| A | B |
|---|
| Sputnik | What was the name of the satellite launched in 1957 by the former Soviet Union? |
| 8.3 light-minutes | How many light-minutes are there in one astronomical unit? |
| No | Must distances within the solar system be measured in light-years? |
| inner planets | In which group of planets does the Earth belong? |
| Mars | This is the only planet besides Earth with some form of water |
| Venus | This planet spins in a clockwise direction. |
| Mercury | This planet has the biggest range in surface temperatures. |
| Mars | The largest mountain in the solar system is on this planet. |
| Venus | On this planet, the sun rises in the west and sets in the east. |
| Venus | This planet has the densest atmosphere of all the inner planets. |
| Mars | This planet has the thinnest atmosphere. |
| solid material | The outer planets are called gas giants because they are not made of a _________? |
| ancient | Jupiter, Uranus, and Neptune were not known to _______________ people. |
| Saturn | Like Jupiter, this planet is composed of hydrogen and helium. |
| Pluto | This planet is covered by nitrogen ice. |
| Pluto | Its moon is more than half it's size. |
| Uranus | This planet may have been tipped over by a massive object. |
| Jupiter | The Great Red Spot is on this planet. |
| Uranus | This planet is about 15 times more massive than Earth. |
| Neptune | This planet's amosphere contains belts of highly visible clouds. |
| Saturn | Like Jupiter, this planet gives off more heat than it receives from the sun. |
| moon | a natural satellite of a planet |
| satellite | a natural or artificial body that revolves around a planet. |
| Mercury and Venus | Which planets do not have moons? |
| phases | the moon's different appearances are called ____________. |
| waxing | When the sunlit part of the moon appears to grow larger, we say the moon is _______________. |
| lunar eclipse | The shadow of the Earth falls on the moon in a _________ ________. |
| solar eclipse | The shadow of the moon falls on the Earth in a __________ ___________. |
| annular aclipse | A thin ring is visible around the outer edge of the moon in a _____________ __________. |
| Phobos and Deimos | Moons of Mars: |
| asteroids | Scientists think Phobos and Deimos came from __________ because the surface materials are the same. |
| Mercury | Ganymede, Jupiter's largest moon is larger than __________. |
| Water | What could be under the icy surface of Europa, one of Jupiter's moons. |
| 8 | Neptune has _____ moons. |
| dozens | Saturn has _________ of moons. |
| more than 20 | Uranus has ___________ moons. |
| 1 | Pluto has ________ moon. |
| Triton | _________ revolves backward around its planet. |
| Titan | ___________ has a hazy orange atmosphere containing nitrogen and methane. |
| Miranda | ___________ has a patchwork surface of plains, grooves, and cliffs. |
| comets | What are "dirty snowballs"? |
| yes | Can comets have more than one tail? |
| elliptical | a comets orbit is ___________. |
| smaller | Meteroites are much _________ than asteroids. |
