| Saturn's largest moon is ____. It is larger than Mercury. |
Charon |
| The ____ comet can be seen about every 75 years. |
Copernicus |
| The ____ Space Telescope was launched in 1990. |
Halley |
| Nicolaus ____ proposed that the planets orbit the Sun. |
Hubble |
| ____ has just two small moons (Phobos and Deimos). |
Mars |
| Pluto's largest moon is ____. It was discovered in 1978. |
Pluto |
| Clyde Tombaugh discovered ____ in 1930. |
Titan |
| ____ is the hottest planet due to a runaway greenhouse effect. |
Venus |
