Work a shift at mission control. Curiosity is in Gale Crater on Mars, on the route it has really driven since 2012. Pick one of the seven places it stopped to do science. Sequence a command, uplink it, and read what comes back on the downlink. You have 60 sols to spend. A sol is one day on Mars, about 24 hours and 39 minutes long.
This sim is built for HS-ESS1-6. Gale Crater holds an unbroken record of 3.3 to 3.7 billion years ago. That is the stretch of its own history Earth mostly lost. The For Teachers tab has the standard, where the ages come from, and the full line of questioning.
Data format
Every downlink adds rows. ChemCam adds five rows at once, one per laser shot. APXS and the drill add one row each. A row carries the sol, the stop, the height and age of the rock unit, the rock texture, the instrument, the target, the shot number, four oxide abundances in weight percent, and clay. Clay is filled in on drill rows only. Nothing else can measure minerals. Plot Clay (wt%) against Height (m). Clay peaks twice, not once.
Model details
The place is real. Terrain comes from the USGS merged Gale elevation model at 1 m per pixel. Surface imagery comes from the USGS Gale orthophoto mosaic at 25 cm per pixel. Both were resampled down for the web. The route and the seven stops are NASA/JPL published Curiosity waypoints, current to sol 4989. Height is elevation above the lowest stop, so the stops span 749 m of rock over 31 km of driving. Map elevation is exaggerated 2.5 times, and the map says so.
The close-up is not a photograph. At 25 cm per pixel a 20 m patch is only 80 by 80 pixels. At rover range you see the real shape of that spot from the elevation model and its real brightness from the orthophoto. Procedural grain and scattered stones carry the finer detail, and the outcrops are built rather than measured. The Hottah outcrop is modelled on the published Mastcam image PIA17062.
Compositions are generated, not replayed. Each unit has a mean set from published Gale measurements. Every reading is drawn fresh around that mean with the noise of the instrument you chose. Your sampling decisions produce your dataset, which a fixed recording could never do. ChemCam is noisy because single laser shots really are. Its first shot is pulled toward dust because the laser really does clear dust before it reaches rock. Only the drill feeds CheMin, and only CheMin sees minerals.
One-way light time is computed from the sol using circular orbits for Earth and Mars. It ignores eccentricity but gives the real 4 to 21 minute swing. Drive costs are compressed to roughly one sol per 1.8 km. The real drives took hundreds of sols. The rover is NASA/JPL-Caltech’s published model. It arrives as one fused shape with no moving parts, and was split into wheels, mast and arm for this sim.
The rock photographs on the analysis card are real. The Martian ones are Curiosity images from NASA/JPL-Caltech and MSSS, in the public domain. The mineral specimens come from GeoDIL at the University of North Dakota, released CC0, photographed by Shannon Heinle and Darla Sondrol. The Earth rocks are by James St. John under CC BY 2.0 and Joseph H. Hartman under CC0. Where an Earth rock is younger than its Martian counterpart, the card says so. Full provenance is in tools/card-images.json.
Standards
- HS-ESS1-6 – Apply scientific reasoning and evidence from ancient Earth materials, meteorites, and other planetary surfaces to construct an account of Earth’s formation and early history.
- HS-ESS2-5 – Plan and conduct an investigation of the properties of water and its effects on Earth materials and surface processes.
Design intent
- Why Mars serves a standard about Earth. Erosion and plate tectonics recycled most of Earth’s first billion years, leaving a few localities such as the Pilbara. Mars never had plate tectonics, so Gale holds the same interval end to end.
- Where the ages come from. Earth’s oldest rocks are dated radiometrically, on samples in hand. Martian ages come from counting craters, calibrated against Moon rocks Apollo returned. Curiosity measured one radiometric age in place, at Yellowknife Bay, and it is still the only one. That chain is what this standard means by evidence from meteorites and other planetary surfaces.
- Two other ways the planets get compared. Geologists read Martian rock against Earth sites that resemble Mars, such as the Atacama. APXS and CheMin run the same X-ray techniques used on Earth rock in a lab.
Discussion prompts
The standard is met by the lesson, not by the sim alone. These are one arc, in order.
Reading your own data
- Which stops did you drill, and what made you spend six sols there?
- Two students report different SiO2 values for the same unit. Who is wrong, or is neither?
- Your first laser shot is usually the odd one out. Should you delete it, and why?
- Clay peaks at two heights with a dry unit between them. What sequence of events produces that?
- Yellowknife Bay is the lowest stop but not the first one reached. What does that say about reading a route as a section?
Turning data into a claim
- Write one sentence about the water at Gale between 3.7 and 3.4 billion years ago. Mark the rows that support it. Say which part of your sentence has no row behind it.
- What could you claim about water here if you had never spent a drill?
- Who has the stronger claim, the student who drilled twice or the one who lasered everywhere?
- What would you have to measure to rule out the explanation you did not pick?
From Mars to Earth
- Earth keeps only scattered rock of this age. Why would someone studying early Earth come to Mars?
- Mars ages come from crater counting, checked against Moon rocks. Does that make your 3.70 Ga worth less? What would it take to check it?
- Why go to the Pilbara in Australia to understand Gale Crater, and why go to Gale Crater to understand the Pilbara?
- Using only your table, write the account. What was Mars like while life was starting on Earth? How much of that account does your data carry?
How do I explore?
- You are at mission control with 60 sols. A sol is one day on Mars. Every drive and every measurement costs sols.
- The map shows Curiosity’s real route and its seven real stops. Click a stop to see what driving there costs.
- Press the uplink button to send the command. Watch it go up, run on Mars, and come back.
- On the surface, click a rock, then pick an instrument. ChemCam fires a laser five times. APXS presses a sensor on the rock once. Only the drill measures clay.
- Every downlink lands in your data table.
What should I do/notice?
- Fire ChemCam five times at one rock. Why are the five answers different?
- Clay minerals only form when rock sits in water a long time. Which stops have clay?
- Write one sentence about the water that used to be here. Which rows back it up? Is any part of your sentence unsupported?
- Earth keeps only scattered rock this old. Why would scientists come to Mars to study early Earth?
- These ages come from counting craters, checked against Moon rocks Apollo brought back. How much would you trust one?
What about the data?
Each downlink adds rows, and Clay is blank unless you drilled. Plot Clay (wt%) against Height (m). Clay peaks twice, not once. Then plot SiO2 (wt%) against Height, coloured by Instrument. Filter to Target = Bedrock before you decide anything about a unit.