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This image, released Aug. 14, 2008 and
taken by NASA's Phoenix Mars Lander's Surface Stereo Imager on June 12,
2008, shows the Lander's Robotic Arm scoop after delivering the first
sample of dug-up soil to Phoenix's Microscopy, Electrochemistry and
Conductivity Analyzer, or MECA, instrument suite. The Lander has sent back
the first-ever image of a speck of red Martian dust taken through an
atomic force microscope. (Xinhua/Reuters Photo) Photo Gallery>>> |
WASHINGTON, Aug. 14 (Xinhua) -- NASA's Phoenix Mars
Lander has taken the first-ever image of a single particle of Mars' ubiquitous
dust, using its atomic force microscope, mission scientists reported Thursday.
The particle -- shown at higher
magnification than anything ever seen from another world -- is a round particle
about one micrometer, or one millionth of a meter, across.
It is a speck of the dust that cloaks Mars. Such dust
particles color the Martian sky pink, feed storms that regularly envelop the
planet and produce Mars' distinctive red soil.
"This is the first picture of a clay-sized particle
on Mars, and the size agrees with predictions from the colors seen in sunsets on
the Red Planet," said Phoenix co-investigator Urs Staufer from the University of
Neuchatel, Switzerland, who leads a Swiss consortium that made the microscope.
The atomic force microscope maps the shape of
particles in three dimensions by scanning them with a sharp tip at the end of a
spring. During the scan, invisibly fine particles are held by a series of pits
etched into a substrate micro fabricated from a silicon wafer.
It can detail the shapes of particles as small as
about 100 nanometers, about one one-thousandth the width of a human hair. That
is about 100 times greater magnification than seen with Phoenix's optical
microscope, which made its first images of Martian soil about two months ago.
"I'm delighted that this microscope is producing
images that will help us understand Mars at the highest detail ever," Staufer
said.
"This is proof of the microscope's potential. We are
now ready to start doing scientific experiments that will add a new dimension to
measurement being made by other Phoenix lander instruments," he added.
After this first success, scientists are now working
on building up "a portrait gallery" of the dust on Mars.
Mars' ultra-fine dust is the medium that actively
links gases in the Martian atmosphere to processes in Martian soil, so it is
critically important to understanding Mars' environment, the researchers
said.