Artificially Controlling Water Condensation Leads to ‘Room-Temperature Ice’
Dr. Albert Verdaguer
Earth’s climate is strongly influenced by the presence of particles of different shapes and origins — in the form of dust, ice and pollutants — that find their way into the lowest portion of the atmosphere, the troposphere. There, water adsorbed on the surface of these particles can freeze at higher temperatures than pure water droplets, triggering rain and snow.
Researchers at Spain’s Centre d’Investigació en Nanociència i Nanotecnologia (CIN2) have studied the underlying mechanisms of water condensation in the troposphere and found a way to make artificial materials to control water condensation and trigger ice formation at room temperature. Described in the Journal of Chemical Physics, which is published by the American Institute of Physics, their work may lead to new additives for snowmaking, improved freezer systems, or new coatings that help grow ice for skating rinks.
“Several decades ago, scientists predicted that materials with crystal faces exhibiting a structure similar to that of hexagonal ice, the form of all natural snow and ice on Earth, would be an ideal agent to induce freezing and trigger rain,” explains Dr. Albert Verdaguer. “This explanation has since proven to be insufficient.”
The research team chose to study barium fluoride (BaF2), a naturally occurring mineral, also known as “Frankdicksonite,” as an option. They examined water adsorption on BaF2 (111) surfaces under ambient conditions using different scanning force microscopy modes and optical microscopy to zoom in on the role atomic steps play in the structure of water films, which can affect the stabilization of water bilayers and, ultimately, condensation. (more…)
Discovery: Water on the Moon is Widespread, Similar to Earth’s
Last fall, researchers, including Larry Taylor, a distinguished professor in the Department of Earth and Planetary Sciences, discovered “lunar dew” on the moon’s surface — absorbed “water” in the uppermost layers of lunar soil. This discovery of water debunked beliefs held since the return of the first Apollo rocks that the moon was bone-dry.
Now, scientists, including Taylor and Yang Liu, research assistant professor in the Department of Earth and Planetary Sciences, have discovered that water on the moon is more widespread — on the outside and inside of the moon — with some similarities to water in volcanic systems on Earth.
Their research will be featured in the article, “Lunar Apatite with Terrestrial Volatile Abundances” in the July 22 edition of the scientific journal, Nature.
Unlike lunar dew which is believed to come from an outside source such as solar wind which brings hydrogen into contact with the Moon’s oxygen, the water discovered by Taylor and Liu is internal, arising from an entirely different origin. How it got there is not yet known. The water may have been added by impacting comets, which contain ice, during or after the formation of the moon and Earth. (more…)
More on Solutions to Southern Asia Poisonous Well-Water Crisis
This man is pumping water from a typical hand-pump tubewell in a rural village in West Bengal, India, where there is also arsenic. (Photo by Prof. Holly Michael/University of Delaware)
Over 100 million people in rural southern Asia are exposed every day to unsafe levels of arsenic from the well-water they drink. It more than doubles their risks for cancer, causes cardiovascular disease, and inhibits the mental development of children, among other serious effects.
The World Health Organization (WHO) has referred to the situation in Bangladesh, where an estimated 60 million people are affected, as “the largest mass poisoning of a population in history.”
In the May 28 issue of the journal Science, researchers from Stanford University, the University of Delaware, and Columbia University review what scientists understand about this groundwater contamination crisis and offer solutions for the region, which spans Bangladesh, Cambodia, China, India, Myanmar, Nepal, Pakistan, and Vietnam.
Holly Michael, assistant professor of geological sciences in the College of Earth, Ocean, and Environment at the University of Delaware, is a co-author of the article, with Scott Fendorf from Stanford and Alexander van Geen from Columbia University. Fendorf received his doctorate from UD in 1992 and is now chair of environmental and Earth system science at Stanford. (more…)
Pedal Power Transforming Rural Lives
An innovative bicycle-powered water pump, created by a student at the University of Sheffield, has proved a huge success and is now in regular production in Guatemala, transforming the lives of rural residents.
Jon Leary, 24, a MEng student in the University´s Department of Mechanical Engineering, took his bicycle machine design from a Steel City drawing board to the heart of Guatemala as part of his dissertation, which required him to `make something useful out of rubbish.´
During his four month stint in Guatemala, Jon spent time improving the design for his bicibomba movil – a mobile bicycle-powered water pump to be used for irrigation and general water distribution - by working with the Guatemalan NGO Maya Pedal, who design and build a variety of weird and wonderful bicycle machines using abandoned bikes sent over from the US and Canada. Maya Pedal´s aim is to produce machines which can improve the daily lives of locals, without them having to resort to expensive electrical or environmentally damaging fossil fuelled machines. Their machines, which are human-powered sustainable energy sources, range from the bicilavadora (bicycle washing machine) to the bicimolino (corn grinder). (more…)
Scientists Offer Solutions to Arsenic Groundwater Poisoning in Southern Asia
Pumping water at a Bangladesh well. (Photo by Seth H. Frisbie. Courtesy Norwich University Office of Communications)
An estimated 60 million people in Bangladesh are exposed to unsafe levels of arsenic in their drinking water, dramatically raising their risk for cancer and other serious diseases, according to the World Health Organization (WHO).
Because most of the contaminated water is near the surface, many people in Bangladesh have installed deep wells to tap into groundwater that’s relatively free of arsenic.
In recent years, farmers have begun using the deep, uncontaminated aquifers for irrigation – a practice that could compromise access to clean drinking water across the country, according to a report in the May 27 issue of journal Science.
The report is co-authored by groundwater experts Scott Fendorf (Stanford University), Holly A. Michael (University of Delaware) and Alexander van Geen (Columbia University).
“Every effort should be made to prevent irrigation by pumping from deeper aquifers that are low in arsenic,” the authors wrote. “This precious resource must be preserved for drinking.”
Every day, more than 100 million people are exposed to arsenic-contaminated drinking water in Bangladesh, Cambodia, China, India, Myanmar, Nepal, Pakistan and Vietnam.
Over the last 10 years, Fendorf, Michael and van Geen have conducted long-term groundwater studies throughout southern Asia with the goal of finding low-cost solutions to what the WHO calls the largest mass poisoning in history. (more…)
Roots Enmeshed in Waste Materials Can Purify Dirty Water
Penn State horticulturist Robert Cameron stands in front of a biofilter that uses plants roots, waste materials and bacterial colonies to clean wastewater as it trickles down the pipes. (Amitabh Avasthi)
Plant roots enmeshed in layers of discarded materials inside upright pipes can purify dirty water from a washing machine, making it fit for growing vegetables and flushing toilets, according to Penn State horticulturists.
“Our global fresh water supplies are fast depleting,” said Robert D. Cameron, doctoral student in horticulture. “So it is critical that we begin to look at alternatives on how we can take wastewater and turn it into a resource.”
Cameron and Robert D. Berghage, associate professor of horticulture, use discarded materials and a combination of plant and bacterial communities to treat water from a washing machine and other wastewater.
According to Cameron, this design is superior to previous living treatment systems in that it requires much less space and is much more efficient at removing contaminants.
“We have shown that with this system we can take wastewater from a washing machine and remove more than 90 percent of the pollutants within three days,” said Cameron. “The treated water had very low levels of suspended solids and no detectable levels of e.coli.”
Cameron presented the work today (May 5) at a meeting on organic and sustainable agriculture in Havana.
The water treatment system consists of two seven-foot long plastic corrugated pipes a foot in diameter. The researchers placed these pipes upright three feet apart in a basin containing a foot of potting soil and crushed limestone. (more…)
Water-Related Conflicts Set to Escalate in Developing World
Mekong River Basin
Population growth, urbanisation, increasing pollution, soil erosion and climate variations are all reflected in the management and adequacy of the world’s waters. The situation is particularly difficult in many developing countries, where there are growing concerns over escalating water crises and even outright water conflicts between countries and regions.
“The current rate of population growth and urbanisation are already impacting food production. We need to improve the efficiency of agricultural output, as it’s unlikely that the acreage under cultivation can be much increased. Improved efficiency requires the efficient use of water resources,” says Professor Olli Varis from the Water and Development Research Group at Aalto University. The Group’s main research interests include integrated approaches to the management and planning of water resources as well as international water issues.
Professor Varis points out that the utility of existing water resources is adversely affected by increasing industrial pollution and the breakdown of natural material circulation. The utilisation of water resources, and groundwater in particular, already exceeds the renewal capacity. “Up to 60?? per cent of the world’s population live in countries that suffer from water shortages, and that figure will rise sharply in the future.” (more…)
American Industry’s Thirst for Water: First Study of its Kind in 30 Years
Manufacturers, farmers, shippers and others in the "supply chain" use almost 270 gallons of water to put $1 worth of sugar on supermarket shelves, according to a new study documenting American industry’s water use. (iStock)
How many gallons of water does it take to produce $1 worth of sugar, dog and cat food, or milk? The answers appear in the first comprehensive study in 30 years documenting American industry’s thirst for this precious resource. The study, which could lead to better ways to conserve water, is in ACS’ Environmental Science & Technology, a semi-monthly journal.
Chris Hendrickson and colleagues note in the new study that industry (including agriculture) long has been recognized as the biggest consumer of water in the United States. However, estimates of water consumption on an industry-by-industry basis are incomplete and outdated, with the last figures from the U.S. Census Bureau dating to 1982.
They estimated water use among more than 400 industry sectors — from finished products to services — using a special computer model. The new data shows that most water use by industry occurs indirectly as a result of processing, such as packaging and shipping food crops to the supermarket, rather than direct use, such as watering crops. (more…)
National Geographic Takes an In-depth Look at Fresh Water
Single-topic issue, "Water: Our Thirsty World," highlights challenges facing our most essential natural resource. (National Geographic)
National Geographic’s April 2010 issue will be devoted to a single topic — fresh water. “Water: Our Thirsty World,” available on newsstands beginning Tuesday, March 30, is a far-reaching exploration of and essential primer on the state of the world’s fresh water and the global implications as supplies of this finite resource are threatened.
Consider these stark realities:
A mere 3 percent of Earth’s water is fresh — 2 percent is locked up in snow and ice, while just 1 percent is liquid surface water and ground water, available for consumption.
Nearly a billion people have no access to clean water, and 3.3 million people die from water-related health problems each year.
Freshwater animal species are disappearing in general four to six times faster than land or sea animals — in the United States, nearly half the 573 animals on the threatened and endangered list are freshwater species.
National Geographic’s April issue not only celebrates the role of water in our lives and landscapes but also identifies the key challenges affecting global supplies and examines novel solutions to address water scarcity. (more…)
Study Examines How US Industry Uses Scarce Water Resources
Chris T. Hendrickson, the Duquesne Light Professor of Civil and Environmental Engineering
Just think, every time you feed Fido or flip a spoonful of sugar into your coffee cup, you use more than 300 gallons of water.
Checking the amounts of water it takes to make a $1 worth of sugar, cat and dog food or milk is part of a comprehensive study by Carnegie Mellon University researchers to document American industry’s thirst for this scarce resource.
Chris T. Hendrickson, the Duquesne Light Professor of Civil and Environmental Engineering, said the study shows that most water use by industry occurs indirectly as a result of processing, such as packaging and shipping of food crops to the supermarket, rather than direct use, like watering crops.
The study found it takes almost 270 gallons of water to produce a $1 worth of sugar; 140 gallons to make $1 worth of milk; and 200 gallons of water to make $1 worth of cat and dog food.
“The study gives us a way to look at how we might use water more efficiently and allows us to hone in on the sectors that use the most water so we can start generating ideas and technologies for better management,” said Hendrickson, co-director of Carnegie Mellon’s Green Design Institute, a major interdisciplinary research effort aimed at making an impact on environmental quality through design.
Hendrickson, along with civil engineering Ph.D. candidates Michael Blackhurst and Jordi Vidal, said his team is trying to help industries track and make better management decisions about how they use water, which makes up more than 72 percent of the earth’s land surface.
The study, featured in the Feb. 23 edition of the journal Environmental Science & Technology, reports that a lot of water consumption is hidden because companies don’t use all the water directly.
“We discovered that among 96 percent of the sectors evaluated, indirect use exceeded direct uses throughout the supply chain,” Hendrickson said.
But Hendrickson and Blackhurst are quick to report that their data are national findings and do not apply regionally. In addition, they could only track withdrawals, and were unable to determine how much water was returned to the system or recycled.
“That is a big deal because water that gets degraded during industrial processes might not be suitable for future uses,” Hendrickson said. “Effective water management is critical for social welfare and our fragile ecosystems.”
New Method to Measure Snow, Soil Moisture With GPS May Benefit Meteorologists, Farmers
CU-Boulder aerospace engineering sciences Professor Kristine Larson,
A research team led by the University of Colorado at Boulder has found a clever way to use traditional GPS satellite signals to measure snow depth as well as soil and vegetation moisture, a technique expected to benefit meteorologists, water resource managers, climate modelers and farmers.
The researchers have developed a technique that uses interference patterns created when GPS signals that reflect off of the ground — called “multipath” signals — are combined with signals that arrive at the antenna directly from the satellite, said CU-Boulder aerospace engineering sciences Professor Kristine Larson, who is leading the study. Since such multipath signals arrive at GPS receivers “late,” they have generally been viewed as noise by scientists and engineers and have largely been ignored, said Larson, who is leading a multi-institution research effort on the project.
In one recent demonstration, the team was able to correlate changes in the multipath signals to snow depth by using data collected at a field site in Marshall, Colo. just south of Boulder, which was hit by two large snowstorms over a three-week span in March and April of 2009. Published in the September issue of Geophysical Research Letters, the snowpack study built on a project Larson and her colleagues have been working on that is funded by the National Science Foundation to measure soil moisture using GPS receivers. (more…)
Cave Study Links Climate Change to California Droughts
California experienced centuries-long droughts in the past 20,000 years that coincided with the thawing of ice caps in the Arctic, according to a new study by UC Davis doctoral student Jessica Oster and geology professor Isabel Montañez.
The finding, which comes from analyzing stalagmites from Moaning Cavern in the central Sierra Nevada, was published online Nov. 5 in the journal Earth and Planetary Science Letters.
The sometimes spectacular mineral formations in caves such as Moaning Cavern and Black Chasm build up over centuries as water drips from the cave roof. Those drops of water pick up trace chemicals in their path through air, soil and rocks, and deposit the chemicals in the stalagmite.
“They’re like tree rings made out of rock,” Montañez said. “These are the only climate records of this type for California for this period when past global warming was occurring.” (more…)
Remote Sensing of Disasters from Space
An image from TAU's orbiting Hyperspectral Remote Sensor (HRS)
One small step for mankind is now a leap for averting natural and man-made disasters on earth.
New Tel Aviv University technology combines sophisticated sensors in orbit with sensors on the ground and in the air to create a “Hyperspectral Remote Sensor” (HRS). It can give advance warnings about water contamination after a forest fire, alert authorities of a pollution spill long before a red flag is raised on earth, or tell people in China where a monsoon will strike.
Prof. Eyal Ben-Dor of TAU’s Department of Geography describes his team’s HRS technology as a combination of physical, chemical and optical disciplines. “When a devastating forest fire hits the Hollywood Hills, for example, we can see from space how the mineralogy of the soil has changed,” he explains. “Because of these changes, the next rainstorm may wash out all the buildings or leach contaminants into the soil. With our new tool, we can advise on how to contain the pollutants after the fire, and warn if there is a risk for landslides.” (more…)
How the Moon Produces Its Own Water
Moon, seen from Chandrayaan-1 on 4 November 2008, from a distance of about 311200 km. (ISRO)
The Moon is a big sponge that absorbs electrically charged particles given out by the Sun. These particles interact with the oxygen present in some dust grains on the lunar surface, producing water. This discovery, made by the ESA-ISRO instrument SARA onboard the Indian Chandrayaan-1 lunar orbiter, confirms how water is likely being created on the lunar surface.
It also gives scientists an ingenious new way to take images of the Moon and any other airless body in the Solar System.
The lunar surface is a loose collection of irregular dust grains, known as regolith. Incoming particles should be trapped in the spaces between the grains and absorbed. When this happens to protons they are expected to interact with the oxygen in the lunar regolith to produce hydroxyl and water. The signature for these molecules was recently found and reported by Chandrayaan-1’s Moon Mineralogy Mapper (M3) instrument team.
The SARA results confirm that solar hydrogen nuclei are indeed being absorbed by the lunar regolith but also highlight a mystery: not every proton is absorbed. One out of every five rebounds into space. In the process, the proton joins with an electron to become an atom of hydrogen. “We didn’t expect to see this at all,” says Stas Barabash, Swedish Institute of Space Physics, who is the European Principal Investigator for the Sub-keV Atom Reflecting Analyzer (SARA) instrument, which made the discovery. (more…)
NASA Crashes Two-Ton Rocket Into The Moon Friday
Key lunar landmarks used to locate Cabeus crater, the site of the LCROSS crash, are colored and labeled in this view. The yellow scale shows angular distances in the plane of the impact site; blue arcs show heights 50, 100 and 200 kilometers above it. (NASA/Goddard Space Flight Center Scientific Visualization Studio)
At 7:30 a.m. EDT on October 9, a two-ton rocket body will slam into a crater near the moon’s south pole. By studying the resulting plume of gas and dust, scientists hope this grand experiment will confirm the presence of ice in permanently shadowed craters at the lunar poles.
The event is the highlight of NASA’s Lunar Crater Observation and Sensing Satellite (LCROSS) mission. The LCROSS spacecraft flies behind its empty upper stage, which is targeted to strike the floor of Cabeus crater. LCROSS will image the impact and provide direct measurements of the plume before it also plunges into the lunar surface. With LCROSS gone, further measurements of the cloud depend on ground-based observatories around the world.
“This is a completely unique mission that will excavate two large holes dozens of meters across on the lunar surface. It will give us composition measurements we wouldn’t otherwise be able to get,” said Tim McClanahan, a scientist at Goddard Space Flight Center in Greenbelt, Md. (more…)
Climate Change and Water Scarcity Will Create Global Security Concerns
‘We have very little time,’ says Nobel winner
Water scarcity as a result of climate change will create far-reaching global security concerns, says Dr. Rajendra K. Pachauri, chair of the intergovernmental panel on climate change, a co-recipient of the 2007 Nobel Peace Prize.
Pachauri spoke this morning at the 2009 Nobel Conference at Gustavus Adolphus College in St. Peter, MN.
“At one level the world’s water is like the world’s wealth. Globally, there is more than enough to go round. The problem is that some countries get a lot more than others,” he says. “With 31 percent of global freshwater resources, Latin America has 12 times more water per person than South Asia. Some places, such as Brazil and Canada, get far more water than they can use; others, such as countries in the Middle East, get much less than they need.”
And the effects of a warmer world will likely include changes in water availability. (more…)
New Research Shows Water Present Across the Moon’s Surface
It turns out the moon is a lot wetter than we ever thought.
When Apollo astronauts returned from the moon 40 years ago, they brought back souvenirs in the form of moon rocks to be used for scientific analysis, and one of the chief questions was whether there was water to be found in the lunar rocks and soils.
The problem was they faced was complicated by the fact that most of the rock boxes containing the lunar samples had leaked. This led the scientists to assume that the trace amounts of water they found came from Earth air that had entered the containers. The assumption remained that, outside of possible ice at the moon’s poles, there was no water on the moon.
Forty years later, a team of scientists including Larry Taylor of the University of Tennessee, Knoxville, has found evidence that the old assumption may be wrong. To do so, they used a high-tech instrument on a satellite in orbit around the moon. (more…)
Water Quality in Orbit
University of Utah chemist Lorraine Siperko experiences weightlessness during a flight aboard a NASA "vomit comet" aircraft. Siperko made several such flights to test a new system designed to monitor drinking water quality aboard spacecraft. The system includes a commercially available color sensor (blue device in foreground) that checks the level of disinfectant in drinking water. The water quality monitoring system was delivered to the International Space Station in August for six months of tests. (NASA)
Space is not a fun place to get a stomach bug. To ensure drinking water is adequately disinfected, University of Utah chemists developed a two-minute water quality monitoring method that just started six months of tests aboard the International Space Station.
“Now they bring water back on the space shuttle and analyze it on the ground. The problem is there is a big delay. You’d like to be able to maintain iodine or silver [disinfectant] levels in real time with an onboard monitor,” says Marc Porter, a University of Utah professor of chemistry and chemical engineering.
The new method involves sampling space station or space shuttle galley water with syringes, forcing the water through a chemical-imbued disk-shaped membrane, and then reading the color of the membrane with a commercially available, handheld color sensor normally used to measure the color and glossiness of automobile paint.
The sensor detects if the drinking water contains enough iodine (used on U.S. spacecraft) or silver (used by the Russians) to kill any microbes. The International Space Station has both kinds of water purification systems. (more…)
Satellites Unlock Secret to Northern India’s Vanishing Water
NASA Hydrologist Matt Rodell discusses vanishing groundwater in India. Credit: NASA
Beneath northern India’s irrigated fields of wheat, rice, and barley … beneath its densely populated cities of Jaiphur and New Delhi, the groundwater has been disappearing. Halfway around the world, hydrologists, including Matt Rodell of NASA, have been hunting for it.
Where is northern India’s underground water supply going? According to Rodell and colleagues, it is being pumped and consumed by human activities — principally to irrigate cropland — faster than the aquifers can be replenished by natural processes. They based their conclusions — published in the August 20 issue of Nature — on observations from NASA’s Gravity Recovery and Climate Experiment (GRACE). (more…)
Bioethanol’s Impact on Water Supply 3 Times Higher Than Once Thought
Production of bioethanol may consume up to three times more water than previously thought, scientists are reporting. (American Chemical Society)
At a time when water supplies are scarce in many areas of the United States, scientists in Minnesota are reporting that production of bioethanol — often regarded as the clean-burning energy source of the future — may consume up to three times more water than previously thought. Their study appeared in ACS’ journal Environmental Science & Technology.
Sangwon Suh and colleagues point out in the study that annual bioethanol production in the U.S. is currently about 9 billion gallons and note that experts expect it to increase in the near future. The growing demand for bioethanol, particularly corn-based ethanol, has sparked significant concerns among researchers about its impact on water availability. Previous studies estimated that a gallon of corn-based bioethanol requires the use of 263 to 784 gallons of water from the farm to the fuel pump. But these estimates failed to account for widely varied regional irrigation practices, the scientists say. (more…)
Technological Advances May Help Solve Water Treatment Challenges
Sandia researchers May Nyman and Tom Stewart take a water sample on the banks of the Rio Grande. The two developed a patent-applied-for, material-based approach to purifying water that has generated commercial interest.
By substituting a single atom in a molecule widely used to purify water, researchers at Sandia National Laboratories have created a far more effective decontaminant with a shelf life superior to products currently on the market.
Sandia has applied for a patent on the material, which removes bacterial, viral and other organic and inorganic contaminants from river water destined for human consumption, and from wastewater treatment plants prior to returning water to the environment.
“Human consumption of ‘challenged’ water is increasing worldwide as preferred supplies become more scarce,” said Sandia principal investigator May Nyman. “Technological advances like this may help solve problems faced by water treatment facilities in both developed and developing countries.” (more…)
Researchers Achieve Major Breakthrough With Water Desalination System
ProfessorYoram Cohen, UCLA Chemical and Biomolecular Engineering
Concern over access to clean water is no longer just an issue for the developing world, as California faces its worst drought in recorded history. According to state’s Department of Water Resources, supplies in major reservoirs and many groundwater basins are well below average. Court-ordered restrictions on water deliveries have reduced supplies from the two largest water systems, and an outdated statewide water system can’t keep up with population growth.
With these critical issues looming large, researchers at the UCLA Henry Samueli School of Engineering and Applied Science are working hard to help alleviate the state’s water deficit with their new mini-mobile-modular (M3) “smart” water desalination and filtration system. (more…)
New Instrument to Detect Water Deep Underground on Mars
These images show the concept for a flight version of the Mars Time Domain Electromagnetic Sounder (MTDEM), which uses induction to detect groundwater up to 5 km deep. (SwRI and Ball Aerospace.)
With the whoosh of compressed gas and the whir of unspooling wire, a team of Boulder scientists and engineers tested a new instrument prototype that might be used to detect groundwater deep inside Mars.
The Mars Time Domain Electromagnetic Sounder (MTDEM) uses induction to generate electrical currents in the ground, whose secondary magnetic fields are in turn detected at the planetary surface. In this way, the electrical conductivity of the subsurface can be reconstructed.
“Groundwater that has been out of atmospheric circulation for eons will be very salty,” says the project’s principal investigator Dr. Robert Grimm, a director in the Space Science and Engineering Division at Southwest Research Institute. “It is a near-ideal exploration target for inductive systems.”
The inductive principle of the MTDEM is distinct from the wavelike, surface-penetrating radars MARSIS and SHARAD presently orbiting Mars. “The radars have been very useful in imaging through ice and through very dry, low-density rock,” says Grimm, “but they have not lived up to expectations to look through solid rock and find water.” (more…)
New Technique Could Find Water on Earth-like Planets Orbiting Distant Suns
This narrow-angle color image of the Earth, dubbed 'Pale Blue Dot', is a part of the first ever 'portrait' of the solar system taken by Voyager 1. The spacecraft acquired a total of 60 frames for a mosaic of the solar system from a distance of more than 4 billion miles from Earth and about 32 degrees above the ecliptic. From Voyager's great distance Earth is a mere point of light, less than the size of a picture element even in the narrow-angle camera.
Since the early 1990s astronomers have discovered more than 300 planets orbiting stars other than our sun, nearly all of them gas giants like Jupiter. Powerful space telescopes, such as the one that is central to NASA’s recently launched Kepler Mission, will make it easier to spot much smaller rocky extrasolar planets, or exoplanets, more similar to Earth.
But seen from dozens of light years away, an Earth-like exoplanet will appear in telescopes as little more than a “pale blue dot,” the term coined by the late astronomer Carl Sagan to describe how Earth appeared in a 1990 photograph taken by the Voyager spacecraft from near the edge of the solar system. (more…)
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