Astronomy Exam 2 (chapter 5-8)
The Van Allen Belts are
where Earth's magnetic field traps charged particles from the Sun.
The largest four moons of Jupiter are referred to as the
Galilean satellites.
The Apollo program was thought to be part of a "race to the Moon" with the Soviet Union. Actually
It was a close race. The Soviets actually built a Moon rocket and tested it.
The force that acts on a rocket because its engine is firing is exerted by
the exhaust from the rocket.
The average radius of the Earth's orbit is
1.0 au.
calculus
calculating the magnitude and direction of the acceleration of a planet that was following Kepler's Laws.
If the planets are numbered from 1 to 8, going outward from the Sun, the planet Neptune is number
8
The magnetic field of Mercury is
about 1% of the Earth's magnetic field.
Uranus has
an atmosphere of Hydrogen and Helium with some methane.
An ion rocket engine produces 1 Newton of thrust. What acceleration can it give to a space probe with a mass of 1000kg?
0.001 m/s².
The angle between the rotation axis of a planet and the perpendicular to the plane of its orbit is called its "axial tilt." The axial tilt of Mercury is
0.01 degrees.
What total force will cause an object with a mass of 1kg to gain 10 meters per second every second?
10 Newtons
Saturn rotates on its axis once in about
10 hours.
Compared to the Earth, the planet Jupiter is roughly
10 times as large.
Uranus rotates on its axis once in about
17 hours.
Suppose that you lift an object by exerting an upward force of 12 Newtons on it. If gravity exerts a force of 10 Newtons downward on the object, what is the total force on the object?
2 Newtons
Compared to the Earth, the planet Uranus is roughly
4 times as large.
What total force will cause an object with a mass of 10kg to gain 5 meters per second every second?
50 Newtons
The density of water is 1000kg/m³ while the density of rock is 3000kg/m³. Which of the following values is a plausible value for the density of a Jovian planet?
700kg/m³
The first spacecraft to go into orbit around Saturn was
Cassini-Huygens.
Most Kuiper Belt Objects are similar in composition to
Comets
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 both objects would hit the ground at the same time?
Galileo
Which of these sequences places the inner planets in the correct order from the Sun, from the closest to the farthest?
Mercury, Venus, Earth, Mars (farthest)
The temperature on Jupiter is
Much colder than anywhere on Earth.
Which of the following space probes flew past Saturn but not past Jupiter?
None of these.
Which of the following spacecraft were the first to fly past Jupiter?
Pioneer 10 and Pioneer 11
The first space probes to land on another planet were from the
Russian Venera series.
When Newton calculated the magnitude of the acceleration of Earth's Moon, and compared it to the acceleration of falling objects on the surface of the Earth, he found that
The Moon's acceleration was smaller.
Why couldn't we just fly a Space Shuttle to the Moon for at least a fly-by?
The Space Shuttle did not have enough fuel to reach escape velocity.
Why don't we just shoot all of our really nasty waste products into the Sun where they could not possibly bother anyone?
The Sun is actually the hardest part of the Solar System to get to from here.
A book, weighing 10 Newtons, sits on a table. Which of the following pairs of forces is an action-reaction pair?
The force that the book exerts on the table and the force that the table exerts on the book.
Which of the following objects is the largest moon of Saturn?
Titan
Which of the following spacecraft is the only one to have flown past Neptune?
Voyager 2
Which of the following spacecraft is the only one to have flown past Uranus?
Voyager 2
A lunar crater is best described as
a circular ring wall surrounding a flat area
Jupiter has what
a few rings made of dark rocks.
The magnetic field of Jupiter indicates that its core must contain large amounts of
a liquid that can conduct electricity.
The magnetic field of Jupiter is
about 10 times the intensity of the Earth's magnetic field.
Saturn's magnetic North and South poles are
almost exactly aligned with its rotation axis.
The rotation axis of Uranus is
almost in the plane of its orbit so that its ring system can sometimes be seen as near-circles.
Jupiter has
an atmosphere of Hydrogen and Helium with no real surface.
Mars has
an atmosphere of carbon dioxide with about 1% the surface pressure of Earth's.
For a planet to have substantial amounts of liquid water on its surface, it must have
atmospheric pressure above the triple point of water.
Milankovich cycles refer to
changes in the intensity of sunlight due to shifts in both the Earth's orbit and rotation axis.
Apollo 11 made the first
crewed landing on the Moon.
Neptune's magnetic North and South poles are
displaced from its rotation axis poles and also from the center of the planet.
Uranus's magne
displaced from its rotation axis poles and also from the center of the planet.
The dark side of the Moon, where the Sun never shines,
does not exist.
The magnetic field of Earth's Moon is
essentially zero.
What we refer to as a `Saturn Ring-plane Crossing' corresponds to what season on Saturn?
fall or spring equinox.
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 a rocket pushes it and quickly increases its speed to 6 miles per second. The ISS will then
follow an ellipse that rises and then descends again.
Freely falling objects with different masses fall with the same acceleration because
gravity exerts more force on the more massive object.
Mars
has a solar day that is very close to an Earth day in length.
The Curiosity Mars rover
has been operating on Mars for eight years so far (as of 2020).
According to our current model of how planets form magnetic fields, the magnetic field of Saturn is much less than the magnetic field of Jupiter because Saturn
has less metallic hydrogen in its core than Jupiter.
The current model for the way that planets acquire magnetic fields suggests that a rapidly rotating planet will
have a magnetic field if its core contains enough liquid electrical conductor.
The statement that lunar material is much "dryer" than Earth material refers to the absence of
hydrated minerals.
Comets are usually made of
ice and possibly frozen gas
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.
If the acceleration of an object is zero, its speed
is not changing
According to Newton's Law of Gravity, the gravitational attraction of the Earth for other objects, such as the Moon, apples on trees and space shuttles in low earth orbit,
is smaller for objects farther from the Earth but never vanishes entirely.
Mercury rotates so that, relative to the Sun
it rotates just once during two complete orbits around the Sun.
Galileo said that a moving object with nothing pushing or pulling on it will always
keep moving at the same speed.
The Law of Inertia states that a moving object will
keep moving if no force acts on it.
The Jovian planets typically have
large systems of moons
The number of maria on the side of the Moon facing away from the Earth is
less than on the side facing Earth.
Compared to the rest of the Lunar surface, the Lunar Maria are
lower and younger.
The Surveyor series of spacecraft
made unmanned landings on the Moon in the 1960s.
The atmospheric pressure at the surface of Venus is
many times the pressure at the surface of the Earth.
Suppose that a comet is spotted while it is still far from the Sun (beyond the orbit of Mars). The tail of this comet is most likely
not yet formed.
acceleration
object that indicates the force on it.
The Opportunity Mars rover
operated on Mars for fifteen years.
The phase diagram for water is presented on a graph with axes for temperature and
pressure.
As viewed from the star Polaris, Venus
rotates clockwise and goes around the Sun counter-clockwise.
Aristotle said that a moving earthly or `mundane' object with nothing pushing or pulling on it will always
slow down and stop.
Since the last Apollo mission to the Moon and the last Soviet LUNA sample-return mission
spacecraft began to be sent there again by 1994.
Between the orbits of Mars and Jupiter you find
the Asteroid Belt.
An artificial satellite such as the International Space Station stays up because
the Earth curves out from under it as fast as it falls.
The capture theory, in which the Moon forms as a separate object similar to Earth and is then captured by the Earth, would predict that
the Moon should have an iron core similar to Earth's.
If you are told that a 20 kilogram object is raised by 10 meters, you know that
the mass of the object is 20 kilograms.
Moon missions since 2007 have mostly been focused on
the search for water needed for a Moon base.
Upon close examination by space probes, the rings of Saturn are found to consist of
thousands of circular rings.
When Newton calculated the magnitude and direction of the acceleration for a planet that was following Kepler's Laws, he found that the direction of the acceleration was
toward the Sun
Once a space probe has gotten far enough from the Earth, it can reach the inner planets by
using its rocket motor and the gravity of various planets to change its speed and direction.
The distance from the Earth to the Moon
varies enough that sometimes we get an annular solar eclipse.
At present (within the last few hundred years) the orbit of Mars around the Sun is
very elliptical so that.the intensity of sunlight varies by 40 percent.
