Imagine that last night you saw the star betelgeuse just starting to rise on your eastern horizon at 7: 15 pm. at 7: 15 pm tonight, will betelgeuse be above, below, or exactly on your eastern horizon?

The Earth orbits around the sun toward the east. Since it takes about 365 days to complete 360 degrees around the sun, the Earth moves about 1 degree each day. In order for us to see Betelgeuse on the eastern horizon the next day, the Earth would only need to rotate 359 degrees. This 359-degree rotation plus the 1 degree motion around the sun would be 360 degrees. So we would look at about 7:11 pm, because it takes the Earth about 4 minutes to rotate 1 degree. Therefore, at 7:15 pm the next night, Betelgeuse will be a little above the eastern horizon.