Astronomy 2 (Questions)
In studying the surfaces of solid bodies in the solar system, astronomers have learned that the number of craters (per unit area):
is roughly proportional to the age of the surface we are examining
Today, scientists believe that the main reason the Earth has had periodic ice ages is:
slow changes in the tilt of our planet's axis of rotation
The majority of the moons orbiting the outer (jovian) planets are:
small moons orbiting in a retrograde direction (opposite to the direction their planet turns and orbits)
In which region of the Earth's atmosphere have you spent most of your life?
troposphere
Which of the following is NOT a correct statement about the ways the jovian planets differ from the terrestrial planets?
all the jovians have satellites around them and none of the terrestrials do
If there are at least a million asteroids, how did spacecraft like Galileo survive their trip through the asteroid belt?
although there are many asteroids, they are widely spaced (there is lots of space between them)
What is one important way in which both the Moon and Mercury are different from Earth?
they do not have an atmosphere
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
The reason that worlds like the Earth are differentiated is that
the continuing impacts on a growing protoplanet eventually melted the entire body
Which of the eight planets has a smaller mass than Mercury?
you can't fool me, Mercury has the smallest mass of the eight planets
Which of the jovian planets does NOT have any satellites?
you can't fool me, all the jovian planets are accompanied by satellites
Comets get significantly brighter in our skies as they approach the Sun because
you can't fool me, more than one of the choices above is correct
The person who really publicized the idea of canals on Mars and impressed it on the public mind was:
Percival Lowell
The reason that Olympus Mons, the tallest mountain on Mars, is taller than Mount Everest (the tallest mountain on Earth) is that (choose all that apply):
-there are no continental plates that move sideways on Mars, while there are such sliding motions on Earth -the gravity on Mars is less, so a larger mass can support itself against its own weight
Jupiter has enough mass to make 318 Earths. In contrast, Uranus and Neptune have only enough mass to make:
15 earths
The largest continental (highland) area on Venus is called:
Aphrodite
Which of the following is NOT one of the largest moons in the Solar System?
Atlas (shepherd moon near Saturn's A ring)
The largest and most massive of Saturn's rings is the ____ Ring
B
A crucial difference that helps explain why Venus is so hot and the Earth isn't is that:
on Venus, there was eventually no ocean to remove carbon dioxide from the atmosphere
The first spacecraft which did not merely fly by a jovian (or giant) planet, but actually went into orbit around it for an extended period of time was:
Cassini
The first trans-Neptunian object astronomers found (in 1930) is called
Ceres
When the Dawn spacecraft explored the largest asteroid Ceres, it discovered white spots that appear to be salt and volcanic mountains made of water ice. This led astronomers to which of the following ideas
Ceres may have (or may have had) a liquid ocean under its crust
For scientists, one bar is
the average height of the ozone layer above the Earth (before we began to deplete it)
The satellite whose surface is characterized by a smooth icy crust with a complex network of cracks is:
Europa
The four large moons of Jupiter were first discovered by:
Galileo with his early telescope
The Galileo spacecraft measured that the moon Ganymede had a magnetic field, indicating that its interior was at least partly melted and warm. What do scientists think is the most likely reason for this?
Ganymede is heated by tidal forces from Jupiter
The two asteroids from which close-up images and data have been returned by the Galileo spacecraft are:
Ida and Gaspra
According to our textbook, what is the best way to defend ourselves against an asteroid which is on course to collide with the Earth in 7 years?
If we do it early enough, we could explode something on or near the asteroid to deflect it slightly, so that years later it would then miss the Earth
Why are there no smaller craters on the surface of Venus, only bigger ones?
In Venus' thick atmosphere all smaller chunks of material burn up before they can reach the surface
A planet in our solar system whose composition resembles that of our Sun is:
Jupiter
The large, roughly circular, dark, and somewhat younger regions on the Moon are called:
Maria
The highest mountain on Venus is also the only feature to be named after a man; its namesake is the Scottish scientist who laid the foundations for our understanding of electro-magnetic waves. This is Mount:
Maxwell
Which of the following statements about Mercury's orbit is TRUE?
Mercury has the highest speed in its orbit of any planet
Which of the following statements about NEO's (Near Earth Objects) is TRUE?
NEO's can include both asteroids and comets that cross the Earth's orbit
The first human being to step out onto the surface of another world was:
Neil Armstrong
In the far future, a daring interplanetary tourist wants to go "hang-gliding" on the jovian planet with the highest equatorial wind speeds. Which planet would have the fastest wind at its equator?
Neptune
The moon Triton orbits which of the planets?
Neptune
The largest volcano on Mars is called:
Olympus Mons
What relatively recent event shows that impacts continue to happen in our solar system even today?
a comet (which broke into more than 20 pieces) hit the planet Jupiter in 1994
Which of the following statements about the tails of comets is FALSE?
a comet always has a nice long tail, even when it is far from the Sun
A type of planet that our surveys of exoplanets are revealing around other stars, but we don't have any examples of around the Sun are:
Super-Earth's
One of the most impressive features of the geology of Mars is an uplifted area about the size of North America, with volcanoes on it, which is called the
Tharsis Bulge
Which of the following statements about the rocks brought back from the Earth's Moon by the astronauts is TRUE?
The Moon rocks were puzzling, because they resemble rocks from the Earth's crust in many ways, but also have subtle differences
Which of the following statements about Saturn's rings is TRUE?
The rings are made of billions and billions of individual "moonlets" (small chunks)
What do astronomers think is the origin of the many irregular moons around the outer planets (irregular meaning they are orbiting backwards and/or have eccentric orbits)?
These moons were likely formed elsewhere and captured by the giant planets
How have astronomers learned what different asteroids are made of?
They examine the spectrum of the sunlight that reflects from the asteroid
How can astronomers measure the age of a meteorite that fell from the skies?
They measure the amount still left of radioactive materials in the meteorite, and how much has turned into decay products
The satellite which has the thickest atmosphere (so thick that it's quite a surprise for a satellite) is:
Titan
The planet that orbits "on its side" (i.e. has its rotation axis perpendicular to the plane of its orbit) is:
Uranus
The planet that most resembles the Earth in size and internal composition is
Venus
What planet can come closest to the Earth in its orbit and look brightest in our skies?
Venus
Which of these worlds is the most active geologically?
Venus
Which of the following is NOT a correct statement about the rotation of Venus?
Venus rotates in roughly the same time period as Earth
Much of what we have learned about the jovian planets and their satellites has come from the work of two spacecraft called:
Voyager
When a projectile (a rock from space, say) hits the surface of the Moon, which of the following do we NOT get?
a gushing out of lots of water that had been frozen inside the ground on the cold Moon, but is briefly heated by the impact
These days the theory of the Earth's Moon's origin that best fits with the facts we have about the Moon is:
a large object hit the Earth and the collision produced a filament of material that condensed to make the Moon
When two objects in orbit have periods of revolution that are simple ratios of each other (such as 1 to 2 or 1 to 3) we say that we have:
a resonance
At the beginning of the solar system's history, a ready supply of proto-planets or mini-planets crashed into the developing planets and each other - something astronomers call the "era of giant impacts." How long do astronomers estimate this era lasted?
about 100 million years (0.1 billion)
One way in which the ozone layer is useful for life forms on the Earth's surface is that it
absorbs ultra-violet light, preventing much of it from reaching the surface
We believe the maria on the Earth's Moon are:
ancient impact craters in which lava beds welled up from inside the Moon
What is one way that astronomers have actually gotten an idea of the age of the surfaces of terrestrial planets other than the Earth?
counting craters
Which of the following is NOT something that was accomplished by the Apollo missions to the Moon?
discovering that the Moon has a great deal of water under its surface
One of the best proofs that our theory of how the solar system formed is correct is that astronomers now observe
disks around other stars which show evidence of gaps where planets may be forming
Which of the following statements about the atmosphere of Mars today is FALSE?
droplets of liquid water fall from thick clouds and irrigate the surface of Mars regularly
A main difference between asteroids and comets is that asteroids are mostly made of rock and comets are mostly made of
ice
Which of the following points about our planet's atmosphere is FALSE?
its mass is a substantial part of the mass of the Earth
Which of the following is a way that the planet Mercury is similar to the Moon?
its surface is heavily cratered
In a bad late-night science fiction film, a villain is using a large collection of rare radioactive atoms as energy for a weapon to threaten the good guys. The atoms have a half-life of 1 hour. The villain has 4 kilograms of the radioactive material now, and he needs a minimum of 1 kg. for his weapon to work. After how much time will the weapon no longer be a threat?
just a little after 2 hours
About 75% of the surface of Venus consists of
lowland lava plains
The first technique that allowed astronomers to find exoplanets involved:
measuring changes in the radial velocity (Doppler shift) of the star caused by the pull of orbiting planets
The bluish color that makes the atmosphere of Neptune so beautiful to the human eye is caused by the interaction of sunlight with what gas?
methane
The lakes found in the north polar region of Titan are filled with liquid
methane
Which part of a comet is the DENSEST?
nucleus
The canals that late 19th and early 20th observers thought they saw on Mars turned out to be:
optical illusions
The Murchison meteorite that was found in Australia in 1969 is important to scientists because it contained
organic materials, such as amino acids
Callisto, the fourth moon of Jupiter's, takes 17 days to orbit Jupiter. If I stand on the surface of Callisto and see Jupiter high in the sky over my head, and then wait 8.5 Earth days in the same spot, where will I see Jupiter?
overhead, where it was before.
How do astronomers know that the age of the solar system is about 4.5 billion years old?
radioactive dating of the primitive meteorites indicates they have that age (since they are left-over building blocks of the solar system)
All the planets (without exception)
revolve around the Sun in the same direction
Scientists have been concerned about a set of industrial chemicals called CFC's (chlorofluorocarbons) because they:
rise into the atmosphere and destroy ozone
The lunar highlands are made mostly of rocks that
rose to the top as the Moon cooled from a molten state early in its history
One way to find a new meteorite is to:
search the area beneath or close to the point where a bright fireball was seen to burn out
Which of the following is NOT a way we have studied the planet Mars so far?
sending spacecraft to Mars which have brought samples of the planet back to Earth
Astronomers now believe that the differences in composition among the planets reflect what characteristic in the early solar system
temperature
Which of the following is not a characteristic that worlds in our solar system have in common:
that all the planets have solid surfaces on which we can see impact craters
Mercury is a small planet and therefore has trouble holding on to an atmosphere. How then do scientist account for the extremely thin atmosphere that was found around the planet in 1985?
the Sun's "wind" of particles is chipping atoms off the surface of Mercury
Which of the following pieces of observational evidence does our modern "solar nebula" theory of the formation of the solar system NOT explain directly?
the ages of the oldest rocks on Earth, the Moon, and meteorites
According to astronomical tradition, who gets to suggest the name for a newly discovered asteroid?
the discoverer of the asteroid
Today, a significant amount of new gas is joining the atmosphere of the Earth from what source:
volcanoes release gas that was trapped within the Earth
What is the most important reason that astronomers have learned more about our planetary system in the last 30-40 years than all of history before then.
we have been able to send spacecraft to gather information about planets and moons up close
What evidence can you give that shows the surface of Jupiter's moon Europa must be relatively young?
we see very few craters compared to the surfaces of Callisto and Ganymede
Which planet in the solar system has notbeen examined by spacecraft instruments that have either flown by or orbited them?
Earth
Mars appears to have long branching channels that have the appearance of being formed by a flowing liquid. Yet we know that liquids would not stay liquid in the very thin atmosphere we have on the Martian surface? So how can we explain the channels?
Mars had a thicker atmosphere long ago when the channels formed
Why is it so much easier to determine the length of the day on Mars than on Venus?
Mars' atmosphere is generally pretty clear (so the surface is visible) while Venus is always cloudy
Valles Marineris is a wide, deep network of chasms stretching for some 2500 miles on the surface of Mars. How do we believe such a big set of canyons formed originally?
it was caused by tectonic pressures from deep within the planet
What makes the rings of Neptune different from those of other planets we know?
they are clumpy (or bulging) in places
Which of these did the June 1908 impact event in Siberia and the 2013 event in the Russian city of Chelyabinsk have in common?
they both exploded high in the atmosphere and produced a shock wave that reached the ground
A key difference between the protoplanets that formed in the outer solar system and those that formed in the inner solar system was that
those in the outer solar system were in a place where ice, not just rock, condensed and thus could grow larger
For a while, after the space age began, astronomers did not know what the surface of Titan looks like, but today they do. Which of the following was NOT a method by which astronomers have learned about the surface of Titan?
using the Hubble Space Telescope in orbit to take a photo of Titan
On which of the planets (other than Earth) could a human being step out of a spacecraft and survive without any protective gear (special suit, oxygen tanks, etc)? Group of answer choices
you can't fool me; there is no other planet on which we could survive unprotected
The first spacecraft to orbit another planet circled Mars in 1971. It was:
Mariner 9
During the process of differentiation,
heavier materials sink to the centers of molten planets
The largest planet in the solar system (by mass) is:
Jupiter
The planet that has an axis that points roughly straight up, and thus has no seasons to speak of, is:
Jupiter
One of the following worlds has an orbit that actually crosses the orbit of another world. This "rude" world is:
Pluto
Which of the following worlds does NOT have a ring?
Pluto
Which planet has the biggest moon relative to its own size? Not the biggest moon in terms of kilometers, but the biggest as a percentage of the size of the planet it orbits
Pluto
The Red Spot of Jupiter is:
all of the above
When chemists say that a planet's upper regions are reduced,they mean that these regions
are dominated by the element hydrogen and its compounds
The mountains on the moon were created by
are the result of giant impacts during the Moon's long history of being hit
Why were asteroids not discovered until the 19th century?
asteroids are generally small compared to planets and require a good telescope and patient searching to spot them
Which of the following is NOT a way that the moon Titan probably resembles the Earth?
at its surface the temperature and pressure are just right for water to exist in all three phases (gas, liquid, and ice)
Why are the largest craters we find on the Moon and Mercury so much larger than the largest craters we find on the Earth?
because the largest craters were made early in each world's history, and geologic activity has erased all traces of this early period on the Earth's surface
Why are almost all the craters we see on the Moon circular?
because the rocks and icebergs that hit the Moon are moving so fast, they explode on impact, making a circular hole
The rings of the outer planets consist of
billions of chunks (of various sizes) that all orbit the equator of each planet
Astronomers estimate that the plains of Venus are only about 500 to 600 million years old. How do they estimate dates like this?
by counting the craters visible on the surface and comparing crater counts to other worlds
More than 75% of the known asteroids:
can be found in a belt between Mars and Jupiter
The same gas makes up most of the atmosphere of Mars and Venus. This gas is:
carbon dioxide
Short-period comets like Comet Halley
come back again and again at predictable intervals
Different asteroids reflect different percentages of the light falling on them. This is due to the fact that they have different:
compositions
Of the people who landed on the Moon, how many were trained scientists?
exactly one
What theory of Mercury's origin can best explain the fact that its core is made of such dense materials?
giant impacts in its early history may have torn away much of its original crust and mantle
When astronomers say that Ganymede is a differentiated body, they mean that it:
has a heavier core, surrounded by a lighter, icy mantle and crust
The large circular coronae on Venus are:
large regions where hot magma rising from the interior of Venus puts pressure on the surface material
Sometimes, when the Moon is a thin crescent, you can still dimly make out the full disk of our satellite. What is the reason for this?
light reflecting from the Earth onto the Moon
The rate at which a collection of the same radioactive atoms will decay depends on:
only on internal processes within the atoms; nothing external matters
Which of the following would NOT be one of the problems faced by an unprotected Earthling stranded on Mars? (Unprotected meaning no space suit.)
the extreme (high) heat at most latitudes
In the four terrestrial planets, the densest, heaviest materials are at the center and not evenly distributed throughout the planet. Scientists interpret this observation to mean that:
the four terrestrial planets must once have been hot enough to be molten (like a liquid)
Comets change as they approach the Sun in their orbits. Which of the following statements about a comet approaching the Sun is FALSE?
the gravity of the comet nucleus holds on to the evaporated material, and it all eventually freezes back into the nucleus
One way in which Mars closely resembles the Earth is:
the length of its day (period of rotation)
What formation or formations are evidence that the planet Mercury may have shrunk (gotten a bit smaller) as it cooled?
the long scarps or cliffs
An increase in the Earth's temperature by several degrees Celsius would result in:
the melting of many glaciers, a rise in sea levels, and more flooding of towns near the coasts of the continents
The ages of stony meteorites have been measured to be roughly equal to:
the oldest ages we have measured for any bodies in the solar system
The process by which Venus became so much hotter than the Earth is called:
the runaway greenhouse effect
At the moment when the Voyager spacecraft got closest to Uranus, the Sun was shining directly on the planet's south pole. Uranus takes about 17 hours to rotate once on its axis. If Voyager took a photo of the south pole 8.5 hours later, what would it observe?
the south pole was brightly lit, with the Sun shining down on it
In the far future, a visiting tourist from another planetary system asks to see the most massive object in our solar system. Where would you take him/her/it?
the sun
Which of the following does the composition of a planet like Jupiter resemble:
the sun
How does Saturn's F ring stay so thin (narrow), when the other rings are so wide?
there are 2 shepherding satellites on either side of it
What makes astronomers think that impact rates for the Moon must have been higher earlier than 3.8 billion years ago?
there are ten times more craters on the older highlands than the younger maria
