Surface of Mars Lab

Caleb W. Skocy

AST 115 Honors

22 March 2016

Surface of Mars Lab

Introduction

In this lab, we closely studied the surface of Mars.  We also located the sites of several U.S. spacecraft landings and a Soviet Union spacecraft landing on Mars.  Studying the surface and geography of Mars can help us understand part of the history of Mars’ formation.  We can learn about the formation of its mountains and valleys.  We can also discover whether there may have once been flowing water on Mars.

Procedure

For this lab, we studied we studied several different features of the surface of Mars.  We compared different pictures of Mars as we have seen it throughout history, from Percival Lowell’s drawings all the way the the Hubble Space Telescope.  Using maps, we studied the geographical features, including the differences in cratering and elevations of the Northern and Southern hemispheres.  Then we located the landing sites of several Mars exploration spacecrafts.  To do all this, we used some large Mars maps and a Mars globe provided for us in class.  We also used Google Mars (https://www.google.com/mars/).

Discussion and Results

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?

• In the earlier 1900s, ships and steamboats were the major form of transportation.  The building of large canals (such as the Panama and Suez canals) during this period was important for trade and showing the prestige of stronger countries.

2. What was Percival seeing instead?

• Likely he was seeing mountain ranges or the rims of some of Mars’s craters.  He could have also been seeing the difference in elevation between a large canyon, such as Valles Marineris and its network of canyons, and the surrounding area.

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?

• The main features are lighter areas in the North and darker features in the South.  There is also a large white spot at the Southern pole.  The lighter and darker areas may be the result of differing compositions and/or elevations.  The white spot could be ice, just as our South pole has ice.  There is also a blue haze around the edges of Mars, this could be evidence of an atmosphere.  Though there don’t appear to be any visible mountains, there are two large dark spots that could be craters.  The large dark area also looks similar to an ocean.

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?

• They are similar in that both sets of images show the Northern half as lighter and the Southern half darker.  They also both have the white spot at the bottom, and they both have the blue haze around the edges.  Our views are changing because of the increased technology with which we have to view Mars with.  We are able to see Mars in greater detail with the Hubble Space Telescope because of our increased technology and the fact that since it is out of Earth’s atmosphere it is not affected by the atmospheric distortion.

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

• No.  This might indicate that volcanic activity continued on Mars longer than Mercury or the Moon.  It also indicates that Mars has a stronger atmosphere, and possible once held water, which helps to erode the surface and erase evidence of craters.

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?

• This is showing the apparent retrograde motion of Mars.  As Mars gets larger, the Earth is getting closer to it.  Then Mars appears to move backwards, but this is because the Earth is passing Mars in its orbit.  Then Mars appears to start shrinking, because Earth is moving away from it.

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?

• There are large dark areas and large areas that appear lighter.  This may indicate differences in surface composition and/or in elevation.  There are also white areas at either pole which appear to be clouds and possibly ice.

2. How are these two images similar and different?

• In both images you can see the white spots at either pole.  You can also see that the southern half appears darker, while the northern half appears lighter.  But the images are different in that the second image appears to be obscured by a kind of red haze.

3. What is going on here?

• There is probably a large planet-wide dust storm of some sort, filling the atmosphere with a red dust.

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?

• The four highest features (Olympus Mons, Pavonis Mons, Arsia  Mons, and Ascraeus Mons) all appear to be volcanoes. These volcanoes would have built up from repeated eruptions until they reached their current height.  This shows evidence for volcanic activity on Mars in the past.

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?

• The Northern hemisphere seems to mostly be at a lower elevation overall.  It also appears to be much less cratered than the Southern hemisphere of Mars.  This seems to hint that there may have once been a liquid ocean on the Northern hemisphere of Mars.

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

• The Southern hemisphere appears to have most of the craters.

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

• Hellas Planitia appear to be the largest impact crater on Mars.  It is large enough than it probably would have contained a sea during the time when there was liquid water on Mars.  There are also small canyons running into it that support the idea of rivers flowing into it.

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?

• They both landed in Planitia terrain, which is very smooth and level.  This would have provided an easier and level landing than in craterous areas.  These are low elevation areas.

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?

• Each of the spacecrafts landed around sea level on Mars.  Pathfinder landed a little lower down, in an area on the border between Planitia and Terra.  Spirit landed in a medium sized crater on the edge of the higher elevations.  Opportunity landed in landed in in a large relatively flat Terra, between the Planitia and the higher elevations.  Curiosity landed in a large crater right at the edge of Mars’s higher elevations.  Each of these landing spots may have be relatively smooth for landing.  Each was one the edge of different elevations, which might allow for observation and soil tests from different level of Mars’s surface.

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.

• Mars 3 landed in a very craterous area.  This would mean that the area would be uneven and full of debris.  Mars 3 probably tipped over into a small crater or fell because it was on some unstable rocky debris.

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.

• Spirit: This landing site is inside of a medium sized crater in the area between the Planitia and the highlands.  Its elevation is about sea level.  This site would have access to soil from both the higher and lower elevations, while also providing somewhat smooth landing.
• Opportunity: This site is also at sea level elevation.  It is in a relatively smooth area of Terra between the Planitia and the cratered highlands.  Once again, it would have provided a relatively smooth landing.  The nearby craters would have also allowed for sample of soil from below the direct surface of Mars.

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.

• For each site, the infrared image is much more detailed.  It allows us to see many more small craters that were not apparent in the visible image.

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.

• It appears to be a large channel running through a canyon and then ending down in the Planitia where it disappears.  It seems that Niger Valles may have once been a river.  The canyon would have been carved out over many years of the river flowing.  It begins up higher where it appears that many smaller streams flow together.  Then at the bottom it would have been deposited in the sea which used to fill Hellas Planitia.

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?

• I would want to land a spacecraft near one of the four giant volcanoes on Mars.  That would give us a view of the higher elevations of Mars, while also providing material from below Mars’s surface.  

Conclusion

Overall, there is much we can learn from studying the surface of Mars.  Using pictures of Mars, we can see that there is a blue tinge around the edges, and we can see that Mars is occasionally obscured by a red haze.  This shows that Mars does have a moderately strong atmosphere.  The relatively light cratering compared to the Moon and Mercury also give evidence to the atmosphere of Mars.  We can see evidence of volcanic activity in Mars’s past, leading to the formation of the four tallest mountains on Mars.  By looking at the elevation differences between the Northern and Southern hemispheres, as well as the absence of almost any craters on the Northern hemisphere, we can guess that there were at one time oceans of liquid water on Mars.  Canyons (such as Valles Marineris and Niger Valles) also show evidence of Mars, at one point in time, having flowing water on its surface.