The six-wheel rover completed another round of science observations of its surroundings before its Martian day ended at 11:13 a.m. ET Wednesday, NASA's Jet Propulsion Laboratory said.
Opportunity became the star of the $820 million double-rover mission for a Washington news conference on Tuesday. Data and images it sent to Earth showed that water once percolated through rocks it has studied and that the ground would have been suitable for life.
Those findings were based on observations made over the past few weeks. This week, the rover studied the Martian atmosphere with its panoramic camera and an instrument called a mini-thermal emission spectrometer, or Mini-TES, which views infrared radiation from objects to determine mineral composition.
It then turned the Mini-TES to stare at the ground for more observations.
Opportunity later focused on an area of soil dubbed "Pay Dirt," making stereo microscopic images and taking readings with its Mössbauer spectrometer, which is designed to determine the composition and abundance of iron-bearing minerals.
The rover then drove about 16 inches (40 centimeters) toward a rock called "Last Chance" and prepared to deploy its instrument-laden robotic arm.
One of its tasks planned for the Martian workday beginning late Wednesday was to take images of a solar eclipse as Mars' moon Deimos crosses in front of the sun, JPL said.
Halfway around Mars, the twin rover Spirit was working on a rock dubbed "Humphrey," which it began examining during a long drive from its landing site toward a big crater that scientists have named "Bonneville." Scientists hope Bonneville will give Spirit a look at rocks well below the surface.
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