Astronomy Final

If no one has ever visited the core of the Earth, how do we know that it is made of metal?

(b) circulating liquid metals in the core set up a measurable magnetic field

The inner planets are made mostly of rock and metal because:

(c) it was so hot where the inner planets formed that only metal and rock condensed

Which of the following is NOT a way that Venus resembles the Earth?

(c) the thickness and pressure of its atmosphere

Given that the density of water and water ice is 1 g/cm3, that of rock 3, and that of metal is 8, what would you expect to be the composition of a solar system object with a density of 5.5?

(d) 50% metal, 50% rock

Which have the most elliptical and tilted orbits?

(d) terrestrial planets

Which statement about planetary rings is not true?

A) Saturn's rings formed along with its moons 4.6 billion years ago.

Which of the following best describes Saturn's rings?

A. Made from many icy particles, ranging from dust grains to bolders, each orbiting according to Kepler's laws

At what stage in its life does a star pass through the protostar phase?

After condensation but before nuclear reactions begin in its core

Which of the following is a correct statement about the distribution of mass in the solar system?

Almost all the mass (99.8%) of the solar system's mass is in the sun, so the solar system is made up of basically 98% hydrogen and helium.

Which of the following is not true about Jupiter?

D. Jupiter is an incredibly cold planet, since it lives in the outer solar system - so cold in its interior that the interior is liquid and solid hydrogen.

This is a good "unit" for the US national deficit (a good way or representing the deficit)

Dollars per US resident

Which of the following statements about Titan is not true?

E) It is the coldest moon in the solar system.

Which of the following is not true about the surfaces of inner solar system planets?

E. Venus doesn't have any craters on its surface, because it's think atmosphere protects it from all impacts

This is the phase of the moon during a lunar eclipse, and the kind of tide experienced on Earth where it is solar noon during that eclipse

Full moon, spring tide

This is the correct ordering of the terrestrial planets from slowest to fastest

Mars, Earth, Venus, Mercury

Which is not true about our solar system? _________

The composition and motions of the planets appear fairly random, without any discernible patterns.

Which of the following is not a clue to how our solar system formed? _______

These are all clues to how the solar system formed

How do we determine the age of a globular cluster?

We plot an HR diagram and look for where the main sequence turns off to become the giant branch.

This is the fundamental reason different elements emit different, specific spectral lines

What are energy levels?

This is the orbital period of a planet orbiting a star the mass of our sun at 4 AU.

What is 8 years?

This is the type of spectrum we get when a star's light passes through a cool, not too dense cloud of gas

What is an absorption spectrum?

This is how the wavelength of a 700nm spectral line would change if it were emitted from a star coming toward us.

What is decreasing in wavelength due to the doppler shift...

This is why astronauts feel weightless.

What is falling around the earth?

This is the phase of the moon that during a solar eclipse, and the phase of the moon during a lunar eclipse.

What is new moon and full moon?

This is what Mars does in the night sky when the Earth catches it and passes it.

What is retrograde motion?

This is why Earth has seasons.

What is the tilt of Earth's axis (which leads to the sun being higher and lower in the sky throughout the year, giving more direct and less direct sunlight)

This is a possible method for determining the radius of a star given it's peak wavelength and luminosity.

What is using Wein's law to find a star's temperature, and then using the Stefan-Boltzmann law with the temperature and luminosity to calculate radius?

An asteroid is

a planetesimal moving in an orbit around the Sun.(b) a meteorite before it enters the atmosphere and plunges to Earth.

Which of these stars has the hottest core?

a white main-sequence star

During which stage is the star's energy supplied by primarily by gravitational contraction?

a) Stage ii

Lava from a volcano partially fills a crater that sits upon a landslide within a large rift valley. Which of these geologic features formed most recently? ________

a) The lava flow

Pulsars are thought to be:

a) rapidly rotating neutron stars

Which of the following statements about electron degeneracy pressure and neutron degeneracy pressure is true?

b) Electron degeneracy pressure is the main source of pressure in white dwarfs, while neutron degeneracy pressure is the main source of pressure in neutron stars.

Which stage lasts the longest?

b) Stage iii

Star A is identical to Star B, but Star A is twice as far from us as Star B. Therefore,

b) both stars have the same luminosity, but the apparent brightness of Star B is four times that of Star A

Stars that lie in different places on the main sequence of the H-R diagram differ from each other mainly by having different:

b) internal structure

Suppose an astronomer discovers a star of M spectral type that is very luminous (intrinsically bright). Which one of the following can he conclude about the star?

c) it is hot

Every second, the Sun converts about 600 million tons of hydrogen into 596 million tons of helium. The remaining 4 million tons of mass is _________.

converted to an amount of energy equal to 4 million tons times the speed of light squared

The source of energy that keeps the sun shining is

d) gravitational contraction

During which stage does the star have an inert (non-burning) helium core?

e) Stage viii

Why can a star with a mass like our Sun not fuse further elements beyond carbon and oxygen

e) because they cannot get hot enough for the fusion of heavier nuclei

This the the path of the sun through the stars over the course of the year.

ecliptic

Conservation of energy

helps us understand this because objects that are higher off the ground - further away from an object, have more gravitational potential energy. When they "fall down" to closer to the object they convert some of that potential energy into kinetic energy, which means they move faster

Newton's law of gravity

helps us understand this because when objects are closer, they feel more gravitational force. Thus to keep orbiting and not fall into the sun, they have to move faster

Kepler's 2nd law

states that objects move faster when they are closer to the sun