1. Astronomy Vocabulary

2. 1. Electromagnetic Spectrum: Waves of particles that travel at the speed of light.Electromagnetic Spectrum

3. 2. Doppler Shift: Objects moving away show a redshift. Objects moving closer show a blueshift.Doppler Shift

4. 3. Radio Telescope: Gathers radio waves and feeds the information to a computer. (Radio)Radio Telescope

5. 4. Reflecting Telescope: Uses a mirror to gather light. (Optical)Reflecting Telescope 5. Refracting Telescope: Uses a convex and concave lens to gather light. (Optical)Refracting Telescope:

6. 6. Big Bang Theory: 14.6 Billion years ago, the universe began in a giant explosion.Big Bang Theory

7. 7. Galaxy: A group of millions or billions of stars.Galaxy 8. Nebula: A cloud of Hydrogen and Helium gas in space.Nebula

8. 9. Parallax: The angle that is created between the Earth and the sun as the Earth orbits.Parallax

9. 10. Light-Year: The distance light travels in one year. 11. Main Sequence: Stars that follow a “normal” life cycle.Main Sequence

10. 12. Astronomical Unit: (AU) The distance from the Sun to the Earth. (About 93 million miles.)

11. 13. Comet: An object made of ice and dust that orbits the sun.Comet

12. 14. Meteor: A small rock in space. Meteoroid: Burning in our atmosphere. Meteorite: Hits the ground.Meteor

13. 15. Asteroid: A rock in space that is larger than a mile across.Asteroid

14. 16. Satellites: Objects that orbit. Natural = Planets, moons, asteroids, etc. Artificial = man made. (spacecraft)

15. 17. Geocentric: The earth is at the center of the universe. 18. Heliocentric: The sun is at the center of the solar system. 19. Nicholas Copernicus: Was the first to believe that the sun was the center of the solar system.Nicholas Copernicus

16. 20. Galileo Galilei: The first Astronomer to use a telescope. Found evidence to support Copernicus.Galileo Galilei 21. Johannes Kepler: Used math to form his 3 laws of planetary motion. Found that planets orbit the sun in ellipses.Johannes Kepler 22. Ellipse: An elongated circle with two foci.

17. 23. Aphelion: The farthest distance in an orbit. 24. Perihelion: The closest distance in an orbit.

18. The Sun Earth Aphelion Earth Perihelion

19. 25. Sphere: A round 3 dimensional object.Sphere 26. Axis: The imaginary line that a planet rotates around.Axis

20. 27. Rotation: A planet spinning on its axis. (A DAY IS ONE ROTATION) 28. Revolution: One orbit around the sun. (A YEAR IS ONE REVOLUTION)

21. 29. Solar Eclipse: The moon gets between the Earth and the sun and makes a shadow on the Earth.Solar Eclipse 30. Lunar Eclipse: The Earth gets between the Sun and the moon and makes a shadow on the moon.Lunar Eclipse

22. 31. Planetesimal: (Dwarf Planet) An astronomical body too small to be defined as a planet (2006 – Pluto)

23. 32. Nebular Theory: The sun and planets formed from a rotating disk of gas and dust.Nebular Theory

24. 33. Nuclear Fusion: Stars combine elements (Lighter to Heavier) To produce energy.

25. 34. Terrestrial: Planets that are made of rock.Terrestrial 35. Jovian: Planets that are made of gasses.Jovian