Saturday, June 30, 2012

What lies in exoplanet HD 189733b: An international team of astronomers using data from NASA's Hubble Space Telescope has made an unparalleled observation, detecting significant changes in the atmosphere of a planet located beyond our solar system

The exoplanet is HD 189733b, a gas giant similar to Jupiter, but about 14 percent larger and more massive. The planet circles its star at a distance of only 3 million miles, or about 30 times closer than Earth's distance from the sun, and completes an orbit every 2.2 days. Its star, named HD 189733A, is about 80 per cent the size and mass of our sun.
An international team of astronomers using data from NASA's Hubble Space Telescope has made an unparalleled observation, detecting significant changes in the atmosphere of a planet located beyond our solar system.
The scientists conclude the atmospheric variations occurred in response to a powerful eruption on the planet's host star, an event observed by NASA's Swift satellite.  The stellar flare, which hit the planet like 3 million X-flares from our own sun, blasted material from the planet's atmosphere at a rate of at least 1,000 tons per second.
Alien Flare (splash)
This artist's rendering illustrates the evaporation of HD 189733b's atmosphere in response to a powerful eruption from its host star. NASA's Hubble Space Telescope detected the escaping gases and NASA's Swift satellite caught the stellar flare. (Credit: NASA's Goddard Space Flight Center)
"The multiwavelength coverage by Hubble and Swift has given us an unprecedented view of the interaction between a flare on an active star and the atmosphere of a giant planet," said lead researcher Alain Lecavelier des Etangs at the Paris Institute of Astrophysics (IAP), part of the French National Scientific Research Center located at Pierre and Marie Curie University in Paris.

The exoplanet is HD 189733b, a gas giant similar to Jupiter, but about 14 percent larger and more massive. The planet circles its star at a distance of only 3 million miles, or about 30 times closer than Earth's distance from the sun, and completes an orbit every 2.2 days. Its star, named HD 189733A, is about 80 percent the size and mass of our sun.
Astronomers classify the planet as a "hot Jupiter." Previous Hubble observations show that the planet's deep atmosphere reaches a temperature of about 1,900 degrees Fahrenheit (1,030 C).
Alien Flare (movie, 200px)
A movie from the Goddard Space Flight Center explores the planet-blasting stellar flare. HD 189733b periodically passes across, or transits, its parent star, and these events give astronomers an opportunity to probe its atmosphere and environment. In a previous study, a group led by Lecavelier des Etangs used Hubble to show that hydrogen gas was escaping from the planet's upper atmosphere. The finding made HD 189733b only the second-known "evaporating" exoplanet at the time.
The system is just 63 light-years away, so close that its star can be seen with binoculars near the famous Dumbbell Nebula. This makes HD 189733b an ideal target for studying the processes that drive atmospheric escape.

"Astronomers have been debating the details of atmospheric evaporation for years, and studying HD 189733b is our best opportunity for understanding the process," said Vincent Bourrier, a doctoral student at IAP and a team member on the new study.
In April 2010, the researchers observed a single transit using Hubble's Space Telescope Imaging Spectrograph (STIS), but they detected no trace of the planet's atmosphere. Follow-up observations in September 2011 showed a surprising reversal, with striking evidence that a plume of gas was streaming away from the exoplanet at 300,000 mph. At least 1,000 tons of gas were leaving the planet's atmosphere every second.

This turn of events was explained by data from Swift's X-ray Telescope. On Sept. 7, 2011, just eight hours before Hubble was scheduled to observe the transit, Swift was monitoring the star when it unleashed a powerful flare.

"The planet's close proximity to the star means it was struck by a blast of X-rays tens of thousands of times stronger than the Earth suffers even during an X-class solar flare, the strongest category," said co-author Peter Wheatley, a physicist at the University of Warwick in England. After accounting for the planet's enormous size, the team notes that HD 189733b encountered about 3 million times as many X-rays as Earth receives from a solar flare at the threshold of the X class.

Astronomical tales of the unknown worlds: Saturn's moon Titan may contain liquid water

On Earth, tides result from the gravitational attraction of the moon and sun pulling on our surface oceans. In the open oceans, those can be as high as two feet (60 centimetres). The gravitational pulling by the sun and moon also causes Earth's crust to bulge in solid tides of about 20 inches (50 centimetres).
Data from NASA's Cassini spacecraft have revealed Saturn's moon Titan likely harbours a layer of liquid water under its ice shell. The finding appeared in the journal Science.
"Cassini's detection of large tides on Titan leads to the almost inescapable conclusion that there is a hidden ocean at depth," said Luciano Iess, the paper's lead author and a Cassini team member at the Sapienza University of Rome, Italy. "The search for water is an important goal in solar system exploration, and now we've spotted another place where it is abundant."
Titan's Underground Ocean (splash)
This artist's concept shows a possible scenario for the internal structure of Titan, as suggested by data from NASA's Cassini spacecraft. Image credit: A. Tavani
The evidence is tidal.  Saturn's powerful gravity stretches and deforms Titan as the moon moves around the gas giant planet. If Titan were composed entirely of stiff rock, the gravitational attraction of Saturn should cause bulges, or solid "tides," on the moon only 3 feet (1 meter) in height. Instead, the data show Saturn creates solid tides approximately 30 feet (10 meters) in height. This suggests Titan is not made entirely of solid rocky material.
At first, scientists were not sure Cassini would be able to detect the bulges caused by Saturn's pull on Titan. Cassini succeeded, however, by measuring Titan's gravitational field during six close flybys from Feb. 27, 2006, to Feb. 18, 2011. These gravity measurements, collected with the aid of NASA's Deep Space Network (DSN), revealed the size of Titan's tides.
"We were making ultrasensitive measurements, and thankfully Cassini and the DSN were able to maintain a very stable link," said Sami Asmar, a Cassini team member at NASA's Jet Propulsion Laboratory in Pasadena, Calif. "The tides on Titan pulled up by Saturn aren't huge compared to the pull the biggest planet, Jupiter, exerts on some of its moons. But, short of being able to drill on Titan's surface, the gravity measurements provide the best data we have of Titan's internal structure."
Titan's Underground Ocean (movie, 200px)
A movie shows "tides" on Titan raised by Saturn's gravity (exaggerated for clarity). 
An ocean layer does not have to be huge or deep to create the observed tides. A liquid layer between the external, deformable shell and a solid mantle would enable Titan to bulge and compress as it orbits Saturn. Because Titan's surface is mostly made of water ice, which is abundant in moons of the outer solar system, scientists believe Titan's ocean is likely mostly liquid water.
On Earth, tides result from the gravitational attraction of the moon and sun pulling on our surface oceans. In the open oceans, those can be as high as two feet (60 centimeters). The gravitational pulling by the sun and moon also causes Earth's crust to bulge in solid tides of about 20 inches (50 centimeters).
The presence of a subsurface layer of liquid water at Titan is not by itself an indicator for life. Scientists think life is more likely to arise when liquid water is in contact with rock, and these measurements cannot tell whether the ocean bottom is made up of rock or ice.
The results have a bigger implication for the mystery of methane replenishment on Titan.  Methane is abundant in Titan's atmosphere, yet researchers believe the methane is unstable, so there must be a supply to maintain its abundance.
"The presence of a liquid water layer in Titan is important because we want to understand how methane is stored in Titan's interior and how it may outgas to the surface," said Jonathan Lunine, a Cassini team member at Cornell University, Ithaca, N.Y. "This is important because everything that is unique about Titan derives from the presence of abundant methane, yet the methane in the atmosphere should be destroyed on geologically short timescales."
A liquid water ocean, "salted" with ammonia, could produce buoyant ammonia-water liquids that bubble up through the crust and liberate methane from the ice. Such an ocean could serve also as a deep reservoir for storing methane.

Unravelling the tales of distant realms: Now we can see the invisible magnetic portals

Magnetic portals are invisible, unstable, and elusive.  They open and close without warning and there are no signposts to guide us in
A favorite theme of science fiction is "the portal"--an extraordinary opening in space or time that connects travelers to distant realms.  A good portal is a shortcut, a guide, a door into the unknown. If only they actually existed....

It turns out that they do, sort of, and a NASA-funded researcher at the University of Iowa has figured out how to find them.

"We call them X-points or electron diffusion regions," explains plasma physicist Jack Scudder of the University of Iowa.  "They're places where the magnetic field of Earth connects to the magnetic field of the Sun, creating an uninterrupted path leading from our own planet to the sun's atmosphere 93 million miles away."
Hidden Portals (splash)
A new ScienceCast video explains how hidden portals form--and how we can find them.
Observations by NASA's THEMIS spacecraft and Europe's Cluster probes suggest that these magnetic portals open and close dozens of times each day.  They're typically located a few tens of thousands of kilometers from Earth where the geomagnetic field meets the onrushing solar wind.  Most portals are small and short-lived; others are yawning, vast, and sustained.  Tons of energetic particles can flow through the openings, heating Earth's upper atmosphere, sparking geomagnetic storms, and igniting bright polar auroras.

NASA is planning a mission called "MMS," short for Magnetospheric Multiscale Mission, due to launch in 2014, to study the phenomenon. Bristling with energetic particle detectors and magnetic sensors, the four spacecraft of MMS will spread out in Earth's magnetosphere and surround the portals to observe how they work.

Just one problem:  Finding them.  Magnetic portals are invisible, unstable, and elusive.  They open and close without warning "and there are no signposts to guide us in," notes Scudder.
Hidden Portals (Polar data, 200px)
Data from NASA's Polar spacecraft, circa 1998, provided crucial clues to finding magnetic X-points.
Actually, there are signposts, and Scudder has found them.

Portals form via the process of magnetic reconnection.  Mingling lines of magnetic force from the sun and Earth criss-cross and join to create the openings. "X-points" are where the criss-cross takes place.  The sudden joining of magnetic fields can propel jets of charged particles from the X-point, creating an "electron diffusion region."
To learn how to pinpoint these events, Scudder looked at data from a space probe that orbited Earth more than 10 years ago.

"In the late 1990s, NASA's Polar spacecraft spent years in Earth's magnetosphere," explains Scudder, "and it encountered many X-points during its mission."

Because Polar carried sensors similar to those of MMS, Scudder decided to see how an X-point looked to Polar. "Using Polar data, we have found five simple combinations of magnetic field and energetic particle measurements that tell us when we've come across an X-point or an electron diffusion region. A single spacecraft, properly instrumented, can make these measurements."

This means that single member of the MMS constellation using the diagnostics can find a portal and alert other members of the constellation. Mission planners long thought that MMS might have to spend a year or so learning to find portals before it could study them.  Scudder's work short cuts the process, allowing MMS to get to work without delay.

It's a shortcut worthy of the best portals of fiction, only this time the portals are real. And with the new "signposts" we know how to find them. 

Wednesday, June 27, 2012

All that you ever wanted to know about obesity and overweight

The World Health Organisation has come out with the following startling facts and simple tips to prevent obesity and lead a healthy life.
 Obesity statistics:

  • Worldwide obesity has more than doubled since 1980.
  • In 2008, more than 1.4 billion adults, 20 and older, were overweight. Of these over 200 million men and nearly 300 million women were obese.
  • 65% of the world's population live in countries where overweight and obesity kills more people than underweight.
  • More than 40 million children under the age of five were overweight in 2010.
  • Obesity is preventable.

What are overweight and obesity?

Overweight and obesity are defined as abnormal or excessive fat accumulation that may impair health.
Body mass index (BMI) is a simple index of weight-for-height that is commonly used to classify overweight and obesity in adults. It is defined as a person's weight in kilograms divided by the square of his height in meters (kg/m2).
The WHO definition is:
  • a BMI greater than or equal to 25 is overweight
  • a BMI greater than or equal to 30 is obesity.
BMI provides the most useful population-level measure of overweight and obesity as it is the same for both sexes and for all ages of adults. However, it should be considered a rough guide because it may not correspond to the same degree of fatness in different individuals.

Facts about overweight and obesity

Overweight and obesity are the fifth leading risk for global deaths. At least 2.8 million adults die each year as a result of being overweight or obese. In addition, 44% of the diabetes burden, 23% of the ischaemic heart disease burden and between 7% and 41% of certain cancer burdens are attributable to overweight and obesity.
Some WHO global estimates from 2008 follow.
  • More than 1.4 billion adults, 20 and older, were overweight.
  • Of these overweight adults, over 200 million men and nearly 300 million women were obese.
  • Overall, more than one in ten of the world’s adult population was obese.
In 2010, more than 40 million children under five were overweight. Once considered a high-income country problem, overweight and obesity are now on the rise in low- and middle-income countries, particularly in urban settings. Close to 35 million overweight children are living in developing countries and 8 million in developed countries.
Overweight and obesity are linked to more deaths worldwide than underweight. For example, 65% of the world's population live in countries where overweight and obesity kill more people than underweight (this includes all high-income and most middle-income countries).

What causes obesity and overweight?

The fundamental cause of obesity and overweight is an energy imbalance between calories consumed and calories expended. Globally, there has been:
  • an increased intake of energy-dense foods that are high in fat, salt and sugars but low in vitamins, minerals and other micronutrients; and
  • a decrease in physical activity due to the increasingly sedentary nature of many forms of work, changing modes of transportation, and increasing urbanization.
Changes in dietary and physical activity patterns are often the result of environmental and societal changes associated with development and lack of supportive policies in sectors such as health, agriculture, transport, urban planning, environment, food processing, distribution, marketing and education.

What are common health consequences of overweight and obesity?

Raised BMI is a major risk factor for noncommunicable diseases such as:
  • cardiovascular diseases (mainly heart disease and stroke), which were the leading cause of death in 2008;
  • diabetes;
  • musculoskeletal disorders (especially osteoarthritis - a highly disabling degenerative disease of the joints);
  • some cancers (endometrial, breast, and colon).
The risk for these noncommunicable diseases increases, with the increase in BMI.
Childhood obesity is associated with a higher chance of obesity, premature death and disability in adulthood. But in addition to increased future risks, obese children experience breathing difficulties, increased risk of fractures, hypertension, early markers of cardiovascular disease, insulin resistance and psychological effects.

Facing a double burden of disease

Many low- and middle-income countries are now facing a "double burden" of disease.
  • While they continue to deal with the problems of infectious disease and under-nutrition, they are experiencing a rapid upsurge in noncommunicable disease risk factors such as obesity and overweight, particularly in urban settings.
  • It is not uncommon to find under-nutrition and obesity existing side-by-side within the same country, the same community and the same household.
Children in low- and middle-income countries are more vulnerable to inadequate pre-natal, infant and young child nutrition At the same time, they are exposed to high-fat, high-sugar, high-salt, energy-dense, micronutrient-poor foods, which tend to be lower in cost. These dietary patterns in conjunction with low levels of physical activity, result in sharp increases in childhood obesity while undernutrition issues remain unsolved.

How can overweight and obesity be reduced?

Overweight and obesity, as well as their related noncommunicable diseases, are largely preventable. Supportive environments and communities are fundamental in shaping people’s choices, making the healthier choice of foods and regular physical activity the easiest choice, and therefore preventing obesity.
At the individual level, people can:
  • limit energy intake from total fats;
  • increase consumption of fruit and vegetables, as well as legumes, whole grains and nuts;
  • limit the intake of sugars;
  • engage in regular physical activity;
  • achieve energy balance and a healthy weight.
Individual responsibility can only have its full effect where people have access to a healthy lifestyle. Therefore, at the societal level it is important to:
  • support individuals in following the recommendations above, through sustained political commitment and the collaboration of many public and private stakeholders;
  • make regular physical activity and healthier dietary patterns affordable and easily accessible too all - especially the poorest individuals.
The food industry can play a significant role in promoting healthy diets by:
  • reducing the fat, sugar and salt content of processed foods;
  • ensuring that healthy and nutritious choices are available and affordable to all consumers;
  • practicing responsible marketing;
  • ensuring the availability of healthy food choices and supporting regular physical activity practice in the workplace.

Tuesday, June 26, 2012

Pets and health: Simple tips to live healthy, free from diseases transmitted by pets

Households with children under 5 years of age should not own reptiles, such as turtles, or amphibians, such as frogs.

Healthy Pets Healthy People

Pets can appear to be healthy even when they have germs. Here are a few tips to keep you and your family healthy.

Picking the Right Pet

Photo: A boy feeding his dog.Before you purchase or adopt a pet, make sure that it is the right one for you and your family. CDC recommends the following:
  • Households with children under 5 years of age should not own reptiles, such as turtles, or amphibians, such as frogs.
  • Pregnant women should avoid contact with pet rodents to prevent exposure to lymphocytic choriomeningitis virus, which is a virus that can cause birth defects.
  • Pregnant women should avoid adopting or handling stray cats, especially kittens.  They particularly should not clean litter boxes to avoid getting toxoplasmosis from them.
  • Immune-compromised persons and persons with HIVinfection or AIDS should take extra precautions when choosing and handling pets. Talk to your veterinarian and health care provider to help make this decision.
To pick the right pet, do some research beforehand about the specific needs of the animal. Some questions to ask are: How much exercise does the pet need? How large will it become? Is the type of animal aggressive? What does the pet eat? How much will it cost for veterinary care? Do I have enough time to properly care for and clean-up after the pet? What exactly does this pet need in its habitat to be healthy? Are pets allowed in my apartment or condominium? How long will this animal live? .

Wash Hands Right after Touching Your Pet

  • A young boy washes his handsAlways wash hands thoroughly with soap and water right after touching a pet, their housing, or anything (for example, food or treats) that comes in contact with them or the areas where they live. It is especially important to wash your hands after touching a pet and before preparing, serving, eating, or drinking.
  • Adults should assist young children with hand washing. See more information on hand washing. See the CDC's Clean Handssite for more information on hand washing.
  • Running water and soap are best for hand washing. Use hand sanitizers if running water and soap are not available. Be sure to wash your hands with soap and water as soon as a sink is available.
  • Call your health care provider if you or a family member are concerned about illness and be sure to tell them about the pets you have contact with.
  • Contact your pet's veterinarian if you are concerned that your pet may be sick.
Many pets, such as dogs, cats, reptiles, rodents, and birds, carry germs that can be spread from animals to people. Always wash hands upon leaving areas where animals live (i.e. coops. barns, stalls, etc.) even if you did not touch an animal, after going to the toilet, before eating and drinking, before preparing food or drinks, and after removing soiled clothes or shoes.
It is also important to wash your hands right after handling pet foods and treats, which can be contaminated with bacteria and other germs. Pet food and treats might include dry dog or cat food, dog biscuits, pig ears, beef hooves, and rodents used to feed reptiles.

Keep Your Pet Healthy

Whether you have a horse, parakeet, or iguana, providing regular, life-long veterinary care is important to having a healthy pet and a healthy family. Keep up with your pet's vaccinesExternal Web Site Icon, deworming, and flea and tick control. Provide your pet with a good diet, fresh water, clean bedding, and exercise. By keeping your pet healthy, you keep yourself and your family healthy. Regular veterinary visits are essential to good pet health. Contact your veterinarian if you have any questions about your pet's health.
Your pet may carry ticks that can spread serious diseases like Lyme disease and Rocky Mountain spotted fever to people. In areas with plague, fleas present a risk to both animals and their owners. Consult your veterinarian about ways to prevent ticks and fleas on your pet.

Practice Good Hygiene Around Your Pet

Two cats lying in a sinkMake sure to wash your hands right after touching an animal, cleaning up after your pet, and before eating or preparing foods. Make sure to remove your dog's feces from your yard or public places by using a device or bag, and dispose of in proper areas. Dog feces contain many types of bacteria, some of which can be harmful to people. Keep young children away from areas that may contain dog or cat feces to prevent the spread of roundworms and hookworms. Cover sand boxes so cats don't use them as a litter box. Clean the cat's litter box daily. Pregnant woman should not change a cat's litter box, because cats can carry a parasite that causes toxoplasmosis, which is a disease that can cause birth defects. Get more information on toxoplasmosis and cats.

Prevent Rabies

Rabies can kill your dog or cat and can even kill you. Get your pet, especially dogs, cats, and other mammals, vaccinated for rabies by a licensed veterinarian. Talk to your veterinarian about whether or not other pets need a rabies vaccine. Make sure your pet gets and wears a tag with its vaccine history, name, and your contact information. Keep your pet in a fenced yard or on a leash. See more information about preventing rabies and dog bites.

Photo: A doe and fawn.Keep Wildlife Wild

Though they may be cute and cuddly, don't encourage wild animals such as raccoons, prairie dogs, or wild rodents to come into your home by feeding them. You may find a young animal that appears to be abandoned and want to rescue it, but often its parent is close by. Refrain from touching wild animals and their habitats, as many carry germs, viruses, and parasites.

Teach Children How to Appropriately Care for Pets

Children younger than 5 years old should be supervised while interacting with animals. Teach children to wash their hands right after playing with animals or anything in the animals' environment (e.g., cages, beds, food and water dishes). Children younger than 5 years old should be extra cautious when visiting farms and having direct contact with farm animals, including animals at petting zoos and fairs. 

Enjoy Your Pet!

There are many health benefits of owning a pet. The companionship of pets can help manage loneliness and depression. Pets can increase your opportunities to exercise, participate in outdoor activities, and socialize. Therefore, regular walking or playing with pets can decrease your blood pressure, cholesterol levels, and triglyceride levels. Remember, healthy pets = healthy people!

Monday, June 25, 2012

The story of voyager 1: Reaching the edge of the solar system, the first man-made object to reach such a far destination

For nearly 35 years, NASA’s Voyager 1 probe has been hurtling toward the edge of the solar system, flying through the dark void on a mission unlike anything attempted before.  One day, mission controllers hope, Voyager 1 will leave the solar system behind and enter the realm of the stars—interstellar space.
That day may be upon us.
"The latest data from Voyager 1 indicate that we are clearly in a new region where things are changing quickly," says Ed Stone, Voyager project scientist at the California Institute of Technology in Pasadena.  This is very exciting. We are approaching the solar system's final frontier."
Final Frontier (splash)
A new ScienceCast video follows Voyager 1 to the edge of the solar system. 
The “frontier” he’s referring to is the edge of the heliosphere, a great magnetic bubble that surrounds the sun and planets.  The heliosphere is the sun’s own magnetic field inflated to gargantuan proportions by the solar wind.  Inside lies the solar system—“home.”  Outside lies interstellar space, where no spacecraft has gone before.
A telltale sign of the frontier’s approach is the number of cosmic rays hitting Voyager 1.  Cosmic rays are high energy particles such as protons and helium nuclei accelerated to near-light speed by distant supernovas and black holes. The heliosphere protects the solar system from these subatomic bullets, deflecting and slowing many of them before they can reach the inner planets.
As Voyager approaches the frontier, the number of cosmic rays has gone up.
"From January 2009 to January 2012, there had been a gradual increase of about 25 percent in the amount of galactic cosmic rays Voyager was encountering," says Stone.
Final Frontier (data, 200px)
A sharp increase in cosmic rays could herald Voyager 1's long-awaited breakthrough to interstellar space.
"More recently, however, we have seen a very rapid escalation in that part of the energy spectrum. Beginning on May 7, 2012, the cosmic ray hits have increased five percent in a week and nine percent in a month."
The sharp increase means that Voyager 1 could be on the verge of a breakthrough 18 billion kilometers from Earth.
When Voyager 1 actually exits the heliosphere, researchers expect to see other changes as well.  For one thing, energetic particles from the sun will become scarce as the spacecraft leaves the heliosphere behind.  Also, the magnetic field around Voyager 1 will change direction from that of the sun’s magnetic field to that of the new and unexplored magnetism of interstellar space. 
So far, neither of these things has happened.  Nevertheless, the sudden increase in cosmic rays suggests it might not be long.
Meanwhile, Voyager 2 is making its own dash for the stars, but because of its slower pace lags a few billion kilometers behind Voyager 1.  Both spacecraft remain in good health.
"When the Voyagers launched in 1977, the Space Age was all of 20 years old," says Stone. "Many of us on the team dreamed of reaching interstellar space, but we really had no way of knowing how long a journey it would be -- or if these two vehicles that we invested so much time and energy in would operate long enough to reach it. "

Friday, June 22, 2012

How much water does our Moon hold? 22 per cent? May be at the poles

Evidence Mounts for Ice in Shackleton Crater

According to data from NASA's Lunar Reconnaissance Orbiter (LRO), ice may make up as much as 22 percent of the surface material in Shackleton crater at the Moon's south pole.

The huge crater, named after the Antarctic explorer Ernest Shackleton, is two miles deep and more than 12 miles wide. The small tilt of the lunar spin axis means Shackleton's interior is permanently dark and very cold..  Researchers have long thought that ice might collect  there.

When a team of NASA and university scientists used LRO's laser altimeter to examine the floor of Shackleton crater, they found it to be brighter than the floors of other nearby craters around the South Pole. This is consistent with the presence of small amounts of reflective ice preserved by cold and darkness. The findings are published in the journal Nature.
Shackleton (splash)
This visualization, created using Lunar Reconnaissance Orbiter laser altimeter data, offers a view of Shackleton Crater located in the south pole of the moon. 
In addition to the possible evidence of ice, the group's map of Shackleton revealed a remarkably preserved crater that has remained relatively unscathed since its formation more than three billion years ago. The crater's floor is itself pocked with several small craters, which may have formed as part of the collision that created Shackleton.

"The crater's interior is extremely rugged," said Maria Zuber, the team's lead investigator from the Massachusetts Institute of Technology in Cambridge in Mass. "It would not be easy to crawl around in there."
Shackleton (elevation, 200px)
In this laser elevation map of Shackleton crater, false colors indicate height, with blue lowest and red highest. Credit: NASA/Zuber, M.T. et al., Nature, 2012
While the crater's floor was relatively bright, Zuber and her colleagues observed that its walls were even brighter. The finding was at first puzzling. Scientists had thought that if ice were anywhere in a crater, it would be on the floor, where no direct sunlight penetrates. The upper walls of Shackleton crater are occasionally illuminated, which could evaporate any ice that accumulates.
"The brightness measurements have been puzzling us since two summers ago," said Gregory Neumann of NASA's Goddard Space Flight Center in Greenbelt, Md., a co-author on the paper.

A theory offered by the team to explain the puzzle is that "moonquakes"-- seismic shaking brought on by meteorite impacts or gravitational tides from Earth -- may have caused Shackleton's walls to slough off older, darker soil, revealing newer, brighter soil underneath. Zuber's team's ultra-high-resolution map provides strong evidence for ice on both the crater's floor and walls.

"There may be multiple explanations for the observed brightness throughout the crater," said Zuber. "For example, newer material may be exposed along its walls, while ice may be mixed in with its floor."

Wednesday, June 20, 2012

Are you a diabetic: Follow these simple rules whenever you travel

Have diabetes? Tips for safe travels

Getting out of the routine is part of the fun of traveling. But if you have diabetes, there's one routine you need to take with you: your care routine.
Meals away from home, changes in how much physical activity you get, and differences in time zones as you travel can affect how well you manage diabetes. Before you hit the road, review these tips for taking care of yourself.

Don't Forget Your Medication

  • Pack twice the amount of diabetes supplies you expect to need, in case of travel delays.
  • Keep snacks, glucose gel, or tablets with you in case your blood glucose drops.
  • Make sure you keep your medical insurance card and emergency phone numbers handy, including your doctor's name and phone number.
  • Carry medical identification that says you have diabetes.
  • Keep time zone changes in mind so you'll know when to take medication.
  • If you use insulin, make sure you also pack a glucagon emergency kit.
  • Have all syringes and insulin delivery systems (including vials of insulin) clearly marked with the pharmaceutical preprinted label that identifies the medications. Keep it in the original pharmacy labeled packaging.
  • Find out where to get medical care if needed when away from home.
  • Take copies of prescriptions with you.

On the Road

  • Reduce your risk for blood clots by moving around every hour or two.
  • Pack a small cooler of foods that may be difficult to find while traveling, such as fresh fruit, sliced raw vegetables, and fat-free or low-fat yogurt.
  • Bring a few bottles of water instead of sugar-sweetened soda or juice.
  • Pack dried fruit, nuts, and seeds as snacks. Since these foods can be high in calories, measure out small portions (¼ cup) in advance.

In the Air

  • If you're flying and do not want to walk through the metal detector with your insulin pump, tell a security officer that you are wearing an insulin pump and ask them to visually inspect the pump and do a full-body pat-down.
  • Place all diabetes supplies in carry-on luggage. Keep medications and snacks at your seat for easy access. Don't store them in overhead bins or checked luggage.
  • If a meal will be served during your flight, call ahead for a diabetic, low fat, or low cholesterol meal. Wait until your food is about to be served before you take your insulin.
  • If the airline doesn't offer a meal, bring a nutritious meal yourself.
  • Make sure to pack snacks in case of flight delays.
  • When drawing up your dose of insulin, don't inject air into the bottle (the air on your plane will probably be pressurized).
  • Reduce your risk for blood clots by moving around every hour or two.

Staying Healthy

  • Changes in what you eat, activity levels and time zones can affect your blood glucose. Check levels often. Talk with your doctor before increasing physical activity, such as going on a trip that will involve more walking.
  • Stick with your exercise routine. Make sure to get at least 150 minutes of physical activity each week.
  • Wash hands often with soap and water.
  • Protect your feet. Be especially careful of hot pavement by pools and hot sand on beaches. Never go barefoot.
  • Make sure you are up-to-date on immunizations.

Simple tips to reduce different cancers in men

Lifestyle Changes

Tobacco Use and Secondhand Smoke

More men in the United States die from lung cancer than any other kind of cancer, and cigarette smoking causes most cases. Smoking also causes cancers of the esophagus, larynx (voice box), mouth, throat, kidney, bladder, pancreas, stomach, and acute myeloid leukemia. Nonsmokers who are exposed to secondhand smoke at home or work increase their lung cancer risk by 20%–30%. Concentrations of many cancer-causing and toxic chemicals are higher in secondhand smoke than in the smoke inhaled by smokers.
One of the most important things you can do to lower your risk of cancer is to stop smokingExternal Web Site Icon if you smoke, and avoid secondhand smoke.

Obesity, Overweight, and Lack of Physical Activity

Photo: A man in a swimming poolFor more than 30 years, excess weight, lack of physical activity, and an unhealthy diet have been considered second only to tobacco use as preventable causes of disease and death in the United States. Since the 1960s, tobacco use has decreased by a third while obesity rates have doubled.
In men, the following cancers are associated with being overweight: colorectal cancer, esophageal adenocarcinoma (a type of cancer of the tube that connects your throat to your stomach), and cancer of the kidney and pancreas. Several of these cancers also are associated with not getting enough physical activity.
Adopting a lifestyle that includes healthy eating and regular physical activity can help prevent these cancers.

Sun Safety

Skin cancer is the most common cancer in the United States. The two most common kinds of skin cancer—basal cell and squamous cell carcinomas—are highly curable. But melanoma, the third most common skin cancer, is more dangerous. About 65%–90% of melanomas are caused by exposure to ultraviolet (UV) light—an invisible kind of radiation that comes from the sun, tanning beds, and sunlamps. Overall, men have higher rates of melanoma. But among young people, women get it more.
A few serious sunburns can increase your risk of skin cancer. To protect your skin from the sun, seek shade or go indoors during midday hours; wear long sleeves and long pants, a hat with a wide brim, and sunglasses; use sunscreen with a sun protective factor (SPF) of 15 or higher; and avoid indoor tanning.

Types of Cancer

Prostate Cancer

Photo: Two menProstate cancer is the second most common cause of cancer death in men. All men are at risk for prostate cancer, but older men, African-American men, and men with a family history of prostate cancer have a higher risk.
Not all medical experts agree that screening for prostate cancer saves lives. Currently, there is not enough evidence to decide if the possible benefit of prostate cancer screening outweighs the risks. CDC supports informed decision making, which occurs when a man—
  • Understands the nature and risk of prostate cancer.
  • Understands the risks of, benefits of, and alternatives to screening.
  • Participates in making the decision to be screened at a level he wants.
  • Makes a decision consistent with his preferences and values.

Colorectal (Colon) Cancer

The third leading cause of cancer deaths in American men is colorectal cancer. Screening tests for colorectal cancer can find precancerous polyps so they can be removed before they turn into cancer. Screening tests also can find colorectal cancer early, when treatment works best. Everyone should be tested for colorectal cancer regularly starting at age 50.

Tuesday, June 19, 2012

The tale of continents: How greener was my Antarctica of the yore!

Large quantities of pollen and algae in sediment cores were taken around
Antarctica. Fossils of plant life in Antarctica are difficult to come by because

the movement of the massive ice sheets covering the landmass grinds and scrapes
away the evidence

A new university-led study with NASA participation finds
ancient Antarctica was much warmer and wetter than previously
suspected. The climate was suitable to support substantial vegetation
-- including stunted trees -- along the edges of the frozen

The team of scientists involved in the study, published online June 17
in Nature Geoscience, was led by Sarah J. Feakins of the University
of Southern California in Los Angeles, and included researchers from
NASA's Jet Propulsion Laboratory in Pasadena, Calif., and Louisiana
State University in Baton Rouge.

By examining plant leaf wax remnants in sediment core samples taken
from beneath the Ross Ice Shelf, the research team found summer
temperatures along the Antarctic coast 15 to 20 million years ago
were 20 degrees Fahrenheit (11 degrees Celsius) warmer than today,
with temperatures reaching as high as 45 degrees Fahrenheit (7
degrees Celsius). Precipitation levels also were found to be several
times higher than today.

"The ultimate goal of the study was to better understand what the
future of climate change may look like," said Feakins, an assistant
professor of Earth sciences at the USC Dornsife College of Letters,
Arts and Sciences. "Just as history has a lot to teach us about the
future, so does past climate. This record shows us how much warmer
and wetter it can get around the Antarctic ice sheet as the climate
system heats up. This is some of the first evidence of just how much
warmer it was."

Scientists began to suspect that high-latitude temperatures during the
middle Miocene epoch were warmer than previously believed when
co-author Sophie Warny, assistant professor at LSU, discovered large
quantities of pollen and algae in sediment cores taken around
Antarctica. Fossils of plant life in Antarctica are difficult to come
by because the movement of the massive ice sheets covering the
landmass grinds and scrapes away the evidence.

"Marine sediment cores are ideal to look for clues of past vegetation,
as the fossils deposited are protected from ice sheet advances, but
these are technically very difficult to acquire in the Antarctic and
require international collaboration," said Warny.

Tipped off by the tiny pollen samples, Feakins opted to look at the
remnants of leaf wax taken from sediment cores for clues. Leaf wax
acts as a record of climate change by documenting the hydrogen
isotope ratios of the water the plant took up while it was alive.

"Ice cores can only go back about one million years," Feakins said.
"Sediment cores allow us to go into 'deep time.'"

Based upon a model originally developed to analyze hydrogen isotope
ratios in atmospheric water vapor data from NASA's Aura spacecraft,
co-author and JPL scientist Jung-Eun Lee created experiments to find
out just how much warmer and wetter climate may have been.

"When the planet heats up, the biggest changes are seen toward the
poles," Lee said. "The southward movement of rain bands associated
with a warmer climate in the high-latitude southern hemisphere made
the margins of Antarctica less like a polar desert, and more like
present-day Iceland."

The peak of this Antarctic greening occurred during the middle Miocene
period, between 16.4 and 15.7 million years ago. This was well after
the age of the dinosaurs, which became extinct 64 million years ago.
During the Miocene epoch, mostly modern-looking animals roamed Earth,
such as three-toed horses, deer, camel and various species of apes.
Modern humans did not appear until 200,000 years ago.

Warm conditions during the middle Miocene are thought to be associated
with carbon dioxide levels of around 400 to 600 parts per million
(ppm). In 2012, carbon dioxide levels have climbed to 393 ppm, the
highest they've been in the past several million years. At the
current rate of increase, atmospheric carbon dioxide levels are on
track to reach middle Miocene levels by the end of this century.

High carbon dioxide levels during the middle Miocene epoch have been
documented in other studies through multiple lines of evidence,
including the number of microscopic pores on the surface of plant
leaves and geochemical evidence from soils and marine organisms.
While none of these 'proxies' is as reliable as the bubbles of gas
trapped in ice cores, they are the best evidence available this far
back in time. While scientists do not yet know precisely why carbon
dioxide was at these levels during the middle Miocene, high carbon
dioxide, together with the global warmth documented from many parts
of the world and now also from the Antarctic region, appear to
coincide during this period in Earth's history.