Lab: Surface of Mars, by Seth Dowler

Seth Dowler

Lab: Surface of Mars

Abstract

In this lab students will identify, via primarily online as well as physical maps, the surface of Mars and its features, and speculate on the formations of these features. Through this an understanding of the process and difficulty of studying Mars will be reached.

Introduction

Before the invention of the telescope it was left up to the naked eyes of astronomers to describe and record the features of Mars, among other planets. But since recent technological advances have allowed clearer and clearer images of the surface of Mars, we can now study with relative ease compared with the difficulties of past centuries. Using precise methods, the atmospheres of Earth and Mars can be navigated in order to yield more detailed images of Mars, which we will be using to study its surface.

Procedures

The following resource, Google Mars, is essential to the project. http://www.google.com/mars/

Also needed to complete the lab is http://science.nasa.gov/missions/

Additionally, sites like Wikipedia.com can be utilized to research possible explanations to questions concerning the lab.

Students will use these resources and the following maps to answer the following questions.

A) Percival Lowell was a businessman and astronomer who died 100 years ago in 1916. This is what Percival Lowell recorded that he saw on the surface of Mars when he looked through his telescope:

Compare Percival Lowell’s drawings to one of the best images taken with the Hubble Space Telescope in 2003:

Percival Lowell thought he was seeing evidence of advanced intelligent people on Mars, as evidenced by vast canals spanning the planet.

1. Why would Percival think he saw canals? Hint: think about our own civilization more than 100 years ago. What were the dominant modes of transportation?

2. What was Percival seeing instead?

B) Here are typical sets of images that can be obtained with Mars from telescopes on the ground (with digital cameras and careful observing practices):

 

1. What are the main features that you can identify from the images taken from surface of the Earth? What might they be caused by or produced by? Can you see anything that resembles craters, mountains or seas?

2. How are these ground-based images similar to the Hubble Space Telescope image? How are they different? Why might our views of Mars be changing? Are they more detailed or less detailed?

3. Does Mars have a lot of visible craters like the moon at Mercury? What does this mean?

4. The “S”-shaped sequence of Mars-shaped images clearly show Mars appearing to change in size. They were taken over several months. What is going on?

C) Here are two more images taken months apart with the Hubble Space Telescope:

Looking at these two images, you can still identify changes in the color of the surface of Mars.

1. What are the main features that you can identify in these images?

2. How are these two images similar and different?

3. What is going on here?

D) We first landed on Mars in the 1970s with the Viking missions, and have sent rovers to Mars for the past 20 years since July 4th, 1997, starting with the Mars Pathfinder mission. We have also sent a series of orbiters, including the Mars Global Surveyor spacecraft that operated until its batteries failed in 2006. Currently there are a total of seven spacecraft either orbiting (MAVEN, Odyssey, Express, and Mars Reconnaissance Orbiter) or roving the surface of (Curiosity, Spirit, Opportunity) Mars today. Use the images below. Google Mars shows a false-color relief (elevation) map of the surface of Mars, revealing many details about the planet.

1.What do the four highest features on Mars appear to be? What could that mean?

2. In the elevation map of the planet, what is the most noticeable difference between the Northern and Southern hemispheres of Mars? What might this mean?

3. Which hemisphere appears to have most of the impact craters?

4. What appears to be the largest impact crater on Mars?

5. Find the landing sites for the US Viking I and II spacecraft, which touched down on July 20th and September 3rd of 1976 (40 years ago). What type of terrain did they land in? What do you think were the reasons for choosing these particular areas? From the elevation map, were they high or low elevation regions on the surface?

6. Find the landing site of the US Mars Pathfinder, Spirit, Opportunity and Curiosity spacecraft. What type of terrain did they land in? What could have been the reasons for choosing these areas?

7. The Soviet Mars 3 spacecraft was the first soft landing on December 2nd, 1971 at the Ptolemaeus Crater on Mars. Find it on your maps. https://en.wikipedia.org/wiki/Mars_3 After 14.5 seconds, transmission from the surface stopped. It may have fallen over, or there was a dust storm raging on Mars at the time that could have fried the electronics. Give a reasonable explanation for why it may have fallen over.

E) With the Google Mars map views (elevation, visible and infrared):

1. Search for the landing sites of the Mars Exploration Rovers (Spirit and Opportunity). They landed at Gusev Crater and Meridiani Terra.

2. Zoom in on each landing site and describe each site as to the features present and their elevations. Suggest reasons why these particular places might have been chosen.

3. Look at each landing site in the visible and infrared and determine whether you can see things in one wavelength of light that you cannot see in the other. Describe your findings.

4. Search for Niger Valles using the Google Mars search tool. Increase the magnification and follow Niger Valles by eye from its high elevation beginning to its low elevation end. What seems to have been going on here? Describe your findings.

F) NASA spacecraft continue to explore MARS today. See

http://science.nasa.gov/missions/. If you were planning the next mission to Mars, what

would its goals be?

Results and Discussion

A)

1 + 2 [combined]. Percival thought he saw canals, but what he really saw were probably places of erosion which looked like constructions by intelligent life. The contemporary mode of transportation – trains – likely influenced this perception. What eroded the surface of Mars? Primarily wind, but also acidic fog which traverses the surface of the planet. Additionally, the places in which Percival thought he saw bodies of water were likely the dark spots: also places of erosion, in which nearly all of the red dust has been swept away by wind.

B)

1. It seems too distant to make out features as small as craters, but there do appear to be what could be interpreted as seas on Mars looking from Earth, as well as possible mountains.

2. One of the ground-based photos has similar coloring to the Hubble images, but the other two do not – they feature lighter colors. More similarities are that all images include visible dark spots, and all images also show what appear to be smaller places made by erosion.

Our views of Mars are changing in that, as technology advances, they become clearer and clearer.

3. Mars does not have many visible craters. This implies that either it does not receive as many foreign object impacts as other planets, or, more likely, that its surface is able to withstand those impacts with less noticeable change: probably by those areas being eventually covered by dust.

4. Mars orbits the sun slower than does Earth – the s-shaped image shows it to become larger then smaller as the distance between it and Earth shrinks, then grows. This is a demonstration of retrograde motion because, as Earth’s orbit approaches Mars in its orbit, Mars appears to slow, then go backward, then eventually begin its original counterclockwise motion again.

C)

1. The main features I can identify in the left side image are small areas of impact which I assume to be craters, dark clouds surrounding the center of Mar’s middle of its surface, and ice caps on its north and south poles. In the left image I see a relatively smooth looking surface with substantially smaller iced areas, and two main portions of differing color: a dark and faintly orange lower half and a brighter orange-red top right segment.

2. As stated above, the main difference is that the right image contains a much smoother surface, as well as mostly lighter coloring.

3. What’s happening to cause these differences seems to be due to the changing of the seasons: at the time of the left photo (June), clouds dominate the surface of Mars and cause its darkness; at the same time the polar caps form. At the time of the right image (September), in contrast, these clouds have dissipated and the surface appears smoother; the ice caps have melted substantially, too.

D)

1. The four highest points on Mars appear to be mountains. These are, in order of highest to lower: Olympus Mons, Ascraeus Mons, Arsia Mons, and Pavonis Mons. This could mean, as one possibility, that Mars has experienced significant impact to cause these formations.

2. The most significant difference between the northern and southern hemispheres of Mars is that the northern is substantially lower, below sea level, than the southern. This could be an indication of Mars having a now-extinct large sea.

3. The southern hemisphere appears to contain most of the impact craters.

4. The largest impact crater appears to be in the Southern hemisphere of Mars. Its name is the Hellas Impact Crater.

5. These landings occurred in areas of low elevation; both were below sea level. These areas were chosen likely because of their relatively flat surfaces in comparison to other areas of Mars (the ones in higher elevation with more impact craters). Also, the Viking II landed next to a pretty substantial impact crater, likely to explore and document its properties.

6. Pathfinder landed in an area of -3 or so below sea level, near what appears to be a bed formed by water previously, likely in order to explore said area, as well as surrounding impact craters of which there were many.

Spirit landed in an area of slightly higher elevation, in an impact crater which leads to another tributary-like formation also likely formed by past bodies of water – likely to explore all these places.

Opportunity landed in an area just under sea level, nearing the southern hemisphere's overarching area of greater than sea level terrain, likely to begin explorations of said area's contents.

Curiosity landed at the edge of an impact crater which contains a large center point of heightened elevation, assumedly to explore the terrain and surface of this point.

7. A possible explanation for the transmission failure of Mars 3 is if the machine underwent corona discharge: due to the raging winds of the dust storm, the fluid surrounding the conductor of the machine could have been statically charged to the point of damaging the communicative abilities of the machine.

E)

1. (Search for Gusev Crater and Meridiani Terra)

2. At the Gusev Crater site, there is a very large crater surrounded by a fair amount of smaller ones (about 1/10 of its size). Importantly, the crater's outer circular edge is not complete; there is a trench or canyon formation that begins at its base. This probably had a lot to do with why it was chosen, so the rover could follow this path and explore the makeup of it.

            At the Meridiani Terra site, the surface is relatively flat, with a few complete impact craters surrounding the site, along with a few incomplete impact markings. Therefore it seems that mobility was the main concern here; the rover was not impended by being stuck in a crater so it could navigate the terrain and freely explore the surrounding formations.

3. At the Gusev Crater, there appears to be little noticeable difference between the infrared and visible spectrums when viewing the terrain, with the one notable exception that the intricate mountain ridges are much more easily viewed with the infrared vision rather than the visible vision.

The only striking difference I noticed on the Meridiani Terra site is that there is a plateau visible in infrared in the area just below the site, which is not so obvious when viewed in the visible spectrum.

4. What appears to have happened in the formation of the Niger Valles feature is that water was involved – that is certain. As to what exactly happened, the most obvious speculation to me involves ice. At the lower level there is a large circular area of low elevation, which appears to have once been a sea. But because the Niger formation rises up out of that area, it seems possible that expanding ice moved upward into this area, a force which lead to its formation. An additional possibility is that moving water somehow formed this through flooding.

F)

If I were planning the next mission to Mars, I would want NASA to fund a rover to explore the inner region of the Hellas Planitia – currently, only the Mars 2 Lander even attempted to land close by, and it failed during descent. There are many possible discoveries to be made, I believe, if we were to support a mission to this region.

Conclusion

This lab was performed in order to further our understanding of the surface of Mars and the differences in technology which now allow us to observe it. In the past, the naked eye sufficed; gradually, advances in the technologies of telescopes and other imaging methods (infrared and elevation, for example) have allowed deeper understandings of the surface of Mars, which we explored in this lab.