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On January 1, 1801, Giuseppi Piazzi noticed a faint object in the gap between Mars and Jupiter while looking for a missing planet. Since it and similar objects appear star-like even when viewed through a telescope, it became known as an “asteroid”, although it has no connection with any star. The official term for an asteroid is a minor planet. Asteroids, like their big brothers, revolve around the Sun. They are mostly located in a doughnut-shaped band between Jupiter and Mars, but some are found closer to the Sun than Mercury, while others are beyond Saturn’s orbit. A few of the larger asteroids are several hundred miles across, while most are much smaller. Although the orbits of only about 2,000 asteroids are known, there are probably 100,000 of them that can be seen through telescopes.
Asteroids possessing an established orbit are give both a number to indicate the order of their discovery, and a name. The asteroid’s discoverer is given the privilege of naming it and so floating in space may be found 1 Ceres (discovered by Piiazzi), 334 Chicago, 616 Elly, 1010 Marlene, and the unforgettable 1381 Limburgia.
The only asteroid that is sometimes visible to the unaided eye is 4 Vesta. Quite a few other asteroids can be seen through binoculars or a telescope if you know where to look. The challenge of asteroid watching is to find one, not to see anything on it. An asteroid will appear as a dim point of light through a telescope or binoculars although we know that they often have extremely irregular shapes. The asteroid, just like the major planets, move across the stellar background of the celestial sphere.