Hoy he leído en la web de la misión phoenix una noticia que anuncia la obtención de la imagen de la partícula más pequeña de suelo marciano a la mayor resolución jamás vista. Esto se ha conseguido gracias a un microscopio especial llamado atomic force microscope (AFM) que utiliza ciertas propiedades físicas para obtener imágenes de objetos de nanómetros.
Esta es la noticia:
August 14, 2008 — NASA’s Phoenix Mars Lander has taken the first-ever image of a single particle of Mars’ ubiquitous dust, using its atomic force microscope.
The particle — shown at higher magnification than anything ever seen from another world — is a rounded 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 of the University of Neuchatel, Switzerland, who leads a Swiss consortium that made the microscope.
It took a very long time, roughly a dozen years, to develop the device that is operating in a polar region on a planet now about 350 million kilometers or 220 million miles away.
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 microfabricated from a silicon wafer. Pike’s group at Imperial College produced these silicon microdiscs.