1.Yes, they can use it as is.
2.The visible night sky changes constantly as the Earth rotates and revolves.
3.Hubble Space Telescope
4.first humans on the moon, first lander on Mars, first space shuttle flight
5.loss of bone and muscle density
6.Week 1 starts with a new moon, while week 3 starts with a full moon.
7.week 3 and week 4
8.They both start with a quarter moon.
9.Half of the moon's surface that is illuminated by the sun is visible from Earth's perspective.
10.a total lunar eclipse
11.partial lunar eclipse
12.on the Northern Hemisphere
15.just put yes, it's worth the money because we become informed a lot more about space with the different explorations but make it into a small paragraph