| A | B |
|---|
| Uranus | World that is a planet |
| Saturn | World that is a gas giant |
| Europa | World that is a moon of Jupiter |
| Charon | World that is farther from the sun than Saturn |
| Venus | Has an atmosphere denser than Earth's |
| Io | Has active volcanoes |
| Triton | World with the lowest surface gravity |
| Moons | Orbit planet but planets do not orbit moons |
| Atmosphere | Protects a world from meteors |
| Magnetic field | Protects a world from solar wind |
| Craters | Caused by meteor impacts |
| No atmosphere | Sun is in the sky, yet the rest of the sky is black and you can see the stars |
| Temperature scales | Fahrenheit and Celsius |
| Ice | Can be made of many substances, not just water |
| Infrared Camera | Can be used to learn about temperature on a world |
| Mass Spectrometer | Determines whether or not a world's surface has carbon |
| Barometer | Used to measure the pressure in a world's atmosphere |
| Narrow Angle Camera | Used to take pictures of a world's surface when you can only afford to send an orbiter |
| Magnetometer | Used to find out if a world's surface has a magnetic field |
| Seismograph | Used to find out whether a world's surface has earthquakes |
| Flyby Probes | Cannot use a mass spectrometer because it needs to come in contact with the substance it analyzes |
