Space Exploration

2. a model of the universe that places the Sun at the center with Earth, the planets, and moons revolving around it.
4. The phenomenon that the observed frequency of a wave changes if the source of the wave and the observe are moving toward or away from one another.
5. The study of spectra spectrum produced when a beam of light is passes through a prism
7. There is almost as much gravity in orbit as there is on Earth; however, gravity is effectively eliminated inside a spacecraft due to the free-falling effect of orbiting earth, which causes the microgravity environment.
10. When spectral lines move toward the longer-wavelength part (red end) of the spectrum.
13. A telescope that has a lens for the objective
15. Varying types of energy waves emitted by stars (radio waves, infrared waves, visible light, ultraviolet waves, rays and gamma rays.
20. the angle measured clockwise from north when measuring altitude-azimuth co-ordinates
22. A device made of thousands of closely spaced slits through which light is passed in order to produce a spectrum.
25. Objects in space that give off large amounts of radio waves

1. Newton’s law states that all objects attract all other objects, and provides an explanation for the planet’s elliptical orbits.
3. A figure that looks like a squashed circle; planets in the solar system move in elliptical orbits around the Sun
6. Using radio waves to learn about the composition of stars
8. a method of acceleration, which enables spacecraft to change speed by using the gravity of a poster.
9. a satellite made by humans, such as a spacecraft or telescope.
11. taking measurements of Earth (and other planets) from space.
12. (AU) is the distance from Earth to the Sun (150 million km)
14. all objects seen in the sky (sun, moon, stars and planets.
16. Orbit of satellites placed about 36000 km above the ground, directly above the equator, orbiting Earth once every 24 hours
17. A technology that electronically connects two (or more) separate telescopes to combine their images.
18. orbit: Orbit of satellites placed about 36,000 km above the ground, directly
19. A rocket with a bomb as a payload, launched in a trajectory that sends it up into space and down onto its target.
21. A method of measuring distance indirectly by creating an imaginary triangle between an observer and an object whose distance is to be estimated.
23. the large lens at the front of a telescope.
24. a Russian term for astronaut.