The Original Interplanetary Mountaineers

Side-looking view of the Apollo 15 traverses
Traverse plots of the first two Apollo 15 EVAs, on which astronauts Scott and Irwin ventured to the lower slopes of Mons Hadley Delta (center left); numbers indicate elevations above the landing site (LM) (oblique LROC NAC M1123519889; north is to the right). For scale, the dogleg distance the astronauts travelled from the LM to Elbow crater along the edge of Hadley Rille (EVA 1) is ~4.5 km [NASA/GSFC/Arizona State University].

The lofty Apennine Mountain Range has two prominent peaks near the Apollo 15 landing site: Mt. (Mons) Hadley (relative height ~4km, or 13,000 ft) to the northeast and Mons Hadley Delta (~3.5 km, 11,500 ft high) to the south. Between these two peaks lies the Swann Range, named for the mission's Geology Team Leader, Gordon Swann. The Apennine Mountain Range contains some of the largest peaks on the Moon! The height of Mt. Hadley rivals the prominences of notable terrestrial mountains like Mt. Rainier (USA), Mt. Fuji (Japan), and Mt. Erebus (Antarctica), when measured from base to summit.

Elevations profiles of some mountains
Elevation profile of Mons Hadley Delta as measured from near the Apollo 15 landing site (left) through the peak (right); data from the GLD100, relative heights (prominences) of notable terrestrial mountains shown for scale. While Hadley Delta is not the largest peak in the Apennine Front, the Apollo 15 astronauts climbed only a small portion of this mountain. How high might future explorers venture [NASA/GSFC/Arizona State University]?

The first Apollo 15 EVA took astronauts David Scott and James Irving southward along the edge of Hadley Rille and to the base of Mt. Hadley Delta near St. George crater. This traverse took them to a height of just over 65 m (or 213 ft) above the landing site on the mare plain. At this height, much of the surface material of the mountain comprises debris that, over eons, slid down the upper slopes through mass-wasting. Materials collected in this area primarily consist of regolith, as there are very few surface boulders.

St. George Crater and Mt. Hadley Delta
St. George crater (upper right) on the base of Mt. Hadley Delta as seen from the surface during the third Apollo 15 EVA (at station 9); AS15-82-11086. Note the lack of angular boulders at St. George, in contrast to the block-rich crater in the foreground [NASA/Apollo Lunar Surface Journal].

The second EVA took the astronauts southeast to "South Cluster" and Spur craters. At Spur crater, a very old crystalline rock fragment was collected, containing evidence of geologic processes more than 4 billion years old and representing a piece of the original anorthositic crust of the Moon. They also discovered an unusual green material composed of volcanic glass.

This traverse ascended about 95 m in elevation up the base of Hadley Delta. At times, the slope was so steep (~18°) that the rover had difficulty getting traction, and the mountain peak loomed so high overhead, that the astronauts could not lean back far enough to get it in the frame of their cameras.

During this traverse, the astronauts commented that they thought they could detect a high-mark where lava might once have filled the basin at the base of nearby Mt. Hadley around a height of 85 meters above the current mare plain.

Slope of Mt. Hadley
Apparent outcrops (arrows) that may represent a high-lava mark ~85 m up the slope of Mt. Hadley; AS15-84-11315 [NASA/Apollo Lunar Surface Journal/Arizona State University].

While the Apollo 15 astronauts scarcely climbed the lower slopes of a lunar mountain, they made many important discoveries. What challenges, findings, and fun (like slope skiing) might future explorers experience on the powdery mountains of the Moon?

Explore the first two of the Apollo 15 traverses in more detail below by panning and zooming. The numbers indicate relative elevations of the paths travelled by the astronauts.

Related Posts:

Bowditch Lava Terraces

Lunar Kipuka

Remnants of the Imbrium Impact

Hadley-Apennine: the Apollo 15 Landing Site

Retracing the Steps of Apollo 15: Constellation Region of Interest

The Mighty Apennine Mountain Range

LROC’s First Look at the Apollo Landing Sites

The Apollo 15 Lunar Laser Ranging Retroreflector - A Fundamental Point on the Moon!

Layers near Apollo 15 Landing Site

LROC Explores Apollo 15 (YouTube video)

Hadley Rille and the Mountains of the Moon

Follow the Tracks

Soaring Over Mighty Mt. Hadley

Published by J. Stopar on 20 June 2014