Heinrich Wilhelm Matthäus Olbers (Arbergen, 1758 / Bremen, 1840) was a German physician and astronomer, best known for his discovery of various asteroids and comets and for formulating Olbers' Paradox. In 1802 he located the asteroid Ceres, previously discovered by Giuseppe Piazzi, but which was soon lost. While searching for Ceres, he discovered another asteroid, Pallas (1802) and years later, in 1807, he discovered Vesta. He hypothesized that asteroids were fragments of an ancient planet that exploded, although this theory is currently not considered very likely. He also discovered 5 stars and calculated the orbit of 18. In 1823 he formulated the so-called Olbers' Paradox.
