On July 19, 1969, the Apollo 11 command module had just achieved orbit around the Moon when the Mission Control Center in Houston, Texas, received word that amateur astronomers reported transient phenomena in the vicinity of the crater Aristarchus. Asked to check out the situation, astronaut Neil Armstrong looked out his window toward the earth lit region and observed an "area that is considerably more illuminated than the surrounding area.
It just has -- seems to have a slight amount of fluorescence to it." Although he wasn't sure, Armstrong believed the region was Aristarchus."