Lunar Reconnaissance Orbiter Camera

Plato Crater Constellation Region of Interest

The Constellation Program region of interest northwest of Plato crater exhibits a wide variety of geologic features. LROC WAC frame M109269483CE; 695 nm in red, 567 nm in green, 415 nm in blue [NASA/GSFC/Arizona State University].

Plato is a large (109 km (67.7 mi) diameter) mare filled crater seen prominently in the northern near side of the Moon. The Constellation Program region of interest is located on the northeast portion of Plato's ejecta blanket (Figure 1).

Figure 1. Regional context image for M104554343R. The large crater on the left is Plato, the white boxes indicate the Constellation Region of Interest, and the long yellow polygon indicates the size of the full outline of M104554343R.

This area appears to be empty, and to an untrained eye it would possibly appear to be uninteresting. However nothing could be farther from the truth. The intent of human exploration in this region is to explore a possible pyroclastic deposit. Radar studies of this region, along with spectroscopic evidence from the US Clementine mission indicate, that this region may be covered with pyroclastic materials. As an added bonus there is a large sinuous rille (Figure 2), possibly related to the pyroclastic deposit, just south of the Constellation site, close enough that astronauts could explore it using a simple rover. 

Figure 2. Portion of NAC Image M104554343R just to the south of the Constellation region of interest detailing a portion of Rimae Plato (which meanders across this image from left to right), a lunar rille that may be an old lava channel associated with the pyroclastic deposits in this area (image is 9 km across).

Pyroclastic deposits consist of small, glassy volcanic beads that subdue and mantle the surrounding terrain, produced by explosive fire-fountaining eruptions billions of years ago when the Moon was more geologically active. When magma cools rapidly (quenched), atoms do not have the time to form orderly structures (minerals) so a glass results. Pyroclastic glasses are actually the most primitive (that is, unmodified by later geologic processes) materials in the lunar sample collection. The study of the pyroclastic materials in the Apollo collection has given geochemists valuable insights into the composition and evolution of the lunar interior. However, there are comparatively few pyroclastic materials in the current collection, and the Apollo sites themselves are not representative of all of the lunar surface from a geological standpoint. Human lunar exploration is needed to complete our understanding of the formation and history of the Moon.

Pyroclastic deposits are potentially some of the most valuable resources to support human lunar habitation. Processing pyroclastic materials can provide relatively easy access to oxygen and water for future lunar explorers. Human exploration of this location will enable access to these important resources, as well as provide key insights into the nature of these pyroclastic materials and the possible source regions of these volcanic eruptions.

Explore the Plato Constellation Region of Interest for yourself!

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