Scientists See A Whole New Dimension

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On sol 8, scientists used the Microscopic Imager (mounted on the robotic arm) to get an up-close look at some of the rocks at the FIDO field site. Had this analysis been on Mars, it would have been the first microscopic image ever taken of martian terrain.

Today, scientists completed another would-be first with the Microscopic Imager. While exploring the Bonneville rock feature - a sandstone slab of rock - they used the Microscopic Imager to take pictures. These pictures were combined into a stereo (3-D) image that shows the rock texture at microscopic resolution.

Lutz Richter

To make a mosaic or 3-D image, scientists need overlapping views. These are obtained by directing the microscopic imager to take a series of pictures that include some amount of overlap among the individual images. This process is not easy, however.

"There was a bit of luck involved in getting the overlapping image. The Microscopic Imager captures images about 2.5 centimeters (1 inch) wide. However, the minimum 'stepping' movement that FIDO's robotic arm can reliably be commanded to make is more than an inch. So, it was possible that the arm would move further than the field of view of the Microscopic Imager and the acquired images would not overlap," explains Scientist Lutz Richter.

After careful commands were sent to the rover by the engineering team, scientists were glad to see the results. The Microscopic Imager was able to acquire four partially overlapping images that were then pieced together to create this mosaic. To go one step further and create the 3-D effect, scientists layered two of the overlapping images on top of each other with about .5 centimeters (.2 inches) of offset.

"All we had to do then is paint one image red and the other blue using image-processing software," said Richter. "The 3-D view can be seen if you put on red-blue glasses." (Red-blue "3-D" glasses are usually available in comic-book stores.)

Scientists don't create mosaics and 3-D images just because they're cool. Both types of images allow scientists to see more clearly the layers and fine-scale texture of sandstone. "We were able to confirm that this sample is made of tiny, sand-sized particles that are in the tens-of-micrometers size range," explained Richter. "Seeing the rock characteristics in stereo revealed what a 2-D image couldn't: the vertical texture of the rock more clearly shows the different layers in the sandstone. This texture gives clues about how each layer formed and what environmental conditions led to the layered deposits of rock, sand, and soil through geologic time."

On Mars, scientists will create 3-D microscopic images to reveal the same processes. What they'd like to learn more about is whether the layers were deposited by water or wind.