Download and Analysis of Mars-Based Temperature Data

How Does Near-Surface Temperature Change with Height on Mars?
Microsoft Excel 4.0 Version

Purpose: to "download" and import data into Microsoft Excel 4.0 so you may analyze it for patterns and significance using the Chart Wizard . Note, if you want to download a set of pre-formatted data click HERE to download the file, save it to your desktop, load it into Excel, and skip to step 12.

Procedure: Print this worksheet to follow along and work with a partner (if possible). Similar procedures are available for those using Claris Works 4.0 or Microsoft Excel 5.0.

1. Begin at the home page of our site (Live from Earth and Mars,

2. Click the "Pathfinder" graphic to get to the Mars Pathfinder mission and data.

3. Choose "Mars Meteorological Data and Graphs: Latest Pathfinder and Viking" by clicking on that link.

4. Scroll down to "Data Tables" and choose "Subset of Pathfinder Temperatures, Sols 2­7 Inclusive" by clicking on it. Wait for the data to be transferred and loaded into a table.

5. Save the file by pulling down under "File" to "Save as..." Save this file as a "Text file" on your computer's desktop. The file you just saved is named "Mars Pathfinder Temperature Dat."

6. Launch Microsoft Excel 4.0 and wait for it to load.

7. Open the saved data file by pulling down "File" to "Open..." In the dialogue box, click "Desktop." Click on the file ("Mars Pathfinder Temperature Dat") to highlight it. Click "Open."

8. Prepare the data to be "parsed" into columns. Highlight the first column of data (starting beneath the labels, and all the way down to the last line). Check to confirm that you highlighted cells A5 to A238 (only).

9. Begin parsing the data by pulling down the "Data" menu and selecting "Parse..."

10. Designate appropriate columns by inserting square brackets "][" between data elements. Under "Parse Line..." you will see a highlighted line showing you where the program intends to separate the data into columns. The data between each set of square brackets will be placed in its own column. Add a set of square brackets between the clock time and decimal sol. [ 11:30:07 2.466424 ] will appear, and you must add brackets to make it look like: [ 11:30:07 ][ 2.466424 ]. You can do this by moving your cursor between the clock time and decimal sol and typing. Continue adding brackets until all separations have been made. Click "OK" when finished bracketing.

11. Voila! The data should now be in columnar format! You can now fix the column headings by typing in the appropriate labels for each of the columns or by using "Parse..." again (with cell A4 only). The headings are: sol, local time, decimal sol, and the three temperature measurements in descending order (1.00 m, 0.50 m, and 0.25 m). Note the following example:

Temperature (Celsius)
 Sol  Local Time  Decimal Sol 1.00 meters 0.50 meters 0.25 meters
2 11:30:07 2.466424 -28.2 -24.2 -21.0
2 11:59:08 2.486035 -25.4 -20.8 -17.4
etc. etc. etc. etc. etc. etc.

12. Save the formatted file by pulling down "File" to "Save As..." Click "options" and select "Normal." Click "OK." Click "Save."

Now we're ready for some data analysis. Scroll the data columns to get a feel for the range of values. Do you notice any patterns?

13. Highlight the data you wish to graph (and related headings) by clicking in cell C4, holding the mouse button, and dragging to cell F238. Release the mouse button.

14. Activate "Chart Wizard" by scrolling to the top of the page (without clicking on the page) and clicking on the "Chart Wizard" button in the toolbar (second button from the right). Notice the highlighted data will have a dashed border.

15. Create an empty box for your graph by moving the pointer to the right of the data, holding the mouse button, and dragging a box about the size of your screen. Release the mouse button.

16. Confirm the data range in the Chart Wizard dialog box (=$C$4:$F$238). Correct if necessary. Click "Next" when ready.

17. Select "XY (Scatter)."Click "Next."

18. Select "connected points" (option #2). "Click "Next."

19. Confirm the settings "Data series in... Columns," Use first column for... X Data," and "Use first row for... Legend Text." Correct if necessary. Click "Next" when ready.

20. Finish the graph by inputting appropriate labels for "Chart Title," "Category X," and "Value Y." Select "Yes" for "Add a legend." Click "OK" when ready to see the graph.

21. Load the graph into its own window by double-clicking on it. This allows you to print the graph separately from the data.

22. Remove the "markers" (so you can see the three temperature curves). Double-click on one of the markers (colored objects on the graph) and select "None" for "Marker" and check the box for "Apply to All." Click "OK."

23. Find the Martian diurnal (daily) cycle of temperature by looking at one of the temperature columns plotted against decimal sol. (No fair just looking at sol number!) How would you describe a Martian diurnal cycle to another person?

The steepness of the temperature curve provides information about the rate at which the Martian atmosphere heats and cools. The steeper the curve the more quickly the temperature changes. Examine the shape of the temperature curves you plotted. Calculate the heating rate and the cooling rates for the Martian atmosphere. Does Mars cool at the same rate as it heats?

24. Compare the diurnal cycle of temperature of these 6 sols with one another. Is there a sol-to-sol variation? Describe any variations you see. What are some possible causes of these variations?

25. Compare the temperatures recorded for the 3 different sensor heights. What patterns do you see over a day? What patterns do you see during the night? Hypothesize about possible causes of these variations. Write your hypothesis and explain it to another person.

26. Print the graphs you believe are particularly representative of what you learned. Make some notes on the graphs that address the above questions.

27. Save the file (with associated graph) by pulling down from "File" to "Save."

Extensions: Try using the Analysis Tools under the Options pull-down menu to analyze these data further. You can calculate daily average temperatures and standard variations, correlations between temperatures at different heights, or with time. You can analyze the variance in the temperature measurements, or compute any number of interesting statistics. Forge on according to your own interests and capabilities!


© 1998 Live from Earth and Mars, Janice DeCosmo, and Rich Edgerton