Lowell (Martian crater) Lowell (Martian crater) The Lowell Crater is a large impact crater on Aonia Terra in the Thaumasia quadrangle of Mars. The crater is about 203 kilometers (127 miles) in diameter. Lowell Crater has a ring of mountains on its floor which gives it a sort of bull's eye appearance. Its nearby features include the craters Slipher to the north, Douglass to the east, and Coblentz to the southwest, the small mountain Aonia Mons to the west, and Aonia Planum to the southeast. Lowell Crater is named for Percival Lowell who built the Lowell Observatory in Flagstaff, Arizona, in 1894, and
Heidelberg-Königstuhl State Observatory Heidelberg-Königstuhl State Observatory Heidelberg-Königstuhl State Observatory () is a historic astronomical observatory located near the summit of the Königstuhl hill in the city of Heidelberg in Germany. The predecessor of the current observatory was originally opened in 1774 in the nearby city of Mannheim but degradation of observational conditions there resulted in a relocation to the Königstuhl in 1898. The observatory forms part of the Center of Astronomy of the University of Heidelberg. The Max Planck Institute for Astronomy opened on an adjacent site in 1967. Prof. Dr. Andreas Quirrenbach is the observatory's director since 2005. The instrumentation of the