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
Goldendale Observatory State Park and north dome a diameter of 10 feet (3 m). The observatory served as the National Astronomical League's official headquarters during a solar eclipse which occurred on February 26, 1979, six years after the observatory opened. Approximately 15,000 people came to the town of Goldendale on that date to observe the eclipse. The Observatory and its lands were acquired by the state of Washington in 1980, after being operated by the Goldendale Observatory Corporation since its dedication on October 13, 1973. The park received its new designation as a "state park heritage site" in 2014. In July 2017, all structures