# Presentation: 467359

## Week in Review               

**Mars Exploration Rover Mission**

**Week in Review               **
**March 20 - March 26**

**Spirit               and Opportunity **

## More Clues Emerge to Mars’ Watery Past!

**Smile-shaped curves in the rocks at Meridiani led scientists to conclude that Opportunity was parked on what was once the shoreline of a salty sea on Mars.**

**Notes:**
After outside peer-reviews validated NASA scientists’ interpretations of cross-bedding, NASA announced more evidence of Mars’ watery past.  
Interpretations of cross-lamination patterns presented as clues to this martian rock's origin under flowing water are marked on images taken by the panoramic camera and microscopic imager on NASA's Opportunity. 

The red arrows point to features suggesting cross-lamination within a rock called "Last Chance" in a panoramic camera image taken at a distance of 4.5 meters (15 feet) during Opportunity's 17th sol (February 10, 2004). The inferred sets of fine layers at angles to each other (cross-laminae) are up to 1.4 centimeters (half an inch) thick. For scale, the distance between two vertical cracks in the rock is about 7 centimeters (2.8 inches). The feature indicated by the middle red arrow suggests a pattern called trough cross-lamination, likely produced when flowing water shaped sinuous ripples in underwater sediment and pushed the ripples to migrate in one direction. The direction of the ancient flow would have been either toward or away from the line of sight from this perspective. The lower and upper red arrows point to cross-lamina sets that are consistent with underwater ripples in the sediment having moved in water that was flowing left to right from this perspective. 

The yellow arrows indicate places in the panoramic camera view that correlate with places in the microscope's view of the same rock. The microscopic view is a mosaic of some of the 152 microscopic imager frames of Last Chance that Opportunity took on sols 39 and 40 (March 3 and 4, 2004). This view shows cross-lamination expressed by lines that trend downward from left to right, traced with black lines in the interpretive overlay. These cross-lamination lines are consistent with dipping planes that would have formed surfaces on the down-current side of migrating ripples. Interpretive blue lines indicate boundaries between possible sets of cross-laminae. 

Image credit: NASA/JPL/Cornell/USGS 

## On its first uphill attempt, Opportunity slipped in the 

**On its first uphill attempt, Opportunity slipped in the **
**loose sand, and rover planners had to find an **
**alternate, sidestep route out of the crater.**

** ****03/22/04**

**Then, Opportunity emerged from Eagle Crater!**

**Notes:**
Looking Back at 'Eagle Crater'
This image is the first 360-degree view from the Mars Exploration Rover Opportunity's new position outside "Eagle Crater," the small crater where the rover landed about two months ago. Scientists are busy analyzing Opportunity's new view of the plains of Meridiani Planum. The plentiful ripples are a clear indication that wind is the primary geologic process currently in effect on the plains. The rover's tracks can be seen leading away from Eagle Crater. 
Image credit: NASA/JPL 

## No two soil patches are alike!

** ****03/26/04**

**As Opportunity drove outside the crater, scientists continued to analyze data **
**collected from the soils inside the crater.**

**Notes:**
No Two Soil Patches Are Alike

This mosaic of microscopic images (each about two centimeters by two centimeters or .8 inches by .8 inches) from the Mars Exploration Rover Opportunity illustrates the tremendous variety of soil types and shapes observed by the science team during the recent "Eagle Crater" five-target soil survey. Scientists are working to understand the sorting mechanisms that have distributed the various soil types. The survey was conducted from sol 52 to sol 56. 

"Punaluu's" largest particles are similar to those seen in the "Eagle Crater" outcrop. There are also some smaller, more irregular rounded particles that have likely been transported by wind. The "Lanikai" target reveals irregularly shaped, light-colored, millimeter-sized (0.04 inch-sized) clasts, or particles, in a fine-grained soil. Lanikai's angular, less-rounded clast shapes interested the science team when compared to other soil targets in the crater area studied by the microscopic imager. The image of "Neopolitan" highlights the border between two different soil types - a lighter, finer-grained unit to the left and a darker, coarser-grained to the right. Scientists are pondering the unusually distinct border between these different soil types. "Cookies and Cream" is a mixture of light and dark soil units in the "Neopolitan" area. There are several different types of clasts, or particles, held in surrounding fine-grained sands: rounded spherules, angular, irregular fragments (containing what are presumably vesicles or small cavities) and smaller, about one millimeter-sized (0.04 inch-sized), rounded clasts. At "Vanilla," the microscopic images have revealed small grains one millimeter (0.04 inch) or less in size and somewhat lighter in color than those in other soil units observed in the crater. "Mudpie" is representative of the soils lower in the crater, a fair distance from the outcrop. It contains spherules and irregularly shaped vesicles held in a dark sand. In the "Black Forest" area at the target referred to as "Brian's Choice" are irregularly shaped clasts, low in hematite content based on miniature thermal emission spectrometer readings. Presumably, the particles in this area are more affected by winds since they are on the outer part of crater and are likely deposited and re-distributed by wind on a fairly frequent basis. 

Image credit: NASA/JPL/Cornell/USGS

## The iron-bearing mineral hematite, which often 

**The iron-bearing mineral hematite, which often **
**forms in water, was found in “blueberries” **
**near the rim of the crater at Punaluu. **

**Various measurements taken inside Eagle Crater showed that volcanic materials (basalts) **
**were in the center of the crater.**

**Notes:**
Keepers of the Hematite

This figure shows spectra, or light signatures, taken by the Mars Exploration Rover Opportunity's Mössbauer spectrometer at various spots in "Eagle Crater." From top to bottom, the spectra represent soil measurements taken from the center of the crater and out to the rim. The top spectrum taken on sol 56 near the center of the crater shows a basaltic mineral composition and only minor amounts of hematite. Basalts are volcanic minerals and hematite is an iron-bearing mineral often formed in water. Moving closer to the rim, the spectra show increasing amounts of hematite with the "Punaluu" site containing the highest amounts seen to date on Mars. Only minor basaltic components are seen in this sample. 

The corresponding microscopic image of Punaluu shows a high density of "blueberries," indicating that these sphere-like grains are responsible for the observed high levels of hematite. 

Image credit: NASA/JPL/Cornell/USGS/University of Mainz

## Meanwhile, Spirit began analyzing a 6.6-foot-wide rock named Mazatzal, with its intriguing scallops, light 

**tone, and sugary surface texture.**
**Wind erosion is the likely “sculptor.”**

**Spirit,**
** ****03/21/04**

***Mazatzal is named after a mountain range and rock formation that was deposited around 1.2 billion years ago in the Four Peaks area of Arizona.***

**Notes:**
"Mazatzal" Rock on Crater Rim 

NASA's Spirit took this navigation camera image of the 2-meter-wide (6.6-foot-wide) rock called "Mazatzal" on sol 76, March 21, 2004. Scientists intend to aggressively analyze this target with Spirit's microscopic imager, Mössbauer spectrometer and alpha particle X-ray spectrometer before brushing and "digging in" with the rock abrasion tool on upcoming sols.

Mazatzal stood out to scientists because of its large size, light tone and sugary surface texture. It is the largest rock the team has seen at the rim of the crater informally named "Bonneville." It is lighter-toned than previous rock targets Adirondack and Humphrey. Its scalloped pattern may be a result of wind sculpting, a very slow process in which wind-transported silt and sand abrade the rock’s surface, creating depressions. This leads scientists to believe that Mazatzal may have been exposed to the wind in this location for an extremely long time. 

The name "Mazatzal" comes from a mountain range and rock formation that was deposited around 1.2 billion years ago in the Four Peaks area of Arizona. 

Image credit: NASA/JPL

## Then Spirit brushed 

**off the surface of **
**Mazatzal in two areas:**
** **
***“******New York” and “Illinois”***
** ****and analyzed the **
**clean rock beneath **
**the dusty surface.**
**  ****Scientists plan to use the rock abrasion tool to grind a hole into the spot called “New York” **
**in the coming week.  **

***Pancam image showing target areas “New York” (left) and “Illinois” (right)***

**Spirit, 03/23/04**

**Notes:**
'Illinois' and 'New York' Wiped Clean

This panoramic camera image was taken by NASA's Mars Exploration Rover Spirit on sol 79 after completing a two-location brushing on the rock dubbed "Mazatzal." A coating of fine, dust-like material was successfully removed from targets named "Illinois" (right) and "New York" (left), revealing the weathered rock underneath. In this image, Spirit's panoramic camera mast assembly, or camera head, can be seen shadowing Mazatzal's surface. This approximate true color image was taken with the 601, 535 and 482 nanometer filters. 

The center of the two brushed spots are approximately 10 centimeters (3.9 inches) apart and will be aggressively analyzed by the instruments on the robotic arm on sol 80. Plans for sol 81 are to grind into the New York target to get past any weathered rock and expose the original, internal rock underneath. 

Image credit: NASA/JPL/Cornell 

## Both rovers are about to embark on long journeys across the martian terrain!

**COMING UP!**

**Both rovers are about to embark on long journeys across the martian terrain!**

** ****(0.5 miles away)**

**(1.4 miles away)**

**Spirit aims for Columbia Hills**

**Opportunity heads for Endurance Crater**

**Notes:**
Next Stop: 'Endurance'

This previously released Opportunity image (PIA05229) shows the terrain surrounding the Mars Exploration Rover Opportunity at Meridiani Planum, Mars. On sol 57 (March 22, 2004), the rover rolled out of 'Eagle Crater' -- its home since landing over two months ago -- and is now headed for a larger crater nicknamed 'Endurance' seen to the right of the image. The journey, covering about 750 meters (2461 feet), is expected to take weeks if not months. Remnants of the rover's landing are also shown, including its lander; backshell and parachute; first bounce mark; and the site where its heat shield impacted the surface. The image was taken by the camera on the Mars Global Surveyor orbiter. 

Image credit: NASA/JPL/MSSS

To the Hills! (SPIRIT)

This image shows the rocky road the Mars Exploration Rover Spirit will travel to reach its ultimate destination - the Columbia Hills. The hills, seen here in the background, are located 2.3 kilometers (1.4 miles) away to the southeast. Rover planners estimate the journey will take about two months, or 60 sols, including stops at interesting targets along the way. As of sol 81 (March 26, 2004), Spirit has traveled 492 meters (1614 feet).