Surface of the Moon - Seth Dowler

Seth Dowler

Lab: Surface of the Moon

Abstract

The experiment was performed primarily via observation of maps of the Moon as well as Mercury.  Observations were recorded and conclusions were then extrapolated from them. Additional research was conducted regarding the purposes of multiple Apollo missions. Lastly, online resources were utilized in addition to printed maps.

Introduction

Students were first asked to study the features of a moon via simple observation. Then, deeper meanings and conclusions were drawn from these observations: what, for example, is the likely cause of the Moon’s maria features? Students then researched the appearances of various Apollo missions’ site landings, the intentions of said missions. Lastly, students performed the same task for three Russian space missions.

Procedures

Students utilized multiple resources to complete the lab. First was a printed map from their lab packet: the Moon Map by Sky and Telescope. Online, two resources were needed: Google Moon, and the government site http://nssdc.gsfc.nasa.gov/planetary/lunar/apollo.html in order to research the Apollo missions. Through these materials, students were able to procure the following findings by answering the following questions.

Results and Discussion

A) 

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

The lowlands contain the maria features on the moon as well as the craters, while the highlands contain the mountains.

2. Which feature frequently is a border between lowlands and highlands?

Craters frequently act as borders between the highlands and the lowlands, i.e. craters are generally more equal to the reference sphere (comparable to ‘sea level’ on Earth), while the maria lie below it and the mountains rise above it.

3. In which Moon quadrant are most of the maria facing us found?

Most of the maria found on the side of the moon facing us are in the southeastern quadrant (third quadrant).

B)

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

It seems that the maria came after the craters because it appears that the craters made their impact onto the maria, surfaces which were already molded by lava, as their surface areas are larger. Additionally, there are no ray systems surrounding these sites (craters within the maria).

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 seems to me that the craters Copernicus and Kepler were formed after the mare in which they are found because of the pattern surrounding their craters. If they were formed before, the ray system (markings projecting outward from the impact site) would likely not be present, or at least not as visible, because they would be covered by the lava flow.

3. Which other maria and craters could be used as examples of the scenarios depicted in questions 1 and 2? (two examples needed only)

Two examples of other craters formed after their maria were formed could be:

            --crater Picard of Mare Crisium

            --crater Ross of Mare Tranquilitatis

  Two examples of craters formed before their maria could be:

            --crater Theophilus of Mare Sinus Asperitatis

            --crater Straight Wall of Mare Nubium

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

The production of craters occurs after the formation of maria; craters are created on top of the surface of maria, which are the cooled remnants of lava. Craters formed before the maria formed were engulfed by the molten lava and thus are no longer visible, filled in by said lava.

C) 

Study the large and small craters in the lunar highlands. Note the type of craters which have high peaks and those which do not. Also note the overlapping of craters on craters in certain regions.

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

Most large craters have central peaks, while most small craters do not.

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

In general, the smaller craters appear to be younger. The way to tell if by which crater is most whole: if one craters has retained its complete circular circumference while the other is intruded by that circumference, then the former crater is the younger crater because its impact destroyed the previously whole structure of the older crater.

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

I suspect the causes of the moon’s craters to be various satellites (mostly asteroids) which enter into the moon’s gravitational pull, eventually being pulled close enough to impact the surface.

D) 

Study the mountain ranges in general, paying particular attention to eh Appenine, Haemus Caucasus, Carpathian and Pyrenes ranges.

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

The highest mountain on the moon is the Mons Huygens, at 5.5 kilometers.

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 of the moon are generally formed in straight lines with slight curves. Therefore, this leads me to believe that they formed via very large impacts from great asteroids. This accounts for their size and the slight curve, as well as the fact that they aren’t formed in circles (in other words aren’t simply very large craters), because of the power of their impact and the resulting lava flows generated from the heat they caused. (The lava flows would destroy most of the circle of the crater, forming a mare, while the remaining piece of the circle would remain as a mountain/mountain range.)

E) 

Using Google Moon or the LRO maps, study the “far side” of the Moon. Compare the features on the far side with those you have studied on the near side.

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

The major difference between the near and far sides of the moon seem to be the amount of crater impacts. The far side has far more visible crater impacts. It’s likely that this is because of the lack of lava flows on the far side, while the near side has had its lava flows obscuring many of its old crater sites as the lava flowed over and covered them.

2. What are the main similarities?

The main similarities are the sizes of the craters, which seem generally the same (though the far side appears to have slightly smaller sites).

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 be formed.

The most prominent feature on the far side is the Mare Moscoviense. It seems to me that this likely formed via a large impact from a foreign object, its heat leading to a lava flow, and thus forming 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)

It appears that there are more crater sites (large or small) on the far side than the near side of the moon. This is likely because of the much higher amounts of lava flows on the near side, which have covered some of the craters.

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

The sizes of the crater sites on each side appear comparable, yet the far side has smaller impact sites in general. This is likely because the near side has a thinner surface, leading to larger impact areas by objects of the same size if they were to hit there, rather than on the thicker surface of the far side.

F) 

After studying the surface of the Moon, study this picture of Mercury:

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

Similarities between the surface of the Moon and Mercury include, foremost, their cratering and color; both surfaces bear much resemblance to one another in this regard: gray, brittle-appearing surfaces coated with an abundance of circular impacts.

2. What major differences do you see?

The primary differences I see between the surfaces of the Moon and Mercury is foremost the absence of maria on Mercury: there are no vast shaded stretches on its surface, unlike on the moon. Additionally, the craters on Mercury appear to be larger than those on the Moon.

3. Suggest a reason for any differences or similarities noted.

A possible reason for the absence of maria on Mercury is that, unlike the Moon, it did not receive the impacts great enough to cause lava flows which would have produced maria. Strangely, this does not correlate well to the other difference noted: the crater marks on Mercury appear to be larger than the Moon’s – plus, Mercury’s diameter is roughly 1.5 times that of the Moon, adding to the significance of this aspect. Therefore, it seems the impacts that the Moon received which led to the formation of its maria were, naturally, quite random.

G) 

Between 1969 and 1972, the National Aeronautics and Space Administration made six successful Apollo manned landings on the Moon in order to learn details about the Lunar surface and interior not obtainable from the Earth. Below are the selenographic (lunar) coordinates for each of these landing sites, latitude and longitude

LRO was able to image the landing sites in enough detail to see the bases of the landers and equipment left behind on the surface of the moon. Follow this link to explore our first steps as a species on another world:

https://www.nasa.gov/mission_pages/apollo/revisited/#.Vpq7tfH19ks

Find the positions of each on your Sky and Telescope Moon map, and then on Google Moon. Briefly comment on the following questions for each site:

What is the most general appearance of each landing site.

Which lunar features did the astronauts learn most about.

What reasons can you see for picking each particular spot?

1.

Apollo 11 0.8*N, 23.5*E

The general appearance of this site is of an area devoid of craters, since it rests in a mare (Mare Tranquillitatis). This was desirable as a flat landing site for the spacecraft, as well as being able to explore the mare itself. The things the astronauts learned most about here were the appearance of the area (they took photos of their surroundings), as well as the composition of the moon’s surface (a sample of the earth’s crust was taken, leading to further examination of the composition back on Earth).

2.

Apollo 12 3.2*S, 23.4*W

The appearance and label of this site is again of a mare: Oceanus Procellarum. This again means that the area was chosen for its levelness and lack of obstructing factors in the landing of the spacecraft. For this mission, the astronauts again took photographs, and this time took two samples of the moon’s crust. Additionally, they examined the Surveyor 3 spacecraft which was nearby, removing pieces of it with which they returned to Earth with in order to study their changes in composition.

3.

Apollo 14 3.7*S, 17.5*W

 Apollo 14 was the third mission in which astronauts traversed the Moon’s surface on foot. The spacecraft landed this time near a crater: the Fra Mauro. One possible reasoning for this was to explore the crater and record its appearance, in order to advance general knowledge of the Moon’s craters. The astronauts again took photographs and moon samples, as well as performing scientific experiments.

4.

Apollo 15 26.1*N, 3.7*E

This site must have been chosen for its close proximity to the Apenninus mountain range. Therefore, observation of said mountain range was conducted: how did the range form? What is its present composition? – possible questions to have been studied.

5.

Apollo 16 9.0*S, 15.5*W

This site is surrounded by many craters, though in its center (at the landing spot) it is relatively flat. It seems apparent that the meaning of this mission was to study more closely the composition of the craters and possibilities of what may have caused them to have formed.

6.

Apollo 17 20.2*N, 30.8*E

The landing site for this mission was near the Mare Serenitatis. The purpose of this mission was to further study the properties of mare. Additionally, there are also craters nearby. Therefore, the mission also conducted examinations of said craters, comparing the properties of the mare and the craters – especially important because of their close proximity to one another.

H)

The Soviet Union also landed spacecraft on the Moon, but they were unmanned. However, the most notable successes are those which returned lunar samples to Earth and those which had a lunar rover for exploring the surface. The coordinates for three of these landings are given below. Find the positions of these sites on your moon map and Google Moon and briefly comment on the following questions for each site:

What is the general appearance of each landing site

Which lunar features were studied.

What reason can you see for picking each particular spot?

1.

Luna 16 0.7*S, 56.3*E

This landing site was near a mare formation: Mare Fecunditatis. This mission (which was the first unmanned one to return a soil sample) returned said sample from the Mare Fecunditatis. The purpose of the mission was foremost to return to the sample to Earth for scientists in Russia to conduct studies upon.

2.

Luna 17 38.3*N, 35.0*W

This landing site was by multiple mare formations; therefore, part of its mission was to study the appearances and structures of them. Additionally, the rover for this mission returned over 2,000 images to Russian scientists.

3.

Luna 21 27.0*N, 31.5*E

This mission landed nearby the Mare Serentatis. The lunar features studied included this mare as well as craters which were situated close by. These formations seem to be the primary causes of the location of this landing.

Conclusion

Much information has been gained regarding the composition of the Moon’s surface through direct evidence brought back by missions – the most meaningful information (information gathered from more than just observation via the Earth, in other words) has all occurred within the last 50 years! As for observations available from the vantage point of the Earth, we are able to see that the Moon has an appearance quite comparable to Mercury: many cratered with a seemingly brittle surface. A major difference, however, is that the Moon includes maria: lowlands that resulted from lava floods, which resulted from great impacts on the surface a long time ago.