home *** CD-ROM | disk | FTP | other *** search
- Nebula: A mass of gas and dust, appearing as a glowing or dark patch in the sky.
-
- Orbit: A specific path followed by a planet or satellite. All 9 planets orbit the Sun.
-
- Planet: A rotating body which is held in orbit by the gravitational pull of a star (Sun).
-
- Probe: An unmanned spacecraft launched into space to collect data about the solar system and beyond. Not all space probes return to Earth.
-
- Rotation: The spinning of an object on its axis.
-
- Satellite: A moon or a man-made body which orbits a planet.
-
- Solar System: Our planetary system, including the Sun and all the planets which orbit it.
-
- Star: A hot, glowing sphere of gas. Usually one that emits energy from its core.
-
- Terrestrial planets: Mercury, Venus, Earth, and Mars. These planets consist mainly of rock and metal.
-
- Ultraviolet rays: Invisible electromagnetic radiation. Ultraviolet radiation is emitted by the Sun, and is very damaging to our skin.
-
- Universe: The vast expanse of space which contains all of the matter and energy in existence.
-