow with spectacular rings
Saturn
The core of Jovian planets are much higher than the earths core temperature. Why is this?
Jovians have more mass and are larger than terrestrials
If you went halfway into a Jovian planet, you’d be more likely to find sufficient pressure to make liquid metallic hydrogen in a planet with
More mass (like a gas giant)
Why do Jovian planets seem to be radiating more energy than they take in from the sun?
They have a lot of heat left over from formation, and energy generated by contraction and condensation
Why do Saturn, Uranus, and Neptune look so bland as compared to the high contrast banded look of Jupiter?
Clouds can form deeper in the atmosphere, since they are colder and are seen through a thick haze of methane
Why does Neptune have faster winds than Uranus?
Neptune has a greater internal energy
What property of a Jovian causes it to have a global magnetic field and makes shape slightly less spherical and more flattened?
Rotating quickly
What would you have to do to the ice giants to make them have layers of liquid metallic hydrogen like the gas giants?
Add more mass
What are the ice giants?
Uranus and Neptune
What are the gas giants?
Jupiter and Saturn
Do Jovian planets have magnetic fields?
Yes
What are seasons like on a Jovian planet?
Summer is warmer and has more clouds and storms, winter is colder with fewer clouds and storms
How would you calculate the mass of Saturn?
Measure the orbit size and orbital period of one of its moons
Can Jovian planets have auroras?
Yes, they have strong magnetic field and an atmosphere
My atmosphere is coldest in the solar system
Uranus
I have the largest storm in the solar system
Jupiter
My rotation axis is tilted so far over that I orbit on my side
Uranus
High wind speeds that reach near super sonic speeds
Neptune
People on earth realized I existed because they saw my gravity messing with another planets orbital speed
Neptune
True or false: all Jovian planets have rings and moons?
True
Why do moons orbit instead of flying away from they host planet?
Gravity ties them to the planet
A tidal force could arise on a moon because one side is farther from the planet and feels a ____ force of gravity than the near side
Weaker
Why don’t we see large moons very close to the planets, like inside the roche limit?
The difference in gravity between the side near the planet and far from the planet would rip apart a large moon
What are planetary rings made of?
Millions of little particles each orbiting the planet
How do the particles in rings orbit?
The inner rings orbit faster than the outer rings
Why are Jupiter, Uranus, and neptunes rings so dark?
They are made of dark particles and there just aren’t many particles in the rings, either
What is the Roche limit?
How close a moon can get to a planet before being ripped apart by gravity
True or false: the moon is the only object that raises the tide on earth
False
Particles inside a planets Roche limit don’t clump as they stay as a ring system, but particles outside of the Roche limit can clump up and form a large moon. Why is this?
Outside the Roche limit the tidal force is much less and won’t tear apart the moon as it tries to form
What is the Roche limit/how far is it?
Usually around 2.5x the planets radius, or slightly more than the planets width
Orbits between mars and Jupiter and is mainly made of rock
Steroid
Fragile, fluffy ball of ice and dust
Comet
Made of rock and has a moon orbiting it but never a tail
Asteroid
Britt streak of light in the sky as air is heated by debris falling from space
Meteror
Piece of rock or metal that survives entry into the earths atmosphere and lands on the ground
Meterorite
Rock (usually) left over from a comet tail that is in space but about to enter the earths atmosphere
Meteoroid
Rock or metal objects orbiting the sun with a semi-major axes between mars and jupiters
Asteroid
Icy and dusty objects orbiting the sun with semi-major axes ranging from just larger than neptunes to the edge of our solar system
Comet
How often does the earth enter the asteroid belt?
Never
Where does the dwarf planet ceres live?
Asteroid belt
Where does the draws planet Pluto live?
Kuiper Belt
Why does the earth experience meteror showers?
The earth sometimes runs into debris as it crosses the orbits of comets
Do asteroids have tails?
No
How do comet tails behave as the comet orbits the sun?
The comet only has tails when it is close to the sun, and the dust tail stays in the orbit and the ion tail always points away from the sun
What method helps us learn the age of our solar system?
Radioactive dating of asteroids and meteorites
How old is our solar system?
4.5 BILLION years old
The atoms that would eventually become all of the planets and animals on earth were
Already present in the solar nebula
What force drive the collapse of a nebula, the first step of the process that would eventually form our solar system?
Gravity
What observation suggests that different material became solid particles at different distances from the proto-sun?
Terrestrials are made of rock and metal, jovians of hydrogen and helium, and dwarf planets of rock and ice
The Kate heavy bombardment was a time when the rate of impacts dramatically increased, and astronomers suspect it was caused by
The Jovian planets migrating, specifically the ice giants hitting the Kuiper belt
How does the intense bombardment affect how life would arise on the planet?
The comets delivered water and life’s building blocks to earth in great numbers making life more likely
If I orbit beyond mars alongside ceres with a semi-major axis of 2.8 AU, I must be a part of the
Asteroid belt
What would you have to do to make Pluto a planet?
Move it out of the kuiper belt and into an empty orbit
What is 1AU?
The average distance between the earth and the sun
The earth and the moon are made of similar materials, so why has the moon cooled off while the earth is still warm inside?
The earth is larger than the moon
More internal heat leads to….
Active geology (volcanoes, plate tectonics)
What is differentiation by gravity
The metal sank to the cores
What is special about the earth that allowed it to go from a CO2 atmosphere to a nitrogen rich atmosphere?
Earth has plate tectonics which helped lock up the CO2
What prevents earths atmosphere from building up too much CO2 like Venus?
Plate tectonics
Do Jovian planets have surfaces?
No , the atmosphere thickens until it behaves like luiquid
Why do the clouds form higher in the atmosphere on Jupiter and deeper on Saturn, Uranus and Neptune?
Jupiter is closer to the sun and warmer
Jovian moons can be volcanic and have oceans of liquid water. What heats these moons?
Tidal forces from the planet and from other moons
Which has a smaller orbit? Comets or asteroids
Asteroids
Which get closer to the sun? Comets or asteroids
Comets
Why do comets grow tails?
The sun heats the ice, turning it into gas
The earth experiences meteror showers as it orbits when it
Crosses the orbit of a comet and runs into debris
When you look into the sky and see a bright streak of light, you just saw:
A meteor
What would you have to do to Pluto to call it a planet?
Add more mass so that it’s the largest thing in the region
List the TERRESTRIAL planets in order of semi-major axis from SMALLEST to LARGEST
Mercury, Venus, Earth, Mars
