Surface of the Moon - Trey Riley

Name: Trey Riley

Lab Partner Name: Abigail Goertzen

Lab Experiment #5: Surface of the Moon

Date: February 10, 2016

Abstract

The purpose of this lab and this report is to study, familiarize, and identify distinct surface features of the Moon. Lunar, topography, and elevation maps, as well as globes of the Moon were analyzed extensively to achieve the objective of this lab. The Moon has distinct surface features much like the Earth. The Moon has mountains, valleys, ridges, craters, lowlands, highlands, and distinct changes between each surface feature. The visible side of the Moon contains large maria, with some distinct cratering and mountains. The hidden side of the Moon is much different in the sense that they are few notable maria, but extensive mountain ranges and crater impacts scarring the hidden side of the Moon. In the lunar maria, there are few craters due to volcanic activity while the Moon was active some 3 billion years ago. On the hidden side of the Moon, there was very little volcanic activity, therefore the heavy cratering remains from billions of years of impacts on the surface of the Moon.

Introduction

The experiments conducted in this lab were to identify maria, craters, and mountains, as well as their most common geographical spot on the surface of the Moon, and to explain which surface feature acts as a natural boarder between the lunar lowlands and lunar highlands. This report has five distinctive experiments. The purpose in doing the first experiment is to be able to easily indentify the different distinctive features that make up the surface of the Moon. If the Earth serves as an example for our Moon, then many times lowlands and highlands are separated by a mountain range due to tectonic activity in the core of the planet. Also, seas are always at a low elevation, while mountain ranges are far above sea level. Seas are a result of tectonic activity, while cratering is independent of the tectonic activity of the planet, therefore craters can be at any spot on the planet’s surface, and seas are in distinctive spots boarding on tectonic plates. It is understood that the Moon lacks tectonic plates, but tidal forces are present.

Maria meets with mountain range

            The second experiment conducted consisted of identifying specific regions of lunar maria, and then determining whether volcanic activity was present in the specific regions under review. In doing so, the relative age and order in which certain features of the Moon formed can be distinguished. It is reasonable to say that volcanic activity renews a surface of its cratering. Therefore, if a specific region has little or no cratering, volcanic activity was present at some time in the past. If a specific region is heavily cratered, then volcanic activity has not been present in an extremely long time. The Moon is roughly 4.5 billion years old. While the Moon was active, volcanic activity was present for a certain period of time, roughly 1 billion years. The maria would have been completely formed after volcanic activity had ceased, while other parts of the Moon with no volcanic activity are the same as they were when the Moon was first formed.

Mare Imbrium with little to no cratering, indicating a relatively new surface

            In the third experiment, the lunar highlands were observed and inspected extensively. Peaks on craters were to be observed, as well as the overlapping of some craters. By understanding which craters have peaks, and which craters overlap, the relative age can be understood, as well as the force of the impact of the crater on the surface of the Moon. If a crater is overlapped by many smaller craters, it is reasonable to say that the crater that is being over lapped was there before the other impacts occurred, making the age of the crater that is overlapped older the crates on top of it. If a crater has a central peak, it is reasonable to say that the force generated by the impact of the object was turned into energy. Once the impact is made, the energy melts some lunar material, and that material forms in the center of the crater, where the elevation is lowest.

           During the fourth experiment, mountain ranges were studied, regardless of planetary position. This was done to find the approximate height of the largest mountain range on the Moon, as well as to determine why mountain ranges follow a curved path instead of a linear path along the surface of the Moon. Since the only force acting on the Moon is the tidal force exerted by the Earth, it is reasonable to say that tidal forces played some part in forming mountain ranges that are curved. The tidal force exerted on the Moon is a bulge along the equator, with the force becoming stronger the closer to the equator. The Earth pulls on the surface of the Moon with more force the closer to the equator. This force paired with the gravitational force on the Moon may account for the curvature of the mountain ranges of the Moon.

Lunar mountains

            Proceeding with the fifth experiment, the major differences were to be noted between the visible side of the Moon and the hidden side of the Moon. These differences tell how the two sides have been acted upon on by the Moon. On the hidden side of the Moon, there is far more cratering than on the visible side, and far less maria. This is due to either a lack of volcanic activity, or far more planetary impacts. 

Visible Side (right) vs Hidden Side (left)

            In the sixth experiment, similarities and differences were to be made with Mercury and the Moon. In doing so, the differences and similarities tell how common the features of the Moon and Mercury may be in our solar system and galaxy with planets and moons of comparable sizes. Both the Moon and Mercury do not have a large enough atmosphere to significantly block impacts. Both should have significant signs of cratering, since volcanic activity has long been gone from Mercury and the Moon. One major difference may be the lack of visible maria on Mercury due to the lack of volcanic activity. 

Moon (right) vs Mercury (left)

            Concluding with the seventh and eighth experiment, coordinates of the American and Russian space expeditions to the Moon were given. Notable surface features were to be mentioned and the purpose of landing at that site was to be inferred. By inferring why certain spots were chosen may show what we have learned about our Moon during our own experiments conducted on the surface. Many spots were most likely chosen to study certain land features, soil composition, and atmospheric conditions. Also, the quest for extraterrestrial life may have been a subsequent reason for investigating soil and atmospheric conditions.

Procedures

Throughout each individual experiment, a certain type of map was consulted, as well as other pictures of the lunar surface. The types of maps used were lunar, topography, and elevation maps. From each of these maps, information could easily be discerned. If information was not clear enough, hi-def resolutions of photos of the lunar surface from NASA were examined to make a better explanation to the experiment.

Results and Discussion

Experiment One:

            Maria are mainly found in the lunar lowlands, while mountains and craters are mainly found in the lunar highlands. Mountains act as borders between lunar lowlands and highlands. In the second quadrant of the Moon that faces Earth lays the most lunar maria. The second quadrant is in the north west direction of the visible side of the Moon. In this quadrant, the most volcanic activity occurred while the Moon was active. This is near the southern pole. On the far side, hardly any volcanic activity occurred, and if it did, the volcanic activity ceased long before it did on the visible side of the Moon.  

Actual View (left) vs Enhanced Color Version (right) of visible side of the Moon

           

Experiment Two:

            In Oceans Procellarum and Mare Imbirum the lunar maria was formed, and then cratered. In Mare Insularum, the lunar maria was formed and then cratered as well. Other maria and craters that fit the same scenario are Julius Caesar, Mare Vaporum, Geminus, and Canon. The surface of the lunar maria is roughly 3.5 billion years old. Cratering in this region would have had to form after this time period. Since the lunar maria formed after volcanic activity ceased, the surface of the maria is newer and less cratered than that of the lunar highlands and mountain ranges, which have not been made new by volcanic activity, subsequently making the surface older than that of the maria. 

Julius Caesar section of the Mare Tranquillitatis

            

Experiment Three:

            Most large craters have central peaks, while most smaller ones do not have central peaks. When overlapping of craters occurs, smaller craters appear younger because they themselves are less impacted, meaning they have been on the surface for a shorter period of time. Lunar cratering is a result of asteroids impacting the surface of the Moon. When overlapping of craters occur, the relative age of the carters can be estimated, likewise, when a central peak is present in a crater, the relative force can be estimated.

Crater with central peak and overlapping

            

Experiment Four:

            The largest mountain range on the Moon is the Apennines, with the largest mountain peak being Mons Huygens at an elevation of 10780m. Mountain ranges appear in a curved formation. Mountains are a direct result of asteroid impacts. Since the Moon doesn’t have plate tectonics like the Earth, elevation changes can happen only be external forces such as asteroid impacts. Volcanic activity due to tidal forces are the reason maria exist, but the volcanic activity did not cover the planet, leaving the asteroid impacts that formed mountains and craters.

            

Experiment Five:

            Some major differences between the visible side and hidden side is that the hidden side has few maria, but many craters. Some similarities are that both sides do have cratering, elevation changes, maria, and mountains. The most prominent feature on the hidden side of the Moon are the mountains and cratering. The cratering is present due to a lack of volcanic activity within the past 3.5 billion years, while the mountains may have formed over time due to the gravitational and tidal of Earth. The maria and mountains are due to either volcanic activity or lack thereof.

            

Experiment Six:

          Some major similarities between Mercury and the Moon are the frequency of craters on the surface, as well as identifiable land features, and the lack of an atmosphere. Some major differences between the two is that Mercury has no mountains or obvious maria, a wide range of chemical composition on the surface, as well as scarps on the surface. Both are heavily cratered due to the lack of an atmosphere and volcanic activity in the past few billion years. Mercury and the Moon have similar and different qualities. Since the Moon came from the Earth, the Moon has the same chemical composition as the Earth, plus the materials deposited by asteroid impacts. Mercury has a different composition because it is independent of the Earth-Moon system. Both Mercury and the Moon lack a livable atmosphere, meaning both are susceptible to asteroid impacts and subsequent cratering.

           

Experiment Seven and Eight:

            Each landing site seemed to be relatively flat with light to moderate cratering. It appears that lunar cratering was studied during expeditions to the Moon. For most spots, the reason for studying the lunar surface seemed to be to observe and experiment on lunar surface features such as craters, or valleys such as Hadley Rille, and to gain the soil composition and other geological items to bring back such as lunar rocks. 

Landing site of Apollo 15, two kilometers from Hadley Rille

Conclusion

The objective of this lab and report was to gain a better understanding of the lunar surface features. Certain features like craters were independently formed from the planet, while mountains and maria were dependent upon planetary functions and forces such as volcanic activity, tidal forces, and gravity. Maria are found in the lunar lowlands, while mountains are in the lunar highlands. Mountains distinguish the border between the two. Mountains have formed as a result of impacts with asteroids, and not plate tectonics like Earth. Maria are formed from volcanic activity from nearly 3.5 billion years ago while the Moon was still active due to tidal forces. Any cratering in the lunar maria is a result of impact after the period of activity on the moon, meaning the craters on the moon are younger than 3.5 billion years old. The cratering on the lunar highlands, can be even older, since volcanic activity has not remade the surface of the lunar highlands. 

          Cratering on the lunar surface is due to asteroid’s impacts with the surface of the moon. Many craters still remain, with some overlapping each other due to a large frequency and close proximity on the hidden side, while on the near side some have been covered by volcanic activity. Some craters have central peaks due to the extreme force of the impact with the lunar surface. During the American and Russian expeditions to the Moon, many places were explored, multiple surface features examined, and many experiments were performed on the atmosphere, soil, and on other geological aspects.