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Showing posts with label the planet. Show all posts
Showing posts with label the planet. Show all posts

Toowoomba Australia Flood

Written By admin on Friday, January 6, 2012 | 6:42 AM




Please pray for them. There are many people who are suffering through this.
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Scientists set to find out is there life on mars

Written By esperanza on Saturday, November 26, 2011 | 5:51 PM

Scientists have been trying to find signs of life on the planet for decades and while some signs have been quite encouraging, they have not been able to find a definitive answer to the question.

This time, yet again, NASA has opened up the chapter in search for extraterrestrial life on Mars. "I'd be surprised if we landed on the surface (of Mars) and didn't find something that looked like it could have been a formerly habitable environment," said California Institute of Technology planetary scientist John Grotzinger, lead researcher for NASA's Mars Science Laboratory.

In the past, several missions have been launched to find life on Mars. A successful mission called the Viking program touched down on Mars in 1976 and found evidence of biological activity. However, those results couldn't be relied upon due to their contested results.

This new mission by NASA is termed Curiosity. It is not going to be a life-detection mission like its predecessors, rather, it is intended to chemically analyze the landing site known as Gale Crater for habitats that could have supported life.

Curiosity is going to be the fourth rover, the previous ones being Pathfinder, Spirit and Opportunity - which all probed for life and even signs of water on Mars. The findings from these previous missions provided overwhelming evidence that Mars was once a warmer and wetter place. These signs show that Mars once sported an ocean, rivers and other water bodies on its surface. The sign of water in turn points towards the sign of life on the planet.

"One of the ingredients of life is water. We're now looking to see if we can find other conditions that are necessary for life by defining habitability or what does it take in the environment to support life," said Mary Voytek, director of NASA's astrobiology program.

Curiosity will reach its destination in August, 2012.
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Bali Was Rocked By Earthquake

Written By esperanza on Thursday, October 13, 2011 | 8:34 AM

Bali was rocked by earthquake

Bali was rocked by an earthquake 6.8 on the Richter scale, According to the report, the earthquake made ​​people panic because the tremor was very strong. According to the Meteorology and Geophysics, Bali residents felt the quake was not large enough caused potential tsunami, while the epicenter was 143 km southwest of Nusa Dua, Bali.
The depth of the earthquake is mentioned 10 kilometers, while the earthquake occurred at 10:16 pm and is felt by not only Bali, but also a number of areas in East Java and West Nusa Tenggara.

Till today there are more 10  number of East Java regions involved in the Bali vibrated following the earthquake which magnitude 6.8 SR. the earthquake shakes also created panic in Yogyakarta .

Denpasar city and surrounding residents scrambled to leave the workplace and their homes during an earthquake measuring 6.8 on the Richter scale, Some schools and office buildings in the area and Jalan Gatot Subroto Nitipraja also suffered cracks, as well as in the office of the Bureau of Housing ANTARA Bali.



Strength of the quake was also felt by civil servants in the Bali provincial government offices in the area of ​​Renon, Denpasar. Thousands of civil servants ran out to save themselves when disaster strikes. Some parts of the walls and roof of the Bali provincial government offices were also damaged by the shaking of the earth.

From Bangli and Gianyar regency also reported that local people panicked when it happened. Community activities left to save themselves.
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A Slight Danger Of World War III.

Written By esperanza on Tuesday, October 11, 2011 | 7:09 PM

After the recent row between Pakistan and USA,Palestian not accepting the peace map given bu USA,Iran's strong action against USA and israel and above all China's ultimatam to USA saying ''Don't mess with Pakistan,if US mess with Paksitan then USA would be messing with China.US should accepth the role of Pakistan in the war against terrorism.China will not compromise on it's integrity and would force USA to respect the integrity of Pakistan'' have started a debate that there is a slight danger of World War III.

Talk on this topic is particularly in US and middle east.

India is also blaming Pakistan and China that China have formed it's base in Pakistan to attack on India while on the other hand China is rejecting this.

US war on iraq and Afghanistan also gives rise to many questions to answer that whether they were started to draw the world into third world war but that doesn't make much sense.

Israel poor behaviour with Palestian is very critical in this aspect because the muslims of the whole world target israel for their acts and blames US for giving their full support to israel.

However there is not a hudge worry of World War III as evey nation know this would be deadly and no one would be able to get benefit.

With the spread nuclear power this war is not likely to happen ever however some journalists say that if there could be any it would be carried out as folows

China,Russia,Korea,Pakistan vs USA,UK,Israel,India.

But for me world would never witness World War III and that is good for mankind
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You Thought NASCAR Was Fast ...? This Thing is 100 times Faster

Written By admin on Tuesday, September 20, 2011 | 4:54 PM

How fast can a NASCAR car really go?

Today, the fastest they can go is 202 mph. Currently with the restrictor plate carbs, they can go about 190, at tracks like Talladega and Daytona. Which they are tracks where you run wide open all the way around and is too fast for safety. Other tracks such as California (Auto Club Speedway) and Atlanta Motor Speedway they run about 200-205 mph.

A Nascar car can usually get up to about 200 miles per hour on a large track. However though, there is a thing called a restrictor plate that makes a Nascar car slow down. They use restrictor plates strictly as a safety matter so the car does not get thrown into the air because of all the air.

Well now what do you thing about Lightning....?

It is an atmospheric electrostatic discharge "spark" accompanied by thunder, which typically occurs during thunderstorms. From this discharge of atmospheric electricity, a leader of a bolt of lightning can travel at speeds of 140,000 miles per hour, and can reach temperatures approaching 54,000 Fahrenheit, hot enough to fuse silica sand into glass channels.

So what can you learn from a lightning ?
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Looks for Possible Moon Resources

Written By Admin on Wednesday, January 5, 2011 | 3:03 AM

NASA is using the unique capabilities of the Hubble Space Telescope for a new class of scientific observations of the Earth's moon.

Hubble's resolution and sensitivity to ultraviolet light have allowed the telescope to search for important oxygen-bearing minerals on the moon. Since the moon does not have a breathable atmosphere, minerals, such as ilmenite (titanium and iron oxide), may be critical for a sustained human lunar presence. Ilmenite is a potential source of oxygen for breathing or to power rockets.

The new Hubble observations are the first high-resolution, ultraviolet images ever acquired of the moon. The images provide scientists with a new tool to study mineral variations within the lunar crust. As NASA plans future expeditions to the moon, such data, in combination with other measurements, will help ensure the most valuable sites are targeted for robotic and human missions.

"These observations of the moon have been a challenging and highly successful technological achievement for NASA and the Hubble team, since the telescope was not originally designed for lunar observations,” said Jennifer Wiseman, program scientist for the Hubble at NASA Headquarters. “The images will inform both scientific studies of lunar geology and future decisions on further lunar exploration," she said.

Hubble's Advanced Camera for Surveys snapped ultraviolet and visible light images of known geologically diverse areas on the side of the moon nearest Earth. These included the Aristarchus impact crater and the adjacent Schroter's Valley. Hubble also photographed the Apollo 15 and 17 landing sites, where astronauts collected rock and soil samples in 1971 and 1972.

Scientists are comparing the properties of the rock and soil samples from the Apollo sites with the new Hubble images, and the Aristarchus region, which neither humans nor robotic spacecraft have visited. The Hubble observations of Aristarchus crater and Schroter's Valley will help refine researchers' understanding of the diverse, scientifically interesting materials in the region and to unravel their full resource potential.

"Our initial findings support the potential existence of some unique varieties of oxygen-rich glassy soils in both the Aristarchus and Apollo 17 regions. They could be well-suited for visits by robots and human explorers in efforts to learn how to live off the land on the moon," said Jim Garvin, chief scientist at NASA's Goddard Space Flight Center, Greenbelt, Md. Garvin is principal investigator for the project.

"While it will require many months before fully quantitative results can be developed, we already have evidence that these new observations will improve the precision by which we can understand materials such as ilmenite to help better inform exploration decisions," Garvin said.

The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency. The Space Telescope Science Institute in Baltimore conducts Hubble science operations. It is operated for NASA by the Association of Universities for Research in Astronomy, Inc., Washington, under contract with Goddard. 

For information and images from this project on the Web,
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What's Up With the Planets?

Written By Admin on Tuesday, January 4, 2011 | 9:28 AM

When kids head back to school this fall, they might have some brand new planets to memorize. ?

The International Astronomical Union, currently meeting in Prague, is expected to vote on the definition of a planet.? The organization, which has named planets and moons since it was founded in 1919, is debating a plan to establish that our solar system has 12 planets. 

Our Solar System, Solar System


The designated dozen would include eight of the traditional nine -- Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune -- plus Ceres, the largest known asteroid.? Pluto would still be a planet, but in a category to be called "plutons."? It would be joined in that category by two other planetary newcomers: Charon, formerly known as Pluto's moon, and the recently-discovered 2003 UB313. The International Astronomical Union says a dozen additional objects are under consideration for planethood, and even more may be added later on.

Since most of us grew up memorizing nine planets, this news of a shakeup in the solar system might be startling.? In reality, a controversy has been brewing for years about whether Pluto is truly a planet or simply an icy remnant of the planet-formation process orbiting in the far reaches of our solar system.? A new twist was added to the controversy in the summer of 2005, when Caltech astronomer Dr. Mike Brown and his colleagues announced they had found a "tenth planet," an object larger and more distant than Pluto.? This object, temporarily dubbed 2003 UB313, is one of the new additions to the solar system under the International Astronomical Union proposal.? ?

In essence, the organization is proposing that two conditions must be met for an object to be called a planet.? It must orbit around a star, but must not be a star itself.? And the object must be massive enough for its own gravity to pull it into a nearly spherical shape. ?

The definition of a planet will have implications reaching beyond our own solar system.? In the past decade, astronomers have used new technologies to discover planets around other stars besides our sun.? These so-called "extrasolar planets" have raised great interest among scientists, who hope to determine whether any of these planets might be habitable. ?

While scientists in Prague and throughout the world debate the question, "What is a planet," there's one thing most everyone can agree on:? our view of the solar system will never be the same. ?
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Reveals First Carbon-Rich Planet

Written By Admin on Sunday, December 12, 2010 | 12:49 AM

PASADENA, Calif. -- Astronomers have discovered that a huge, searing-hot planet orbiting another star is loaded with an unusual amount of carbon. The planet, a gas giant named WASP-12b, is the first carbon-rich world ever observed. The discovery was made using NASA's Spitzer Space Telescope, along with previously published ground-based observations.

"This planet reveals the astounding diversity of worlds out there," said Nikku Madhusudhan of the Massachusetts Institute of Technology, Cambridge,

It's possible that WASP-12b might harbor graphite, diamond, or even a more exotic form of carbon in its interior, beneath its gaseous layers. Astronomers don't currently have the technology to observe the cores of exoplanets, or planets orbiting stars beyond our sun, but their theories hint at these intriguing possibilities.

The research also supports theories that carbon-rich rocky planets much less massive than WASP-12b could exist around other stars. Our Earth has rocks like quartz and feldspar, which are made of silicon and oxygen plus other elements. A carbon-rich rocky planet could be a very different place.

"A carbon-dominated terrestrial world could have lots of pure carbon rocks, like diamond or graphite, as well as carbon compounds like tar," said Joseph Harrington of the University of Central Florida, in Orlando, who is the principal investigator of the research.

Carbon is a common component of planetary systems and a key ingredient of life on Earth. Astronomers often measure carbon-to-oxygen ratios to get an idea of a star's chemistry. Our sun has a carbon-to-oxygen ratio of about one to two, which means it has about half as much carbon as oxygen. None of the planets in our solar system is known to have more carbon than oxygen, or a ratio of one or greater. However, this ratio is unknown for Jupiter, Saturn, Uranus, and Neptune. Unlike WASP-12b, these planets harbor water -- the main oxygen carrier -- deep inside their atmospheres, making it hard to detect.

WASP-12b is the first planet ever to have its carbon-to-oxygen ratio measured at greater than one (the actual ratio is most likely between one and two). This means the planet has excess carbon, some of which is in the form of atmospheric methane.

"When the relative amount of carbon gets that high, it's as though you flip a switch, and everything changes," said Marc Kuchner, an astronomer at NASA Goddard Space Flight Center, Greenbelt, Md., who helped develop the theory of carbon-rich rocky planets but is not associated with the study. "If something like this had happened on Earth, your expensive engagement ring would be made of glass, which would be rare, and the mountains would all be made of diamonds."

Madhusudhan, Harrington and colleagues used Spitzer to observe WASP-12b as it slipped behind its star, in a technique known as secondary eclipse, which was pioneered for exoplanets by Spitzer. These data were combined with previously published observations taken from the ground with the Canada-France-Hawaii Telescope at Mauna Kea, Hawaii. Madhusudhan used the data to conduct a detailed atmospheric analysis, revealing chemicals such as methane and carbon monoxide in the planet's atmosphere.

WASP-12b derives its name from the consortium that found it, the Wide Angle Search for Planets. It is 1.4 times as massive as Jupiter and located roughly 1,200 light-years away from Earth. This blistering world whips around its star in a little over a day, with one side always facing the star. It is so close to its star that the star's gravity stretches the planet into an egg-like shape. What's more, the star's gravity is siphoning mass off the planet into a thin disk that orbits around with it.

The Spitzer data also reveal more information about WASP-12b's temperature. The world was already known to be one of the hottest exoplanets found so far; the new observations indicate that the side that faces the star is 2,600 Kelvin, or 4,200 degrees Fahrenheit. That's more than hot enough to melt steel.
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Theorize Final Growth Spurt for Planets

Written By Admin on Saturday, December 11, 2010 | 3:50 PM

A team of NASA-funded researchers has unveiled a new theory that contends planets gained the final portions of their mass from a limited number of large comet or asteroid impacts more than 4.5 billion years ago. These impacts added less than one percent of the planets' mass.

Scientists hope the research not only will provide a better historical picture of the birth and evolution of Earth, the moon and Mars, but also allow researchers to better explore what happened in our solar system's beginning and middle stages of planet formation.

“No one has a model of precisely what happened at the end of planet formation—we’ve had a broad idea—but variables such as impactor size, the approximate timing of the impacts, and how they affect the evolution of the planets are unknown,” said William Bottke, principal investigator from the Southwest Research Institute (SWRI) in Boulder, Colo. “This research hopefully provides better insights into the early stages of planet formation.”

The team used numerical models, lunar samples returned by Apollo astronauts and meteorites believed to be from Mars to develop its findings. The scientists examined the abundances of elements such as gold and platinum in the mantles, or layers beneath the crust, of Earth, the moon and Mars. Consistent with previous studies, they concluded the elements were added by a process called late accretion during a planet's final growth spurt.

"These impactors probably represent the largest objects to hit Earth since the giant impact that formed our moon," Bottke said. “They also may be responsible for the accessible abundance of gold, platinum, palladium, and other important metals used by our society today in items ranging from jewelry to our cars’ catalytic convertors.”

The results indicate the largest Earth impactor was between 1,500 - 2,000 miles in diameter, roughly the size of Pluto. Because it is smaller than Earth, the moon avoided such enormous projectiles and was only hit by impactors 150 - 200 miles wide. These impacts may have played important roles in the evolution of both worlds. For example, the projectiles that struck Earth may have modified the orientation of its spin axis by 10 degrees, while those that hit the moon may have delivered water to its mantle.

"Keep in mind that while the idea the Earth-moon system owes its existence to a single, random event was initially viewed as radical, it is now believed that large impacts were commonplace during the final stages of planet formation,’ Bottke said. “Our new results provide additional evidence that the effects of large impacts did not end with the moon-forming event."

The paper, "Stochastic Late Accretion to the Earth, Moon, and Mars," was published in the Dec. 9 issue of Science. It was written by Bottke and David Nesvorny of SWRI; Richard J. Walker of the University of Maryland; James Day of the University of Maryland and Scripps Institution of Oceanography, University of California, San Diego; and Linda Elkins-Tanton of the Massachusetts Institute of Technology. The research is funded by the NASA Lunar Science Institute (NLSI) at the agency's Ames Research Center in Moffett Field, Calif.

The NLSI is a virtual organization that enables collaborative, interdisciplinary research in support of NASA lunar science programs. The institute uses technology to bring scientists together around the world and comprises competitively selected U.S. teams and several international partners. NASA's Science Mission Directorate and the Exploration Systems Mission Directorate at the agency's Headquarters in Washington, funds the institute, which is managed by a central office at Ames.

For more information on NLSI, visit: http://www.nasa.gov/


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M81 Galaxy is Pretty in Pink

Written By Admin on Friday, December 10, 2010 | 2:24 PM


The perfectly picturesque spiral galaxy known as Messier 81, or M81, looks sharp in this new composite from NASA's Spitzer and Hubble space telescopes and NASA's Galaxy Evolution Explorer. M81 is a "grand design" spiral galaxy, which means its elegant arms curl all the way down into its center. It is located about 12 million light-years away in the Ursa Major constellation and is one of the brightest galaxies that can be seen from Earth through telescopes.

The colors in this picture represent a trio of light wavelengths: blue is ultraviolet light captured by the Galaxy Evolution Explorer; yellowish white is visible light seen by Hubble; and red is infrared light detected by Spitzer. The blue areas show the hottest, youngest stars, while the reddish-pink denotes lanes of dust that line the spiral arms. The orange center is made up of older stars.


Image credit: NASA/JPL
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Unlocking The Secret of Saturn's

Written By Admin on Saturday, December 4, 2010 | 11:15 AM

Cassini spacecraft successfully dipped near the surface of Saturn's moon Enceladus on Nov. 30. Though Cassini's closest approach took it to within about 48 kilometers (30 miles) of the moon's northern hemisphere, the spacecraft also captured shadowy images of the tortured south polar terrain and the brilliant jets that spray out from it. 

Many of the raw images feature darkened terrain because winter has descended upon the southern hemisphere of Enceladus. But sunlight behind the moon backlights the jets of water vapor and icy particles. In some images, the jets line up in rows, forming curtains of spray. 

The new raw images can be seen at http://saturn.jpl.nasa.gov/photos/raw/ .
The Enceladus flyby was the 12th of Cassini's mission, with the spacecraft swooping down around 61 degrees north latitude. This encounter and its twin three weeks later at the same altitude and latitude, are the closest Cassini will come to the northern hemisphere surface of Enceladus during the extended Solstice mission. (Cassini's closest-ever approach to Enceladus occurred in October 2008, when the spacecraft dipped to an altitude of 25 kilometers, or 16 miles.) 

Among the observations Cassini made during this Enceladus flyby, the radio science subsystem collected gravity measurements to understand the moon's interior structure, and the fields and particles instruments sampled the charged particle environment around the moon. 

About two days before the Enceladus flyby, Cassini also passed the sponge-like moon Hyperion, beaming back intriguing images of the craters on its surface. The flyby, at 72,000 kilometers (45,000 miles) in altitude, was one of the closest approaches to Hyperion that Cassini has made. 

Scientists are still working to analyze the data and images collected during the flybys.
The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory manages the project for NASA's Science Mission Directorate in Washington. The Cassini orbiter was designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo. 

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Research Discovers Life Built With Toxic Chemical

Written By Admin on Thursday, December 2, 2010 | 6:21 PM

NASA-funded astrobiology research has changed the fundamental knowledge about what comprises all known life on Earth.

Researchers conducting tests in the harsh environment of Mono Lake in California have discovered the first known microorganism on Earth able to thrive and reproduce using the toxic chemical arsenic. The microorganism substitutes arsenic for phosphorus in its cell components.

"The definition of life has just expanded," said Ed Weiler, NASA's associate administrator for the Science Mission Directorate at the agency's Headquarters in Washington. "As we pursue our efforts to seek signs of life in the solar system, we have to think more broadly, more diversely and consider life as we do not know it."

This finding of an alternative biochemistry makeup will alter biology textbooks and expand the scope of the search for life beyond Earth. The research is published in this week's edition of Science Express.

Carbon, hydrogen, nitrogen, oxygen, phosphorus and sulfur are the six basic building blocks of all known forms of life on Earth. Phosphorus is part of the chemical backbone of DNA and RNA, the structures that carry genetic instructions for life, and is considered an essential element for all living cells.


Phosphorus is a central component of the energy-carrying molecule in all cells (adenosine triphosphate) and also the phospholipids that form all cell membranes. Arsenic, which is chemically similar to phosphorus, is poisonous for most life on Earth. Arsenic disrupts metabolic pathways because chemically it behaves similarly to phosphate.

"We know that some microbes can breathe arsenic, but what we've found is a microbe doing something new -- building parts of itself out of arsenic," said Felisa Wolfe-Simon, a NASA Astrobiology Research Fellow in residence at the U.S. Geological Survey in Menlo Park, Calif., and the research team's lead scientist. "If something here on Earth can do something so unexpected, what else can life do that we haven't seen yet?"

The newly discovered microbe, strain GFAJ-1, is a member of a common group of bacteria, the Gammaproteobacteria. In the laboratory, the researchers successfully grew microbes from the lake on a diet that was very lean on phosphorus, but included generous helpings of arsenic. When researchers removed the phosphorus and replaced it with arsenic the microbes continued to grow. Subsequent analyses indicated that the arsenic was being used to produce the building blocks of new GFAJ-1 cells.

The key issue the researchers investigated was when the microbe was grown on arsenic did the arsenic actually became incorporated into the organisms' vital biochemical machinery, such as DNA, proteins and the cell membranes. A variety of sophisticated laboratory techniques was used to determine where the arsenic was incorporated.

The team chose to explore Mono Lake because of its unusual chemistry, especially its high salinity, high alkalinity, and high levels of arsenic. This chemistry is in part a result of Mono Lake's isolation from its sources of fresh water for 50 years.

The results of this study will inform ongoing research in many areas, including the study of Earth's evolution, organic chemistry, biogeochemical cycles, disease mitigation and Earth system research. These findings also will open up new frontiers in microbiology and other areas of research.

"The idea of alternative biochemistries for life is common in science fiction," said Carl Pilcher, director of the NASA Astrobiology Institute at the agency's Ames Research Center in Moffett Field, Calif. "Until now a life form using arsenic as a building block was only theoretical, but now we know such life exists in Mono Lake."

The research team included scientists from the U.S. Geological Survey, Arizona State University in Tempe, Ariz., Lawrence Livermore National Laboratory in Livermore, Calif., Duquesne University in Pittsburgh, Penn., and the Stanford Synchroton Radiation Lightsource in Menlo Park, Calif.

NASA's Astrobiology Program in Washington contributed funding for the research through its Exobiology and Evolutionary Biology program and the NASA Astrobiology Institute. NASA's Astrobiology Program supports research into the origin, evolution, distribution, and future of life on Earth.
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Cosmic Snow Storm During Comet Encounter

Written By Admin on Thursday, November 18, 2010 | 11:06 AM

PASADENA, Calif. -- The EPOXI mission's recent encounter with comet Hartley 2 provided the first images clear enough for scientists to link jets of dust and gas with specific surface features. NASA and other scientists have begun to analyze the images.

The EPOXI mission spacecraft revealed a cometary snow storm created by carbon dioxide jets spewing out tons of golf-ball to basketball-sized fluffy ice particles from the peanut-shaped comet's rocky ends. At the same time, a different process was causing water vapor to escape from the comet's smooth mid-section. This information sheds new light on the nature of comets and even planets.

Scientists compared the new data to data from a comet the spacecraft previously visited that was somewhat different from Hartley 2. In 2005, the spacecraft successfully released an impactor into the path of comet Tempel 1, while observing it during a flyby.

"This is the first time we've ever seen individual chunks of ice in the cloud around a comet or jets definitively powered by carbon dioxide gas," said Michael A'Hearn, principal investigator for the spacecraft at the University of Maryland. "We looked for, but didn't see, such ice particles around comet Tempel 1."

The new findings show Hartley 2 acts differently than Tempel 1 or the three other comets with nuclei imaged by spacecraft. Carbon dioxide appears to be a key to understanding Hartley 2 and explains why the smooth and rough areas scientists saw respond differently to solar heating, and have different mechanisms by which water escapes from the comet's interior.

"When we first saw all the specks surrounding the nucleus, our mouths dropped," said Pete Schultz, EPOXI mission co-investigator at Brown University. "Stereo images reveal there are snowballs in front and behind the nucleus, making it look like a scene in one of those crystal snow globes."

Data show the smooth area of comet Hartley 2 looks and behaves like most of the surface of comet Tempel 1, with water evaporating below the surface and percolating out through the dust. However, the rough areas of Hartley 2, with carbon dioxide jets spraying out ice particles, are very different.

"The carbon dioxide jets blast out water ice from specific locations in the rough areas resulting in a cloud of ice and snow," said Jessica Sunshine, EPOXI deputy principal investigator at the University of Maryland. "Underneath the smooth middle area, water ice turns into water vapor that flows through the porous material, with the result that close to the comet in this area we see a lot of water vapor."
Engineers at NASA's Jet Propulsion Laboratory in Pasadena, Calif., have been looking for signs ice particles peppered the spacecraft. So far they found nine times when particles, estimated to weigh slightly less than the mass of a snowflake, might have hit the spacecraft but did not damage it.

"The EPOXI mission spacecraft sailed through Hartley 2's ice flurries in fine working order and continues to take images as planned of this amazing comet," said Tim Larson, EPOXI project manager at JPL.
Scientists will need more detailed analysis to determine how long this snow storm has been active, and whether the differences in activity between the middle and ends of the comet are the result of how it formed some 4.5 billion years ago or are because of more recent evolutionary effects.

EPOXI is a combination of the names for the mission's two components: the Extrasolar Planet Observations and Characterization (EPOCh), and the flyby of comet Hartley 2, called the Deep Impact Extended Investigation (DIXI).

JPL manages the EPOXI mission for the Science Mission Directorate at NASA Headquarters in Washington. The spacecraft was built for NASA by Ball Aerospace & Technologies Corp., in Boulder, Colo.
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How Sun Steals Martian Atmosphere II

Written By Admin on Tuesday, November 16, 2010 | 3:39 PM

Although the solar wind might be the primary method, like an accomplished burglar, the sun’s emissions can steal the martian atmosphere in many ways. However, most follow a basic M.O., the solar wind and the sun’s ultraviolet radiation turns the uncharged atoms and molecules in Mars' upper atmosphere into electrically charged particles (ions). Once electrically charged, electric fields generated by the solar wind carry them away. The electric field is produced by the motion of the charged, electrically conducting solar wind across the interplanetary, solar-produced magnetic field, the same dynamic generators use to produce electrical power.

An exception to this dominant M.O. are atoms and molecules that have enough speed from solar heating to simply run away, they remain electrically neutral, but become hot enough to escape Mars' gravity. Also, solar extreme ultraviolet radiation can be absorbed by molecules, breaking them into their constituent atoms and giving each atom enough energy that it might be able to escape from the planet.

There are other suspects. Mars has more than 20 ancient craters larger than 600 miles across, scars from giant impacts by asteroids the size of small moons. This bombardment could have blasted large amounts of the martian atmosphere into space. However, huge martian volcanoes that erupted after the impacts, like Olympus Mons, could have replenished the martian atmosphere by venting massive amounts of gas from the planet's interior.

It's possible that the hijacked martian air was an organized crime, with both impacts and the solar wind contributing. Without the protection of its magnetic shield, any replacement martian atmosphere that may have issued from volcanic eruptions eventually would also have been stripped away by the solar wind.

Earlier Mars spacecraft missions have caught glimpses of the heist. For example, flows of ions from Mars' upper atmosphere have been seen by both NASA's Mars Global Surveyor and the European Space Agency's Mars Express spacecraft.

"Previous observations gave us 'proof of the crime' but only provided tantalizing hints at how the sun pulls it off — the various ways Mars can lose its atmosphere to solar activity," said Joseph Grebowsky of NASA's Goddard Space Flight Center in Greenbelt, Md. "MAVEN will examine all known ways the sun is currently swiping the Martian atmosphere, and may discover new ones as well. It will also watch how the loss changes as solar activity changes over a year. Linking different loss rates to changes in solar activity will let us go back in time to estimate how quickly solar activity eroded the Martian atmosphere as the sun evolved." Grebowsky is the Project Scientist for MAVEN.

As the martian atmosphere thinned, the planet got drier as well, because water vapor in the atmosphere was also lost to space, and because any remaining water froze out as the temperatures dropped when the atmosphere disappeared. MAVEN can discover how much water has been lost to space by measuring hydrogen isotope ratios.

Isotopes are heavier versions of an element. For example, deuterium is a heavy version of hydrogen. Normally, two atoms of hydrogen join to an oxygen atom to make a water molecule, but sometimes the heavy and rare, deuterium takes a hydrogen atom's place.

On Mars, hydrogen escapes faster because it is lighter than deuterium. Since the lighter version escapes more often, over time, the martian atmosphere has less and less hydrogen compared to the amount of deuterium remaining. The martian atmosphere therefore becomes richer and richer in deuterium.
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How Sun Steals Martian Atmosphere I

The Red Planet bleeds. Not blood, but its atmosphere, slowly trickling away to space. The culprit is our sun, which is using its own breath, the solar wind, and its radiation to rob Mars of its air. The crime may have condemned the planet's surface, once apparently promising for life, to a cold and sterile existence.

Features on Mars resembling dry riverbeds, and the discovery of minerals that form in the presence of water, indicate that Mars once had a thicker atmosphere and was warm enough for liquid water to flow on the surface. However, somehow that thick atmosphere got lost in space. It appears Mars has been cold and dry for billions of years, with an atmosphere so thin, any liquid water on the surface quickly boils away while the sun's ultraviolet radiation scours the ground.

Such harsh conditions are the end of the road for known forms of life. Although it's possible that martian life went underground, where liquid water may still exist and radiation can't reach.

The lead suspect for the theft is the sun, and its favorite M.O. may be the solar wind. All planets in our solar system are constantly blasted by the solar wind, a thin stream of electrically charged gas that continuously blows from the sun's surface into space. On Earth, our planet's global magnetic field shields our atmosphere by diverting most of the solar wind around it. The solar wind’s electrically charged particles, ions and electrons, have difficulty crossing magnetic fields.

"Mars can't protect itself from the solar wind because it no longer has a shield, the planet's global magnetic field is dead," said Bruce Jakosky of the University of Colorado, Boulder. Jakosky is the Principal Investigator for NASA's MAVEN mission, which will investigate what is responsible for the loss of the martian atmosphere.

Mars lost its global magnetic field in its youth billions of years ago. Once its planet-wide magnetic field disappeared, Mars' atmosphere was exposed to the solar wind and most of it could have been gradually stripped away. "Fossil" magnetic fields remaining in ancient surfaces and other local areas on Mars don't provide enough coverage to shield much of the atmosphere from the solar wind.
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Universe Island

'Island Universe' in the Coma Cluster
 A long-exposure Hubble Space Telescope image shows a majestic face-on spiral galaxy located deep within the Coma Cluster of galaxies, which lies 320 million light- years away in the northern constellation Coma Berenices. The galaxy, known as NGC 4911, contains rich lanes of dust and gas near its center. These are silhouetted against glowing newborn star clusters and iridescent pink clouds of hydrogen, the existence of which indicates ongoing star formation. Hubble has also captured the outer spiral arms of NGC 4911, along with thousands of other galaxies of varying sizes. The high resolution of Hubble's cameras, paired with considerably long exposures, made it possible to observe these faint details.

This natural-color Hubble image, which combines data obtained in 2006, 2007, and 2009 from the Wide Field Planetary Camera 2 and the Advanced Camera for Surveys, required 28 hours of exposure time.





Into the Night
 Researchers do not yet know what is lighting up IRAS 05437+2502, a small, faint nebula that spans only 1/18th of a full moon toward the constellation of the Taurus. Particularly enigmatic is the bright upside-down V that defines the upper edge of this floating mountain of interstellar dust.

This ghost-like nebula involves a small star-forming region filled with dark dust that was first noted in images taken by the IRAS satellite in infrared light in 1983. This recently released image from the Hubble Space Telescope shows many new details, but has not uncovered a clear cause of the bright sharp arc.

Bright Lights

Two extremely bright stars illuminate a greenish mist in this image from the Spitzer Space Telescope's "GLIMPSE360" survey. This mist is comprised of hydrogen and carbon compounds called polycyclic aromatic hydrocarbons (PAHs), which also are found here on Earth in sooty vehicle exhaust and on charred grills. In space, PAHs form in the dark clouds that give rise to stars. These molecules provide astronomers a way to visualize the peripheries of gas clouds and study their structures in great detail. They are not actually green; but are color coded in these images to allow scientists see their glow in infrared.

This image is a combination of data from Spitzer and the Two-Micron All-Sky Survey (2MASS). The Spitzer data was taken after Spitzer's liquid coolant ran dry in May 2009, marking the beginning of its "warm" mission.
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The moon was bombarded by two distinct populations of asteroids

The moon was bombarded by two distinct populations of asteroids or comets in its youth, and its surface is more complex than previously thought, according to new results from NASA's Lunar Reconnaissance Orbiter (LRO) spacecraft featured in three papers appearing in the Sept. 17 issue of Science.


Meteorite impacts can radically alter the history of a planet. The moon, Mars, and Mercury all bear scars of ancient craters hundreds or even thousands of miles across. If Earth was subjected to this assault as well -- and there's no reason to assume our planet was spared -- these enormous impacts could have disrupted the initial origin of life. Large impacts that occurred later appear to have altered life's evolution. The approximately 110-mile-diameter, partially buried crater at Chicxulub, in the Yucatan Peninsula of Mexico, is from an impact about 65 million years ago that is now widely believed to have led or contributed to the demise of the dinosaurs and many other lifeforms.

Scientists trying to reconstruct the meteorite bombardment history of Earth face difficulty because impact craters are eroded by wind and water, or destroyed by the action of plate tectonics, the gradual movement and recycling of the Earth's crust. However, a rich record of craters is preserved on the moon, because it has only an extremely thin atmosphere – a vacuum better than those typically used for experiments in laboratories on Earth. The moon’s surface has no liquid water and no plate tectonics. The only source of significant erosion is other impacts.

"The moon is thus analogous to a Rosetta stone for understanding the bombardment history of the Earth," said Head. "Like the Rosetta stone, the lunar record can be used to translate the 'hieroglyphics' of the poorly preserved impact record on Earth."

Even so, previous lunar maps had different resolutions, viewing angles, and lighting conditions, which made it hard to consistently identify and count craters. Head and his team used the LOLA instrument on board LRO to build a map that highlights lunar craters with unprecedented clarity. The instrument sends laser pulses to the lunar surface, measures the time that it takes for them to reflect back to the spacecraft, and then with a very precise knowledge of the orbit of the LRO spacecraft, scientists can convert this information to a detailed topographic map of the moon, according to Head.

Objects hitting the moon can be categorized in different “impactor populations,” where each population has its own set of characteristics. Head also used the LOLA maps to determine the time when the impactor population changed. "Using the crater counts from the different impact basins and examining the populations making up the superposed craters, we can look back in time to discover when this transition in impactor populations occurred. The LRO LOLA impact crater database shows that the transition occurred about the time of the Orientale impact basin, about 3.8 billion years ago. The implication is that this change in populations occurred around the same time as the large impact basins stopped forming, and raises the question of whether or not these factors might be related. The answers to these questions have implications for the earliest history of all the planets in the inner solar system, including Earth," says Head.

In the other two Science papers, researchers describe how data from the Diviner Lunar Radiometer Experiment instrument on LRO are showing that the geologic processes that forged the lunar surface were complex as well. The data have revealed previously unseen compositional differences in the crustal highlands, and have confirmed the presence of anomalously silica-rich material in five distinct regions.

Every mineral, and therefore every rock, absorbs and emits energy with a unique spectral signature that can be measured to reveal its identity and formation mechanisms. For the first time ever, LRO's Diviner instrument is providing scientists with global, high-resolution infrared maps of the moon, which are enabling them to make a definitive identification of silicate minerals commonly found within its crust. "Diviner is literally viewing the moon in a whole new light," says Benjamin Greenhagen of NASA’s Jet Propulsion Laboratory in Pasadena, Calif., lead author of one of the Diviner Science papers.

Lunar geology can be roughly broken down into two categories – the anorthositic highlands, rich in calcium and aluminium, and the basaltic maria, which are abundant in iron and magnesium. Both of these crustal rocks are what’s deemed by geologists as 'primitive'; that is, they are the direct result of crystallization from lunar mantle material, the partially molten layer beneath the crust.

Diviner’s observations have confirmed that most lunar terrains have spectral signatures consistent with compositions that fall into these two broad categories. However they have also revealed that the lunar highlands may be less homogenous than previously thought.

In a wide range of terrains, Diviner revealed the presence of lunar soils with compositions more sodium rich than that of the typical anorthosite crust. The widespread nature of these soils reveals that there may have been variations in the chemistry and cooling rate of the magma ocean which formed the early lunar crust, or they could be the result of secondary processing of the early lunar crust.

Most impressively, in several locations around the moon, Diviner has detected the presence of highly silicic minerals such as quartz, potassium-rich, and sodium-rich feldspar - minerals that are only ever found in association with highly evolved lithologies (rocks that have undergone extensive magmatic processing).

The detection of silicic minerals at these locations is a significant finding for scientists, as they occur in areas previously shown to exhibit anomalously high abundances of the element thorium, another proxy for highly evolved lithologies.

"The silicic features we've found on the moon are fundamentally different from the more typical basaltic mare and anorthositic highlands," says Timothy Glotch of Stony Brook University in Stony Brook, N.Y., lead author of the second Diviner Science paper. "The fact that we see this composition in multiple geologic settings suggests that there may have been multiple processes producing these rocks."

One thing not apparent in the data is evidence for pristine lunar mantle material, which previous studies have suggested may be exposed at some places on the lunar surface. Such material, rich in iron and magnesium, would be readily detected by Diviner.

However, even in the South Pole Aitken Basin (SPA), the largest, oldest, and deepest impact crater on the moon -- deep enough to have penetrated through the crust and into the mantle -- there is no evidence of mantle material.

The implications of this are as yet unknown. Perhaps there are no such exposures of mantle material, or maybe they occur in areas too small for Diviner to detect.

However it's likely that if the impact that formed this crater did excavate any mantle material, it has since been mixed with crustal material from later impacts inside and outside SPA. "The new Diviner data will help in selecting the appropriate landing sites for potential future robotic missions to return samples from SPA. We want to use these samples to date the SPA-forming impact and potentially study the lunar mantle, so it's important to use Diviner data to identify areas with minimal mixing," says Greenhagen.

The research was funded by NASA's Exploration Systems Missions Directorate at NASA Headquarters in Washington. LRO was built and is managed by NASA's Goddard Space Flight Center in Greenbelt, Md. LOLA was built by NASA Goddard. David E. Smith from the Massachusetts Institute of Technology and NASA Goddard is the LOLA principal investigator. The Diviner instrument was built and is managed by NASA’s Jet Propulsion Laboratory in Pasadena, Calif. UCLA is the home institution of Diviner’s principal investigator, David Paige.
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Virtual Exploration of Mars

Besides providing a rich, immersive 3D view of Mars that will aid public understanding of Mars science, the new mode, Google Mars 3D, also gives researchers a platform for sharing data similar to what Google Earth provides for Earth scientists.

The mode enables users to fly virtually through enormous canyons and scale huge mountains on Mars that are much larger than any found on Earth. Users also can explore the Red Planet through the eyes of the Mars rovers and other Mars missions, providing a unique perspective of the entire planet.

Users can see some of the latest satellite imagery from NASA's Mars Reconnaissance Orbiter and other probes orbiting the Red Planet. Viewers can learn about new discoveries and explore indexes of available Mars imagery. The new Mars mode also allows users to add their own 3D content to the Mars map to share with the world.

Today's announcement is the latest benefit from a Space Act Agreement NASA's Ames Research Center in Moffett Field, Calif., signed with Google in November 2006. Under its terms, NASA and Google agreed to collaborate to make NASA's data sets available to the world.

NASA Ames, along with its partners at Google, Carnegie Mellon University, SETI, and other institutions, helped produce the data to make this possible.

Google's innovative search technologies connect millions of people around the world with information every day. Google is headquartered close to Ames in Silicon Valley with offices throughout the Americas, Europe and Asia.

For more information about NASA and agency programs, visit:



For more information about Google, visit:


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Cassini's CIRS Reveals Saturn Is on a Cosmic Dimmer Switch

Written By Admin on Saturday, November 13, 2010 | 4:37 AM

Like a cosmic light bulb on a dimmer switch, Saturn emitted gradually less energy each year from 2005 to 2009, according to observations by NASA’s Cassini spacecraft. But unlike an ordinary bulb, Saturn's southern hemisphere consistently emitted more energy than its northern one. On top of that, energy levels changed with the seasons and differed from the last time a spacecraft visited in the early 1980s. These never-before-seen trends came from an analysis of comprehensive data from the Composite Infrared Spectrometer (CIRS), an instrument built by NASA's Goddard Space Flight Center in Greenbelt, Md., as well as a comparison with earlier data from NASA's Voyager spacecraft. When combined with information about the energy coming to Saturn from the sun, the results could help scientists understand the nature of Saturn's internal heat source.

The findings were reported November 9 in the Journal of Geophysical Research-Planets by Liming Li of Cornell University in Ithaca, N.Y. (now at the University of Houston), and colleagues from several institutions, including Goddard and NASA's Jet Propulsion Laboratory in Pasadena Calif., which manages the Cassini mission. "The Cassini CIRS data are very valuable because they give us a nearly complete picture of Saturn," says Li. "This is the only single data set that provides so much information about this planet, and it's the first time that anybody has been able to study the power emitted by one of the giant planets in such detail."

The planets in our solar system lose energy in the form of heat radiation in wavelengths that are invisible to the human eye. The CIRS instrument picks up wavelengths in the thermal infrared region, which is beyond red light, where the wavelengths correspond to heat emission.

"In planetary science, we tend to think of planets as losing power evenly in all directions and at a steady rate," says Li. "Now we know Saturn is not doing that." (Power is the amount of energy emitted per unit of time.)

Instead, Saturn's flow of outgoing energy was lopsided, with its southern hemisphere giving off about one-sixth more energy than the northern one, Li explains. This effect matched Saturn's seasons: during those five Earth years, it was summer in the southern hemisphere and winter in the northern one. (A season on Saturn lasts about seven Earth years.) Like Earth, Saturn has these seasons because the planet is tilted on its axis, so one hemisphere receives more energy from the sun and experiences summer while the other receives less energy and is shrouded in winter. Saturn’s equinox, when the sun was directly over the equator, occurred in August 2009.

In the study, Saturn's seasons looked Earth-like in another way: in each hemisphere, its effective temperature, which characterizes its thermal emission to space, started to warm up or cool down as a change of season approached. Because Saturn's weather is variable and the atmosphere tends to retain heat (called heat inertia), the temperature changes in complicated ways throughout the atmosphere. "The effective temperature provides us a simple way to track the response of Saturn's atmosphere, as a system, to the seasonal changes," says Li. Cassini's observations in the northern hemisphere revealed that the effective temperature gradually dropped from 2005 to 2008 and then started to warm up again by 2009. In Saturn's southern hemisphere, the effective temperature cooled from 2005 to 2009, as the equinox started to approach.

The emitted energy for each hemisphere rose and fell along with the effective temperature. Even so, during this five-year period, the planet as a whole seemed to be slowly cooling down and emitting less energy.

To find out if similar changes were happening one Saturn year ago, the researchers looked at data collected by Voyager in 1980 and 1981. Like Cassini CIRS, Voyager recorded fluctuations in the energy emitted by the planet and in the effective temperature. But Voyager did not see the imbalance between the southern and northern hemispheres; instead, the two regions were much more consistent with each other.

Why wouldn't Voyager have seen the same summer-versus-winter difference between the two hemispheres? The amount of energy coming from the sun (called solar radiance), which drives weather and atmospheric temperatures, could have fluctuated from one Saturn year to the next. The patterns in Saturn's cloud cover and haze could have, too.

"It's reasonable to think that the changes in Saturn's emitted power are related to cloud cover," says Amy Simon-Miller, who heads the Planetary Systems Laboratory at Goddard and is a co-author on the paper. "As the amount of cloud cover changes, the amount of radiation escaping into space also changes. This might vary during a single season and from one Saturn year to another. But to fully understand what is happening on Saturn, we will need the other half of the picture: the amount of power being absorbed by the planet."

Li is finishing an analysis of the solar energy that came to Saturn, based on data sets collected by two other Cassini instruments, the imaging science subsystem and the visual and infrared mapping spectrometer. He agrees that this information is crucial because Saturn, like its fellow giant planets Jupiter and Neptune, is thought to have its own source of internal energy. (The fourth giant planet, Uranus, does not seem to have an internal source.) By studying the changes in Saturn's outgoing energy along with the changes in incoming solar energy, scientists can learn about the nature of the planet's internal energy source and whether it, too, changes over time.

"The differences between Saturn's northern and southern hemisphere and that fact that Voyager did not see the same asymmetry raise a very important question: does Saturn's internal heat vary with time?" says Li. "The answer will significantly deepen our understanding of the weather, internal structure and evolution of Saturn and the other giant planets."

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency, and the Italian Space Agency. NASA's Jet Propulsion Laboratory, Pasadena, Calif., a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The composite infrared spectrometer team is based at NASA Goddard, where the instrument was built.
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Sensor on Mars Rover to Measure Radiation Environment

Written By Admin on Friday, November 12, 2010 | 5:32 AM

About eight months before the NASA rover Curiosity touches down on Mars in August 2012, the mission's science measurements will begin much closer to Earth.
The Mars Science Laboratory mission's Radiation Assessment Detector, or RAD, will monitor naturally occurring radiation that can be unhealthful if absorbed by living organisms. It will do so on the surface of Mars, where there has never before been such an instrument, as well as during the trip between Mars and Earth.

RAD's measurements on Mars will help fulfill the mission's key goals of assessing whether Curiosity's landing region on Mars has had conditions favorable for life and for preserving evidence about life. This instrument also will do an additional job. Unlike any of the nine others in this robotic mission's science payload, RAD has a special task and funding from the part of NASA that is planning human exploration beyond Earth orbit. It will aid design of human missions by reducing uncertainty about how much shielding from radiation future astronauts will need. The measurements between Earth and Mars, as well as the measurements on Mars, will serve that purpose.

"No one has fully characterized the radiation environment on the surface of another planet. If we want to send humans there, we need to do that," said RAD Principal Investigator Don Hassler of the Boulder, Colo., branch of the Southwest Research Institute.
Whether the first destination for human exploration beyond the moon is an asteroid or Mars, the travelers will need protection from the radiation environment in interplanetary space. Hassler said, "The measurements we get during the cruise from Earth to Mars will help map the distribution of radiation throughout the solar system and be useful in mission design for wherever we send astronauts."

RAD will monitor high-energy atomic and subatomic particles coming from the sun, from distant supernovas and from other sources. These particles constitute the radiation that could be harmful to any microbes near the surface of Mars or to astronauts on a Mars mission. Galactic cosmic rays, coming from supernova explosions and other events extremely far from our own solar system, are a variable shower of charged particles. In addition, the sun itself spews electrons, protons and heavier ions in "solar particle events" fed by solar flares and ejections of matter from the sun's corona. Astronauts might need to move into havens with extra shielding on an interplanetary spacecraft or on Mars during solar particle events.

Earth's magnetic field and atmosphere provide effective shielding for our home planet against the possible deadly effects of galactic cosmic rays and solar particle events. Mars, though, lacks a global magnetic field and has only about one percent as much atmosphere as Earth. Just to find high-enough radiation levels on Earth for checking and calibrating RAD, the instrument team needed to put it inside major particle-accelerator research facilities in the United States, Europe, Japan and South Africa.

An instrument on NASA's Mars Odyssey orbiter, which reached Mars in 2001, assessed radiation levels above the Martian atmosphere. Current estimates of the radiation environment at the planet's surface rely on modeling of how the thin atmosphere affects the energetic particles, but uncertainty in the modeling remains large. "A single energetic particle hitting the top of the atmosphere can break up into many particles -- a cascade of lower-energy particles that might be more damaging to life than a single high-energy particle," Hassler noted.

The 1.7-kilogram (3.8-pound) RAD instrument has an upward-pointing, wide-angle telescope with detectors for charged particles with masses up to that of iron. It can also detect secondary neutrons coming from both the Mars atmosphere above and Mars surface material below. Hassler's international RAD team includes experts in instrument design, astronaut safety, atmospheric science, geology and other fields.
Southwest Research Institute, in Boulder and in San Antonio, Texas, and Christian Albrechts University, in Kiel, Germany, built RAD with funding from the NASA Exploration Systems Mission Directorate and Germany's national aerospace research center: Deutschen Zentrum für Luft- und Raumfahrt. The team assembling and testing the Mars Science Laboratory spacecraft at NASA's Jet Propulsion Laboratory in Pasadena, Calif., installed RAD onto Curiosity last month for the late-2011 launch.

RAD measurements during the trip from Earth to Mars will enable correlations with instruments on other spacecraft that monitor solar particle events and galactic cosmic rays in Earth's neighborhood, then will yield data about the radiation environment farther from Earth.Once on Mars, the rover's prime mission will last a full Martian year -- nearly two Earth years. A one-time set of measurements by RAD would not suffice for determining the radiation environment on the surface, because radiation levels vary on time frames both longer than a year and shorter than an hour. Operational planning for Curiosity anticipates that RAD will record measurements for 15 minutes of every hour throughout the prime mission.

Radiation levels probably make the surface of modern Mars inhospitable for microbial life. The measurements from RAD will feed calculations of how deeply a possible future robot on a life-detection mission might need to dig or drill to reach a microbial safe zone. For assessing whether the surface radiation environment could have been hospitable for microbes in Mars' distant past, researchers will combine RAD's measurements with estimates of how the activity of the sun and the atmosphere of Mars have changed in the past few billion years.

"The primary science goal of Curiosity is to determine whether its landing site is, or ever was, a habitable environment, a place friendly to life," said JPL's Ashwin Vasavada, deputy project scientist for the Mars Science Laboratory. "That involves looking both for conditions that would support life as well as for those that would be hazardous to life or its chemical predecessors. Natural, high-energy radiation is just such a hazard, and RAD will give us the first look at the present level of this radiation and help us to better estimate radiation levels throughout Mars' history."
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