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
Fremont Peak Observatory Fremont Peak Observatory Fremont Peak Observatory (FPOA) is an astronomical observatory owned and operated by Fremont Peak Observatory Association. Built in 1986, it is located in Fremont Peak State Park, near San Juan Bautista, California. Fremont Peak Observatory houses the Challenger telescope. The observatory is named after the mountain it resides on, Fremont Peak which was itself named for American explorer and U.S. Army Captain John C. Frémont. Previously the peak had been named for the Spanish word for hawk, Gabilan Peak. The California state park service "acquired the peak in 1936". The first group to use the peak as