Taurus–Littrow

• 1. Impact And Lava Flows

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  The Taurus, Littrow valley formed between 3.8 and 3.9 billion years ago when a massive object struck the Moon. This collision created the Serenitatis basin and pushed rock outward to form a ring of mountains. Several million years later, lava began to upwell from the lunar interior. These molten flows filled the basin and created what is now known as Mare Serenitatis. The valley itself sits on the southeastern edge of this dark sea of basalt. It lies within the Taurus mountain range and south of Littrow crater. Scientists determined that large massifs flank both sides of the valley floor. The North Massif and South Massif funnel into the main outlet of the valley. This gap opens toward Mare Serenitatis but remains partially blocked by Family Mountain. The height of these surrounding cliffs gives the valley a depth greater than the Grand Canyon in the United States.

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• 2. Mission Selection Process

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  Apollo 17 planners selected Taurus, Littrow as the final crewed landing site for the Apollo program in December 1972. Mission objectives required sampling ancient highland material alongside young volcanic deposits at one location. Planners considered Tycho crater but eliminated it due to rough terrain exceeding safety constraints. They also rejected Tsiolkovskiy crater on the far side because maintaining communication would require expensive satellites. Data from Apollo 12 had already provided sufficient timing history for the Copernicus impact. Engineers chose Taurus, Littrow to maximize scientific productivity during the last lunar mission. The International Astronomical Union approved the name coined by the Apollo 17 crew in 1973. Eugene Cernan and Harrison Schmitt landed there to explore these specific geological features. Their work provided insight into the natural history and geologic timeline of the Moon.

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• 3. Troctolite And Basalt Samples

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  Astronauts retrieved Troctolite 76535, a 4.25 billion-year-old coarse-grained rock composed primarily of olivine and plagioclase. This sample came from a rake operation within the valley floor. Scientists called it the most interesting specimen returned from the Moon. Thermochronological calculations suggest the Moon once generated an active core dynamo. Analysis by Garrick-Bethell et al. revealed nearly unidirectional magnetism parallel to a larger field. Rocks near the Lunar Module were mostly vesicular coarse-grained subfloor basalt with some fine-grained varieties. Seismic studies indicate the basalt layer below the valley floor exceeds one kilometer in thickness. Plagioclase makes up 20 to 50 percent of the mineral volume while clinopyroxene accounts for 30 to 70 percent. These samples allow researchers to study the composition of the lunar interior without drilling deep shafts.

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• 4. Tycho Impact Evidence

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  The Tycho impact occurred between 15, 20 million years ago and formed secondary crater clusters across the Moon. Data suggests the central cluster in Taurus, Littrow resulted directly from that distant collision. Most secondary impacts display a distinctive birdsfoot pattern in their downrange ejecta blanket. The debris pattern points toward Tycho and supports the hypothesis that light mantle material formed as an avalanche. Craters farther from the South Massif penetrate through the light mantle to reveal darker underlying material. Meanwhile, craters close to the massif do not appear to reach the dark layer at all. The age of this light mantle is estimated to be about 70, 95 million years old. Large-scale analysis indicates these smaller clusters could form part of a larger ray system originating from Tycho.

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• 5. Orange Soil And Glass Beads

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  Volcanic glass beads found at Shorty crater created a unique orange soil deposit within the valley floor. These tiny spheres formed when lava fountains blanketed the surrounding area with molten droplets during ancient eruptions. Most beads are dark in coloration which explains why Mare Serenitatis appears black from Earth. The orange discoloration occurs where specific glass beads came to rest after cooling. This volcanic activity happened somewhere between 100 and 200 million years after the initial basin formation. The valley floor has an unusually low albedo or reflectivity due to these volcanic materials. Scientists used deep craters on the floor as natural drill holes to sample subfloor basalt layers. The presence of these beads provides critical data regarding the timing and nature of lunar volcanism.

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• 6. Preservation And Future Plans

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  NASA issued guidelines in 2011 to protect Apollo lunar landing sites from new exploration activities. These protocols recommend keeping future missions away from the vicinity of aging hardware like the Lunar Module. Aerospace company PTScientists announced plans for their ALINA lander to touch down 3 kilometers from the original site in early 2020. That mission was later postponed to an indefinite date no earlier than the second half of 2021. Planners aim to respect the historical significance of the location while gathering new scientific data. Boulders scattered throughout the valley average about four meters in size near the experiment deployment area. These rocks are higher in concentration than other areas of the valley floor. Future teams must navigate around these obstacles while preserving the integrity of the historic landing zone.

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