U.S. spacecraft takes first image of Martian dust particle

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.
Source:Xinhua