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<blank>. <blank>. Mars Exploration Rover Mission -El Capitan and the Sweet Spots in Eagle Crater - Opportunity - April 2004.
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Mars Exploration Rover Mission-El Capitan and the Sweet Spots in Eagle Crater- Opportunity - April 2004
The strategy for NASA’s Mars Exploration program is to follow the water because water is key to life as we know it.- Mars today (NASA/JPL/MSSS)- Mars of the Past? (Artist’s conception)- Long-term water on Mars might indicate Mars was once -- or still could be -- a habitat for life.
The geologic record of water is “written in the rocks.”- Opportunity is specially designed “to read” the history of water on Mars by analyzing rocks and soils.
The rock outcrop along the edge of Eagle Crater is a treasure trove of information for the science team, who were anxious to drive the rover along its edge, stopping to study interesting spots along the way.
As soon as Opportunity rolled off the lander, the rover team began a a process called “Shoot and Scoot” to survey the rock outcrop within Eagle Crater.
Based on their experiences in field geology on Earth, the science team first built a base map of Eagle Crater on Mars, then used it to guide Opportunity to the most exciting parts of the rock outcrop.- Geology students surveying Guadalupe National Park in Texas.
After one drive-by of the entire outcrop, scientists quickly identified multiple targets of interest with three major “sweet spots” for further investigation, and Opportunity made a U[turn on Valentine’s Day.
Before driving back to the rock outcrop, Opportunity dug a trench to see what lurked beneath the surface.- The trench measured 19.7 inches long (50 centimeters), by 7.9 inches wide (20 centimeters) by 3.5 inches deep (9 centimeters).
Opportunity then drove 50 feet (15 meters) to El Capitan, the first “sweet spot” to be studied.- The robotic arm reaches out toward El Capitan on Mars.- El Capitan is named after the most dramatic peak inside Guadalupe National Park in Texas.
Earth’s El Capitan is a training ground for students and professional geologists who want to understand what layering means in relation to the formation of the Earth.- Scientists are now studying Mars’ El Capitan to understand what the layering there can tell them about the history of the red planet.
Beyond studying the outer vertical layers, scientists studied the inner layers of two areas in El Capitan with the help of the rock abrasion tool (RAT).- The upper hole is called “Guadalupe” and the lower hole is named “McKittrick.”
The RAT provides a deeper peek into the geologic history of Mars by grinding into rocks using its diamond teeth. It exposes a more pristine rock surface that has seen less weathering through time.- Grinding at the spot named “Guadalupe.”
Scientists analyzed the freshly exposed rock areas and discovered signs of a watery past on Mars! The German-built Moessbauer spectrometer identified the mineral jarosite, which contains water in the form of hydroxyl.
The other German-built instrument, the alpha particle X-ray spectrometer, detected the element sulfur. On Earth, rocks with this much sulfur in the form of a sulfate salt either formed in water or, after formation, were highly altered by long exposures to water.
Randomly scattered on the surface are mysterious spheres that the science team nicknamed “blueberries.”
Scientists were very interested in learning more about these strange spheres, so Opportunity drove to an area full of the blueberries, dubbed “Berry Bowl.”- Spheres are 2 to 4 millimeters in size/
The blueberries were too small to analyze individually with the science instruments……so the team brushed an area free of blueberries, took measurements at Berry Bowl, then subtracted out the known composition of the sand and soil to discern what the blueberries are made of.
The Moessbauer spectrometer detected hematite in the areas heavily covered in blueberries, and low hematite on the empty surface with no blueberries. Hematite gives scientists another clue top Mars’ watery past, because it is a mineral that often forms in the presence of water!
Layers in “Last Chance” provided the last piece of evidence that lead scientists to say that Opportunity was parked on what might have been the shoreline of a salty sea on Mars.
The dips of fine layers at angles to each other are telltale signs that water flowed from left to right in this rock.- Panoramic camera image of Last Chance.
With evidence that Eagle Crater might have had standing water, scientists and engineers have sent Opportunity up and out of the crater……in search of clues of how far and how long water flowed through Meridiani Planum.
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Mars Exploration Rover Mission-El Capitan and the Sweet Spots in Eagle Crater- Opportunity - April 2004
