A priceless moon rock lies locked in a glowing pyramid of lucite a few blocks from Lake Superior in Duluth today. NASA’s “Journey to Tomorrow” traveling exhibit pulled into town a few days ago, and among the displays is a palm-sized lunar rock collected by Apollo 17 astronaut Gene Cernan sometime on December 13,1972.
The 152 gram (1/3 lb.) concrete-gray rock measures about 3 inches (7.6 cm) across. It was part of a larger rock picked up by Cernan on his third moonwalk with fellow astronaut Harrison Schmitt. Moon-drive might be a better description. The two boarded the Lunar Rover that Wednesday evening and drove 2.5 miles (4 km) northeast of their landing site in Taurus-Littrow Valley, a relatively smooth area snaking between the rugged peaks of the Taurus Mountains just beyond the lava plains of the Sea of Serenity.
During one of their stops to collect samples, Cernan’s curiosity must have been peaked by the rock’s appearance. Using a set of tongs (or possibly a hammer to bust a chip off a larger formation), he retrieved the sample and dropped it in a bag. Schmitt and Cernan later placed the bags into specially sealed storage boxes and loaded them — along with our featured rock — into the lunar module ascent stage for the trip back to lunar orbit and Earth.
After Apollo 17 safely landed, the boxes were taken to the Lunar Receiving Laboratory at the Johnson Space Center near Houston, Texas and opened in a vacuum chamber to avoid contamination by the atmosphere. Before our 152 gram “rock star” began its 50-state tour, it was sliced (hence the smooth face on one side), classified and its age determined by radioactive dating methods.
It looks so ordinary to the eye. Like I said, a gray rock. I’ve seen better tossed up by the waves of Lake Superior. But before you lies a 3.9 billion-year-old stone far older than most Earth rocks.
Here in Duluth, we admire the tough 1.1 billion-year-old lava formations that tower above the waves of Lake Superior and underlie the region for miles. Ancient for sure, but the traveling moon rock provides a fresh perspective on exactly how old is old. It solidified just 400 million years after the moon itself took shape from the debris released during the cataclysmic impact of a Mars-sized planet with Earth.
The display next to the sample describes it as a “polycrystalline breccia” orof many
Check out the melt veins, cracks and vesicles (little holes) in the cut face — all indications of the violence that visited not only the moon but all the planets and moons during the solar system’s formative years.
You can see all this history wrapped up in a single rock with your own eyes still today. The big NASA truck with the moon rock and other space-themed exhibits will be open through 5 p.m. today (April 12) at the annual Home and Builder Show at the Duluth Entertainment Convention Center (DECC). If you can’t make it, the traveling exhibit may be coming to a town near you, although they don’t have a set schedule. For more information, click HERE.