Earth like planets in our universe?

Spotting true Earth-sized planets is challenging with current technology.
by

Dr. Nitish Priyadarshi

Twinkle, twinkle little star, goes the nursery rhyme, but what scientists are really wanting to find is planet’s similar to our earth.

When scientists confirmed in October that they had detected the first rocky planet outside our solar system, it advanced the longtime quest to find an Earth-like planet hospitable to life.

Rocky planets -- Earth, Mercury, Venus and Mars -- make up half the planets in our solar system. Rocky planets are considered better environments to support life than planets that are mainly gaseous, like the other half of the planets in our system: Jupiter, Saturn, Uranus and Neptune.

We know that earth is a pretty rare planet in our universe. Only a relative handful of planets are rocky and even fewer are in the habitable zones of their stars. At the same time, there is still a lot that we don't know about our universe outside the solar system.
The challenge in finding earth-like planets is the sheer distances involved. It involves light years even between our sun and the nearest star. We can currently observe stars and other galaxies, but it is even more difficult to find a planet. The first challenge is that planets are often much smaller than the stars they orbit. The earth is one millionth the size of the sun. The second challenge is that planets don't emit or reflect much light. With these two conditions using ordinary astronomy tools to find planets is impossible

Many scientists speculate that our galaxy could be full of places like Pandora from the movie "Avatar" -- Earth-like worlds in solar systems besides our own.

That doesn't mean such worlds have been easy to find, however. Of the 400-plus planets so far discovered, none could support life as we know it on Earth.
"The problem with finding Earth-like planets," "is that their host stars can emit 10 million times more infrared light than the planet itself. And because planets like ours are small and orbit very close to their respective stars, it makes Earths almost impossible to see."

The rocky planet CoRoT-7 b was discovered circling a star some 480 light years from Earth. It is, however, a forbidding place and unlikely to harbor life. That's because it is so close to its star that temperatures might be above 4,000 degrees F (2,200 C) on the surface lit by its star and as low as minus 350 F (minus 210 C) on its dark side.

GJ 1214 b is an extrasolar super-Earth discovered in December 2009 orbiting the star GJ 1214, at a distance of 13 parsecs or approximately 40 light-years from earth, in the constellation Ophiuchus. It is the second exoplanet (after COROT-7b) discovered to have an established mass and radius less than those of the gas giants in the Solar System, and is the first of a new class of planets with small size and relatively low density. It is also the first super-Earth around which an atmosphere has been found. The planet is believed to be too hot to sustain Earth-type life, but could consist of 75 per cent water.

The planet is also significant because of its proximity to Earth, and because it transits a small parent star, which should allow its atmosphere to be studied using current technologies.

Fig. GJ 1214 b

Recently I was going through an article published in Scientific American (August issue) written by Dimitar D. Sasselov and Diana Valencia. Article is about the planets which could be similar to our earth. From last several years we are searching such planets in outer space which can support life. But we are still groping in darkness. Many claims have been made earlier but science needs evidence to accept such claims.

One such claim was in the year 2007, when some Swiss astronomers were studying a star close to the brightest star in the constellation of Libra, a red dwarf called Gliese 581, when they noticed that it was wobbling. They were intrigued by this as they understood that there must be something massive though invisible fairly near it exerting a gravitational pull on it. The result of this was the discovery of a large planet, which they called Gliese 581-B. It was obviously too close to its star, subject to too much radiation and just far too hot for it to support any form of life. Then in 2007 the same team of astronomers noticed a second wobble in the star’s movement, which implied the existence of a smaller planet further out. This was the cause of great excitement: the first earth-like planet outside the solar system had been discovered. It is twenty light-years away from the earth.

Imagine yourself grazing at the sky on a summer night. You look in the direction of a particular star that, you have heard, has a special planet orbiting around it. Although you cannot actually see the planet- you can barely see the star itself- you know it is several times larger than earth and, like earth, is made mostly of rock, quakes sometimes shake its surface, much of which is covered by oceans. Its atmosphere is not too different from the one we breathe, and its sky is swept by frequent storms and often darkened by the ash of volacanoes. But most of all, you know that scientists think it could harbor life – and that they plan to seek evidence for it.

This scenario could become reality within the next decades. Although most of the 450- odd extrasolar planets found so far are giants more similar to Jupiter, astronomers are beginning to discover some that may not be two different from earth. And NASA’s Kepler probe, a planet hunter sent aloft last year, will discover many more.

Of course, these worlds are light-years away, so even our most advanced instruments cannot actually see the details of their surfaces- the mountains, the clouds, the volcanoes- and perhaps never will. Usually all our telescopes can do is detect indirect signs of a planet’s presence and help us estimate its mass and how wide its orbit is. In some cases, they can also give information about a planet’s diameter and perhaps a few other details. In the case of the giant exoplanets, these details may include estimates about the atmosphere composition and wind dynamics.

That is a far cry from being able to measure anything specific about geology, chemistry or other features. Yet from those few numbers, researches can deduce surprisingly complex portraits of the far-off planets, using theoretical modeling, computer simulations and even laboratory experiments, combined with established knowledge of earth and other planets of the solar system.

Finding a planet that harbors life may have to wait until astronomers are better able to detect rocky planets that are farther from their stars. Spotting true Earth-sized planets is challenging with current technology, but the presence of super-Earths suggests finding a world like ours is just a matter of time, researchers say.

Jurassic Space: Ancient Galaxies Come Together after Billions of Years.

Hickson Compact Group 31 is one of 100 compact galaxy groups catalogued by Canadian astronomer Paul Hickson. Credit: NASA, ESA, S. Gallagher (University of Western Ontario), and J. English (University of Manitoba). Photo No. STScI-PRC10-08a

Imagine finding a living dinosaur in your backyard. Astronomers have found the astronomical equivalent of prehistoric life in our intergalactic back yard: a group of small, ancient galaxies that has waited 10 billion years to come together. These "late bloomers" are on their way to building a large elliptical galaxy. Such encounters between dwarf galaxies are normally seen billions of light-years away and therefore occurred billions of years ago. But these galaxies, members of Hickson Compact Group 31, are relatively nearby, only 166 million light-years away.New images of these galaxies by NASA's Hubble Space Telescope offer a window into what commonly happened in the universe's formative years when large galaxies were created from smaller building blocks. The Hubble observations have added important clues to the story of this interacting foursome, allowing astronomers to determine when the encounter began and to predict a future merger.Astronomers know the system has been around for a while because the oldest stars in a few of its ancient globular clusters are about 10 billion years old. The encounter, though, has been going on for about a few hundred million years, the blink of an eye in cosmic history. Everywhere the astronomers looked in this compact group they found batches of infant star clusters and regions brimming with star birth. Hubble reveals that the brightest clusters, hefty groups each holding at least 100,000 stars, are less than 10 million years old.The entire system is rich in hydrogen gas, the stuff of which stars are made. Astronomers used Hubble's Advanced Camera for Surveys to resolve the youngest and brightest of those clusters, which allowed them to calculate the clusters' ages, trace the star-formation history, and determine that the galaxies are undergoing the final stages of galaxy assembly.The composite image of Hickson Compact Group 31 shows the four galaxies mixing it up. The bright, distorted object at middle, left, is actually two colliding dwarf galaxies. The bluish star clusters have formed in the streamers of debris pulled from the galaxies and at the site of their head-on collision. The cigar-shaped object above the galaxy duo is another member of the group. A bridge of star clusters connects the trio. A longer rope of bright star clusters points to the fourth member of the group, at lower right. The bright object in the center is a foreground star. The image was composed from observations made by the Hubble Space Telescope's Advanced Camera for Surveys, NASA's Spitzer Space Telescope, and the Galaxy Evolution Explorer (GALEX). The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency. NASA's Goddard Space Flight Center manages the telescope. The Space Telescope Science Institute conducts Hubble science operations. The institute is operated for NASA by the Association of Universities for Research in Astronomy, Inc. in Washington, D.C.

High levels of black carbon likely to impact Tibetan Plateau's temperature.

The Dark Side of Black Carbon

by

Dr. Nitish Priyadarshi

Image Credit: NASA

As interest in Earth's changing climate heats up, a tiny dark particle is stepping into the limelight: black carbon. Commonly known as soot, black carbon enters the air when fossil fuels and biofuels, such as coal, wood, and diesel are burned. Black carbon is found worldwide, but its presence and impact are particularly strong in Asia. Black carbon, a short-lived particle, is in perpetual motion across the globe. The Tibetan Plateau's high levels of black carbon likely impact the region's temperature, clouds and monsoon season.

Black soot deposited on Tibetan glaciers has contributed significantly to the retreat of the world's largest non-polar ice masses, according to new research by scientists from NASA and the Chinese Academy of Sciences. Soot absorbs incoming solar radiation and can speed glacial melting when deposited on snow in sufficient quantities.
Temperatures on the Tibetan Plateau -- sometimes called Earth's "third pole" -- have warmed by 0.3°C (0.5°F) per decade over the past 30 years, about twice the rate of observed global temperature increases. New field research and ongoing quantitative modeling suggests that soot's warming influence on Tibetan glaciers could rival that of greenhouse gases.

Since melt water from Tibetan glaciers replenishes many of Asia's major rivers -- including the Indus, Ganges, Yellow, and Brahmaputra -- such losses could have a profound impact on the billion people who rely on the rivers for fresh water. Areas going to most affected in India would be Uttrakhand, Uttar Pradesh, Bihar, Jharkhand, West Bengal and Assam. While rain and snow would still help replenish Asian rivers in the absence of glaciers, the change could hamper efforts to manage seasonal water resources by altering when fresh water supplies are available in areas already prone to water shortages.
Researchers led by Baiqing Xu of the Chinese Academy drilled and analyzed five ice cores from various locations across the Tibetan Plateau, looking for black carbon (a key component of soot) as well as organic carbon. The cores support the hypothesis that black soot amounts in the Himalayan glaciers correlate with black carbon emissions in Europe and South Asia.
Black carbon or BC is formed through the incomplete combustion of fossil fuel, biofuel, and biomass, and is emitted in both anthropogenic and naturally occurring soot. Black carbon warms the planet by absorbing heat in the atmosphere and by reducing albedo, the ability to reflect sunlight, when deposited on snow and ice. Black carbon stays in the atmosphere for only several days to weeks, whereas CO2 has an atmospheric lifetime of more than 100 years. The term black carbon is also used in soil sciences and geology, referring either to deposited atmospheric BC or to directly incorporated BC from vegetation fires. Especially for the tropics, BC in soils significantly contributes to fertility as it is able to adsorb important plant nutrients .

Black carbon is a potent climate forcing agent, estimated to be the second largest contributor to global warming after carbon dioxide (CO2). Because black carbon remains in the atmosphere only for a few weeks, reducing black carbon emissions may be the fastest means of slowing climate change in the near-term.

Black carbon emissions from northern Eurasia, North America, and Asia have the greatest absolute impact on Arctic warming.

In some regions, such as the Himalayas, the impact of black carbon on melting snowpack and glaciers may be equal to that of CO2.Warmer air resulting from the presence of black carbon in South and East Asia over the Himalayas contributes to a warming of approximately 0.6°C. An “analysis of temperature trends on the Tibetan side of the Himalayas reveals warming in excess of 1°C.

Black carbon sources vary by region. For example, the majority of soot emissions in South Asia are due to biofuel cooking, whereas in East Asia, coal combustion for residential and industrial uses plays a larger role.

Black carbon can be controlled in developing countries through the implementation of cleaner fuels, new cooking technologies, and changing crop management practices.

Reference:

http://www.sciencedaily.com/releases/2009/12/091214173658.htm
http://fixtheclimate.com/component-1/the-solutions-new-research/black-carbon/
http://www.nasa.gov/multimedia/imagegallery/image_feature_1546.html
http://en.wikipedia.org/wiki/Black_carbon

Successful Flight Through Enceladus Plume.

The Cassini spacecraft has weathered the Monday, Nov. 2, 2009, flyby of Saturn’s moon Enceladus in good health and has been sending images and data of the encounter back to Earth. Cassini had approached Enceladus more closely before, but this passage took the spacecraft on its deepest plunge yet through the heart of the plume shooting out from the south polar region. Scientists are eagerly sifting through the results.

In this unprocessed image, sunlight brightens a crescent curve along the edge of Saturn's moon Enceladus and highlights its misty plume. The image was captured by Cassini's narrow-angle camera as the spacecraft passed about 190,000 kilometers (120,000 miles) over the moon. This image has not been validated or calibrated. A validated/calibrated image will be archived with the NASA Planetary Data System in 2010.

At its closest point on Nov. 2, Cassini flew about 100 kilometers (60 miles) above the surface of Enceladus.

Since the discovery of the plume in 2005, scientists have been captivated by the enigmatic jets. Previous flybys detected water vapor, sodium and organic molecules, but scientists need to know more about the plume’s composition and density to characterize the source, possibly a liquid ocean under the moon’s icy surface. It would also help them determine whether Enceladus has the conditions necessary for life.

Mission managers did extensive studies to make sure the spacecraft could fly safely through the plumes and not use an excessive amount of propellant.

Tattooed Mars.

This high-resolution picture from the HiRISE camera on board the Mars Reconnaissance Orbiter shows twisting dark trails criss-crossing light-colored terrain on the Martian surface. Newly formed trails like these had presented researchers with a tantalizing mystery but are now known to be the work of miniature wind vortices known to occur on the red planet, in other words Martian dust devils. Such spinning columns of rising air heated by the warm surface are also common in dry and desert areas on planet Earth. Typically lasting only a few minutes, dust devils become visible as they pick up loose red-colored dust leaving the darker and heavier sand beneath intact. Ironically, dust devils have been credited with unexpectedly cleaning the solar panels of the Mars rovers.

Image Credit: NASA, HiRISE, MRO, LPL (U. Arizona)

NASA Spacecraft Impacts Lunar Crater in Search for Water Ice.

MOFFETT FIELD, Calif. -- NASA's Lunar Crater Observation and Sensing Satellite, or LCROSS, created twin impacts on the moon's surface early Friday in a search for water ice. Scientists will analyze data from the spacecraft's instruments to assess whether water ice is present. The satellite traveled 5.6 million miles during an historic 113-day mission that ended in the Cabeus crater, a permanently shadowed region near the moon's south pole. The spacecraft was launched June 18 as a companion mission to the Lunar Reconnaissance Orbiter from NASA's Kennedy Space Center in Florida. "The LCROSS science instruments worked exceedingly well and returned a wealth of data that will greatly improve our understanding of our closest celestial neighbor," said Anthony Colaprete, LCROSS principal investigator and project scientist at NASA's Ames Research Center in Moffett Field, Calif. "The team is excited to dive into data." In preparation for impact, LCROSS and its spent Centaur upper stage rocket separated about 54,000 miles above the surface of the moon on Thursday at approximately 6:50 p.m. PDT. Moving at a speed of more than 1.5 miles per second, the Centaur hit the lunar surface shortly after 4:31 a.m. Oct. 9, creating an impact that instruments aboard LCROSS observed for approximately four minutes. LCROSS then impacted the surface at approximately 4:36 a.m. "This is a great day for science and exploration," said Doug Cooke, associate administrator for the Exploration Systems Mission Directorate at NASA Headquarters in Washington. "The LCROSS data should prove to be an impressive addition to the tremendous leaps in knowledge about the moon that have been achieved in recent weeks. I want to congratulate the LCROSS team for their tremendous achievement in development of this low cost spacecraft and for their perseverance through a number of difficult technical and operational challenges."‪ Other observatories reported capturing both impacts. The data will be shared with the LCROSS science team for analysis. The LCROSS team expects it to take several weeks of analysis before it can make a definitive assessment of the presence or absence of water ice. "I am very proud of the success of this LCROSS mission team," said Daniel Andrews, LCROSS project manager at Ames. "Whenever this team would hit a roadblock, it conceived a clever work-around allowing us to push forward with a successful mission." The images and video collected by the amateur astronomer community and the public also will be used to enhance our knowledge about the moon. "One of the early goals of the mission was to get as many people to look at the LCROSS impacts in as many ways possible, and we succeeded," said Jennifer Heldmann, Ames' coordinator of the LCROSS observation campaign. "The amount of corroborated information that can be pulled out of this one event is fascinating." "It has been an incredible journey since LCROSS was selected in April 2006," said Andrews. "The LCROSS Project faced a very ambitious schedule and an uncommonly small budget for a mission of this size. LCROSS could be a model for how small robotic missions are executed. This is truly big science on a small budget."

Does water really exists on the Moon surface?

It is very early to predict about water on the moon.
by

Dr. Nitish Priyadarshi

Fig.1. Image Credit: ISRO/NASA/JPL-Caltech/Brown Univ./USGS

Answer may be No! The tests on moon rock that has reached earth, either from meteorites or from rock brought back by astronauts, have brought a new meaning to the word dry!

NASA's Moon Mineralogy Mapper, an instrument on the Indian Space Research Organization's Chandrayaan-1 mission, took this image of Earth's moon. It is a three-color composite of reflected near-infrared radiation from the sun, and illustrates the extent to which different materials are mapped across the side of the moon that faces Earth.Small amounts of water were detected on the surface of the moon at various locations. This image illustrates their distribution at high latitudes toward the poles.Blue shows the signature of water, green shows the brightness of the surface as measured by reflected infrared radiation from the sun and red shows an iron-bearing mineral called pyroxene.
It is giant leap for India’s space programme and the biggest scientific discovery of the 21st century. India’s maiden moon mission, Chandryaan-1 has found water, a discovery that scientists say will up-end thinking about space and boost research.
The first object in the night sky most of us ever saw, the Moon remains a mystery. Haunted by poets, looked upon by youngsters in love, studied intensely by astronomers for four centuries, examined by geologists for the last 50 years, walked upon by twelve humans, this is Earth's satellite.
And as we look towards the Moon with thoughts of setting up a permanent home there, one new question is paramount: does the Moon have water? Although none has been definitely detected, recent evidence suggests that it's there.
Is it true? Seeing the early analytical report of the moon rock samples, it is very early to predict about water on the moon.
The Apollo missions (1969-1972) place a number of instruments on the Moon and brought back 382 kg of lunar rocks. The Russian Luna programme also returned samples.
According to the analysis reports on the samples, moon bear many similarities to rocks on earth, they differ on one basic point –they contain no water, no hydrated minerals, and no minerals with OH groups in their crystal structures. In contrast, minerals that are hydrated or contain the OH group are plentiful on earth.

Fig.2 A close-up view of Apollo 15 lunar sample no. 15415 in the Lunar Receiving Laboratory (LRL).

Fig.3. Apollo 16 astronaut Charles Duke collects rock samples near Plumb crater on the Moon.

"Compared with terrestrial samples, all lunar rocks are oddballs because they are so dry," said Ryder a researcher. "They contain no molecules of water, they're not oxidized and they contain no ferric iron. They're easy to distinguish from rocks on Earth."
All rocks collected are igneous - formed by cooling lava. The mission failed to find any sedimentary rocks - those deposited by water - on the moon. The moon rocks were found to contain no water and were formed in an environment lacking free oxygen. Iron then occurs as crystals of metallic iron. Exposure to Earth's atmosphere would result in the rocks rusting. A new mineral, Armalcolite, was found by the Apollo 11 astronauts. It was later discovered on Earth.
The other report also supports saying that the lunar surface being free of water (as liquid) there are no water transported sediments on it.
The moon is a small planet that cooled quickly and has been geologically quiet for billions of years. There are no volcanoes and no earthquakes; there is also no atmosphere to cause weathering and erosion. The Moon is at the same mean distance from the Sun as Earth. But because it does not have the thermal protection of an atmosphere its surface temperature ranges from a searing 125 degree C at the lunar noon to a chilling -160 degree C during the lunar night. Having such a variation in temperatures it is very hard to believe the presence of water in any form on the surface of the Moon. On the earth ponds and lakes generally gets dry when temperature rises up to 40 degree C and remains for few days. How can we imagine that in such a high temperature water molecules can be found even in form of soil moisture on the surface of the Moon. Lacking an atmosphere, the Moon lost almost all of this water when the molten rock spewed onto the surface and cooled.
Other theory says that since it has only a tiny fraction of Earth's gravity, most of the Moon's water supply should have evaporated and drifted off into space long ago.

If the water is really present on the moon surface the process by which the water exists means that it likely also exists on other similarly dry bodies like Mercury and the countless asteroids in the Asteroid Belt between Mars and Jupiter and also it could only be found deep inside the moon.

According to a news published by Press Trust of India (PTI), dated Jun 15, 2009, ISRO Chairman G. Madhavan Nair said that no trace of water was found on the Moon's surface. "But, we have found traces of magnesium and calcium." How the statement has now changed?

Reference:
http://science.nasa.gov/headlines/y2005/14apr_Moonwater.htm
http://www.impactlab.com/2008/07/11/is-there-water-on-the-moon/
http://www.space-travel.com/reports/Next_ISRO_Launch_In_July_August_999.html
https://www.space.com/scienceastronomy/solarsystem/moon_rock_analysis_000522_MB_.html http://www.suite101.com/article.cfm/science_surfing/116801

Satellites Unlock Secret to Northern India's Vanishing Water.

Reviewed and Submitted by
Dr. Nitish Priyadarshi

As animated here, groundwater storage varied in northwestern India between 2002 and 2008, relative to the mean for the period. These deviations from the mean are expressed as the height of an equivalent layer of water, ranging from -12 cm (deep red) to 12 cm (dark blue). Credit: NASA/Trent Schindler and Matt Rodell.

The map, showing groundwater withdrawals as a percentage of groundwater recharge, is based on state-level estimates of annual withdrawals and recharge reported by India's Ministry of Water Resources. The three states included in this study are labeled. Credit: NASA/Matt Rodell

The map shows groundwater changes in India during 2002-08, with losses in red and gains in blue, based on GRACE satellite observations. The estimated rate of depletion of groundwater in northwestern India is 4.0 centimeters of water per year, equivalent to a water table decline of 33 centimeters per year. Increases in groundwater in southern India are due to recent above-average rainfall, whereas rain in northwestern India was close to normal during the study period. Credit: I. Velicogna/UC Irvine

WASHINGTON -- Using NASA satellite data, scientists have found that groundwater levels in northern India have been declining by as much as one foot per year over the past decade. Researchers concluded the loss is almost entirely due to human activity. More than 26 cubic miles of groundwater disappeared from aquifers in areas of Haryana, Punjab, Rajasthan and the nation's capitol territory of Delhi, between 2002 and 2008. This is enough water to fill Lake Mead, the largest manmade reservoir in the United States, three times. A team of hydrologists led by Matt Rodell of NASA's Goddard Space Flight Center in Greenbelt, Md., found that northern India's underground water supply is being pumped and consumed by human activities, such as irrigating cropland, and is draining aquifers faster than natural processes can replenish them. The results of this research were published today in Nature. The finding is based on data from NASA's Gravity Recovery and Climate Experiment (GRACE), a pair of satellites that sense changes in Earth's gravity field and associated mass distribution, including water masses stored above or below Earth's surface. As the twin satellites orbit 300 miles above Earth's surface, their positions change relative to each other in response to variations in the pull of gravity. Changes in underground water masses affect gravity enough to provide a signal that can be measured by the GRACE spacecraft. After accounting for other mass variations, such changes in gravity are translated into an equivalent change in water. "Using GRACE satellite observations, we can observe and monitor water storage changes in critical areas of the world, from one month to the next, without leaving our desks," said study co-author Isabella Velicogna of NASA's Jet Propulsion Laboratory in Pasadena, Calif., and the University of California, Irvine. Groundwater comes from the natural percolation of precipitation and other surface waters down through Earth’s soil and rock, accumulating in cavities and layers of porous rock, gravel, sand or clay. Groundwater levels respond slowly to changes in weather and can take months or years to replenish once pumped for irrigation or other uses. Data provided by India's Ministry of Water Resources to the NASA-funded researchers suggested groundwater use across India was exceeding natural replenishment, but the regional rate of depletion was unknown. Rodell and colleagues analyzed six years of monthly GRACE data for northern India to produce a time series of water storage changes beneath the land surface. "We don't know the absolute volume of water in the northern Indian aquifers, but GRACE provides strong evidence that current rates of water extraction are not sustainable," said Rodell. "The region has become dependent on irrigation to maximize agricultural productivity. If measures are not taken to ensure sustainable groundwater usage, the consequences for the 114 million residents of the region may include a collapse of agricultural output and severe shortages of potable water." Researchers examined data and models of soil moisture, lake and reservoir storage, vegetation and glaciers in the nearby Himalayas in order to confirm that the apparent groundwater trend was real. The loss is particularly alarming because it occurred when there were no unusual trends in rainfall. In fact, rainfall was slightly above normal for the period. The only influence they couldn't rule out was human. "For the first time, we can observe water use on land with no additional ground-based data collection," said co-author James Famiglietti of the University of California, Irvine. "This is critical because in many developing countries, where hydrological data are both sparse and hard to access, space-based methods provide perhaps the only opportunity to assess changes in fresh water availability across large regions." GRACE is a partnership between NASA and the German Aerospace Center, DLR. The University of Texas Center for Space Research in Austin has overall GRACE mission responsibility. GRACE was launched in 2002.

Article source:

http://www.nasa.gov/topics/earth/features/india_water.html

NASA, Japan Release Most Complete Topographic Map of Earth.

WASHINGTON -- NASA and Japan released a new digital topographic map of Earth Monday that covers more of our planet than ever before. The map was produced with detailed measurements from NASA's Terra spacecraft. The new global digital elevation model of Earth was created from nearly 1.3 million individual stereo-pair images collected by the Japanese Advanced Spaceborne Thermal Emission and Reflection Radiometer, or ASTER, instrument aboard Terra. NASA and Japan's Ministry of Economy, Trade and Industry, known as METI, developed the data set. It is available online to users everywhere at no cost. "This is the most complete, consistent global digital elevation data yet made available to the world," said Woody Turner, ASTER program scientist at NASA Headquarters in Washington. "This unique global set of data will serve users and researchers from a wide array of disciplines that need elevation and terrain information." According to Mike Abrams, ASTER science team leader at NASA's Jet Propulsion Laboratory in Pasadena, Calif., the new topographic information will be of value throughout the Earth sciences and has many practical applications. "ASTER's accurate topographic data will be used for engineering, energy exploration, conserving natural resources, environmental management, public works design, firefighting, recreation, geology and city planning, to name just a few areas," Abrams said. Previously, the most complete topographic set of data publicly available was from NASA's Shuttle Radar Topography Mission. That mission mapped 80 percent of Earth's landmass, between 60 degrees north latitude and 57 degrees south. The new ASTER data expands coverage to 99 percent, from 83 degrees north latitude and 83 degrees south. Each elevation measurement point in the new data is 98 feet apart. The ASTER data fill in many of the voids in the shuttle mission's data, such as in very steep terrains and in some deserts," said Michael Kobrick, Shuttle Radar Topography Mission project scientist at the Jet Propulsion Laboratory. "NASA is working to combine the ASTER data with that of the Shuttle Radar Topography Mission and other sources to produce an even better global topographic map." NASA and METI are jointly contributing the ASTER topographic data to the Group on Earth Observations, an international partnership headquartered at the World Meteorological Organization in Geneva, Switzerland, for use in its Global Earth Observation System of Systems. This "system of systems" is a collaborative, international effort to share and integrate Earth observation data from many different instruments and systems to help monitor and forecast global environmental changes. NASA, METI and the U.S. Geological Survey validated the data, with support from the U.S. National Geospatial-Intelligence Agency and other collaborators. The data will be distributed by NASA's Land Processes Distributed Active Archive Center at the U.S. Geological Survey's Earth Resources Observation and Science Data Center in Sioux Falls, S.D., and by METI's Earth Remote Sensing Data Analysis Center in Tokyo. ASTER is one of five Earth-observing instruments launched on Terra in December 1999. ASTER acquires images from the visible to the thermal infrared wavelength region, with spatial resolutions ranging from about 50 to 300 feet. A joint science team from the U.S. and Japan validates and calibrates the instrument and data products. The U.S. science team is located at NASA's Jet Propulsion Laboratory.

Death Valley

Death Valley, Calif., has the lowest point in North America, Badwater at 85.5 meters (282 feet) below sea level. It is also the driest and hottest location in North America. Located in eastern California and western Nevada, Death Valley forms part of Death Valley National Park. The region is characterized by deep valleys and high mountain ranges, located in the large Basin and Range province of the western United States. This view looking towards the northwest was created by draping an Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) simulated natural color image over digital topography from the ASTER Global Digital Elevation Model (GDEM) data set. Furnace Creek ranch in the right foreground is the only place on the valley floor where vegetation grows year-round due to water channeled through Furnace Creek. The ASTER scene was acquired September 24, 2003, and is located near 36.4 degrees north latitude, 116.9 degrees west longitude.

Himalayan glaciers in Bhutan

In the Bhutan Himalayas, Advanced Spaceborne Thermal Emission and Reflection Radiometer data have revealed significant spatial variability in glacier flow, such that the glacier velocities in the end zones on the south side exhibit significantly lower velocities (9 to 18 meters, or 30 to 60 feet per year), versus much higher flow velocities on the north side (18 to 183 meters, or 60 to 600 feet per year). The higher velocity for the northern glaciers suggests that the southern glaciers have substantially stagnated ice. This view looking towards the northwest was created by draping an ASTER simulated natural color image over digital topography from the ASTER Global Digital Elevation Model (GDEM) data set. The ASTER scene was acquired November 20, 2001, and is centered near 28.3 degrees north latitude, 90.1 degrees east longitude.

Source of the article and photographs:

http://www.nasa.gov/topics/earth/features/20090629.html

NASA Satellite Detects Red Glow to Map Global Ocean Plant Health

[Fig. Ocean scientists can now remotely measure the amount of fluorescent red light emitted by ocean phytoplankton and assess how efficiently the microscopic plants are turning sunlight and nutrients into food through photosynthesis. (picture source http://www.nasa.gov/)

WASHINGTON -- Researchers have conducted the first global analysis of the health and productivity of ocean plants using a unique signal detected by NASA's Aqua satellite.
Ocean scientists can now remotely measure the amount of fluorescent red light emitted by phytoplankton and assess how efficiently these microscopic plants turn sunlight and nutrients into food through photosynthesis. Researchers also can study how changes in the global environment alter these processes at the center of the ocean food web. Single-celled phytoplankton fuel nearly all ocean ecosystems, serving as the most basic food source for marine animals. Phytoplankton account for half of all photosynthetic activity on Earth and play a key role in the balance of carbon dioxide in the atmosphere. The health of these marine plants affects the amount of carbon dioxide the ocean can absorb from the atmosphere and how the ocean responds to a changing climate. "This is the first direct measurement of the health of the phytoplankton in the ocean," said Michael Behrenfeld, a biologist who specializes in marine plants at Oregon State University. "We have an important new tool for observing changes in phytoplankton every week, all over the planet." All plants absorb energy from the sun, typically more than they can consume through photosynthesis. A small fraction of this extra energy is re-emitted as fluorescent light in red wavelengths. Using the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA's Aqua satellite, scientists have now observed "red-light fluorescence" over the open ocean. MODIS is the first instrument to observe this signal on a global scale. "The amount of fluorescent light emitted is not constant; it changes with the health of the plant life in the ocean," said Behrenfeld. Scientists previously used satellite sensors to track the amount of plant life in the ocean by measuring the amount and distribution of chlorophyll. "Chlorophyll gives us a picture of how much phytoplankton is present," said co-author Scott Doney, a marine chemist from the Woods Hole Oceanographic Institution in Woods Hole, Mass. "Fluorescence provides insight into how well they are functioning in the ecosystem." With this new measurement, the scientists discovered large areas of the Indian Ocean where phytoplankton were under stress from iron deficiency. They were surprised to see large portions of the ocean "light up" seasonally as phytoplankton responded to a lack of iron in their diet. The amount of fluorescence increases when phytoplankton have too little iron, a nutrient in seawater. Iron reaches the sea surface on winds blowing dust from deserts and other arid areas, and from upwelling currents. The research team detected new regions of the ocean affected by iron deposition and depletion. In the fall and winter and especially the summer, significant southwesterly winds over the Indian Ocean stir up ocean currents and bring more nutrients up from the depths for the phytoplankton to feed on. At the same time, the amount of iron-rich dust delivered by winds is reduced. Climate change could mean stronger winds pick up more dust and blow it to the sea, or less intense winds leave waters dust-free. Some regions will become drier and others wetter, changing the regions where dusty soils accumulate and get swept up into the air. Phytoplankton will reflect and react to these global changes. "On time-scales of weeks to months, we can use this data to track plankton responses to iron inputs from dust storms and the transport of iron-rich water from islands and continents," Doney said. "Over years to decades, we also can detect long-term trends in climate change and other human perturbations to the ocean." These findings appeared in the May edition of the journal Biogeosciences.

Fore more information :

http://www.nasa.gov/topics/earth/features/modis_fluorescence.html

Did warming helped water to vanish from Mars?

Will our Earth will look same as Mars in future?

by

Dr. Nitish Priyadarshi

When I began studying Environmental Geology, I was told that the depletion of water, global warming crisis are going to be the most important issues the planet Earth would have to face in coming decades or centuries.
The political pundits were not impressed. After years of neglect, global warming and water depletion have suddenly become matters of wide spread international concern. Water is depleting, desert is expanding and lots more.

You must be now thinking that why I am writing on such issues which is related to Earth and not to Mars. Answer is below.

According to latest concept it is now clear that Mars once definitely supported a watery environment. It is clear from the pictures that Mars is covered with features that are best explained by the movement of water, either in catastrophic floods or the slow movement of groundwater.

If the water really existed on the Mars, which is now proved by different pictures, then where all the waters vanished? Was it the effect of warming or climate change which helped the water to escape from atmosphere? Our Earth is also passing through the same phase. If all the water from our atmosphere escapes, will our Earth will look same as Mars, devoid of water and life.

My concern is hidden in the present environmental condition of the Mars which is now devoid of water and life. Is our Earth is going to become desert like that of Mars in coming centuries.
Many of you must be thinking that my theory is merely hypothetical and nothing like this is going to happen to Earth. Future of Earth can never be Mars

It may be speculations but we must have to think seriously to save our planet for our coming generations. Really what happened to the water on Mars no body knows.

Evidences of ancient water on Mars:

Photo credits: NASA

It’s dustier than the road to death, colder than the devil’s kiss. Like much of Mars, the butter scotch plain is inhospitable, empty, ancient and dull.

Mars has always exerted a powerful attraction for people on Earth. Every two years it disappears, to stage a spectacular reappearance some time later as a fiery red object in the sky. Its blood-red color has inspired terror and war. In Hindu mythology this planet governs the health and carrier of humans.

It was only after the theoretical work Copernicus at the end of 15th century, and the observations Galileo at the beginning of the 17th, that Mars became just another world.
The quest for water on Mars has motivated many geologists and astronomers. The space probes have shown definitively that the amount of water vapor in the Martian atmosphere is only 0.003%. If it were to be condensed, it would form a layer on the surface with a thickness of just one-tenth of a millimeter.
The atmospheric composition is 95% carbon dioxide, 3% nitrogen, and only 0.1% oxygen: utterly unsuitable for any animal life.

Despite their disappointment, astronomers have not been discouraged. There was considerable surprise when the Viking Orbiters that had accompanied the Landers to Mars revealed other Martian landscapes. These Orbiters took 51,000 photographs of the surface, some of which had a resolution of as little as 10m. The photographs, distributed in the form of magnetic tapes to the principal research institutes around the world, have enabled us to study the whole of the Martian globe. Its general appearance is that of a inanimate, cold, desert world. But there are some notable features, including volcanoes, one of which, Olympus Mons, with a base 700 km across and a height of 27000 m, is the largest in the whole solar system. There are enormous impact basins, such as Argyre, which is 600 km in diameter and 1000 m deep.

Above all, however, the great surprise was the dried-up river-beds, some as much as 15 km wide, and whose discharge must have been 1000 times that of the Amazon, our greatest river! If liquid water existed on Mars in such quantity, would there not have been a denser atmosphere, which would imply a far more temperate climate, perhaps favorable to the spontaneous appearance of life?

In previous centuries, astronomers thought that the dark areas they saw on Mars through their telescopes might be seas, and, at the end of the 19th century there was much speculation, led by Percical Lowell, about the possibility of Martian canals. By the the early decades of this century, however, it had become clear, because of the very low atmospheric pressure, that little or no surface water could exist on the Red Planet today. In 1969, Mariner 9 provided the first strong evidence that liquid water had flowed on the surface of Mars in the remote past. Among the thousands of images it sent back from orbit were those of flat-floored channels with eroded banks, sand bars and teardrop-shaped islands, channels with second- and third-order tributary systems, and braided channels which, had they been encountered on Earth, would unhesitatingly have been attributed to episodic flooding. Later probes have added to the evidence of water-carved channels and other features on Mars. The fact that Mars had flowing water implies that conditions on the planet were once very different than they are today. Yet, curiously, there are no signs that it ever rained on the fourth planet. The water-carved systems on Mars are short and stubby, dividing little upstream, and ending abruptly as if the water had suddenly appeared at that spot rather than having fallen over a large area and become collected. The assumption is that the Martian water erupted from beneath the surface, welling up as a result of volcanic eruptions or asteroid impacts, and then flooded to form channels, and lakes, and perhaps even seas. Seeing the large amounts of fossilized evidences of the ancient water flow, it can also be assumed that water flowed in this red planet in the remote past and gradually vanished from the planet either due to global warming, which our Earth is facing today, or due to some other factors like geological or climate change.

How much liquid water existed on Mars in the past, and when? Does liquid water exist on Mars today? These are questions that fascinate scientists, especially astrobiologists, because they have a direct bearing on whether there was once life on Mars and, if so, whether it has survived to the present day. For this we have to search for fossils. The biological exploration of Mars is based on the idea that life appeared on that planet four billion years ago. Subsequently, it either disappeared 3.8 billion years ago (which is why we need to search for fossils), or else adapted to current conditions.

A large lake in the southern highlands of Mars is thought to have overflowed about 3.5 billion years ago, gouging out canyon as the torrent headed north and then spilled into the crater, forming a new lake. More evidences of catastrophic floods indicate ancient water flow on the surface of the red planet.

Images taken by Mars Global Surveyor (MGS) have provided some of the best evidence yet that water still occasionally flows on the Martian surface. Two gullies on the inside of craters, which were originally photographed by MGS in 1999 and 2001, and imaged again in 2004 and 2005, showed changes consistent with water flowing down the crater walls,

Other scientists, however, have challenged this explanation, pointing out that the gullies, and many others like them discovered by MGS, could have been caused not by water but by liquid carbon dioxide. The atmosphere of Mars is so thin and the temperature so cold that liquid water couldn't persist at the surface but would rapidly evaporate or freeze. Liquid carbon dioxide, on the other hand, has a lower freezing point (-56.6°C) and could stay liquid on the surface longer.

Striking new images of the Red Planet have raised hopes life could be found on Mars after all.

Scientists say they have photographic evidence that suggests liquid water may have been on the planet as little as five years ago.

In some of the pictures released by NASA, structures resembling to deltas formed on our Earth adds more evidence of water flow in past.

Whatever may be the truth, but it is now sure that there are ample of evidences that water did existed on this planet. According to the recent theories there are some fresh evidences of water flow. To me these are the ancient waters which were trapped in the remote past beneath the surface and which flow out from time to time carving latest flow structures on the upper surface of the red planet.

Where all the water went is an important question to scientists piecing together the planet’s geologic history. Perhaps some water seeped into the ground and froze, wound up in polar ice, or was lost from the atmosphere, but scientists can’t account for all of it.
Today, based on our observations from orbit, Mars appears to be very dry. There is little water in the atmosphere and only a small amount of water ice in evidence on the surface. Yet the planet is covered with features that are best explained by the movement of water, either in catastrophic floods or the slow movement of groundwater. Whether that water was present early in the history of Mars and was lost to space over eons, or is still present in great underground deposits of ice and groundwater, is a question whose answer must be left for the future exploration of Mars.

Sources:
National Geographic Magazine, Jan. 2004. Mars, Is there life in the ancient ice?
http://www.dailymail.co.uk/news/article-420833/Does-water-STILL-flow-Mars.html
http://www.cnn.com/2004/TECH/space/12/03/marschances.water/index.html
http://www.msss.com/http/ps/channels/channels.html
http://en.wikipedia.org/wiki/Geology_of_Mars

Mysterious burst of light in Universe.

A mysterious flash of light from somewhere near or far in the universe is still keeping astronomers in the dark long after it was first detected by NASA's Hubble Space Telescope in 2006. It might represent an entirely new class of stellar phenomena that has previously gone undetected in the universe, say researchers.
Astronomers commonly observe intense flashes of light from a variety of stellar explosions and outbursts, such as novae and supernovae. Hubble discovered the cosmic flash on February 21, 2006. It steadily rose in brightness for 100 days, and then dimmed back to oblivion after another 100 days.
The rise and fall in brightness has a signature that simply has never been recorded for any other type of celestial event. Supernovae peak after no more than 70 days, and gravitational lensing events are much shorter. Therefore, this observation defies a simple explanation, reports Kyle Barbary of the Lawrence Berkeley National Laboratory (LBNL) in Berkeley, Calif. He is describing the bizarre Hubble observation at the 213th meeting of the American Astronomical Society in Long Beach, Calif. "We have never seen anything like it," he concludes.
The spectral fingerprints of light coming from the object, cataloged as SCP 06F6, also have eluded identification as being due to any specific element. One guess is that the features are redshifted molecular carbon absorption lines in a star roughly one billion light-years away.
But searches through various astronomical survey catalogs for the source of the light have not uncovered any evidence for a star or galaxy at the location of the flash. The Supernova Cosmology Project at LBNL discovered it serendipitously in a search for supernovae.
Hubble was aimed at a cluster of galaxies 8 billion light-years away in the spring constellation Bootes. But the mystery object could be anywhere in between, even in the halo of our own Milky Way galaxy.
Papers published by other researchers since the event was reported in June 2006, have suggested a bizarre zoo of possibilities: the core collapse and explosion of a carbon rich star, a collision between a white dwarf and an asteroid, or the collision of a white dwarf with a black hole.
But Barbary does not believe that any model offered so far fully explains the observations. "I don't think we really know what the discovery means until we can observe similar objects in the future."
All-sky surveys for variable phenomena, such as those to be conducted with the planned Large Synoptic Survey Telescope, may ultimately find similar transient events in the universe.
CONTACT
Ray Villard Space Telescope Science Institute, Baltimore, Md. 410-338-4514 villard@stsci.edu
Kyle Barbary University of California Berkeley/Lawrence Berkeley National Lab, Berkeley, Calif. 510-486-4652 kbarbary@berkeley.edu / kbarbary@lbl.gov
source:
http://hubblesite.org/newscenter/archive/releases/2009/04

NASA Radar provides first look inside Moon's shadowed craters.

Moon's shadowed Crater

Using a NASA radar flying aboard India's Chandrayaan-1 spacecraft, scientists are getting their first look inside the moon's coldest, darkest craters.
The images show the floors permanently-shadowed polar craters on the moon that aren’t visible from Earth. Scientists are using the instruments to map and search the insides of the craters for water ice. The image was taken on November 17, 2008.