By Tim Lambert
The asteroids are small heavenly bodies, almost all of which orbit between Mars and Jupiter. The first asteroid to be discovered was Ceres. It was discovered by Giuseppe Piazzi in 1801. He named it after the Greek goddess of Agriculture. In 1802 Wilhelm Olbers discovered a second tiny heavenly body. He named it Pallas after Pallas Athene, the Greek goddess of wisdom. Soon other asteroids were discovered. In 1804 Karl Ludwig Harding discovered Juno. Wilhelm Olbers discovered Vesta in 1807.
In 1845 Karl Ludwig Hencke discovered a fifth asteroid, which he called Astraea. By the end of the 19th century hundreds of asteroids had been discovered. By the end of the 20th century over 100,000 were known. Today more than 1 million asteroids are known. (After 1891 photography was used to discover astroids).
In 1802 William Herschel coined the term asteroids, derived from Greek words meaning star-like.
In 1993 a spacecraft, Galileo discovered that the asteroid Ida has a small moon. We now know that many asteroids have tiny moons orbiting them. An asteroid called Kleopatra has two moons orbiting it.
However, in 2006 the International Astronomical Union reclassified Ceres, the largest asteroid, as a dwarf planet.
Ceres