Term | Definition |
absolute magnitude | the apparent magnitude that star would have to an observer located 10 parsecs from the star |
Aldebaran | Taurus |
Altair, Deneb and Vega | stars that form the Summer Triangle |
Andromeda galaxy | largest galaxy in the Local Group |
asterism | small group of stars that is used to form a picture or represent an object |
asteroid belt | large ring of asteroids located between the orbits of Mars and Jupiter |
astronomical unit | unit of measurement that is equal to the distance between the sun and the earth |
astronomy | study of God's creation beyond the atmosphere |
barred spiral | shape of the Milky Way galaxy |
Betelgeuse | Orion |
black hole | an object so massive and dense that not even light can escape its gravity |
Castor | Gemini |
celestial sphere | imaginary sphere with Earth at the center and the heavenly bodies on its inner surface |
circumpolar | describes a star that is always above the horizon to an observer at a particular location |
coma | the cloud of gas and dust that surrounds the center of a comet |
comets | frozen chunks of ice and dust that orbit the sun |
Deimos and Phobos | Mars's moons |
ellipses | symmetrical oval shape of planets orbits |
full moon | moon phase the entire sunlit side is visible |
Ganymede | largest moon in our solar system |
geocentric | earth-centered view of the universe |
granules | convection cells that cover the sun's visible surface |
Hertzsprung-Russell diagram | two-dimensional graph comparing stars by their temperature and brightness |
Isaac Newton | developed the law of universal gravitation |
Jupiter | planet that shares an orbit with the Trojan asteroids |
Kuiper belt | group of small, icy objects orbit the sun outisde the orbit of the outermost planet |
lunar month | name for the period of time that the moon takes to the orbit of earth |
main sequence | category of stars that includes the sun |
mare | Latin word used to refer to the lunar "seas" |
Mars | notable feature is Olympus Mons |
Mercury | fastest-moving planet |
meteor | small rock from space that is burning up as it passes through Earth's atmosphere |
nebula | large cloud of gas and dust in space |
Neptune | the outermost planet in our solar system |
parallax | the apparent change in the position of an object daused by an actual change in the position of the observer |
perihelion | planet's closest approach to the sun |
photosphere | visible portion of the sun |
Polaris | Ursa Major |
pulsar | a rapidly rotating star that emits directional beams of radio waves |
Regulus | Leo |
retrograde | describes a planet that rotates backwards on its axis |
satellite | an object that orbits another object |
Saturn | known for its ring system |
Sirius | Canis Major |
solar eclipse | phenomenon when the moon passes between the sun and the earth |
Spica | Virgo |
spicules | the flamelike columns of gas that continually erupt from the lowest layer of the sun's atmosphere |
supernova | explosion of a star |
third law | the scientific law which dstates the relationship between a planet's period and average distance from the sun |
Uranus | gas giant that seems to lie on its side |
Vega | Lyra |
Venus | sometimes called the "morning star" and "evening star" |
zodiac | imaginary "band" in the sky in which the sun, moon and planets travel |