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
Lowell Observatory and Chile. Past Anderson Mesa, on the peak of Happy Jack, Lowell Observatory has also built and is commissioning the Discovery Channel Telescope in partnership with Discovery Communications, Inc. The observatory has carried out a wide array of research. One of its programs was the measurement of the variability of solar irradiance. When Harold L. Johnson took over as the director in 1952, the stated objective became to focus on light from the Sun reflecting from Uranus and Neptune. In 1953, the current telescope was erected. Beginning in 1954, this telescope began monitoring the brightness of these two planets, and