NASA News - NASA Awards Engineering And Science Services And Skills Augmentation Services Contract
HUNTSVILLE -- NASA has selected Jacobs Technology, Inc., of Tullahoma,Tenn., for its Engineering and Science Services and Skills
Augmentation contract at Marshall Space Flight Center in Huntsville,
Ala. The approximate, potential maximum quantity value of the
contract, including all options, is $600 million.
Jacobs will provide the continuous requirement for engineers,
scientists and technicians necessary to support Marshall's
Engineering Directorate; Science and Technology Office; Flight
Programs and Partnerships Office; and future programs, projects and
other offices with similar needs.
The contract begins August 1 with a two-year base period, followed by
three one-year options that may be exercised at NASA's discretion. It
is a performance-based, cost-plus-fixed-fee less deductions
indefinite delivery/indefinite quantity contract.
Jacobs will provide all the necessary management, personnel, and
equipment/supplies required to perform the engineering and science
tasks as defined in contract.
For information about NASA and agency programs, visit:
http://www.nasa.gov
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NASA Mars Spacecraft Detects Large Changes in Martian Sand Dunes
WASHINGTON -- NASA's Mars Reconnaissance Orbiter (MRO) has revealedthat movement in sand dune fields on the Red Planet occurs on a
surprisingly large scale, about the same as in dune fields on Earth.
This is unexpected because Mars has a much thinner atmosphere than
Earth, is only about one percent as dense, and its high-speed winds
are less frequent and weaker than Earth's.
For years, researchers debated whether or not sand dunes observed on
Mars were mostly fossil features related to past climate, rather than
currently active. In the past two years, researchers using images
from MRO's High Resolution Imaging Science Experiment (HiRISE) camera
have detected and reported sand movement.
Now, scientists using HiRISE images have determined that entire dunes
as thick as 200 feet are moving as coherent units across the Martian
landscape. The study was published online today by the journal Nature.
"This exciting discovery will inform scientists trying to better
understand the changing surface conditions of Mars on a more global
scale," said Doug McCuistion, director of NASA's Mars Exploration
Program in Washington. "This improved understanding of surface
dynamics will provide vital information in planning future robotic
and human Mars exploration missions."
Researchers analyzed before-and-after images using a new software tool
developed at the California Institute of Technology (Caltech) in
Pasadena. The tool measured changes in the position of sand ripples,
revealing the ripples move faster the higher up they are on a dune.
The study examined images taken in 2007 and 2010 of the Nili Patera
sand dune field located near the Martian equator. By correlating
ripples' movement to their position on the dune, the analysis
determined the entire dunes are moving. This allows researchers to
estimate the volume, or flux, of moving sand.
"We chose Nili Patera because we knew there was sand motion going on
there, and we could quantify it," said Nathan Bridges, a planetary
scientist at Johns Hopkins University Applied Physics Laboratory in
Laurel, Md., and lead author of the Nature paper. "The Nili dunes
also are similar to dunes in places like Antarctica and to other
locations on Mars."
The study adds important information about the pace at which blowing
sand could be actively eroding rocks on Mars. Using the new
information about the volume of sand that is moving, scientists
estimate rocks in Nili Patera would be worn away at about the same
pace as rocks near sand dunes in Antarctica, where similar sand
fluxes occur.
"Our new data shows wind activity is indeed a major agent of evolution
of the landscape on Mars," said Jean-Philippe Avouac, Caltech team
leader. "This is important because it tells us something about the
current state of Mars and how the planet is working today, geologically."
Scientists calculate that if someone stood in the Nili Patera dunes
and measured out a one-yard width, they would see more than two cubic
yards of sand pass by in an Earth year, about as much as in a
children's sand box.
"No one had estimates of this flux before," said Bridges. "We had seen
with HiRISE that there was dune motion, but it was an open question
how much sand could be moving. Now, we can answer that."
Scientists will use the information to understand broader mysteries on
Mars, like why so much of the surface appears heavily eroded, how
that occurred, and whether it is a current process or it was done in
the past. Scientists can now point to sand flux as a mechanism
capable of creating significant erosion today on the Red Planet.
The HiRISE camera provides unprecedented resolution in studying the
Martian landscape. NASA's Jet Propulsion Laboratory manages MRO for
NASA's Science Mission Directorate in Washington. Lockheed Martin
Space Systems, Denver, built the spacecraft. HiRISE is operated by
the University of Arizona and was built by Ball Aerospace &
Technologies Corp., Boulder, Colo.
For related images and more information about MRO, visit:
http://www.nasa.gov/mro
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Overfed Black Holes Shut Down Galactic Star-Making
WASHINGTON -- The Herschel Space Observatory has shown galaxies withthe most powerful, active black holes at their cores produce fewer
stars than galaxies with less active black holes. The results are the
first to demonstrate black holes suppressed galactic star formation
when the universe was less than half its current age.
Herschel is a European Space Agency-led mission with important NASA
contributions.
"We want to know how star formation and black hole activity are
linked," said Mathew Page of University College London's Mullard
Space Science Laboratory in the United Kingdom and lead author of the
Nature paper describing these findings. "The two processes increase
together up to a point, but the most energetic black holes appear to
turn off star formation."
Supermassive black holes, weighing as much as millions of suns, are
believed to reside in the hearts of all large galaxies. When gas
falls upon these monsters, the material is accelerated and heated
around the black hole, releasing great torrents of energy. Earlier in
the history of the universe, these giant, luminous black holes,
called active galactic nuclei, were often much brighter and more
energetic. Star formation was also livelier back then.
Studies of nearby galaxies suggest active black holes can squash star
formation. The revved-up, central black holes likely heat up and
disperse the galactic reservoirs of cold gas needed to create new
stars. These studies have only provided "snapshots" in time, however,
leaving the overall relationship of active galactic nuclei and star
formation unclear, especially over the cosmic history of galaxy formation.
"To understand how active galactic nuclei affect star formation over
the history of the universe, we investigated a time when star
formation was most vigorous, between eight and 12 billion years ago,"
said co-author James Bock, a senior research scientist at NASA's Jet
Propulsion Laboratory (JPL) in Pasadena, Calif., and co-coordinator
of the Herschel Multi-tiered Extragalactic Survey. "At that epoch,
galaxies were forming stars 10 times more rapidly than they are today
on average. Many of these galaxies are incredibly luminous, more than
1,000 times brighter than our Milky Way."
For the new study, Page and colleagues used Herschel data that probed
65 galaxies at wavelengths equivalent to the thickness of several
sheets of office paper, a region of the light spectrum known as the
far-infrared. These wavelengths reveal the rate of star formation,
because most of the energy released by developing stars heats
surrounding dust, which then re-radiates starlight out in
far-infrared wavelengths.
The researchers compared their infrared readings with X-rays streaming
from the active central black holes in the survey's galaxies,
measured by NASA's Chandra X-ray Observatory. At lower intensities,
the black holes' brightness and star formation increased in sync.
However, star formation dropped off in galaxies with the most
energetic central black holes. Astronomers think inflows of gas fuel
new stars and supermassive black holes. Feed a black hole too much,
however, and it starts spewing radiation into the galaxy that
prevents raw material from coalescing into new stars.
"Now that we see the relationship between active supermassive black
holes and star formation, we want to know more about how this process
works," said Bill Danchi, Herschel program scientist at NASA
Headquarters in Washington. "Does star formation get disrupted from
the beginning with the formation of the brightest galaxies of this
type, or do all active black holes eventually shut off star
formation, and energetic ones do this more quickly than less active ones?"
Herschel is a European Space Agency cornerstone mission, with science
instruments provided by consortia of European institutes and
important participation by NASA. NASA's Herschel Project Office is
based at JPL. JPL contributed mission-enabling technology for two of
Herschel's three science instruments. The NASA Herschel Science
Center, part of the Infrared Processing and Analysis Center at
Caltech, supports the United States astronomical community. Caltech
manages JPL for NASA.
For NASA'S Herschel website, visit:
http://www.nasa.gov/herschel
For ESA'S Herschel website, visit:
http://www.esa.int/SPECIALS/
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