Astronomy final exam weeks 7-9
What is the likely source of Earth's early atmosphere that consisted of carbon dioxide and water vapor?
It was outgassed from Earth's interior during volcanic activity and it arrived in the form of icy planetesimals that impacted Earth.
Briefly describe the greenhouse effect.
Sunlight is absorbed by Earth's surface then reemitted as infrared radiation. Greenhouse gasses absorb this radiation, resulting in a higher surface temperature for the planet.
Why does the Moon not have an atmosphere?
Because the Moon's mass is so small, its gravity cannot prevent gas molecules from quickly escaping into space.
How does the large-impact hypothesis explain the moon's lack of iron?
Both planetesimals were differentiated, and the two iron cores went to Earth
Which of the following is due to the moon's small size? - all of the below - The moon has no atmosphere. - The moon does not have a dipole magnetic field. - The moon does not have plate tectonics. - The moon's surface geology is dominated by impact craters.
all of the below
Which of the following statements about our Moon is FALSE?
on Earth, we can see all its sides in the course of a month as it goes around us
Summarize the four main hypotheses for the origin of the Moon:
- The Moon formed elsewhere in the solar system and was captured by Earth. - The Moon was once part of the Earth, but they separated early in their history. - A large object collided with Earth and ejected a large amount of Earth's mass into space, which became the Moon. - The Moon and the Earth formed at the same time, but separately.
Frozen water exists on the lunar surface primarily in which location? why?
- in craters near the poles (why)- These craters are permanently covered by shadows not allowing enough energy from the sun to melt the ice.
What is Earth's core and mantle made of? (Select all that apply.) -The mantle is made of rock. - The core is primarily made of rock. - The mantle is made of iron and nickel. - The core is primarily made of iron and nickel.
-The mantle is made of rock. - The core is primarily made of iron and nickel.
What creates Earth's strong dipole magnetic field?
Convection in Earth's outer liquid iron-nickel core combined with Earth's rotation.
What happened to the majority of the carbon dioxide that was formerly in Earth's atmosphere?
Most of it dissolved into the oceans and now is in the form of limestone rocks of Earth's crust
What is, by far, the most abundant component of Earth's atmosphere?
N2
The first human being to step out onto the surface of another world was _____.
Neil Armstrong
What distinguishes Earth's inner core from its outer core?
The inner core is solid, and the outer core is liquid.
Why does the same side of the moon always face Earth?
The moon rotates in the same direction that it revolves and the moon's period of rotation is equal to its orbital period.
a) What evidence would you expect to find on the Moon if it had been subjected to plate tectonics? (Select all that apply.): - the presence of vesicular basalts - long folded mountains - the equivalent of mid-ocean rifts and rift valleys - the presence of jumbled terrain - the absence of smooth plains b) Do you find such evidence?
a) - long folded mountains - the equivalent of mid ocean rifts and rift valleys b) no
a) Which is not true about the greenhouse effect? b) What is not true about global warming?
a) It is bad for the environment. b) It is just another name for the greenhouse effect.
a) How was the Hawaiian-Emperor island chain formed? b) How does the formation of the Hawaiian-Emperor island chain help in the understanding of tectonics?
a) Motion of the Pacific plate allowed volcanic hot-spots to punch through the crust. b) It is an example of tectonics and volcanism working together to form mountains.
a) What must be true about Earth's core to generate Earth's magnetic field? b) Which of these conducting materials is not found in the Earth's core? c) What must be true for a large portion of Earth's core in order for convection to occur?
a) The material must be conductive, The core must be rotating, The material must convecting. b) copper c) It must be liquid.
a)Rank each atmospheric composition in order of when it occurred on Earth, oldest first: carbon dioxide, and oxygen. b) Rank the following atmospheric gases in order of their abundance in Earth's current atmosphere: carbon dioxide, nitrogen, oxygen.
a) oldest: carbon dioxide Youngest: oxygen b) most: nitrogen middle: oxygen least: carbon dioxide
a) Mercury's core is probably which of the following? b) What evidence do astronomers have for the answer to the previous question? c) Mercury's core is probably which of the following? d) What evidence do astronomers have for the answer to the previous question?
a) partially molten b) a weak magnetic field c) metallic d) Mercury is small and of high density.
In what ways is Earth unique among the Terrestrial worlds? - oceansa - nitrogen-oxygen atmosphere - life - all of the above
all of the above
Where on Earth are two plates being pushed apart and new crust created?
along the center of the Atlantic Ocean and along the center of the Red Sea
The average temperature on planet Earth is higher than you would expect just from the heating of sunlight alone. What is the explanation for this?
carbon dioxide (and other gases) in the atmosphere cause a greenhouse effect
What produced the oxygen in Earth's atmosphere?
plants
Which theory of the Moon's origin do astronomers (and the evidence) favor?
the giant impact theory
What is one important way in which both the Moon and Mercury are different from Earth?
they do not have an atmosphere
week 7
week 7
week 8 + 9
week 8 + 9