Cancer, a constellation and the fourth sign of the zodiac. Cancer is the Latin name for crab; presumably, the unknown person who named it thought the constellation resembled that animal in shape. The Tropic of Cancer, an imaginary line 23 27' north of the Equator, marks the northernmost points reached by the sun's vertical rays. It is so named because in ancient times the sun was highest in the northern sky when it was in the same area of the sky as Cancer.
A lunar land rush is the most likely thing in the world (or, rather, out of it). As private companies gaze spaceward with dollar signs in their eyes, it's time to start settling some questions about space ownership, use and management.
A single pulsar is fascinating enough, but as a set, these rapidly rotating neutron stars help scientists figure out mysteries of the universe.