4

Ngorongoro Crater, Tanzania

3

The Moon

4

Maddy's Oregon Diary

3

The Earth

3

Meteorites, Meteoroids, and Meteors

4

Mount Fuji, Japan

3

Asteroids

4

Maddy's Arizona Diary

3

Neil Armstrong

4

Maddy's Idaho Diary

2

Solar System

4

Serengeti, Tanzania

3

Mars

4

Chip's Tips on Kenya

4

Chip's Tips on Chile

3

Mercury

3

Vasco da Gama