NASA TWIN SPACECRAFT CREATE MOST ACCURATE GRAVITY MAP OF MOON
WASHINGTON -- Twin NASA probes orbiting the moon have generated the
highest resolution gravity field map of any celestial body.
The new map, created by the Gravity Recovery and Interior Laboratory
(GRAIL) mission, is allowing scientists to learn about the moon's
internal structure and composition in unprecedented detail. Data from
the two washing machine-sized spacecraft also will provide a better
understanding of how Earth and other rocky planets in the solar
system formed and evolved.
The gravity field map reveals an abundance of features never before
seen in detail, such as tectonic structures, volcanic landforms,
basin rings, crater central peaks, and numerous simple, bowl-shaped
craters. Data also show the moon's gravity field is unlike that of
any terrestrial planet in our solar system.
These are the first scientific results from the prime phase of the
mission, and they are published in three papers in the journal
Science.
"What this map tells us is that more than any other celestial body we
know of, the moon wears its gravity field on its sleeve," said GRAIL
principal investigator Maria Zuber of the Massachusetts Institute of
Technology in Cambridge. "When we see a notable change in the gravity
field, we can sync up this change with surface topography features
such as craters, rilles or mountains."
According to Zuber, the moon's gravity field preserves the record of
impact bombardment that characterized all terrestrial planetary
bodies and reveals evidence for fracturing of the interior extending
to the deep crust and possibly the mantle. This impact record is
preserved, and now precisely measured, on the moon.
The probes revealed the bulk density of the moon's highland crust is
substantially lower than generally assumed. This low bulk crustal
density agrees well with data obtained during the final Apollo lunar
missions in early 1970s, indicating that local samples returned by
astronauts are indicative of global processes.
"With our new crustal bulk density determination, we find that the
average thickness of the moon's crust is between 21 and 27 miles (34
and 43 kilometers), which is about 6 to 12 miles (10 to 20
kilometers) thinner than previously thought." said GRAIL
co-investigator Mark Wieczorek of the Institut de Physique du Globe
de Paris. "With this crustal thickness, the bulk composition of the
moon is similar to that of Earth. This supports models where the moon
is derived from Earth materials that were ejected during a giant
impact event early in solar system history."
The map was created by the spacecraft transmitting radio signals to
define precisely the distance between them as they orbit the moon in
formation. As they fly over areas of greater and lesser gravity
caused by both visible features, such as mountains and craters, and
masses hidden beneath the lunar surface, the distance between the two
spacecraft will change slightly.
"We used gradients of the gravity field in order to highlight smaller
and narrower structures than could be seen in previous datasets,"
said Jeff Andrews-Hanna, a GRAIL guest scientist with the Colorado
School of Mines in Golden. "This data revealed a population of long,
linear, gravity anomalies, with lengths of hundreds of kilometers,
crisscrossing the surface. These linear gravity anomalies indicate
the presence of dikes, or long, thin, vertical bodies of solidified
magma in the subsurface. The dikes are among the oldest features on
the moon, and understanding them will tell us about its early
history."
While results from the primary science mission are just beginning to
be released, the collection of gravity science by the lunar twins
continues. GRAIL's extended mission science phase began Aug. 30 and
will conclude Dec. 17. As the end of mission nears, the spacecraft
will operate at lower orbital altitudes above the moon.
When launched in September 2011, the probes were named GRAIL A and B.
They were renamed Ebb and Flow in January by elementary students in
Bozeman, Mont., in a nationwide contest. Ebb and Flow were placed in
a near-polar, near-circular orbit at an altitude of approximately 34
miles (55 kilometers) on Dec. 31, 2011, and Jan. 1, 2012.
NASA's Jet Propulsion Laboratory in Pasadena, Calif., manages the
mission for NASA's Science Mission Directorate in Washington. GRAIL
is part of the Discovery Program managed at NASA's Marshall Space
Flight Center in Huntsville, Ala. Lockheed Martin Space Systems of
Denver built the spacecraft.
Friday, December 7, 2012
Looking at the earth quite differently: Now satellites see the earth both during day and night
Unprecedented New Images of Earth at Night
Dec. 5, 2012: Today at the American Geophysical Union meeting in San Francisco, scientists unveiled an unprecedented new look at our planet at night. A global composite image, constructed using cloud-free night images from a new NASA and National Oceanic and Atmospheric Administration (NOAA) satellite, shows the glow of natural and human-built phenomena across Earth in greater detail than ever before.
"For all the reasons that we need to see Earth during the day, we also need to see Earth at night," said Steve Miller, a researcher at NOAA's Colorado State University Cooperative Institute for Research in the Atmosphere. "Unlike humans, the Earth never sleeps."
Many satellites are equipped to look at Earth during the day, when they can observe our planet fully illuminated by the sun. With a new sensor aboard the NASA-NOAA Suomi National Polar-orbiting Partnership (NPP) satellite launched last year, scientists now can observe Earth's atmosphere and surface during nighttime hours. The sensor, called "VIIRS" (short for Visible Infrared Imaging Radiometer Suite), is sensitive enough to detect the light from a single ship in the sea.
The day-night band of VIIRS observed Hurricane Sandy, illuminated by moonlight, making landfall over New Jersey on the evening of Oct. 29. Night images showed the widespread power outages that left millions in darkness in the wake of the storm. With its night view, VIIRS is able to detect a more complete view of storms and other weather conditions, such as fog, that are difficult to discern with infrared, or thermal, sensors. Night is also when many types of clouds begin to form.
"NOAA's National Weather Service is continuing to explore the use of the day-night band," said Mitch Goldberg, program scientist for NOAA's Joint Polar Satellite System. "The very high resolution from VIIRS data will take forecasting weather events at night to a much higher level."
"It's like having three simultaneous low-light cameras operating at once and we pick the best of various cameras, depending on where we're looking in the scene," Miller said. The instrument can capture images on nights with or without moonlight, producing crisp views of Earth's atmosphere, land and ocean surfaces.Unlike a camera that captures a picture in one exposure, the day-night band produces an image by repeatedly scanning a scene and resolving it as millions of individual pixels. Then, the day-night band reviews the amount of light in each pixel. If it is very bright, a low-gain mode prevents the pixel from oversaturating. If the pixel is very dark, the signal is amplified.
"The night is nowhere as dark as we might think," Miller said. And with the VIIRS day-night band helping scientists to tease out information from human and natural sources of nighttime light, "we don't have to be in the dark anymore, either."
The day-night band of VIIRS observed Hurricane Sandy, illuminated by moonlight, making landfall over New Jersey on the evening of Oct. 29. Night images showed the widespread power outages that left millions in darkness in the wake of the storm. With its night view, VIIRS is able to detect a more complete view of storms and other weather conditions, such as fog, that are difficult to discern with infrared, or thermal, sensors. Night is also when many types of clouds begin to form.
"NOAA's National Weather Service is continuing to explore the use of the day-night band," said Mitch Goldberg, program scientist for NOAA's Joint Polar Satellite System. "The very high resolution from VIIRS data will take forecasting weather events at night to a much higher level."
"It's like having three simultaneous low-light cameras operating at once and we pick the best of various cameras, depending on where we're looking in the scene," Miller said. The instrument can capture images on nights with or without moonlight, producing crisp views of Earth's atmosphere, land and ocean surfaces.Unlike a camera that captures a picture in one exposure, the day-night band produces an image by repeatedly scanning a scene and resolving it as millions of individual pixels. Then, the day-night band reviews the amount of light in each pixel. If it is very bright, a low-gain mode prevents the pixel from oversaturating. If the pixel is very dark, the signal is amplified.
"The night is nowhere as dark as we might think," Miller said. And with the VIIRS day-night band helping scientists to tease out information from human and natural sources of nighttime light, "we don't have to be in the dark anymore, either."
Icrisat's innovative methods for enhanced food production: Information and communication technologies help to reach out to farmers in remote villages
Using information technology to revitalize agricultural extension and education
Hyderabad, December 6 2012 – Millions of smallholder farmers worldwide could improve their yields, incomes and resilience if only they had better access to appropriate information and knowledge that helps them make informed choices about farming practices.
Yet, despite new information and communication technologies (ICT), reaching out to these farmers with the right information at the right time is still a largely unmet challenge.
Using ICT to revitalize agricultural extension and education towards providing knowledge access to smallholder farmers was the subject of an international workshop held at the Infosys Campus here in Hyderabad on 3-4 December.
The global consultation on Innovative ICT and Knowledge Sharing Platforms for Revitalizing Agricultural Extension and Education: Opportunities and Challenges organized by a global team led by the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), brought together about 60 ICT, research, extension and education experts from India, USA and Africa.
The two-day workshop was successful in laying the groundwork for the formation of a global partnership that will push the ‘knowledge to the poor’ revolution through ICT application in agricultural extension and education.
Partners from India, USA and Africa have agreed to develop tri-lateral educational programs to enhance the capacities of students, faculty members, extension agents, smallholder farmers, and various stakeholders in using ICT to promote the sharing and use of agricultural information among the poor and marginalized. To initiate this activity, a global AgED open courseware platform was launched during the workshop.
“ICT innovations enable the poor and drought-prone farmers in Asia and sub-Saharan Africa greater access to research data and knowledge outputs,” said ICRISAT Director General William Dar in his inaugural address. Working with partners and stakeholders, ICRISAT has developed and supported many information systems that have helped smallholder farmers become more food secure and resilient to drought, he added.
Partnering with ICRISAT in the workshop were: Infosys Limited, Infrastructure Leasing & Financial Services Limited (IL&FS), National Institute of Agricultural Extension Management (MANAGE), University of Florida (UFL), Indian Council of Agricultural Research (ICAR), and the International Fund for Agricultural Development (IFAD).
Samson David, Vice President and Global Head – Business Platforms, Infosys, emphasized on using the power of information technology in lifting smallholder farmers to a higher level of knowledge and productivity.
IL&FS Executive Director for Agriculture and Rural Development, AK Krishna Kumar, stressed the need to address the lack of information infrastructure to reach farmers in India, and to customize ICT solutions based on farmers’ needs.
B Srinivas, Director General of MANAGE, highlighted the importance of capacity building for agricultural officers in state governments, envisioning a single-window availability of agricultural information to farmers through ICT.
“India’s contribution in feeding 60 percent of the global population lies in its potential to upgrade its agricultural knowledge through ICT and in exploring opportunities brought about by the changing food habits of the people,” said ICAR Deputy Director General for Education, Arvind Kumar.
On the other hand, ICAR Deputy Director General for Agricultural Extension, KD Kokate, emphasized on the link between research and extension and the need to strengthen partnerships to achieve a knowledge revolution through ICT innovations.
Catching outbursts of high-energy light mysteriously produced above thurderstorms: Fermi lab gets better vision, 10 times better than ever
FERMI IMPROVES ITS VISION FOR THUNDERSTORM GAMMA-RAY FLASHES
WASHINGTON -- Thanks to improved data analysis techniques and a new
operating mode, the Gamma-ray Burst Monitor (GBM) aboard NASA's Fermi
Gamma-ray Space Telescope is now 10 times better at catching the
brief outbursts of high-energy light mysteriously produced above
thunderstorms.
The outbursts, known as terrestrial gamma-ray flashes (TGFs), last
only a few thousandths of a second, but their gamma rays rank among
the highest-energy light that naturally occurs on Earth. The enhanced
GBM discovery rate helped scientists show most TGFs also generate a
strong burst of radio waves, a finding that will change how
scientists study this poorly understood phenomenon, according to a NASA report.
Before being upgraded, the GBM could capture only TGFs that were
bright enough to trigger the instrument's on-board system, which
meant many weaker events were missed.
"In mid-2010, we began testing a mode where the GBM directly downloads
full-resolution gamma-ray data even when there is no on-board
trigger, and this allowed us to locate many faint TGFs we had been
missing," said lead researcher Valerie Connaughton, a member of the
GBM team at the University of Alabama in Huntsville (UAH). She
presented the findings Wednesday in an invited talk at the American
Geophysical Union meeting in San Francisco. A paper detailing the
results is accepted for publication in the Journal of Geophysical
Research: Space Physics.
The results were so spectacular that on Nov. 26 the team uploaded new
flight software to operate the GBM in this mode continuously, rather
than in selected parts of Fermi's orbit.
Connaughton's team gathered GBM data for 601 TGFs from August 2008 to
August 2011, with most of the events, 409 in all, discovered through
the new techniques. The scientists then compared the gamma-ray data
to radio emissions over the same period.
Lightning emits a broad range of very low frequency (VLF) radio waves,
often heard as pop-and-crackle static when listening to AM radio. The
World Wide Lightning Location Network (WWLLN), a research
collaboration operated by the University of Washington in Seattle,
routinely detects these radio signals and uses them to pinpoint the
location of lightning discharges anywhere on the globe to within
about 12 miles (20 km).
Scientists have known for a long time TGFs were linked to strong VLF
bursts, but they interpreted these signals as originating from
lightning strokes somehow associated with the gamma-ray emission.
"Instead, we've found when a strong radio burst occurs almost
simultaneously with a TGF, the radio emission is coming from the TGF
itself," said co-author Michael Briggs, a member of the GBM team.
The researchers identified much weaker radio bursts that occur up to
several thousandths of a second before or after a TGF. They interpret
these signals as intracloud lightning strokes related to, but not
created by, the gamma-ray flash.
Scientists suspect TGFs arise from the strong electric fields near the
tops of thunderstorms. Under certain conditions, the field becomes
strong enough that it drives a high-speed upward avalanche of
electrons, which give off gamma rays when they are deflected by air
molecules.
"What's new here is that the same electron avalanche likely
responsible for the gamma-ray emission also produces the VLF radio
bursts, and this gives us a new window into understanding this
phenomenon," said Joseph Dwyer, a physics professor at the Florida
Institute of Technology in Melbourne, Fla., and a member of the study
team.
Because the WWLLN radio positions are far more precise than those
based on Fermi's orbit, scientists will develop a much clearer
picture of where TGFs occur and perhaps which types of thunderstorms
tend to produce them.
The GBM scientists predict the new operating mode and analysis
techniques will allow them to catch about 850 TGFs each year. While
this is a great improvement, it remains a small fraction of the
roughly 1,100 TGFs that fire up each day somewhere on Earth,
according to the team's latest estimates.
Likewise, TGFs detectable by the GBM represent just a small fraction
of intracloud lightning, with about 2,000 cloud-to-cloud lightning
strokes for every TGF.
The Fermi Gamma-ray Space Telescope is an astrophysics and particle
physics partnership and is managed by NASA's Goddard Space Flight
Center in Greenbelt, Md. Fermi was developed in collaboration with
the U.S. Department of Energy, with important contributions from
academic institutions and partners in France, Germany, Italy, Japan,
Sweden and the United States.
The GBM Instrument Operations Center is located at the National Space
Science Technology Center in Huntsville, Ala. The GBM team includes a
collaboration of scientists from UAH, NASA's Marshall Space Flight
Center in Huntsville, the Max Planck Institute for Extraterrestrial
Physics in Germany and other institutions.
WASHINGTON -- Thanks to improved data analysis techniques and a new
operating mode, the Gamma-ray Burst Monitor (GBM) aboard NASA's Fermi
Gamma-ray Space Telescope is now 10 times better at catching the
brief outbursts of high-energy light mysteriously produced above
thunderstorms.
The outbursts, known as terrestrial gamma-ray flashes (TGFs), last
only a few thousandths of a second, but their gamma rays rank among
the highest-energy light that naturally occurs on Earth. The enhanced
GBM discovery rate helped scientists show most TGFs also generate a
strong burst of radio waves, a finding that will change how
scientists study this poorly understood phenomenon, according to a NASA report.
Before being upgraded, the GBM could capture only TGFs that were
bright enough to trigger the instrument's on-board system, which
meant many weaker events were missed.
"In mid-2010, we began testing a mode where the GBM directly downloads
full-resolution gamma-ray data even when there is no on-board
trigger, and this allowed us to locate many faint TGFs we had been
missing," said lead researcher Valerie Connaughton, a member of the
GBM team at the University of Alabama in Huntsville (UAH). She
presented the findings Wednesday in an invited talk at the American
Geophysical Union meeting in San Francisco. A paper detailing the
results is accepted for publication in the Journal of Geophysical
Research: Space Physics.
The results were so spectacular that on Nov. 26 the team uploaded new
flight software to operate the GBM in this mode continuously, rather
than in selected parts of Fermi's orbit.
Connaughton's team gathered GBM data for 601 TGFs from August 2008 to
August 2011, with most of the events, 409 in all, discovered through
the new techniques. The scientists then compared the gamma-ray data
to radio emissions over the same period.
Lightning emits a broad range of very low frequency (VLF) radio waves,
often heard as pop-and-crackle static when listening to AM radio. The
World Wide Lightning Location Network (WWLLN), a research
collaboration operated by the University of Washington in Seattle,
routinely detects these radio signals and uses them to pinpoint the
location of lightning discharges anywhere on the globe to within
about 12 miles (20 km).
Scientists have known for a long time TGFs were linked to strong VLF
bursts, but they interpreted these signals as originating from
lightning strokes somehow associated with the gamma-ray emission.
"Instead, we've found when a strong radio burst occurs almost
simultaneously with a TGF, the radio emission is coming from the TGF
itself," said co-author Michael Briggs, a member of the GBM team.
The researchers identified much weaker radio bursts that occur up to
several thousandths of a second before or after a TGF. They interpret
these signals as intracloud lightning strokes related to, but not
created by, the gamma-ray flash.
Scientists suspect TGFs arise from the strong electric fields near the
tops of thunderstorms. Under certain conditions, the field becomes
strong enough that it drives a high-speed upward avalanche of
electrons, which give off gamma rays when they are deflected by air
molecules.
"What's new here is that the same electron avalanche likely
responsible for the gamma-ray emission also produces the VLF radio
bursts, and this gives us a new window into understanding this
phenomenon," said Joseph Dwyer, a physics professor at the Florida
Institute of Technology in Melbourne, Fla., and a member of the study
team.
Because the WWLLN radio positions are far more precise than those
based on Fermi's orbit, scientists will develop a much clearer
picture of where TGFs occur and perhaps which types of thunderstorms
tend to produce them.
The GBM scientists predict the new operating mode and analysis
techniques will allow them to catch about 850 TGFs each year. While
this is a great improvement, it remains a small fraction of the
roughly 1,100 TGFs that fire up each day somewhere on Earth,
according to the team's latest estimates.
Likewise, TGFs detectable by the GBM represent just a small fraction
of intracloud lightning, with about 2,000 cloud-to-cloud lightning
strokes for every TGF.
The Fermi Gamma-ray Space Telescope is an astrophysics and particle
physics partnership and is managed by NASA's Goddard Space Flight
Center in Greenbelt, Md. Fermi was developed in collaboration with
the U.S. Department of Energy, with important contributions from
academic institutions and partners in France, Germany, Italy, Japan,
Sweden and the United States.
The GBM Instrument Operations Center is located at the National Space
Science Technology Center in Huntsville, Ala. The GBM team includes a
collaboration of scientists from UAH, NASA's Marshall Space Flight
Center in Huntsville, the Max Planck Institute for Extraterrestrial
Physics in Germany and other institutions.
Wednesday, December 5, 2012
Most women who have breast cancer do not know it
Facts About Breast Cancer
Most women who have breast cancer don’t know it. But mammography can pick up X-ray signs of the disease before there are symptoms such as the lump in the breast.
And the earlier the diagnosis, the better the odds of survival.
But researchers at the Centers for Disease Control and Prevention say all women don’t benefit equally. The CDC says that, despite improvements in diagnosis and treatment, black women still are diagnosed when the cancers are more advanced, and are more likely than white women to die.
CDC researcher Lisa Richardson says early detection is crucial for all women:
“For women who are diagnosed at the earliest stages, five-year survival is greater than 95 per cent.”
Fighting the risk of breast cancer: Simple tips to screen breast cancer
Kinds of Screening Tests for Breast Cancer
Breast cancer screening means checking a woman's breasts for cancer before there are signs or symptoms of the disease.
Mammogram
Breast self-exam
Breast cancer screening means checking a woman's breasts for cancer before there are signs or symptoms of the disease.
Three main tests are used to screen the breasts for cancer. Talk to your doctor about which tests are right for you, and when you should have them.
Mammogram
A mammogram is an X-ray of the breast. Mammograms are the best method to detect breast cancer early when it is easier to treat and before it is big enough to feel or cause symptoms. Having regular mammograms can lower the risk of dying from breast cancer.
If you are age 50 to 74 years, be sure to have a screening mammogram every two years. If you are age 40–49 years, talk to your doctor about when and how often you should have a screening mammogram.
Clinical breast exam.
Clinical breast exam.
A clinical breast exam is an examination by a doctor or nurse, who uses his or her hands to feel for lumps or other changes.
Breast self-exam
A breast self-exam is when you check your own breasts for lumps, changes in size or shape of the breast, or any other changes in the breasts or underarm (armpit).
Which tests to choose
Which tests to choose
Having a clinical breast exam or a breast self-exam have not been found to decrease risk of dying from breast cancer. Keep in mind that, at this time, the best way to find breast cancer is with a mammogram.
If you choose to have clinical breast exams and to perform breast self-exams, be sure you also get regular mammograms.
Where Can I Go to Get Screened?
Most likely, you can get screened for breast cancer at a clinic, hospital, or doctor's office. If you want to be screened for breast cancer, call your doctor's office. They can help you schedule an appointment. Most health insurance companies pay for the cost of breast cancer screening tests.
Most likely, you can get screened for breast cancer at a clinic, hospital, or doctor's office. If you want to be screened for breast cancer, call your doctor's office. They can help you schedule an appointment. Most health insurance companies pay for the cost of breast cancer screening tests.
(Courtesy: CDC, USA)
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