Space Challenge Practice
| # | Answer |
|---|---|
| 1 | Gravity. |
| 2 | An orbit. |
| 3 | The Sun. |
| 4 | The Moon. |
| 5 | The solar system. |
| 6 | Mars. |
| 7 | Mercury. |
| 8 | A meteor. |
| 9 | A meteorite. |
| 10 | A galaxy. |
| 11 | Because the Sun’s gravity pulls them inward while their forward motion keeps them moving around the Sun. |
| 12 | The Sun. |
| 13 | A unit of distance equal to how far light travels in one year. |
| 14 | Mercury, Venus, Earth, Mars. |
| 15 | Jupiter, Saturn, Uranus, Neptune. |
| 16 | A star makes its own light and heat, while a planet does not and reflects light from a star. |
| 17 | Because we see different amounts of the Moon’s sunlit side as it orbits Earth. |
| 18 | A waxing crescent moon. |
| 19 | The Moon phase when the side facing Earth is fully lit by the Sun. |
| 20 | Earth’s rotation on its axis. |
| 21 | About 24 hours. |
| 22 | About 365.25 days, or one year. |
| 23 | Earth’s axial tilt as it orbits the Sun. |
| 24 | Because Earth’s tilt makes one hemisphere receive more direct sunlight while the other receives less. |
| 25 | The axis. |
| 26 | It appears to move because Earth rotates from west to east. |
| 27 | A small rocky object that orbits the Sun, mostly found in the asteroid belt. |
| 28 | Ice, dust, and rock. |
| 29 | Heat from the Sun causes ice to vaporize, releasing gas and dust that form a tail pushed away by solar wind and sunlight. |
| 30 | A region between Mars and Jupiter where many asteroids orbit the Sun. |
| 31 | Because it has no thick atmosphere to burn up incoming meteoroids and little erosion to remove impact marks. |
| 32 | Earth’s gravity. |
| 33 | Rotation is spinning on an axis; revolution is moving around another object in an orbit. |
| 34 | The tilt causes one hemisphere to have longer days in its summer and shorter days in its winter. |
| 35 | The heliocentric model. |
| 36 | It correctly explained that planets, including Earth, orbit the Sun. |
| 37 | A lunar eclipse happens when Earth blocks sunlight from the Moon; a solar eclipse happens when the Moon blocks sunlight from Earth. |
| 38 | A new moon. |
| 39 | A full moon. |
| 40 | Patterns of stars seen from Earth that people have named and grouped together. |
| 41 | Because Earth’s atmosphere bends and changes the light from the stars. |
| 42 | It is likely in a similar distance range from the Sun as Earth, though its orbit shape and exact path may still differ. |
| 43 | The same side of Earth would face the Sun for a very long time, so day and night would no longer change every 24 hours. |
| 44 | Because closer to the Sun it was hot and only rock and metal could stay solid, while farther away cooler temperatures allowed gases and ices to form. |
| 45 | Gravity pulls the satellite toward the planet, while its forward motion keeps it from falling straight down, so it keeps circling. |
| 46 | Distant galaxies show redshift, meaning their light is stretched and they are moving away from us. |
| 47 | It tells them the galaxy is moving away from Earth. |
| 48 | The person would weigh more because weight depends on the strength of gravity. |
| 49 | They are above Earth’s atmosphere, so they avoid blurring, absorbing, and distorting effects from the air. |
| 50 | This is incorrect because seasons are caused by Earth’s axial tilt, not by changes in distance from the Sun. In fact, Earth’s distance changes only a little during the year. |