If Apollo 16 astronaut Charlie Duke can get his fingers a little farther under the rock pressed against his right thigh, he will be able to bring back to Earth the heaviest moonrock that has been picked up by any of us moonwalkers so far.

Charlie, and his teammate John Young, have parked their rover at their first geology site and are beginning their exploration of the Descartes Highlands. As they went about their business, CapCom Tony England said the geologists in Mission Control wanted Charlie to pick up a large rock near the rim of Plum Crater that they could see on the video being transmitted by the Rover camera.

As Charlie skip-shuffled over, kicking up dust all the way, he was thinking, that request has to have come from Bill Muehlberger, our geology principal investigator. My guess he was also thinking that the rock was awfully close to the lip of Plum Crater. I don't know if this is a good idea or not.

"That's a football-size rock," observed Charlie.

John chimed in, "Are you sure you want one that big, Houston? That's 20 pounds of rock right there."

Tony came right back, "Yeah, let's go ahead and get it."

Charlie steadied himself using the scoop and dropped to his knees and reached for the rock. It was just too large to grip with his right glove. Maybe if he rolled the rock over against his right leg he could use the tips of his fingers to slide and roll it up onto his thigh. It was a clumsy maneuver, but it worked. Finally he stood.

Charlie couldn't resist, "if I fall into Plum Crater getting this rock, Muehlberger has had it".

Over at the Rover John exclaimed, "look at the size of that moose!" Indeed, the rock wouldn't fit in any of their sample bags. So Charlie put it in a stowage bag under his seat.

"Big Muley", sample number 61016, later named in honor of Professor Muehlberger by Charlie Duke, was the largest rock collected during the six lunar landing missions. It weighs 25.8 earth pounds (11.7 kilograms) but only 4.3 moon pounds (1.95 kilograms).