5 Questions: 1-4 Planets

1 of 5
How many planets in our Solar System were discovered by American astronomers?
one
two
three
four
2 of 5
How many planets in our Solar System are not viewable from Earth at any time with the unaided eye?
one
two
three
four
3 of 5
How many planets in our Solar System are surrounded by rings?
one
two
three
four
4 of 5
How many planets in our Solar System do not have moons?
one
two
three
four
5 of 5
How many planets in our Solar System are smaller than Earth?
one
two
three
four