Understanding Earth's Rings and the Roche Limit

What is the Roche limit?

• The distance at which tidal forces equal the gravitational pull of a smaller body.

• The distance at which a smaller body is repelled by a larger body.

• The distance at which a smaller body can orbit a larger body without disintegrating.

• The distance at which a smaller body is completely absorbed by a larger body.

Which of the following is NOT a proposed way a planetary disc can form?

• During the birth of a planet.

• A satellite being torn apart by tidal forces.

• A satellite being captured by a planet's gravity.

• A massive impact ejecting debris into a planet's Roche limit.

Why didn't Earth form a stable ring during its formation?

• There wasn't enough material to form a ring.

• Earth was too close to the sun.

• Earth's gravity was too weak.

• The presence of the Moon prevented it.

What is a significant difference between Earth and Saturn that affects their rings?

• Earth has a stronger magnetic field than Saturn.

• Earth rotates faster than Saturn.

• Saturn has a larger radius and is more massive than Earth.

• Saturn is closer to the sun than Earth.

What happened to the temporary ring that Earth might have had?

• It dissipated into space.

• It coalesced into the Moon.

• It formed a second moon.

• It was absorbed by the sun.