Astro Glossary

Chinese Astronomy and Folklore

See Asian Astronomy

Chinese Space Program

Clementine Spacecraft

The Clementine Spacecraft was launched in 1994 to test sensors and spacecraft components under extended space exposure and to make scientific observations of the Moon and an asteroid. It completed its lunar observations, producing the most detailed map of the composition of the lunar surface to date, but failed en route to the asteroid. It was jointly sponsored by the Ballistic Missile Defense Organization and NASA.

Climate change

An alteration in Earth's climate caused by human activities. Burning fossil fuels releases carbon dioxide and other "greenhouse" gases into the atmosphere, trapping the Sun's heat and causing the planet to grow warmer. (Although some areas will get cooler, the net is a planet-wide temperature increase.) That is causing widespread effects, such as the extinction of entire species of life. 

Cold War

Coma Berenices

Coma Berenices is a northern constellation and the only constellation named for a real person: Queen Berenice II of Egypt, the wife of Ptolemy III. Although it is relatively faint, under a dark sky many of its stars are visible as pretty streamers that look like strands of hair.Berenice married Ptolemy, who was her cousin, in 246 B.C. As king, Ptolemy later went to war. The tale of Berenice says that to protect her husband, she promised to cut her beautiful hair and offer it to the gods if Ptolemy returned safely. He did, so she did. She placed her locks in a temple, dedicated either to the goddess Aphrodite, or to all the gods, depending on the version of the story. The hair soon disappeared. The court astronomer told the king that the locks had been taken by the gods and placed in the sky — streamers of stars near Leo, the lion. The story might be true, or might have been created — or at least embellished — to raise the king’s profile.Coma Berenices didn’t become a constellation until 1536. And it didn’t enter wide-spread use until 1602, when it was included in an atlas published by Tycho Brahe.It is best known for the Coma Cluster, a collection of thousands of galaxies centered within the constellation's borders.  

Comet

A chunk of ice and rock that orbits a star. In our solar system, the majority of comets orbit well beyond Pluto, in regions known as the Kuiper Belt and the Oort Cloud. Most comets are no more than a few miles in diameter. Upon close encounters with the Sun, comet ices vaporize, creating a coma, or cloud, around the comet, and a long tail that always points away from the Sun.

Configurations, Conjunctions and Oppositions

Constellations and Asterisms

Constellations are patterns of stars visible to the unaided eye, or regions of space seen from Earth that are bounded by borders designated by the International Astronomical Union. Asterisms are also naked-eye star patterns, but they do not form constellations on their own. An example is the Big Dipper, which is part of Ursa Major. Americans know northern hemisphere constellations by the names given them by ancient Babylonians and Greeks. Seafaring explorers named those in the southern hemisphere. Every culture created its own constellations, although most of those in use today came from western sources.

Contact Binaries and Merging Stars

A contact binary is two stars that are so close that their surfaces are touching. In profile, such a system would resemble a peanut. As the two stars orbit each other, they lose momentum, so they eventually spiral together. Such a merger could produce a bright outburst, known as a nova, with the two stars forming a single, more-massive star. It could also produce a supernova explosion, which would completely destroy the two stars.