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
Custer Observatory Custer Observatory Custer Observatory is an astronomical observatory owned and operated by Custer Institute. Located in Southold, New York (US), facing Peconic Bay and Shelter Island, Custer's location boasts some of the darkest skies on Long Island. Long Island's oldest public observatory, Custer Institute was founded in 1927 by Charles Wesley Elmer (co-founder of the Perkin-Elmer Optical Company), along with a group of fellow amateur-astronomers. The name was adopted to honor the hospitality of Mrs. Elmer, the Grand Niece of General George Armstrong Custer. In 1942, the Custer Institute was incorporated as a non-profit educational corporation in the State of