Surface of the Moon

Caleb W. Skocy

AST 115 Honors

10 February 2016

Lab Report #2

Surface of the Moon

Introduction

In this lab, we studied in detail various characteristics of the Moon.  These features include the maria, craters, and mountains.  We also located several of the Apollo mission landings and the Soviet Union’s Luna landings.  By inspecting the geography of the Moon, we can learn many things about the Moon’s history and formation, like when the maria or certain craters are likely to have appeared.  Along with learning about the Moon’s history, we can also infer some information about the history of our solar system as well.

 

Procedure

We studied several different features of the Moon and of specific landing sites for Apollo and Luna missions.  Then we attempted to answer several questions concerning the Moon’s surface.  To do this we used Sky & Telescope’s Moon Map, a large National Geographic Moon map, several Moon globes, and other online maps and resources.  The links to the online sources are given below:

https://www.google.com/moon/

http://www.usgs.gov/blogs/features/usgs_top_story/visit-the-moon-withoutleaving-your-desk/ http://pubs.er.usgs.gov/publication/sim3316 https://www.nasa.gov/mission_pages/apollo/revisited/

A) In this section of the lab, we simply familiarized ourselves with the features and coordinate systems of the Moon maps.  We also studied some of the more general features of the Moon (such as maria, mountains, and crater).

B) Here we closely inspected the features and craters of Mare Imbrium and Oceanus Procellarum.

C) Next, we studied the characteristics of craters in the lunar highlands, noting peaks and the overlap of craters.

D) Then we studied the Moon’s mountain ranges, especially the Apennine, Haemus Caucasus, Carpathian, and Pyrenes mountain ranges.

E) We studied the “hidden side” of Moon and compared its features with that of the side facing Earth.

F) We compared the surface of the Moon with this picture of Mercury:

G) We located and observed the landing areas of the following manned Apollo missions:

1. Apollo 11 0.8°N, 23.5°E
2. Apollo 12 3.2°S, 23.4°W
3. Apollo 14 3.7°S,17.5°W
4. Apollo 15 26.1°N, 3.7°E
5. Apollo 16 9.0°S, 15.5°W
6. Apollo 17 20.2°N, 30.8°E

H) Finally, we located and observed the landing areas of the following unmanned Soviet Union missions to the moon:

1. Luna 16 0.7°S, 56.3°E
2. Luna 17 38.3°N, 35.0°W
3. Luna 21 27.0°N, 31.5°E

Results and Discussion

A) General features of the moon.

1. Which of these features (maria, mountains and craters) are found mainly in the lunar lowlands and which are found mainly in the lunar highlands?

• Maria are mostly found in the lunar lowlands, while the craters and mountains are more prominent in the highlands.  

2. Which of these features frequently act as borders between the lowlands and highlands?

• The mountains seem to often act as borders between lunar highlands and lowlands.  Many half filled craters can also be seen at the liminal area between highlands and lowlands.

3. As reckoned on the moon, in which Quadrant of the side facing us are the maria mostly found?

• Most of the maria are in the Northwest (or upper left) quadrant facing us.

B) Craters in the maria.

1. If you restrict your view to the craters Plato, Archimedes, Wallace and Cassini in Mare Imbrium and to the craters Flamsteed, Letroone, Marius, Prinz and Herodotus in Oceanus Procellarum, which would you say came first, these craters or the mare? Explain your reasoning.

• I would say that the craters were formed before the mare.  This is because these craters are little more than the upper rim of craters, and they have apparently flat bottoms at about the same level as that of the mare.  This can be explained by the lava that formed the mare spilling into the craters.

2. Now look at the craters Kepler and Copernicus located in Mare Insularum, next to Oceanus Procellarum, and explain which came first, these craters or the mare? Explain your reasoning.

• It would seem that these craters appeared after the mare was formed.  This is because they do not have flat, even bottoms like the previous craters.  Also, their bottoms seem to go lower than the mare, giving proof that the ground was broken afterwards.

3. Which other maria and craters could be used as examples of the scenarios depicted in questions 1 and 2 (two examples of each will suffice).

• Posidonius on the edge of Mare Serenitatis and Taruntius near Mare Fecunditatis both appear to be examples of mare filled craters.
• Manilius in Mare Vaporum and Plinius in Mare Tranquilitatus are examples of craters which appeared after the mare had formed.

4. Comment on the history of the lava flows that produced the lunar maria relative to when crater production occurred.

• Just from observing the surface of the Moon, we can make assumptions about the history of the Moon’s surface formations.  We can see that the volcanic activity of the Moon continued after a large part of its cratering occurred, as can be seen by the minuscule amount of cratering in the mare opposed to the large amount of cratering elsewhere.

C) Craters in the lunar highlands.

1. Do most large craters have central peaks? Do most small ones?

• It appears that, mostly, only larger craters have central peaks, while smaller craters do not.

2. When overlapping occurs, do the larger or the smaller craters appear to be younger? Why?

• It appears that the smaller ones are usually younger, impacting and marring the larger craters.  If the larger craters were younger, they would probably have destroyed most evidence for the smaller craters.

3. Based on the evidence you see on the maps, what do you suspect the origin of lunar craters to be? Explain your reasoning.

• I would say that the cratering of the Moon’s surface is caused by the impact of asteroids and other foreign objects from space impacting the Moon’s surface.  It can be seen that the larger part of the cratering would have occurred earlier on, during the more violent time near the beginning of our solar system’s formation.  Since then, impacts have been smaller and farther in between, as seen by the small craters within the larger craters and the small amount of cratering within the maria.

D) The Moon’s mountains.

1. What is the highest mountain or mountain range on the Moon? What is the approximate elevation?

• The highest mountain on the Moon is Mons Huygens within the Apennine range, standing about 5.5km tall; while Montes Cordillera is the mountain range reaching the highest elevation, around 8,500m.

2. In general, do the mountain ranges extend in straight or curved lines? Based on the evidence you see on the maps, what do you suspect the origin of lunar mountain ranges to be? Explain your reasoning.

• The mountain ranges seem to extend in curved lines.  I suspect the mountain ranges to be the remains of large craters caused by collisions between the Moon and other large objects.  As we can see around Mare Orientale, Montes Cordillera and Montes Rook take on a completely circular shape.  It seems obvious that this was caused by a very large impact long ago, with volcanic activity (possibly caused by the impact) filling in the bottom of the crater and creating the mare.  It would seem that most of the mountain ranges were created long ago, as the rims of very large craters.  The rest of these craters have since been filled by the mare, or been covered by myriads of other craters.

E) Hidden vs. Near side of the Moon

1. What seems to be the major differences between the two sides?

• The far side is much more cratered than the near side of the Moon, while the near side has a much greater number of maria.  This is probably because the near side would have been affected by tidal forces from the Earth causing the volcanic activity.

2. What are the main similarities?

• In the areas without maria, both are very heavily cratered.  The maria also appear in the lowlands on either side, while the highlands are characterized by craters.  The North and South poles on either side also seem to be much more cratered than the areas closer to the equator.

3. What would you say is the most prominent feature on the far side of the Moon? What kind of feature is it? Speculate on how it may have formed.

• The most prominent feature is Mare Moscoviense. It is a singular mare surrounded by highlands. It appears that it was caused by a large impact.  This impact probably struck hard and deep enough to cause lava to spill up through the crust and fill in the crater, creating the mare.

4. Do the numbers of large and small craters appear to be the same on both sides of the moon? If not, what differences do you note? (Do not count the maria as craters).

• The number of small craters seem to be about the same on either side, but the number of large craters is not the same.  It appears that the far side has a much larger number of large craters.  This would be because most of the larger craters would have occurred earlier, before most of the maria were formed.

5. Do the shape and detail of the craters on each side seem to be the same? Explain.

• They seem to be about the same.  They are, of course, mostly round in shape.  Larger ones often have cratering from smaller craters within them.  The one’s on the far side though seem to overlap more often.  

F) Moon vs. Mercury

1. What similarities do you find between the surface of the Moon and Mercury?

• They are both heavily cratered.  Both also have craters with rays shooting out from them.  They also both appear to not have a very strong atmosphere.

2. What major differences do you note?

• Mercury does not appear to have large smooth areas, such as the maria on the Moon.

3. Suggest a reason for any differences or similarities.

• They are both old enough to have been heavily cratered.  The weak atmosphere of each would contribute to the heavy cratering and the rays of debris, as there would be almost no erosion.  The reason that the Moon has maria but Mercury does not appear to have any may be that the Moon’s volcanic activity continued longer after Mercury ceased to be volcanically active, so all of Mercury’s maria have already been covered by craters.

G) The Apollo missions’ locations.

1. What is the most general appearance of each landing site, which lunar features did the astronauts learn most about, and what reasons can you see for picking each particular spot?

• Apollo 11: This landing site would have been relatively flat, being on the edge of Mare Tranquilitatis.  The astronauts would have mostly only learn about the mare, but the was a small crater (Little West) nearby also.  The reason for this spot was that it is smooth, providing an easy landing, and it was a good area to set up several small experiments, including the Laser Ranging RetroReflector (LRRR) and Passive Seismic Experiment Package (PSEP).
• Apollo 12: This landing area was once again flat and in a mare. There are also several small craters nearby.  The astronauts took rock and soil samples of both mare and crater material.  This was a good spot to land because it would have again provided a smooth landing.  Also, it was close to where the Surveyor 3 had landed, so they were able to retrieve some parts from it.
• Apollo 14: This mission also landed in a mare, not far from Apollo 12.  These astronauts collected samples from nearby crater debris, helping us learn more about the lunar crust.  This site was chosen because of the large Cone Crater nearby which would allow for good samples of the Moon’s crust, also, it would have been an easy landing.
• Apollo 15: This mission landed right at the edge of Mare Imbrium, next to the Apennine mountain range.  The crew would have been able to learn more about the makeup of the nearby mountainous highlands, but there was also a “young” volcanic rille nearby for them to survey.  This was a good site to learn more about the geography of the Moon’s surface, with the nearby mountain range.
• Apollo 16: This landing site was in a relatively smooth area of the lunar highlands, but there are several smaller highland craters nearby.  They would have made discoveries about the composition of the lunar highlands and their craters.  This site was chosen partly because of its proximity to the North Ray, a young bright-rayed crater.  Also, it it would give insight into the makeup of rocks in the highlands.
• Apollo 17: This mission landed at the edge of Mare Serenitatis, right on the border of the cratered highlands.  This site would have provided information about both mare and craters in the liminal area of the highlands.  It was a good location for surveying both the mare and cratered region leading into the highlands.

H) The Luna mission landings.

1. What is the general appearance of each landing site, which lunar features were studied, and what reason can you see for picking each particular spot?

• Luna 16: This landed in the eastern region of Mare Fecunditatis.  This landing provided a soil sample from the mare.  This area would have been good for the easy and smooth landing it would have given the Luna 16, and was perfect for collecting a sample from the mare.
• Luna 17: Luna 17 landed in the northwestern region of Mare Imbrium.  It would have been very flat with some small craters nearby.  Luna 17 would have provided pictures and soil tests.  This area was ideal for the Luna 17 rover, being flat and maneuverable.
• Luna 21: This mission landed at the eastern edge of Mare Serenitatis in the Le Monnier crater.  This area would provide information (including photos and soils tests) about the mare as well as the border of the highlands.  This site, once again, would have provided a smooth and manageable surface for the rover, while also giving a view of the highlands.

Conclusion

As we can see, there is much that can be learned just by observing the surface geography of the Moon.  We can infer when the maria were most likely formed, which gives us an idea of the age of craters in the maria.  We can assume where a large crater is most likely to be found, as well as infer a relative age to it.  Soil tests from the surface can also tell us about the composition of the Moon’s crust.  Along with all of this, the surface of the Moon can help tell us about the history of our solar system, such as when the most violent collisions would have been occurring.