New Microscope Method for Phoenix
“The same day we first touched a target with the thermal and electrical conductivity probe, we first touched another target with a needle about three orders of magnitude smaller — one of the tips of our atomic force microscope,” said Michael Hecht of NASA’s Jet Propulsion Laboratory, Pasadena, Calif., lead scientist for the suite of instruments on Phoenix that includes both the conductivity probe and the microscopy station.
For the very first time, a fork-like probe has touch Martian soil, using a microscope that examines shapes of tiny particles simply by reaching into undisturbed soil as a validation test of the insertion procedure past Tuesday. About half-an-inch long, the prongs of the thermal and electrical conductivity probe is used by the science team to assess how easily heat and electricity move through the soil from one spike to another. This type of measurement is used for information about frozen or unfrozen water in soil. The probe sits on the Phoenix lander’s robotic arm, called a “knuckle”. As it is held up in the air, it has provided assessments of the atmospheric water vapor several times so far.
Returning the first image from its atomic force microscope, the Phoenix’s Swiss-made microscope built an image of a particle’s surface by sensing it with a sharp tip at the end of a spring, all microfabricated from a sliver of silicon. According to the University of Arizona, the sensor rides up and down following the contour of the surface, which provides information about the shape of the target. High details are provides by the microscope of the soil-particle shapes as small as about 100 nanometers, less than one-hundredth the width of a human hair. Twenty times smaller than what is resolved using the Phoenix’s optical microscope, previously providing much higher-magnification imaging than anything used so far on Mars.
The interesting thing about the atomic force microscope is the first touch to a substrate, which will be used to hold soil particles in place for inspection by the microscope. When its first imaging began, it produced a calibration of a grooved substrate. “It’s just amazing when you think that the entire area in this image fits on an eyelash. I’m looking forward to exciting things to come,” Hecht said.
This entry was posted on Thursday, July 10th, 2008 at 8:05 pm and is filed under Space Agency News, Technical Concerns, Uncategorized. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.
