The Earth's Moon: Using LRO Data to Learn About Lunar Geology and Geological History
Emma Schultz, Frances Trotter, Bailey Wicks
The goal of our research project was to answer the question of; how can we use data collected by the Lunar Reconnaissance Orbiter to learn about the geological makeup and history of the Moon?
What is the Lunar Reconnaissance Orbiter?
The LRO was a space endeavour launched by NASA in 2009. The Lunar Reconnaissance Orbiter mission had eight goals to complete on the moon. They were to find possible landing sites, map and observe regions of interest to create high-resolution images, develop a deeper understanding of mineralogical components of the Moon, and characterize and determine specific lunar geological components.
These instruments, shown in the image to the left, aid the LRO to give a detailed, high-resolution image of the lunar surface geology.
The Geological Composition of the Moon
Much of the data collected by the LRO is geological and mineralogical composition information. After the Apollo programs when many more moon rocks were brought back, scientists were able to determine from this lunar rubble that the surface of the moon was once molten due to the majority of basaltic rocks and is composed of olivine, pyroxene and, plagioclase feldspar.
The results from the LRO grants us the ability to explore the Far Side of the Moon’s surface a little further and observe more than ever before. The rear side has minimal surface contrast compared to the landlocked lunar face; around 4.4 billion years ago to 4.3 billion years ago while the young Moon's surface was molten, gravitational effects – the exact ones that create tidal influences here on Earth – pulled and warped the molten rock structure which evidently solidified due to the sub-zero temperatures in the vacuum of space. Which in return gave the Moon its famous face and giving it the slight bulge facing Earth.
There have not been many missions that have explored this rear side of the Moon, therefore, leaving us with not much information about what else could have been deposited there from the constant onslaught from space junk. Many countries, however, are working towards learning more and starting missions to launch this endeavor. One country, China, for example, has launched many missions to the moon, mainly all regarding the visible side of the moon. However, on May 21st 2018, China recently launched their Chang'e 4 to explore specifically the rear side.
The Geological History of the Moon
Although our moon was created approximately 4.55 billion years ago, the Lunar Reconnaissance Orbiter has gathered data to suggest that the Moon has undergone ‘recent’ changes, recent being approximately 50 million years ago.
A timeline of astronomical events which formed the Moon contains pieces of history which we can research today to learn more about the Moon, the Earth, and our solar system in general. For example, by studying the effects of lunar bombardment on the Moon we notice there is a noticeably greater number of craters on the lunar highlands compared to the maria is because during formation “rocky debris rained down on the surface of the young Moon”, thus forming the lunar highlands. Lunar highlands are the lighter surface of the Moon, whereas lunar maria is the darker region of the Moon, also called seas. The lunar maria were formed shortly after as the “rocky rain” was ending, when lava flowed into the craters formed by colliding asteroids.
A high-resolution image taken by the LRO, on the left, displays one lunar 'sea', Mare Imbrium.
Conclusion
Because of the LRO, we are able to take a closer look at the far side of the Moon, which has not been explored much prior to this mission. We connected findings from the LRO mission to the geological history of the Moon. One key observation was that the Moon has undergone recent geological changes, this alone tells us that the Moon and its geology is much more complicated than one may think. Current data from the LRO can also be connected to past geological events in the shaping of the Moon during the formation of our solar system.
Overall, though the LRO may not be able to answer all of our questions about lunar geology, it can begin to connect important pieces of history to lunar surface elements. It helps the everyday person to take a closer, more scientific look at lunar geology and geological history. It is because of missions such as the LRO that we are still learning about the early formation of the Moon, even 4.55 billion years later.
References
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