Apollo Expeditions to the Moon: Chapter 14

Apollo Expeditions to the Moon

CHAPTER 14.6

BEADS OF ORANGE GLASS

The modification of the surface of the valley basalt included the addition of mantles of beads of chemically distinctive orange glass (the "orange soil") and black devitrified glass. The beads appear to have been formed by volcanic processes having their origins in the deep interior of the Moon. The titanium-, magnesium-, and iron-rich nature of these silicate glasses surprised us in many ways. Their approximately 10- to 30-million-year age of exposure to the Sun is young and was expected for the dark mantling deposits seen in photographs; but their 3.5- to 3.7-billion-year age of cooling from a liquid was not expected. The explanation for this difference is not yet obvious.

Mysterious Aristarchus and Schrüter's Valley also await some future explorers of the Moon to give us insight. Once considered for a mission, the sinuous rilles and volcanic features on the Aristarchus plateau have puzzling characteristics that are little understood.

All the Apollo missions left the Moon before the lunar sunrise had progressed into the vast regions of the lunar west: Mare Procellarum, where the mysterious features of that region's central ridge system still await the crew of a mission diverted after Apollo 13, and Mare Orientale, whose stark alpine rings have been viewed only in the subdued blue light of Earth. The promise of these regions and of the far side of the Moon has not diminished. They seemingly watch the progression of sunrises, awaiting the landing craft of another generation of explorers.

A panorama of lunar history is captured in this view looking south over the Valley of TaurusLittrow. A huge fragmented boulder had rolled almost a mile down the side of the North Massif to here, Station 6 on our traverse (see here). Our LM and its light area of surface alteration can be seen on the photo about an inch to the right of the top point of the boulder. That's me at the left. Note the marks of my sampling scoop on the debris resting on a slanting surface of the boulder at left. Gene Cernan took the photos from which this mosaic was assembled.

A parked Rover awaits our return from sleep before we set out on the third EVA of Apollo 17's surface exploration. We've parked it in an orientation that will minimize heating of its surfaces while we are eating and sleeping in the LM. Our activities around the LM have exposed dark soil beneath the lighter soil caused by our descent-engine exhaust.

A lonely Rover watches with its television eye as the last Apollo explorers depart from the Moon.