Wolf was the first astronomer to use time lapse photography in astronomy, a method he used for detecting astroids. At the time Wolf was the only German Astronomer that developed new photographic methods for observational astronomy. He discovered several nebulae, both inside and outside the Milky
Way.. More than 200 astroids and in 1883 a comet which now bears his name. In 1903 he discovered the first of the so-called Trojan satellites (number 588, later named Achilles), whose orbits are in precise line up with that of Jupiter. Wolf discovered that the dark voids in the universe is in fact nebulae blocked by big clouds of dust. He studied the spectral characteristics and distribution. Wolf also was the first to view Haley's cometwhen it approached the Earth in 1909.