No Terminal Velocity on the Moon

http://www.newton.dep.anl.gov/askasci/phy00/phy00814.htm

"Our moon has no atmosphere. High vacuum right down to the surface.A feather dropped on the moon from 100 miles above the surface would keep on accelerating at1/6 of earth-gravity (earth: 9.8m/sec2 or 32ft/sec/sec or 22mph/sec, moon: 1.6m/sec2 or 5.3ft/sec/sec or 3.6mph/sec)until it hit the surface at about 1600 miles per hour."

I was reading about craters as part of my daily fascination with something... There is an impact crater on the moon named Albategnius. The outer wall attains a height of 4,000 meters. I wondered how fast an astronaut would be travelling as he plunged towards the bottom.