Astronomy Exam 2
What are five fun facts about the Sun?
(1) The Sun is almost a perfect sphere. (2) The Sun travels at 220 km/s. (3) If the Sun disappeared, we would only notice it after eight minutes. (4) The Sun is actually white. (5) The energy created by the Sun's core is nuclear fusion.
The type of rock we find predominant in the crust of the Earth's continents is called...
Granite
Sun
Gravity (274 m/s^2), Radius (6.8x10^8 meters), Distance from Moon (1.5x10^11), Mass (1.989x10^30), Weight (5.4x10^32), Gravitational Force (4.3x10^26), Composition (Hydrogen and Helium)
When astronomers say that Ganymede is a differentiated body, the mean that it...
Has a heavier core, surrounded by a lighter, icy mantle and crust.
By far the most abundant element in the giant (jovian) planets is...
Hydrogen
Any rock in the Earth's crust that has cooled from an originally molten state is called...
Igneous
In what way is the Moon similar to the Earth?
None of the above
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.
Of the people who landed on the Moon, how many were trained scientists?
One
Venus
Otherwise known as the hottest planet, it is the second from the Sun and is named after the Roman goddess of love and beauty. Its composition is mainly made up of carbon dioxide. There is no water, and it is an unlikely place for life.
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.
The first spacecraft to explore the environment of the planet Jupiter was called...
Pioneer
The first trans-Neptunian object astronomers found (in 1930) is called...
Pluto
Which planet has the biggest moon relative to its own size? Not the biggest moon in terms of its own size, but the biggest as a percentage of the size of the planet it orbits.
Pluto
Which of the following is not a way that Venus resembles Earth?
The thickness and pressure of its atmosphere.
Earth
The third planet from the Sun, it is named after the German word 'Erder', as well as the Old English words 'eorthe' and 'eortha'. Its atmosphere is mostly nitrogen and oxygen, and the planet is made of around 75% water.
Which of the following is not one of the key reasons that so many spacecraft from Earth have visited Venus and Mars?
Their atmospheres are very similar to Earth in terms of their chemical makeup.
An important way that scientists have been able to study the interior of the Earth is by:
There is no way we can study the Earth's deep interior at the present time.
What do astronomers think is the origin of the many irregular moons around the outer planets (meaning they orbit backwards or have eccentric orbits)?
These moons were likely formed elsewhere and captured by the giant planets.
Which of the following characteristics do all four terrestrial planets have in common?
They all have solid surfaces with signs of geological activity on them.
What is one way in which both the Moon and Mercury are different from Earth?
They do not have an atmosphere.
The satellite which has the thickest atmosphere (so thick that it's quite a surprise for a satellite) is...
Titan
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 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 have come from the work of two spacecraft called...
Voyager
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.
How many moons does Pluto have?
5, including Charon and Hydra.
How many moons does Jupiter have?
79, including Europa and Callisto.
How many moons does Saturn have?
82, including Titan and Pan.
What is gravity on Earth?
9.8 m/s^2
Magnetic Field
A condition found in the region around a magnet or electric current, characterized by the existence of detectable magnetic force at every point in the region and by the existence of magnetic poles.
Atmosphere
A layer of gases surrounding a planet, moon, or star. The Earth's atmosphere is 120 miles thick and is mostly composed of nitrogen, oxygen, carbon dioxide, and a few other trace gases.
Terrestrial Planets
A name given to a planet mostly composed of rock and iron, similar to Earth.
Satellite
A natural or artificial body in orbit around the planet.
The Van Allen belt is...
A region of trapped charged particles in the Earth's magnetosphere.
Asteroid
A rocky object smaller than a planet that orbits the Sun.
Catena
A series or chain of craters.
Meteor
A small particle of rock and dust that burns away in Earth's atmosphere.
Astronomical Unit (AU)
A unit of measurement equal to the average distance between the Earth and the Sun, approximately 93 million miles.
Which of the jovian planets does not have any satellites?
All the jovian planets are accompanied by satellites.
Which of the following is not a correct statement about the ways the jovian planets differ from the terrestrial planets?
All the jovian planets have satellites around them and none of the terrestrials do.
Jupiter
Fifth planet of the Sun and named after the King of the Roman gods. Its atmosphere is mostly hydrogen and helium. It cannot support life, but it's possible its moons can.
The first spacecraft which did not merely fly by a jovian planet, but actually went into orbit around it for an extended period of time was...
Galileo
Which of the following spacecraft is not leaving our solar system?
Galileo
The four large moons of Jupiter were first discovered by...
Galileo with his early telescope.
The largest satellite (moon) in the solar system is...
Ganymede
What is the gravity on the Moon?
1.62 m/s²
How many moons does Neptune have?
14, including Triton and Nereid.
How many moons does Mars have?
2, Phobos and Deimos.
How many moons does Uranus have?
27, including Umbriel and Ariel.
Which of the following is not one of the largest moons in the solar system?
Atlas (the shepherd moon near Saturn's A ring)
The same gas makes up most of the atmosphere of Mars and Venus. This gas is...
Carbon dioxide
If no one has ever visited the core of the Earth, how do we know that it is made of metals?
Circulating liquid metals in the core set up a large (measurable) magnetic field.
Scientists now understand that Earth consists of layers, with the densest materials in the core. What allowed the differentiation of the Earth's layers to happen?
Continental drift and plate tectonics made this happen.
Which part of the Earth has the greatest density?
Core
Where has frozen water been discovered on the Moon?
Deep inside craters in the regions near the Moon's poles.
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.
Neptune
Eighth planet from the Sun, it is named after the Roman god of the sea. The composition is mostly molecular hydrogen, atomic helium and methane. It cannot support life.
Which of the following statements about the Earth's magnetosphere is false?
Its shape and size are the same on the sides facing toward and away from the Sun.
Which of the following is not a way that Jupiter differs from terrestrial planets?
Its surface has many more craters and collisions.
Which of the following ways that jovian (giant) planets differ from the terrestrial planets is not correct?
Jovians (being larger) rotate significantly more slowly than terrestrials.
The largest planet in the solar system (by mass) is...
Jupiter
Which of the following is not a terrestrial planet?
Jupiter
The first human being to step out onto the surface of another world was...
Neil Armstrong
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 spacecraft that sent back the most detailed radar images of Venus and showed us features as small as a football field is...
Magellan
The region around the Earth where charged particles are trapped and spiral around is called...
Magnetosphere
The largest part of Earth is its...
Mantle
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.
The planet closest to the Sun in the solar system is...
Mercury
You are the captain of an interplanetary tour ship and a wealthy tourist from Texas asks you to take him to see only the "largest darn planets" in the solar system. Which of the following would you NOT include in your tour?
Mercury
Mercury
Named after the Roman messenger God, the first planet from the Sun was formed because of gravity pulling dust and gas together. It is made up of oxygen, sodium, hydrogen, helium, and potassium. There is water, but only in the form of ice.
I want to examine the surface of a planet which is completely covered by a thick layer of clouds all the time. What wavelength of electromagnetic radiation would I be smartest to use...
Radio waves (like radar)
All of the planets (without exception)...
Rotate on their axes in the same direction that they revolve around the Sun
Uranus
Seventh planet from the Sun, it's named after the Greek god of the sky. Its atmosphere is made up of molecular hydrogen and atomic helium, as well as a small amount of methane. It would be unable to support life.
Saturn
Sixth and second largest planet from the Sun, it is named after the Roman god of agriculture and wealth, who was also the father of Jupiter. Its composition is made of mostly hydrogen and helium. It is not able to support life.
The majority of the moons orbiting the outer (jovian) planets are...
Small moons orbiting in retrograde direction.
Which of the following does the composition of a planet like Jupiter resemble?
Sun
In its overall composition, the Moon roughly resembles...
The Earth's crust and mantle
Which of the following 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.
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.
What allowed the Voyager 2 spacecraft to make a "tour" of all four of the jovian planets in the late 1970's and the 1980's?
The four planets were approximately aligned on one side of the Sun and we used the gravity of each planet to speed up the spacecraft to get to the next one in its path.
Mars
The fourth planet from the Sun, it's named after the Roman god of War. Its atmosphere is thin and composed of nitrogen, carbon dioxide, argon, and a little bit of oxygen and water vapor. It is incapable of supporting life.
Why does Mars have an overall reddish color when we see its surface from afar?
The material of Mars' surface contains a lot of iron oxide, the same chemistry that makes rusting metals look reddish.
Orbit
The path of a celestial body as it moves through space
Aphelion
The point in the orbit of a planet or other celestial body where it is farthest from the Sun.
Which planet in the solar system has not been examined by spacecraft instruments that have either flown by or orbited them?
You can't fool me, spacecraft have visited all the planets in our solar system.