NASA's Phoenix Mars Lander Delivers Soil Sample to Microscope
TUCSON, Ariz. -- New observations from NASA's Phoenix Mars Lander
provide the most magnified view ever seen of Martian soil, showing
particles clumping together even at the smallest visible scale.
In the past two days, two instruments on the lander deck -- a microscope
and a bake-and-sniff analyzer -- have begun inspecting soil samples
delivered by the scoop on Phoenix's Robotic Arm.
"This is the first time since the Viking missions three decades
ago that a sample is being studied inside an instrument on Mars," said
Phoenix Principal Investigator Peter Smith of the University of Arizona, Tucson.
Stickiness of the soil at the Phoenix site has presented challenges for
delivering samples, but also presents scientific opportunities.
"Understanding the soil is a major goal of this mission and the soil
is a bit different than we expected," Smith said. "There could be real
discoveries to come as we analyze this soil with our various instruments.
We have just the right instruments for the job."
Images from Phoenix's Optical Microscope show nearly 1,000 separate soil
particles, down to sizes smaller than one-tenth the diameter of a human
hair. At least four distinct minerals are seen.
"It's been more than 11 years since we had the idea to send a microscope to
Mars and I'm absolutely gobsmacked that we're now looking at the soil of
Mars at a resolution that has never been seen before," said Tom Pike of
Imperial College London. He is a Phoenix co-investigator working on the
lander's Microscopy, Electrochemistry and Conductivity Analyzer.
The sample includes some larger, black, glassy particles as well as smaller
reddish ones. "We may be looking at a history of the soil," said Pike. "It
appears that original particles of volcanic glass have weathered down to
smaller particles with higher concentration of iron."
The fine particles in the soil sample closely resemble particles of airborne
dust examined earlier by the microscope.
Atmospheric dust at the Phoenix site has remained about the same day-to-day
so far, said Phoenix co-investigator and atmospheric scientist Nilton Renno
of the University of Michigan, Ann Arbor.
"We've seen no major dust clouds at the landing site during the mission so far,"
Renno said. "That's not a surprise because we landed when dust activity is at a
minimum. But we expect to see big dust storms at the end of the mission. Some of
us will be very excited to see some of those dust storms reach the lander."
Studying dust on Mars helps scientists understand atmospheric dust on Earth, which
is important because dust is a significant factor in global climate change.
"We've learned there is well-mixed dust in the Martian atmosphere, much more mixed
than on Earth, and that's a surprise," Renno said. Rather than particles settling
into dust layers, strong turbulence mixes them uniformly from the surface to a few
kilometers above the surface.
Scientists spoke at a news briefing today at the University of Arizona, where new
color views of the spacecraft's surroundings were shown.
"We are taking a high-quality, 360-degree look at all of Mars that we can see from
our landing site in color and stereo," said Mark Lemmon, Surface Stereo Imager lead
from Texas A&M University, College Station.
"These images are important to provide the context of where the lander is on the
surface. The panorama also allows us to look beyond our workspace to see how the
polygon structures connect with the rest of the area. We can identify interesting
things beyond our reach and then use the camera's filters to investigate their
properties from afar."
The Phoenix mission is led by Smith at the University of Arizona with project
management at JPL and development partnership at Lockheed Martin, Denver. International
contributions come from the Canadian Space Agency; the University of Neuchatel, Switzerland;
the universities of Copenhagen and Aarhus, Denmark; Max Planck Institute, Germany;
and the Finnish Meteorological Institute. For more about Phoenix, visit:
Media contacts: Guy Webster 818-354-6278
Jet Propulsion Laboratory, Pasadena, Calif.
Dwayne Brown 202-358-1726
NASA Headquarters, Washington
Sara Hammond 520-626-1974
University of Arizona, Tucson