On this day in 1969, Apollo 11’s Lunar Module Eagle touched down in the Sea of Tranquility on the Moon. While Michael Collins stayed in the Command Module Columbia, Neil Armstrong stepped out of Eagle to become the first human on the Moon. He was followed by Lunar Module Pilot Edwin Aldrin.
Also on this date, in 1976, the Viking I landed on Mars.
That juxtaposition has always said Something Deep to me about the trajectory of space exploration.
I look up at the moon, and wonder: When will we be going back? And who will that be?"–Jim Lovell
Probably somebody Chinese. 
Google is running a tribute at http://moon.google.com. Be sure to zoom in all the way on the Lunar imagery. 
In 500 years, the year 1969 will be remembered the way 1492 is remembered today. The average person will know it was the year man reached the moon, and be unable to cite anything else that happened within plus or minus 50 years.
Well, that handles the supplies problem! 
Seriously, though; 20 July is a momentous day in the history of space exploration. I wonder how much farther along we’d be had we not stopped going to the Moon in 1972?
I’m glad we keep landing on Mars. What wonders will we discover in future missions?
Bwaaaah hahahah!
But it’s the wrong color . . .
For anyone who’s interested, I started a "“Where were you when the Eagle landed?” thread in IMHO.