| A | B |
|---|
| Core | Has fission, very very hot 15,000 degrees C |
| Middle Layer | (Radiative Zone) rays of heat are sent through it |
| Outer Layer | Convenction Zone- Circulation currents of heated particles |
| Photosphere | Glowing layer- produces visible light that comes from the sun |
| Chromosphere | Inner part of the suns atmosphere |
| Corona | Outer part of the suns atmosphere |
| Sunspots | Dark spots on the surface of the sun caused by cool gases |
| Prominence | Huge sheets of glowing gases that leap from the sun. Archs |
| Flare | Powerful explosions on the sun that give off light. |
| Astronomy | The study of the universe and the objects in it |
| Universe | The totality of matter and energy in space and time, including all galaxies and other celestial bodies |
| Galaxy | Our galaxy is called "Milky Way". A system of stars, cosmic dust, and gas held together by gravitation. |
| Retrograde Motion | Motion in which a planet appears to make a loop in the sky, going backward for a while before continuing it forward motion |
| AU | Astronomical unit. 1=150 KM |
| Constellations | Ancient groupings of stars used for navigation and for marking the seasons, etc |
| Zodiac | Circular backdrop of 12 constellations through which the planets appear to move, located along the ecliptic |
| Plane of the ecliptic | The plane in which the earth orbits the sun |
| Rotation | The turning of an object about its own axis |
| Revolution | The turning of an object around another object in a circle, eclipse, or curve |
| Axis | A real or imaginary line about which an object rotates |
| Equinox | Equal hours of daylight and darkness on earth. March 20 and Sept 22 |
| Solstice | Longest daylight of the year-1st day summer June 20 |
| Asteroids | Rocks and boulders that have been observed in the solar system. They are different from comets in that they do not have tails |
| Comets | Frozen masses consisting of ice, dust, and other material, that slowly orbits the sun |
| Meteors | Lumps of rock and metals that sometimes enter the earth's atmosphere |
| Meteorites | Meteors that have made an impact with the earth's surface |
| Supernova | A high mass star that explodes producing a bright light and leaving behind a neutron star or black hole |
| Red Supergiant and Red Giant | A star even larger that a giant star that is very near the end of its life. Cool star. |
| Neutron Star | A very small star consisting of the remnants of an exploded star |
| Black hole | A small and dense object formed from a massive collapsing star. It has a gravitational pull so strong that even light cannont escape |
| Light Year | The distance light travels in one year about 9.5 trillion km |
| Big Bang | A cosmic event that took place 15-20 billion years ago and created the universe |
