| A | B |
|---|
| Revolution | one complete trip around the sun |
| rotation | a complete spin on the Earth's axis |
| axis | an imaginary line that goes through the center of the Earth |
| satellite | an object that moves around a larger object in space |
| tides | the regular rise and fall of the water level caused by the pull of the Moon |
| planet | a large body orbiting the sun or other star |
| telescope | a device that collects light and makes distant objects appear closer and larger |
| tilt | slant; sloping position |
| lunar eclipse | the time when the Moon passes through the Earth's shadow |
| solar eclipse | the time when the Earth passes through the Moon's shadow |
| solar system | A star and all the objects orbiting it |
| asteroid | a rocky, metallic object that orbits the Sun |
| comet | a ball of ice and rock that orbits the Sun |
| meteorite | any part of a meteor that reaches the Earth's surface |
| apogea | point in the Moon's path where it is farthest from Earth |
| space shuttle | a vehicle that can be used to carry passengers and materials to space |
| meteor | a meteoroid that enters the Earth's atmosphere and burns with a streak of light |
| meteoroid | small, rocky objects that orbit the Sun in both the outer and inner regions of the solar system |
| universe | everything that exists |
| galaxy | a large group of stars that are held together by gravity |
| light year | the distance light travels in a year |
| astronomer | a person that studies the universe |
| perigee | point in the Moon's path where it is closest to Earth |
| space station | a satellite used to conduct experiments |
