A large, ancient crater – nearly as wide as Arizona – now carries the
name of Greeley Crater, in honor of Ron Greeley, the Mars science pioneer and
longtime professor of planetary science at Arizona State University.
Ron was involved in almost every major solar system robotic
mission flown since the late 1960s and advanced the study of planetary
science at ASU.
The crater, which spans 284 miles, lies in Noachis Terra, the
geologically oldest terrain on Mars. Although the crater's exact age is
not known, the smaller impact craters superimposed on it plus its
preservation state all suggest an age of at least 3.8 billion years.
It is centered just east of Mars' "Greenwich meridian" and is 37 degrees south of its equator.
Kenneth Tanaka, a planetary geologist at the U.S. Geological Survey's
Astrogeology Science Center in Flagstaff and longtime colleague of Ron's, proposed the name, noting that it was the oldest, relatively
well-preserved impact crater on Mars that remained still unnamed.
Tanaka announced the crater’s naming in his keynote talk at the
24th annual Arizona/NASA Undergraduate Research Symposium on April 17 in
The International Astronomical Union, the world's authority for
feature names on extraterrestrial bodies, formally approved the name on
April 11. The union's rules require that a person must be deceased for
at least three years before any commemoration can be made; Ron died
in October 2011.
[this post was drawn from the announcement by ASU's School of Earth & Space Exploration]