Download and Analysis of Mars-Based Temperature Data
How Does Near-Surface Temperature Change with
Height on Mars?
Microsoft Excel 5.0 (Macintosh) Version
Purpose: to "download" and import data into Microsoft Excel 5.0 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 4.0.
1. Begin at the home page of our site (Live from Earth and Mars, http://www-k12.atmos.washington.edu/k12/).
2. Click the "Pathfinder" graphic to link to the Mars Pathfinder mission 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 2 - 7 inclusive." by clicking on it. Wait for the data to be transferred and loaded into a table.
5. From the File menu, choose the "Save as..." command. 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 5.0 and wait for it to load.
7. From the Excel menu, choose File and Open. From the Open window, locate the data file (on your computer's desktop), highlight it, and click "Open." The file is called "Mars Pathfinder Temperature Dat."
8. Now you should have the Text Import Wizard dialog box on your screen. Select delimited by clicking on the circle next to it. Click "Next" at the bottom of the dialog box.
9. Check "space" under "Delimiters" and check "Treat multiple delimiters as one." Make sure no other boxes are checked. Click "Next" at the bottom of the dialog box.
10. Select General by clicking on the circle next to it, then click "Finish" at the bottom of the dialog box.
11. Voila! The data should now be in columnar format. Correct the column headings by typing in the appropriate labels for each of the columns (use row D for the headings). Make sure the headings are immediately above the data (as in the following example ("Decimal Sol" is in cell D4):
|Sol||Local Time||Decimal Sol||1.00 meters||0.50 meters||0.25 meters|
12. Save the formatted file by pulling down "File" to "Save as..." and select the "Microsoft Excel Workbook" option where is asks "Save file as type:" Give the file a unique name (such as "Mars data--Excel format") and click "Save." If "Summary Info" is requested, click "Cancel."
Now we're ready for some data analysis. Scroll the data columns to get a feel for the range of values. What patterns do you notice?
13. Highlight the relevant data (and related headings) by clicking in cell D4, holding the mouse button, and dragging to cell G238. 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. 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 (=$D$4:$G$238). Correct if necessary. Click "Next" when ready.
17. Select "XY (Scatter)."Click "Next."
18. Select "line graph" (option #6). "Click "Next."
19. Confirm the settings "Data series in... Columns," Use first... 1 ...Column(s) for X Data," and "Use first... 1 ... Row(s) for Legend Text." Correct if necessary. Click "Next" when ready.
20. Finish the graph by checking "Yes" for "Add Legend" and inputting appropriate labels for "Chart Title," "Category X," and "Value Y." Click "Finish" when ready to see the graph.
21. Resize the graph if necessary by dragging the handles on the border of the graph.
22. Load the graph into its own window by double-clicking on it. This allows you to print the graph separately from the data.
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