| A | B |
|---|
| The brightest star in the constellation Centaurus | Alpha Centauri |
| A large constallation of the northern hemisphere, adjoining the Square of Pegasus | Andromeda |
| A spiral galaxy 2.4 million light years away. Known as M31 or NGC224. | Andromeda Galaxy |
| German astronomer who in 1852 began the undertaking of preparing an atlas and catalog of all stars down to magnitude 9.5 in the northern hemisphere. | Friedrich Wilhelm August Argelander |
| A small solar system body indepedently orbiting the sun. Most are between the orbits of Mars and Jupiter. | Asteroids |
| The branch of astronomy that deals with measuring the precise positions of celestial objects | Astrometry |
| The study of the physical properties of celestial bodies. | Astrophysics |
| Fast moving particles arriving in the solar wind collide with atoms of oxygen and nitrogen whoch emit energy at red and green wavelengths illuminating the night sky. | Aurora (Northern Hemisphere Aurora Borealis, Southern Hemisphere Aurora Australis) |
| Pioneer of exact measurements in positional astronomy. In 1838 through "wobbles" in the motions of Sirius and Procyn he was able to determine the parallax of a star. | Friedrich Wilhelm Bessel (1784-1846) |
| Second brightest star in Centaurus. It is also known as Hadar or Agena. It is 525 light years away. | Beta Centauri |
| This star is an organ-red supergiant in the constellation Orion. It is about 500 times larger than Earth's sun. | Betelgeuse (also known as Alpha Orionis) |
| He developed the theory of how energy is produced in the Sun, how hydrogen is converted to helium by nuclear fusion | Hans Albrecht Bethe |
| Two stars in orbit around a command center of mass. | Binary Stars |
| A localized region of space where matter and radiation cannot escape. | Black Hole |
| A second full Moon in a calendar month. | Blue Moon |
| This Danish astronomer was the most skilled observer of the pre-telescope era. | Tycho Brahe (1546-1601) |
| An object with mass less than .08 solar masses, the core temperature does not get hot enough to have a thermonculear reaction. | Brown Dwarf |
| The second largest and outermost of Jupiter's Galilean satellites | Callisto |
| A dim and largely barren constellation between Gemini and Leo. | Cancer |
| A joint space mission between NASA and the European Space Agency to explore Saturn and its moon Tian in 1997. | Cassini (Also a famous family of astronomers who ran the Paris Observatory for four generations) |
| Small objects orbiting the Sund between Jupiter and Neptune | Centaur |
| The satellite of Pluto discovered in 1978 by James Christy | Charon |
| Polish churchman and astronomer. Developed the theory that the Earth revolved around the Sun. | Nicholas Copernicus (1473-1543) |
| The outermost layer of the Sun's atmosphere extending for many millions of kilometers into space. | Corona |
| The eruption into interplanetary space of millions of tons of plasma from the Sun's corona. | Coronal Mass Ejection (CME) |
| The sutdy of the structure of the universe on the largest scale. | Cosmology |
| The nebula M1 about 6500 light years away in Taurus, the remnant of a supernova that was noted by Chinese astronomers in 1054. | Crab Nebula |
| The smallest constellation in the sky, known as the Southern Cross | Crux |
| This constellation is nicknamed the Northern Cross | Cygnus |
| Unseen matter existing in the space between galaxies. Makes up 90% of the mass of the Universe | Dark Matter |
| Cloud of gas and dust that can only be oberved silhouetted against stars and bright nebulae | Dark Nebula |
| Bright nebula in the constellation Serpens. Contains many newborn stars. | Eagle Nebula |
| The two points were the Sun crosses the celestial equator | Equinox (Spring March 21, Fall Sept. 23) |
| Smallest of Jupiter's Galilean moons | Europa |
| Study of the possibility of life outside the Earth | ExoBiology (Astrobiology) |
| Huge assembly of stars, dust, and gas. | Galaxy (Three types: Elliptical, Spiral, Barred Spiral) |
| Galilean Satellites, the four chief satellites of Jupiter discovered by Galileo | Io, Europa, Ganymede, Callisto |
| Italian astronomer who invented the telescope | Galileo (1564-1642) |
| Largest of Jupiter's Galilean Satellites | Ganymede |
| Large oval area in the southern hemisphere of Jupiter first observed by Heinrich Schwabe | Great Red Spot (GRS) |
| The newest moon of Neptune | Hippocamp (It is 21 miles in diameter and named for a sea creature from Greek mythology |
