Some numbers to consider

Radius of Earth = 6.4 x 10^6 m

Radius of Moon = 1.74 x 10^6 m

Radius of Sun = 6.96 x 10^8 m

Distance from Earth to Sun (on average; one "Astronomical Unit" or AU) = 1.5 x 10^11 m

Distance from Earth to Moon = 3.84 x 10^8 m

Mass of Sun (one "solar mass") = 2 x 10^30 kg

Mass of Earth = 6 x 10^24 kg

Speed of light (in a vacuum) = c = 3 x 10^8 m/s

Find the following:

1.  Distance between Earth and Moon, in Moon diameters.  Visualize this with a globe and ball to represent the Moon.

2.  Distance from Earth to Sun, in Earth diameters

3.  Amount of time it takes light to reach the Earth from the Moon, in seconds.

4.  Amount of time it takes light from the Sun to reach Earth, in minutes

5.  Amount of time required for light to travel from the Sun to Pluto (40 AU from the Sun, on average) in hours

6.  How far light travels in one second (called 1 Light-Second, LS)

7.  How far light travels in one minute (LM)

8.  How far light travels in one year (LY)

9.  Distance to nearest star (other than Sun) - find the star and the distance (by looking it up)

10.  How many times around the Earth that a light pulse could travel in one second

11.  How many Moons across is the Earth?

12.  How many Earths across is the Sun?

13.  If you could travel at Earth's escape velocity (11,200 m/s), how long would it take you to reach the Moon?  How long would it take you to reach the nearest star (see 9 above)?