1 Which portion of the HR diagram has stars with the greatest luminosity?
2 What is the solar system?
3 What is the fourth planet in the solar system?
4 How many Moons could be stacked from the horizon to the zenith (the point directly overhead)?
5 Earth is a gas planet.
6 How many planets are in our Solar system?
7 What planet was known as Planet "X"?
8 Which is closest to the number of Earth days equal Pluto's rotational period?
1 How many planets are considered to be inner planets?
2 Why are the outer planets solid instead of gas? NEEDS WORK TOO EASY
3 When can Mercury not appear in Earth's Sky?
4 Mercury's core consists of what element that's more abundant than in any other planet?