A tour of other worlds

Compare planets, change worlds and follow the clues left by smaller objects.

Choose any question to begin.

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1. 1

   What makes a planet rocky or giant?

   Compare the material and outer layers of familiar planets.

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2. 2

   Would the same object weigh less on the Moon?

   Keep mass fixed while comparing gravitational force on Earth, the Moon and Mars.

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3. 3

   Why do different planets have different years?

   Run two orbital clocks using published planetary periods.

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4. 4

   Is a shooting star really a star?

   Follow small Solar System bodies and distinguish an object from an atmospheric event.

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5. 5

   What can overlapping craters tell us?

   Inspect a real NASA lunar image and compare a separate impact-order model.

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Each discovery includes all five reading levels. Journey progress reflects the checkpoints answered on this browser.

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