Chapter 22: Astronomy

Question 1

What is a solar system?

Answer 1

Collection of planets and moons that orbit a star or stars

Question 2

What is a galaxy?

Answer 2

Millions of solar systems

Question 3

What is a universe?

Answer 3

Millions of galaxies

Question 4

What does the moon orbit?

Answer 4

The moon orbits the Earth. Other planets also have their own moons.

Question 5

What is gravitational field strength and does it change?

Answer 5

Gravitational field strength is how strongly something pulls an object towards it. It is different on different planets and moons, because they have different masses. Larger mass = larger g.

Question 6

What does gravitational force do?

Answer 6

If an object is sighing the field of another object’s gravitational force, then it will travel around it in a path known as an orbit.

Question 7

What is the relationship between orbital speed, orbital radius and time period?

Answer 7

Orbital speed = (2 x Pi x orbital radius) / time period

Question 8

How does the orbit of a comet differ from that of a planet?

Answer 8

Comets have elliptical orbits, which means they have two focal points that they orbit.