Mars Perseverance Rover Landing Site Jezero Crater: Mars Lesson built with the "NASA Mars Trek" & QGIS by GrowFlavor

Last crawled date: 3 years ago

"How Many Oceans & How Many Atmospheres has Mars lost to Rust celebrating the 2021 February 18 Arrival at Mars of Perseverance Rover"
NASA "Where is Perseverance Rover" Map
including various size & scale terrain models of the landing region, class discussion topic ideas, and fun web links with remarkable insights & detail relevant to Mars.
This is also an example of a high detail terrain model making process (more details in the "Print" section below). This work expands upon the easier 'point, click, drag' "Generate 3D Print file" tool which is built into the NASA Mars, Moon, Mercury, Vesta & Ceres Treks. Students may enjoy using the Trek tool to make their own mid-detail 3D printable models of their favorite craters, etc. I describe that built-in web tool in more detail in a separate Moon Trek 'thingi' https://www.thingiverse.com/thing:4732510.
I have included a variety of model sizes & scales from relatively small & easier to print up to a large quad that is more difficult to print.
'smallest' model: ~1cm = 1km (1:100k) .STL model with 5x height exaggeration of the Jezero Crater Perseverance Rover Landing Ellipse region.
'larger' model (included in a .ZIP file): ~1cm = 200m (1:20k) .STL model with 5x height exaggeration to show the detail of the dunes in features like Belva crater
'larger' area model (included in a .ZIP file): ~1cm = 2.5km (1:250k) .STL model with 10x height exaggeration showing western Jezero Crater area. Made from a preliminary DEM that still shows stitching in areas.
Quad of adjacent models (included in a .ZIP file) for the landed rover's planned science & exploration region: ~1cm = 200m (1:20k) .STL model with 5x height exaggeration

JEZ_hirise_SE.stl (rover's actual landing area)
JEZ_hirise_SW.stl (Belva crater & potential rover path area)
JEZ_hirise_SE.stl.stl (eroded alluvial fan)
JEZ_hirise_NW.stl (Neretva Vallis entrance) (I had several challenges printing this one.)

Why Send a unique Rover to a very special place on Mars? A few example gains from such an endeavor:

Attempt a significant engineering unknown: Fly an extremely special helicopter (images & description) in air so thin, on another planet, after the 'shake, rattle & roll' of launch, plus about 8 months of space travel !
Help us understand important long-term planet dynamics affecting our ability to grow food & live in cities near flooding shorelines as climate changes on our own planet Earth.
Look for signs of life on Mars from the distant past to further appreciate & understand life on Earth.
Inspire students & governments by demonstrating the "power to accomplish" when skilled people harness their differences, in a collaborative yet challenging process of working together to identify, emphasize, & solve beforehand key factors that can go wrong rather than to downplay serious flaws, in order to innovate new tools & techniques that actually perform well in new & difficult environments.

So, what engineering unknown makes the Mars Helicopter special? Exploring a few similarities & differences between current Mars & Earth will help reveal the difficult & remarkable challenge of flying a Mars Helicopter...
Mars & Earth today are quite different, but both have day times & night times & a Mars 'day' which is called a sol, is only about 40 minutes longer than the current 24 hour Earth 'day' (Earth had much shorter days in the past & will have much longer days in the future as the Moon continues to move farther away...).
Mars today has a dry surface. No rain puddles to trap the Mars Helicopter....but, sand dust in the air, & sand pits & sand dunes (Perseverance's 1st Mars panorama) & cold nights freezing the electronics & batteries will be a challenge. Where on the Mars terrain model(s) do you see or would expect sand dunes? Where on Earth could you find a dry dune surface similar to places on Mars?
Mars in the distant past may have been more similar to Earth today & more parts of Earth could continue to become more like Mars (description). Mars is a bit further from the Sun than Earth, but both Earth & Mars are at 'friendly' distances from the Sun...not too close & not too far. However, Mars has a very different size than Earth & that changes many important things.

Is Mars bigger or smaller than Earth?

Mars is about half the diameter of Earth (NASA Mars facts) & you would weight less than half of what you weigh on Earth. This also makes it easier for some 'air' molecules to escape to space & is partly why Mars likely lost a lot of atmosphere. Less 'air' makes it much more difficult for 'air'planes or helicopters to glide or fly. But, how much less air is there compared with Earth?



To find air this 'thin' on Earth you would need to chase this garlic bread to its highest point where the weather balloon burst (video)! Look at the altitude in the video screenshot: 35.8 km ! This is far above the 10 to 13 km altitude where commercial jet airplanes often fly here on Earth.

What color is the sky above the garlic bread?
What color do you think the sky might mostly be on Mars even in the day?
What color might the Mars sky & sun look if you were standing under all the dust (images & description) the Mars helicopter might kick up? Sometimes Mars gets dust storms so big that the entire planet gets obscured in dust (animated images & description).
What color are sunsets (& often also the clouds) on Mars (images & description)?



Could you glide a plane even at the surface of Mars in such thin air?

Not any normal Earth plane...not even the very high flying Lockheed Martin U2 spy plane would glide (video) because the current air pressure near the surface of Mars is only around 6 millibars...that's very thin compared with Earth's current surface pressure that is around 1000 millibars (1 bar)...Students as well as NASA Ames/NRL projects AME & MAGE as well as the team that designed, tested & built the current Mars helicopter (video) did a fair bit of work to identify some of the real unknowns with 'flying' on Mars.
To use this thin air to move around the small Mars Helicopter uses very large rotor blades that spin extremely fast. Maybe the rover will take a video of the test flight(s) so we can see if those fast blades kick up a lot of dust & sand. If this helicopter works in the very thin air on Mars, then this will become a new way to explore Mars with 'drones'. (& maybe someone also wants to use such a mini helicopter here on Earth, perhaps launched from a 'Rockoon', to chase something like that garlic bread, or a science lab project, in the thin air at the edge of space).



Could you hear sounds on Mars?

Even though the Mars air is currently very thin, sound can still travel through it. If you wanted to go for a walk on Mars today, you would need a pressure suit (space suit) to prevent your body water from boiling. On Earth, that is called being above the Armstrong line (images & description) So while your ears would not directly hear sounds; you could have microphones on your suit to detect the real Mars sounds around you & play them on speakers inside your helmet. NASA JPL is posting sounds recorded by Perseverance Rover's microphones at soundcloud.



Could you survive breathing the atmosphere on Mars compressed into your space suit?

Not today without a tool like MOXIE, but maybe around 3.7 billion years ago. Mars has 'lost' a lot of parts of its atmosphere since that time...some escaped to space, some bonded with surface rocks, some froze as ices ( for those with terraforming interests: atmospheres can collapse & be remade...for example, see Io's current frequent naturally collapsing atmosphere ).
Today, the little amount of Mars' atmosphere 'air' that is left is mostly in the form of carbon dioxide (NASA Mars www page).


While the thin air on Mars today makes it very hard for even a small 'drone' helicopter to fly and liquid water & Earth type life like you to stay at the surface of Mars today, NASA JPL chose to send Perseverance Rover to Jezero Crater, because Mars in the distant past likely once had a much thicker atmosphere with rain storms. Mars probably had:

even more 'air' than Earth's atmosphere today, possibly at times with between 1 to 4 bar surface pressure!
plenty of surface water &
'slow falling' rain with the lower gravitational acceleration & denser atmosphere of past Mars than present day Earth.


Compare the model with the NASA 'artists' drawing of the probable ancient lake in Jezero crater...

Match the river in the NASA drawing to similar looking features on the model(s). What features might have been under water in the past? Where might there have been ancient shore lines?


What signs of that ancient water can you see in this model? For example, large alluvial fan (maybe students have seen such a pattern in a nearby creek, pond, or rain puddle), Neretva Vallis water cut through the crater's rim,...


Which meteor craters likely formed from impacts that occurred after this Mars lake became dry...for example, craters that show well defined rims with minimal erosion?

Identify on your model(s) the regions shown in different colors in the USGS coloring activity or USGS geologic map. What differences in texture, flat/steepness/slope, height/elevation, & number of meteor craters do you observe on the models between the different colored regions shown in the geologic map?


The USGS colors represent different types of rock formations...some formed by erupting volcanoes, some by sands blown by the wind, and others made by 'dirt' sediments carried by flowing water.
However, Mars's actual surface color is generally 'rusty'. This color might be because Mars may have lost about one Earth ocean's amount of water (specifically the hydrogen(H) part of water high in the upper atmosphere) to space...possibly leaving the oxygen part of water behind to leave both the Mars ancient ocean & atmosphere to become rock 'rust' on the surface rocks. Rocks with iron will rust with oxygen to make the 'rusty' colored dusts that help make Mars appear to have a reddish/orangish/pinkish colors from a distance..


Now the remaining 'water' is in a few, sometimes very pretty, clouds as shown in these images, but appears to be mostly in salt brines (pdf) or frozen as ices in polar caps & under the dust 'soil':
An amazing high resolution mosaic of images taken by Curiosity rover with Mars clouds, as well as dust & desert rocks
NASA Phoenix Mars Lander Confirms Frozen Water (images & description)
Steep Slopes on Mars Reveal Structure of Buried Ice (images & description)
"Seasonal Streaks Point to Recent Flowing Water on Mars" (images & description)
& some still in under-'dirt' glacier like forms (closeup visual example)
marked as green dots shown in this wide area via the NASA Mars Trek.

With the 'smaller' model = 1:100,000 = 1cm:1km:

Use a string and small ruler to measure & record an estimate of the diameter of Belva crater
locate the center of the landing target ellipse on the model, then measure & record an estimate of its diameter
Why is the target landing area such a 'big' ellipse? Compare the approximate diameter of the ellipse that you just measured and compare it to the 470 million kilometers Perseverance has traveled to get to that landing site...that is even farther than the distance light travels from the Sun to Earth. "By time of landing, Perseverance will have covered 292.5 million miles (470.8 million kilometers), and Mars will be about 130 million miles (209 million kilometers) away from Earth; at that point, a transmission will take about 11.5 minutes to reach the spacecraft." Remarkable since the flight was a direct shot from Earth with no stops along the way.
If you also printed one of the 1:20k models such as the 'larger' model or the "quad", find its area & features in the 'smaller' 1:100k model or 'larger area' 1:250k model & compare the difference in detail. Also, compare details within 1cm = 200m (1:20K) model itself such as the locations & orientations of the sand dunes in various features.


Choose a 'favorite feature of interest' on the model & discuss why.

For example, my 3rd grade child suggested the peaks near the center of the landing ellipse as 'ancient islands in the crater when it was a lake' & we discussed the impact of a change in water depth over time.


There is also the option to follow the rover: mark its path on the model(s) over the next few years & put colored dots at places of key discoveries (and possibly print a matching handout with details of the discovery index keyed with the same color dot) as the science team explores.