1834 – He was born on the 8th day of November in Berlin.
1861 – He wrote numerous papers on photometry.
1872 – He held the Chair of Astrophysics at Leizpig University. He outspokenly criticized the lithopanspermia hypothesis of William Thomson based on two grounds which are no explanation as to how life arose in the first place and that it failed to explain how organisms could survive the high-temperature passage of a meteorite through the Earth’s atmosphere.
1874 – He concluded from Mercury’s low Albedo, that the innermost planet probably had no significant atmosphere.
1882 – He died at Leipzig on the 25th of April this year.