Question 1

Which of the following orbital periods for asteroids would NOT be associated with one of the Kirkwood gaps given that Jupiter's orbital period is 11.9 years?

Accepted Answer

Kirkwood gaps occur at orbital resonances with Jupiter. The gaps are typically at simple fractions of Jupiter's orbital period. 3.72 years does not correspond to a simple fraction of 11.9 years, unlike the other options.

Question 2

How does the tidal stress on the Earth's oceans due to the Moon vary with latitude on the Earth? Consider four points on the Earth: (1)on the equator on the side closest the Moon, (2)on the equator on the side farthest from the Moon, (3)at the North Pole,and (4)at the South Pole.Draw a diagram and show the direction of the tidal stress at each point.

Accepted Answer

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Question 3

The Trojan asteroids are classified as a distinct group of asteroids because they are found

Accepted Answer

Trojan asteroids are asteroids that share an orbit with a planet or a larger moon, but does not collide with them due to their location at stable Lagrange points in the planet's orbit. In the case of Jupiter, there are two Lagrangian points (L4 and L5) where Trojan asteroids can exist, making choice A the correct answer.

Question 4

What causes the tides on Earth,and how frequently do high and low tides occur?

Accepted Answer

The answer of What causes the tides on Earth,and how...

Question 5

In a three body system,gravity controls the motion of each of the objects,

Accepted Answer

The motion in a three body system can be chaotic, meaning that small changes in initial conditions can lead to vastly different outcomes. This makes accurate predictions of future positions very difficult, if not impossible. Friction is not a factor in gravitational interactions, so option C can be eliminated. Options A and B are incorrect because while gravity does control the motion of each object, chaotic behaviour means that predictions cannot be made with complete accuracy.

Question 6

Comet Shoemaker-Levy 9 split into many pieces before crashing into Jupiter because

Accepted Answer

The Roche limit is the distance from a planet at which tidal forces exceed the strength of an object, causing it to break apart. Comet Shoemaker-Levy 9 came within the Roche limit of Jupiter, which caused it to break up into many pieces before crashing into the planet.

Question 7

Explain why a person at the center of Earth would be weightless.

Accepted Answer

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Question 8

Neptune's radius is 25,000 km.Which of the following would we be UNLIKELY to see orbiting Neptune?

Accepted Answer

A ring with a semimajor axis of 90,000 km would lie well within Neptune's radius and therefore be unlikely to exist without colliding with the planet or being torn apart by its gravity.

Question 9

If the mass of the Sun is roughly 30,000,000 times greater than the mass of the Moon,and its distance is roughly 400 times farther,estimate the strength of the Sun's tidal forces compared to the Moon's tidal forces.

Accepted Answer

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Question 10

The moons of Saturn named Tethys and Dione have a 2:3 orbital resonance with Tethys orbiting closer to Saturn than Dione.If the semimajor axis of Dione's orbit is 380,000 km,what is the semimajor axis of Tethy's orbit?

Accepted Answer

In a 2:3 orbital resonance, Tethys completes 2 orbits for every 3 orbits of Dione. Using Kepler's third law, the ratio of the semimajor axes is (2/3)^(2/3). Solving for Tethys' semimajor axis: a_Tethys = 380,000 * (2/3)^(2/3) ≈ 290,000 km.

Question 11

Saturn's ring system has a very sharp outer edge because

Accepted Answer

The correct answer is A because the particles at the edge of Saturn's ring system have a 7:6 orbital resonance with a pair of co-orbiting moons that lie just outside the rings. This resonance prevents the particles from moving beyond the outer edge of the ring system.

Question 12

Tides play a role in the interaction between which types of systems?

Accepted Answer

Tides are caused by the gravitational interaction between two celestial objects, such as a planet and its moon or a star and its planets. Therefore, tides can play a role in any system involving celestial bodies, including those described in choices B, C, and D.

Question 13

The SOHO satellite is located in

Accepted Answer

The SOHO satellite is located in a stable orbit at the L1 Lagrangian point in the Earth/Sun system.

Question 14

When the Moon was half its present distance to the Earth,how much larger was its tidal force on the Earth's oceans?

Accepted Answer

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Question 15

The Cassini Division in Saturn's rings is caused by an orbital resonance with its moon named

Accepted Answer

The Cassini Division is caused by a 2:1 orbital resonance with Saturn's moon Mimas, which gravitationally perturbs the particles in the division, preventing them from coalescing into a ring.

Question 16

When a tiny change in a system's parameters.such as position or speed,can develop into large differences in later motion or behavior,the system is called

Accepted Answer

This is the definition of chaos theory, where small changes in initial conditions can lead to vastly different outcomes later on. The other choices (A, C, D) do not accurately describe this phenomenon.

Question 17

Assume for a moment that Earth has a uniform density throughout its interior.Given this,how would the force of gravity felt at an interior distance of half an Earth radius compare to the surface force of gravity?

Accepted Answer

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Question 18

Why is the space station not torn apart by tides from Earth?

Accepted Answer

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Question 19

Why does Saturn have rings while Earth does not?

Accepted Answer

Saturn's rings are made up of ice particles, dust and rocks that are believed to be remnants of comets, asteroids and other space debris. Because Saturn is more massive than Earth, its gravity is stronger and is able to hold onto these particles, which orbit around the planet, forming its famous rings. Earth, on the other hand, is less massive and has weaker gravity that cannot hold onto such particles, hence why it does not have rings.

Question 20

Gaps in Saturn's rings are caused by

Accepted Answer

Shepherd moons, orbital resonances, and moons colliding with ring material can all contribute to the formation of gaps in Saturn's rings.

Quiz 10: Gravity Is More Than Keplers Laws