## INTRODUCTION

Beginning on Sol 296, Viking Lander 1 began constructing conical piles of soillike materials by collecting materials from the sample field and depositing them on top of rocks and among rocks with the surface sampler collector head (a scoop).

The purpose of the piles of soillike materials was to create topographic configurations of disturbed materials that are not in equilibrium with the present-day environment of Mars.

All but one of these piles were made of a weak powder-like "soil" and one was made of a garden-like "soil."

## OBSERVATION PART

Three of these piles can be seen in high-resolution (0.04 degrees/pixel) Camera 1 picture 11J013/921. They look like miniature stratovolcanoes. (In this image, the sun was toward the right so that the shadows are on the left sides of piles and rocks)

1. One pile is perched atop a rock (#2) and was made on Sol 324.
2. Another pile (#3) can seen be near the left edge of the picture about 0.3 of the way from the bottom. Pile #3 was also made on Sol 324.
3. The third (#5), and smaller pile, is located to the right of #3 and was made on Sol 639.
4. Can you find these three piles in picture 11J013/921?
5. The starting azimuth for this Camera 1 picture is 269.5 degrees and the ending azimuth is 279.5 degrees (thus, it is 10.0 degrees wide). The beginning (top) and ending (bottom) elevation angles are -9.78 and -30.22 degrees.
6. The range or distance to pile #3 is about 3.3 meters (and 3.6 meters to pile #2).
7. How wide is pile #3?. Roughly, how tall is the pile? Hints: You can use the information in 5 and 6 and the picture in 4 to estimate the width of pile #3. Estimate the angular width of the pile by scaling from the full width of the picture (10 degrees). If you understand radians, convert the angle to radians and multiply the angle in radians by the range. If you do not understand radians, determine the angular width of the pile from the picture, draw a line 3.3 units long, draw a second line 3.3 units long to form a narrow wedge with an angle equal to the one that you measured on the picture. Now measure the distance [in the same units as above] between the two open ends of the wedge. This distance represents the approximate width of the pile in meters.

Can you also find these three piles in low-resolution (0.12 degrees/pixel) Camera 1 picture 11J081/1402?

Splendid! You are a good observer.

Did you also notice that you can see the horizon and sky near the top? The elevation angles go from +0.66 degrees to -60.66 degree. Starting and ending azimuths are 264.5 and 287.0 degrees.

Compare picture 11J081/1402 with picture 11J171/2068.

1. Are there any changes?
2. What are the changes?
3. List the changes.

Compare high-resolution (0.04 degrees/pixel) picture 11J100/1543 or 11J013/921 with picture 11J190/2209. (Note that the starting and ending azimuths for J100 and J190 are 269.5 degrees and 277.0 degrees and starting and ending elevations are -9.78 and -30.22 degrees - all three are Camera 1 pictures).
1. Are there any changes?
2. What are the changes?
3. List the changes.

The right part of Camera 1 picture 11J013/921 and Camera 2 picture 12J108/1601 form a stereopair (if you want to look at the piles in stereo - see EXERCISE 3). The starting and ending azimuths for Camera 2 picture 12J108/1601 are 82.5 and 90.0 degrees and starting and ending elevations are -9.78 and -30.22 degrees.

Lander 1 took many pictures of the same scene separated by many sols in order to detect changes. Three sets of such images are narrow low-resolution color pictures taken of the sky and surface. In the color images below, the horizon and a rock named "Big Joe" are included; Big Joe is 8 to 10 meters from Camera 1. The starting and ending azimuths for each picture are 160.0 and 165.56 degrees and starting and ending elevations are +30.66 and -30.66 degrees. About how tall is Big Joe?

Sol 1409 red, green, blue image.
Sol 1742 red, green, blue image.
Sol 2149 red, green, blue image.
What is different between these three sets of images?
What do the differences represent?

## SYNTHESIS PART

What do you think happened on Mars?

Which way did the wind blow?

What are the largest sizes of fragments that were moved?

What are the largest sizes of fragments that remained in pile #5?

## REPORTING PART

Why don't you write a story about what happened? Scientists have to write stories (they call them papers).

## MAP PART (See EXERCISE 4: "WHERE IS MR. TOAD?")

The map that has been furnished (see note, link, and warning below) shows a plan view of Viking Lander 1.

If you look carefully at the map, you can see two pairs of concentric circles with "plus" signs in their centers. They are labeled Camera 1 (left one) and Camera 2 (right one).

The dashed lines extending from the "pluses" are the reference directions for each camera. The reference direction for Camera 1 extends to the right of the Camera 1 "plus" and the reference direction for Camera 2 extends to the left of the Camera 2 "plus."

1. For the pictures given above, measure the starting and ending azimuths from the reference directions in a clockwise direction for each camera and plot a point for each.
2. Draw lines from the "pluses" through the plotted points for each camera.
3. You will get wedges for each picture that extend from the "pluses." These wedges include parts of the fields of view of each camera on the map.
4. The area on the map enclosed by the concentric "dash-X" lines (----- x ------ x -----) represent the sample field of Lander 1 (the area that could be sampled with the "scoop").

Can you find the three piles of "soil" within the area formed by the sample field and the wedges on the map?. What else can you see in the images within the wedges on the map? Can you find two other conical piles (#1 and #4) on the map?.

(Note. Approximate "boltdown and diode" corrections are included in the azimuths given)

(Note. The working map on this WEB site, which is linked below, is a suitable base map. The extended mission map in the back of Professional Paper 1389 is also suitable. If the Lander 1 map is difficult to read, or too large for your computer and you do not have Professional Paper 1389, you can request copies of the map from James E. Tillman or Henry J. Moore .

## WARNING:

This section includes a link to the map for this exercise. Do not click on the link below unless you have a very fast link, a large memory and a capable system. The biggest, fastest workstations, with high speed interfaces take about 30 seconds to ingest and display them.
Lander 1, end extended mission. [Bit Map: 3.98 Mbytes]

 The data, maps, and text for this exercise were supplied by: Dr. Henry John Moore Scientist Emeritus Astrogeology Team MS 975 U.S. Geological Survey 345 Middlefield Road Menlo Park, CA 94025 moore@astmnl.wr.usgs.gov The images, layout, and presentation for this exercise were supplied by; James E. Tillman, Research Prof. (mars@atmos.washington.edu ) and George F. LeCompte (a volunteer) Department of Atmospheric Sciences PO Box 351640 University of Washington Seattle, WA 98195-1640

Copyright: These data, maps and exercises are in the public domain.
Please credit Dr. Moore, Prof. Tillman and Mr. LeCompte.