Elementary Astronomy Final Exam

The diameter of the Milky Way Galaxy is close to

100,000 light years

A star is found to have absolute magnitude 4 and apparent magnitude 24. How far away is it?

100,000 parsecs Module 022.403 Stellar Magnitudes and Distance Luminosity, Finding the distance

The length of a sidereal month is 27 days. The time from one full Moon to the next is closest to

29.5 days

An example of a planet with no liquid water at all and a dense carbon dioxide atmosphere is

Venus

Which of the following planets or moons has an atmosphere with about 90 times the surface pressure of Earth's? a. Venus b. Mercury c. Mars d. Titan

Venus

The temperature at the poles of Mercury is expected to be

Very hot all of the time on mountain peaks hit by the Sun and very cold all of the time in craters never hit by the Sun

An encounter between Earth and an iron asteroid fifty meters in diameter would most likely cause

a large explosion on the ground

For a star to give rise to a Nova, the star must be

a member of a multiple star system

When the Earth passes through the orbit of a broken-up comet, we see

a meteor shower

Underneath a place where the sea floor is spreading, one expects there to be

a rising convection current in the Earth's mantle.

The time it takes for the Celestial sphere to rotate once relative to the Earth is called

a sidereal day

A planetary nebula forms when

a star becomes a white dwarf

Newton's explanation of Kepler's Laws relied upon a force that

acted on all objects

Because of the electrical repulsion between atomic nuclei, nuclear fusion happens only

at high tempertures

Which of the following temperatures is closest to what you might expect on the planet Neptune? a. -450F b. -350F c. -150F d. 50F e. -250F

b. -350F

The density of water is 1000kg/m3 , the density of rock is about 3000kg/m3 , and the density of iron is 7800kg/m3 . Which of the following densities would indicate an object that consists mostly of substances much less dense than rock or iron? a. 4000kg/m3 b. 1000kg/m3 c. 3000kg/m3 d. 20,000kg/m3 e. 8000kg/m3

b. 1000kg/m3 Module 010.301-g01 Solar System Overview The Jovian Planets

Just before sunrise, you might find a. A waning crescent Moon setting in the east. b. A waning crescent Moon rising in the east. c. A waxing crescent Moon setting in the north. d. A waning crescent Moon setting in the west. e. A waning crescent Moon rising in the west.

b. A waning crescent Moon rising in the east

The angle between the rotation axis of a planet and the perpendicular to the plane of its orbit is called its "axial tilt." Which of these planets has an axial tilt that is less than one degree? a. Uranus. b. Saturn. c. Mars. d. Earth. e. Mercury.

e. Mercury

The most common element in the universe is

hydrogen

The molecules of both water ice and liquid water are attached to one another by

hydrogen bonds, different parts of each molecule have opposite charges

The stars of the Milky Way are found

in a band of stars stretching across the sky.

A model in which the Moon forms by breaking away from the Earth would predict that the Moon's orbit should be

in the plane of the Earth's equator

In the time of Galileo, telescopes were

know as novelty items but not used for much

The Russian Venera 9 space probe was sent to Venus, where it

landed on the surface and took pictures

In comparison to Cepheid variables, RR Lyra variable stars are

less luminous and more common

Aristarchus measured the angle between the Sun and the Moon when exactly half of the Moon was illuminated. If the Sun were actually just two or three times as far away as the Moon, he would have found that angle to be

less than 90 degrees by an amount that was easy for him to measure

The thickest part of the visible Milky Way is near the constellation

SAGITTARIUS

Pioneer 11 was an early space probe sent to fly past

Saturn

The Law of Inertia states that a moving object will

keep moving if no force acts on it

The distance modulus of a star at a distance of 10 parsecs would be

0 Module 022.302 Stellar Magnitudes and Distance Luminosity, Apparent and Absolute Magnitudes (50%)

A solar sail is a large sheet of light-reflecting plastic spread on an extremely low-mass framework and attached to a spacecraft. Sunlight exerts a force on the sail and moves the spacecraft. Suppose the spacecraft has a total mass of 2000kg (including the sail) and sunlight exerts a total force of 10N on the sail. What will be the acceleration of the spacecraft?

0.005m/s2 EModule 008.518-g01 Science Models of Motion Force and Mass a = F/m QR1

The mass of a carbon atom is 12.00amu while the mass of a helium-4 atom is 4.003amu. If three atoms of helium fuse to form carbon, how much mass is converted into energy?

0.009amu Module 025.201 Mass and Energy (042.21)

The average radius of the Earth's orbit is

1 au

Barnard's star is a near neighbor of the Sun whose properties we know quite well. It is a type M4V with absolute magnitude 13.22. Suppose that another star of spectral type M4V is observed to have apparent magnitude 8.22. How far away is it?

1 parsec

In the Earth's atmosphere, the percentage that is water vapor is roughly

1%

Suppose that the color and behavior of a star identify it as a type that we know has absolute magnitude -3. If the star's apparent magnitude is found to be 7, how far away is it?

1000 parsecs

Cruising far from the Sun, we notice that the Sun's apparent brightness has dimmed to 10 watts per square meter. We know that the apparent brightness at a distance of 1au is 1000 watts per square meter. How far from the Sun are we?

10au

At 8pm, you see that the pointer stars of the Big dipper and the star Polaris are arranged in a vertical line at what time, give or take a minute or so, would you see them arranged at 45 degrees to the vertical?

11pm the same day

Suppose that a sound wave has a wavelength of 12 meters and a frequency of 100Hz. What is the speed of sound?

12 x 100Hz = 1200m/s

The asteroid 2008 AF4 has one chance in 21,000 of hitting the Earth between the years 2078 and 2100. The asteroid is 390 meters in diameter compared to 250 meters in diameter for Apophis. Assuming that an impact could cause the death of 30,000,000 people the average death rate for this type of event is approximately

1500 people per event

Barnard's Star shows a heliocentric stellar parallax near 1/2 seconds of arc. The distance from our Sun to Barnard's Star is

2 parcecs Module 020.405-g01 Stellar Parallax and Distance Parallax Angle and Distance QR2

What total force will cause an object with a mass of 20kg to gain 0.5 meters per second every second?

20 x 0.5 = 10 Newtons

The velocity of sound waves is roughly the same for all wavelengths. Suppose that a sound wave has a wavelength of one meter and a frequency of 1000Hz. The wavelength of a 500Hz sound wave would then be

2m How?

The star epsilon-Eridani shows a heliocentric stellar parallax near 1/3 seconds of arc. The distance from our Sun to epsilon-Eridani is near

3 parsecs

The violet lines in the Hydrogen spectrum are normally seen with wavelengths 410nm and 434nm. In the light of a star that is moving toward us, we might expect to see those lines at wavelengths of

400mn and 424nm or slower wavelenghts

What total force will cause an object with a mass of 10kg to gain 5 meters per second every second?

50 newtons Multiply the mass times the time

At 10pm, you see that the pointer stars of the Big dipper and the star Polaris are arranged in a vertical line. How long, give or take a few minutes, would you need to wait to see them arranged in a horizontal line?

6 hours

The star 3 -Orionis is 8 parsecs from our Sun. The light from 3 -Orionis has been traveling for

8 x 3.3 = 26.4

If we should find micro-organisms on Mars that reproduce using a DNA/RNA scheme and set of amino acids that are mirror images of those used in all Earth life-forms, that would support the

Abiogenesis Model

Underneath the Atlantic Ocean is an undersea mountain range called the MidAtlantic Ridge. That ridge is caused by

An upward current in the Earth's Mantel

The first human landing on the Moon was

Apollo 11 in 1969

Suppose that you drop two objects from the same height at the same time. Both objects are heavy enough to be unaffected by air resistance and one object is twice as heavy. Who predicted that the heavier object would hit the ground long before the lighter one?

Aristotle

The first generally accepted example of Sea-floor spreading was under the

Atlantic Ocean

A pair of sugar phosphate chains connected by pairs of nitrogenous bases describes a molecule of

DNA

Of all the things that might go wrong with distances found by using the method that astronomers refer to as the "distance ladder," which of these is the one that an astronomer would say is most likely? a. The parallax-distance formula is incorrect. b. The parallaxes of nearby objects have been measured incorrectly. c. The apparent magnitudes of distant objects have been measured incorrectly. d. The distance-distance modulus formula is incorrect. e. Distant objects are not behaving the same as nearby objects.

Distant objects are not behaving the same as nearby objects.

Which moon has patterns of cracks in the ice on its surface, indicating a subsurface ocean?

Europa

Joseph Weber designed a series of devices to detect ripples in space-time, called gravitational waves. After several years of effort, Joe announced that he had detected gravitational waves. He built several versions of his devices and they all detected the waves. When other people tried to build similar devices, none of them detected anything at all. Joe's evidence was ignored by the scientific community because

Joe's observations were not produced by others

Pioneer 10 was an early space probe sent to fly past

Jupiter

The second space probe to reach the planet Mercury was

MESSENGER

An example of a planet which may occasionally have liquid water but retains an atmosphere of mostly carbon dioxide is

Mars

Viking 1 and 2 were sent to explore

Mars

The Asteroid Belt is between the orbits of

Mars and Jupiter

Suppose that an asteroid, about 1 kilometer in diameter, shows a 1 in 100 probability of an Earth impact fifty years in the future. Assume that an impact will trigger climate changes that would kill one billion (1,000,000,000) people. Also assume that each of these deaths represents $100,000 in lost production. Using the cold economic logic that we discussed in class, how much money should be budgeted to deflect the asteroid?

One trillion dollars

Voyager 2 is the only space probe so far to have visited

Uranus

The star Wemadeit shows a stellar parallax angle of 0.4 seconds of arc while the star Waytoofar shows a stellar parallax angle of 0.3 seconds of arc. From this, you can conclude that

Wemadeit is closer to our Sun than Waytoofar

When an interstellar cloud fragment does not have enough mass to form a star powered by nuclear fusion, but gets hot enough to glow for a while, it is called

a brown dwarf

The Earth's core consists of

a central core of solid iron and an outer core of liquid iron.

A lunar crater is best described as

a circular ring wall surrounding a flat area

It is expected that a normal Jovian planet, with no accidental encounters that could add or subtract moons, should have

a family of moons, all orbiting in the plane of the planets' equator

In a particular binary star system, we are able to determine the masses of both stars in the system as well as the angle between our line of sight and the plane of the stars' orbits but cannot determine the diameters or atmospheric compositions of the two stars. This system is most likely

a visual binary system

Which of the following spectral types corresponds to the star with the highest surface temperature? a. G0 b. K0 c. G5 d. K5

a. G0

Which of the following spectral types corresponds to a star on the main sequence? a. G2V b. A2Ib c. O2Ia d. K2III e. B4IV

a. G2V

Which of the following objects has no overall magnetic field except for small regions due to magnetized ore deposits? a. Mars b. Jupiter c. Earth's Moon d. Mercury e. Saturn

a. Mars

Which of the following space probes flew past Saturn but not past Jupiter? a. None of these. b. Pioneer 10 c. Cassini-Huygens d. Voyager 1 e. Pioneer 11

a. None of these

A motorcycle is accelerating from rest. Which of the following pairs of forces is an action-reaction pair? a. The force of the motorcycle on the road and the force of the road on the motorcycle. b. The force of the motorcycle engine on the motorcycle and the force of the road on the motorcycle. c. None of these pairs because acceleration requires an unbalanced force. d. The force of the motorcycle on the road and the force exerted on the road by the ground underneath it. e. The downward force of gravity on the motorcycle and the upward force of the road on the motorcycle.

a. The force of the motorcycle on the road and the force of the road on the motorcycle

Which of the following statements is falsifiable? a. There are no green fish in Lake Nyak. b. There are green fish in Lake Nyak. c. All of the fish in Lake Nyak are ugly

a. There are no green fish in Lake Nyak

Which of these moons has landmarks that are not rotating with the rest of the moon, indicating a subsurface ocean? a. Titan. b. Ganymede. c. Europa. d. Enceladus.

a. Titan

Kepler's Laws a. are explained by a force that attracts each planet to the Sun. b. are explained by the action of magnetic fields on each planet. c. have never been explained. d. are explained by a force in the direction of each planet's motion. e. are explained by a force that repels each planet from the Sun.

a. are explained by a force that attracts each planet to the Sun

Which of the following types of radiation has the second lowest frequency on this list? a. infrared light. b. red light. c. X-rays. d. green light. e. heat radiation.

a. infrared light

If the frequency of electromagnetic radiation goes from 31014Hz to 61014Hz, the energy of each individual photon in the radiation a. is multiplied by 2. b. is multiplied by 3. c. is divided by 3. d. does not change. e. is divided by 2.

a. is multiplied by 2

Consider a planet that is similar to Earth in size and Mass with a semiliquid interior. According to our current understanding, which of the following things is also necessary for that planet to have active plate tectonics? a. The core temperature should be much higher than the surface temperature. b. The core temperature should be the same as the surface temperature. c. The intensity of sunlight should be the same as on Earth. d. The core temperature should be much lower than the surface temperature. e. The amount of liquid surface water should be the same as on Earth.

a. the core temperature should be much higher than the surface temperature

Which of the following phases of the Moon would be seen high in the south at dawn? a. waning quarter. b. waxing quarter. c. waning crescent. d. full. e. waxing crescent.

a. waning quarter

In addition to being accurate, Tycho Brahe's observations focused on measuring the positions of the planets

all the time

The ancient Greeks were able to calculate the distance from the Earth to the Moon by using a geometrical model of

an eclipse of the Moon

Kepler's First Law of Planetary Motion is that the orbit of each planet is

an ellipse with the Sun at one focus

Large numbers of protostars can be seen by using

an infra-red telescope

The main reason that telescope mirrors can be much larger than lenses is that the mirrors

are lighter because they are thinner

The brightest star in the constellation Centaurus might be named a. Alpha Cepheus. b. Alpha Centauri. c. Delta Cepheus d. Delta Centauri

b. Alpha Centauri

Which of the following was the spacecraft that operated in Mars orbit for nine years, finding traces of water and an early magnetic field? a. Viking orbiter 2 b. Mars Global Surveyor c. Viking orbiter 1 d. Mariner 9 e. Surveyor 1

b. Mars Global Surveyor

Galileo was the original discoverer of a. Kepler's First Law of Planetary Motion b. Newton's First Law of Motion. c. Galileo's First Law of Motion. d. The reflecting telescope. e. The Planet Uranus.

b. Newton's First Law of Motion

The capture theory, in which our Moon forms separately and is captured by the Earth, enjoyed a brief popularity when computer models showed that such a capture would have been possible. a. The capture theory was dropped because it predicts that the Moon should orbit in the plane of the Earth's equator and it does not. b. The capture theory was dropped because it predicts that the Moon should have hydrated rocks and it does not. c. The capture theory is still the accepted model for the formation of the Moon. d. The capture theory was dropped because it predicts that the Moon should not have a large iron core and it does.

b. The capture theory was dropped because it predicts that the Moon should have hydrated rocks and it does not.

Einstein's Theory of Relativity has passed every observational test for over 100 years. Cliff has analyzed a large family of alternative theories and figured out what each one predicts for the results of observational tests. Cliff presents his analysis at a scientific meeting. Which of the following would be the most likely reaction of the scientists at the meeting to this new development? a. There is great hostility because the alternative theories challenge the established theory, so lots of scientists come to Fred's talk to debate the issue. b. There is great interest because the analysis suggests new tests that could prove that Relativity is wrong, so lots of scientists come to Cliff's talk to congratulate him. c. There is great disinterest because there is no need to replace a theory that has passed every observational test. Nobody at all comes to Cliff's talk.

b. There is great interest because the analysis suggests new tests that could prove Relativity is wrong, so lots of scientists come to Cliff's talk to congratulate him

Which of the following particles has the smallest mass? a. neutron. b. neutrino. c. proton. d. deuteron. e. positron.

b. neutrino

Carbon is a. relatively uncommon, not in the top ten most common elements. b. one of the four most common elements in the universe. c. the most common element in the universe. d. a compound and not an element. e. the second most abundant element in the universe

b. one of the four most common elements in the universe

The newspaper says that the Moon was full last night. That statement is most likely

based on some authoritative reference such as the US Navel Observatory

A star that forms an iron core most likely has a mass of

between 15 and 20 solar masses

The objects of the Kuiper belt are mostly orbiting

beyond all of the Jovian planets

The Oort Cloud is located

beyond the orbit of Pluto

A large asteroid impact can affect the Earth's climate primarily by

blocking the sunlight with its smoke and dust

The source that is called Sgr A* emits

both infrared light and radio waves

A star at a distance of 1000pc should have an apparent brightness equal to its absolute brightness multiplied by a. 10-6 b. 10-5 c. 10-4 d. 10-2 e. 10-3

c. 10-4

Which of the following statements is falsifiable? a. All of the fish in Lake Nyak are beautiful. b. There are fish in Lake Nyak. c. All of the fish in Lake Nyak are green.

c. All of the fish in Lake Nyak are green

The Ptolemaic System continued to be accepted long after such people as Aristarchus and Copernicus had proposed alternatives. All of the following reasons why it lasted so long are at least partly true. Which reason is the one that would be stressed by the philosophy of science that we have been discussing? a. It was easier to understand and people do not like to learn new things. b. Church authorities supported it and did not want it replaced. c. It correctly predicted what was observed and thus did not need to be replaced.

c. It correctly predicted what was observed and thus did not need to be replaced

Which of the following statements best describes the presence of water on Mars? a. Mars has liquid water flowing steadily on its surface at the present time. b. At the present time, Mars is completely covered by a thin layer of frozen water ice. c. Mars probably had liquid water flowing on its surface at some time in the past. d. At the present time, Mars is completely without water in any form.

c. Mars probably had liquid water flowing on its surface at some point in the past

An example of a life form that does not get its energy originally from the Sun would be a. a fish in the ocean. b. a tree on land. c. a tube worm near a black smoker.

c. a tube worm near a black smoker

The Tau-Tauri wind from the Sun's final collapse toward ignition a. moved Jupiter to its present orbit. b. provided gas to Jupiter and the other Jovian planets. c. blew away the fuel that Jupiter needed to become a star. d. provided the heat that Jupiter needed to become a star. e. had no effect on the Jovian planets.

c. blew away the fuel Jupiter needed to become a star

As of 2009, the search for near-Earth asteroids that could threaten global effects has most likely a. found only a small fraction of them. b. found none of them since it has not started yet. c. found about 90% of them. d. found all of them.

c. found about 90% of them

The rotation axis of Saturn is a. nearly perpendicular to the plane of its orbit, so it has no seasons. b. almost in the plane of its orbit so that its ring system can sometimes be seen as near-circles. c. inclined at an angle to the perpendicular that is similar to Earth's rotation axis.

c. inclined at an angle to the perpendicular that is similar to Earth's rotation axis

A star with an absolute magnitude of -8.4 and an apparent magnitude of -1.0 would appear in our sky as a star a. of average naked-eye brightness. b. visible only with a telescope. c. of dazzling brightness. d. barely visible to the naked eye.

c. of dazzling brightness

Asteroids a few meters in diameter hit the Earth's atmosphere a. once in a thousand years, and create widespread devastation. b. once in a hundred years and cause local devastation. c. once every few years and cause air bursts similar to small nuclear weapons. d. once every few years and cause only meteor trails.

c. once every few years and cause air bursts similar to small nuclear weapons.

Compared to the frequency of photons absorbed during a transition from a from a -6ev state to a -4ev state, transitions from the -5ev state to a -3ev state would correspond to absorbing photons whose frequency is a. 2 times as high. b. 5 times as high. c. the same. d. 3 times as high. e. 4 times as high.

c. the same

Milankovich cycles refer to

changes in the intensity of sunlight due to shifts in both the Earth's orbit and rotation axis.

The Ptolemaic model of the Solar System has each planet moving along a

circular epicycle whose center, in turn, moves around the Earth

Which of the following magnitudes corresponds to the brightest star? a. -1.2 b. -2.6 c. -4.1 d. -4.2 e. -1.0

d. -4.2

Which of the following spectral types corresponds to the star with the highest surface temperature? a. F5 b. G5 c. G0 d. F0

d. F0

The International Space Station (ISS) is in a roughly circular orbit near the surface of the Earth, moving at around 5 miles per second. Suppose that it is desired to raise it to a new circular orbit, farther from the surface by having the space shuttle give it one or more short boosts. Which of the following schemes will work? a. Push it directly upward, away from the Earth. b. Increase its speed to 8 miles per second to put it on a rising path. c. Decrease its speed to 4.9 miles per second and then give it a speed boost when its distance from the Earth stops decreasing. d. Increase its speed to 6 miles per second and then give it another speed boost when its distance from the Earth stops increasing. e. Increase its speed to 6 miles per second to put it on a rising path.

d. Increase its speed to 6 miles per second and then give it another speed boost when its distance from the Earth stops increasing.

Which of the following systems is closest to the plan of most current Earth life-forms? a. Lots of RNA molecules copy themselves and also act as enzymes which construct and operate a life-form. b. One DNA molecule carries out all of the chemical processes needed to construct and operate a life-form. c. One RNA molecule carries out all of the chemical processes needed to construct and operate a life-form. d. One DNA molecule is used to make RNA molecules which, in turn make the proteins and enzymes that construct and operate a life-form. e. One RNA molecule is used to make the proteins and enzymes that carry out all of the chemical processes needed to construct and operate a life-form.

d. One DNA molecule is used to make RNA molecules which, in turn make the proteins and enzymes that construct and operate a life-form.

Which of the following particles would be attracted to a neutron through the strong force? a. electron. b. neutrino. c. positron. d. proton.

d. proton

Copernicus argued that the final version of the Ptolemaic System failed to satisfy a basic assumption of the original Ptolemaic System because it

did not really have anything fixed in place at the center of the universe.

Liquid water tends to remove carbon dioxide from the atmosphere of a planet by

dissolving it and washing it out of the atmosphere

You would expect to see a waning crescent Moon a. Setting in the West right after the Sun. b. Rising in the West just before the Sun. c. In the North at around midnight. d. Setting in the East right after the Sun. e. Rising in the East just before the Sun.

e. Rising in the East just before the Sun

So far (as of 2008), the planet Venus has been visited by a. two or three successful space probes. b. just one successful space probe. c. no successful space probes. d. about 48 successful space probes. e. about 20 successful space probes.

e. about 20 successful space probes

Which of the following objects is the most likely to be considered a scientific model? a. A blackboard. b. A computer program. c. An oil painting of a person. d. A test-tube. e. An accurate map of Richmond

e. an accurate map of Richmond

Sedna is thought to be a. in the Main Kuiper Belt. b. in the Outer Oort Cloud. c. in the asteroid belt. d. a Scattered Disk Object. e. in the Inner Oort Cloud.

e. in the Inner Oort Cloud

Comets usually follow orbits which are

elliptical with aphelia far outside the orbit of Mars.

A brown dwarf shines primarily with

energy left over from its formation

The magnetic field of Earth's Moon is

essentially zero

One objection to a solar system model that has the Earth moving around the Sun is that we would then see nearby stars seem to shift back and forth relative to more distant stars. The correct answer to that objection is that

even the closest stars are so far away that the shift is very small

The point at which even an outwardly directed light ray is pulled into a black hole is called the

event horizon

The time from one solar noon to the next is

exactly 24 hours

Kepler was an early advocate of the Copernican Theory. When he applied it to Tycho's observations, it

failed but led to a better theory

Suppose that the Space Shuttle is in a roughly circular orbit near the surface of the Earth, moving at around 5 miles per second. Suppose the Space Shuttle flips over backwards and fires its rocket engine to slow its speed to 4.96 miles per second. The shuttle will then

follow an ellipse that descends a bit and then rises again

Supernova explosions tend to

form elements heavier than iron

Carbon is essential for all life we know about because it

forms complex compounds

To measure the heliocentric stellar parallax of a star, you mostly need a telescope with

high resolving power

For stars on the main-sequence, stars with increasing mass have

increasing surface temperature and absolute brightness

The portion of the Earth that is solid iron and nickel is the

inner core

The reason that the Crab Pulsar is slowing down is

its magnetic field is dragging through nearby gas

The eclipse or transit photometry method of searching for exoplanets can be expected to find

less than one out of every 10 exoplanets

Apollo 8 made the first

manned orbit of the Moon

The motions of the stars near Sgr A* make it possible to determine its

mass

The X-rays that reveal the possible presence of a black hole are the result of

matter heating up as it falls toward the hole

Near the center of the Milky Way there is an intense radio source whose mass is approximately three

million solar masses within several light days of the center.

The gravitational energy that is released when the core of a massive star collapses is usually

much larger than the nuclear energy that the star has generated

In the Earth's atmosphere, the amount of carbon dioxide is

much less than the typical amount of water

The main ingredient in the atmosphere of Titan is

nitrogen

The patent for inventing the telescope was obtained by

nobody because it was too simple an idea to patent

The part of a protostar where the density first becomes low enough for light to escape is called the

photosphere

It has been theorized that planets do not easily form in binary star systems. If they do form, there are three possible arrangements: (1) Planets with orbits similar in radius to the distance between the two stars. (2) Planets with orbits much smaller in radius than the distance between the two stars. (3) Planets with orbits much larger in radius than the distance between the two stars. Observations so far (2009) indicate that

possibilities (2) and (3) actually happen

The "Little Green Men Standard Time" hypothesis for the repeating radio signals seen in 1968 was rejected partly because the repetition rate was

slowing down

The role of the DNA molecule in current Earth life is to

provide the patterns for the enzymes that carry out the chemical processes of life

When a red giant star begins to burn helium, it

returns part way to the main sequence in an HR diagram

The idea that science only deals with statements that are falsifiable, subject to possible disproof by observation, suggests that

science produces revisable facts

As seen from North America, the constellation Orion

sets in the west and southwest

A black hole that has formed from the collapse of a star is expected to be

similar in size to a neutron star

The chlorophyll in plants uses sunlight to

split water into hydrogen and oxygen

Consider a light source whose absolute magnitude can be deduced from the properties of the light that reaches us from that source. Astronomers often refer to this sort of object as a

standard candle

In the picture that we used in class, with the Sun above the top of the picture and the Earth shown with its North Pole facing you, the part of the Earth that is to the right of the North pole in the picture is experiencing

sunrise

In the picture that we used in class, with the Sun above the top of the picture and the Earth shown with its North Pole facing you, the part of the Earth that is to the left of the North pole in the picture is experiencing

sunset

The average energy of motion of an atom or molecule in a gas is called its

temperture

From his observations of the phases of Venus, Galileo concluded that the Ptolemaic model of planetary motion was wrong because it predicted

that there could never be a full Venus but Galileo saw one

The ancient Greeks concluded that the Sun is farther from the Earth than the Moon because

the Moon's shadow falls on the Earth during a solar eclipse

Icy objects were ejected outward from the neighborhood of the Jovian planets to form

the Oort Cloud

The period of a proto-star's evolution when its size and brightness decrease just before the ignition of nuclear reactions in its core is called

the Tau Tauri phase

The term "greenhouse effect" refers to

the absorption of infrared light by gases in the atmosphere

During the Tau Tauri phase of a protostar's evolution,

the brightness decreases

For an object that is moving along a straight path, the acceleration is

the change in the object's speed divided by the time it takes

A converging lens will send light rays that are parallel to the axis through

the focal point of the lens

The frequency of a wave is defined to be

the number of crests that pass in one second

The ecliptic is

the path of the Sun on the Celestial Sphere

The two Hydrogen atoms in a water molecule are both attached

to the Oxygen atom, but offset so that the molecule looks bent..

Pathfinder was the first

to use airbags to land on Mars

The Moon rotates on its axis so that it always keeps the same side

toward the Earth

A planet that is following Kepler's Laws, accelerates

toward the Sun

The wavelength of the sound waves that correspond to middle-C is about 4 feet. If you are standing 8 feet away from a piano that is playing that note, then between you and the piano there will usually be

two regions of maximum pressure

Astronomy is known for claiming to have measured many things that cannot possibly be probed directly. These measurements are made by combining actual measurements with

well-tested models

A disadvantage of the flat Earth model is that it fails to provide a complete explanation of

what holds up the surface of the Earth

The idea that a worthwhile model of a situation must predict what is actually observed seems to have started

with ancient Greek philosophers