Posted on by Fraser Cain

New Research Helps Explain Dust Bowl Drought

Image credit: NOAA
NASA scientists have an explanation for one of the worst climatic events in the history of the United States, the “Dust Bowl” drought, which devastated the Great Plains and all but dried up an already depressed American economy in the 1930’s.

Siegfried Schubert of NASA’s Goddard Space Flight Center, Greenbelt, Md., and colleagues used a computer model developed with modern-era satellite data to look at the climate over the past 100 years. The study found cooler than normal tropical Pacific Ocean surface temperatures combined with warmer tropical Atlantic Ocean temperatures to create conditions in the atmosphere that turned America’s breadbasket into a dust bowl from 1931 to 1939. The team’s data is in this week’s Science magazine.

These changes in sea surface temperatures created shifts in the large-scale weather patterns and low level winds that reduced the normal supply of moisture from the Gulf of Mexico and inhibited rainfall throughout the Great Plains.

“The 1930s drought was the major climatic event in the nation’s history,” Schubert said. “Just beginning to understand what occurred is really critical to understanding future droughts and the links to global climate change issues we’re experiencing today,” he said.

By discovering the causes behind U.S. droughts, especially severe episodes like the Plains’ dry spell, scientists may recognize and possibly foresee future patterns that could create similar conditions. For example, La Ni?as are marked by cooler than normal tropical Pacific Ocean surface water temperatures, which impact weather globally, and also create dry conditions over the Great Plains.

The researchers used NASA’s Seasonal-to-Interannual Prediction Project (NSIPP) atmospheric general circulation model and agency computational facilities to conduct the research. The NSIPP model was developed using NASA satellite observations, including; Clouds and the Earth’s Radiant Energy System radiation measurements; and the Global Precipitation Climatology Project precipitation data.

The model showed cooler than normal tropical Pacific Ocean temperatures and warmer than normal tropical Atlantic Ocean temperatures contributed to a weakened low-level jet stream and changed its course. The jet stream, a ribbon of fast moving air near the Earth’s surface, normally flows westward over the Gulf of Mexico and then turns northward pulling up moisture and dumping rain onto the Great Plains. As the low level jet stream weakened, it traveled farther south than normal. The Great Plains dried up and dust storms formed.

The research shed light on how tropical sea surface temperatures can have a remote response and control over weather and climate. It also confirmed droughts can become localized based on soil moisture levels, especially during summer. When rain is scarce and soil dries, there is less evaporation, which leads to even less precipitation, creating a feedback process that reinforces lack of rainfall.

The study also shed light on droughts throughout the 20th century. Analysis of other major U.S. droughts of the 1900s suggests a cool tropical Pacific was a common factor. Schubert said simulating major events like the 1930s drought provides an excellent test for computer models. While the study finds no indication of a similar Great Plains drought in the near future, it is vital to continue studies relating to climate change. NASA’s current and planned suite of satellite sensors is uniquely poised to answer related climate questions.

Original Source: NASA News Release

Posted on by Fraser Cain

Minerals in Martian Spherules Point to Water

Image credit: NASA/JPL
A major ingredient in small mineral spheres analyzed by NASA’s Mars Exploration Rover Opportunity furthers understanding of past water at Opportunity’s landing site and points to a way of determining whether the vast plains surrounding the site also have a wet history.

The spherules, fancifully called blueberries although they are only the size of BBs and more gray than blue, lie embedded in outcrop rocks and scattered over some areas of soil inside the small crater where Opportunity has been working since it landed nearly two months ago.

Individual spherules are too small to analyze with the composition-reading tools on the rover. In the past week, those tools were used to examine a group of berries that had accumulated close together in a slight depression atop a rock called “Berry Bowl.” The rover’s Moessbauer spectrometer, which identifies iron-bearing minerals, found a big difference between the batch of spherules and a “berry-free” area of the underlying rock.

“This is the fingerprint of hematite, so we conclude that the major iron-bearing mineral in the berries is hematite,” said Daniel Rodionov, a rover science team collaborator from the University of Mainz, Germany. On Earth, hematite with the crystalline grain size indicated in the spherules usually forms in a wet environment.

Scientists had previously deduced that the martian spherules are concretions that grew inside water-soaked deposits. Evidence such as interlocking spherules and random distribution within rocks weighs against alternate possibilities for their origin. Discovering hematite in the rocks strengthens this conclusion. It also adds information that the water in the rocks when the spherules were forming carried iron, said Dr. Andrew Knoll, a science team member from Harvard University, Cambridge, Mass.

“The question is whether this will be part of a still larger story,” Knoll said at a press briefing today at NASA’s Jet Propulsion Laboratory, Pasadena, Calif. Spherules below the outcrop in the crater apparently weathered out of the outcrop, but Opportunity has also observed plentiful spherules and concentrations of hematite above the outcrop, perhaps weathered out of a higher layer of once-wet deposits. The surrounding plains bear exposed hematite identified from orbit in an area the size of Oklahoma — the main reason this Meridiani Planum region of Mars was selected as Opportunity’s landing site.

“Perhaps the whole floor of Meridiani Planum has a residual layer of blueberries,” Knoll suggested. “If that’s true, one might guess that a much larger volume of outcrop once existed and was stripped away by erosion through time.”

Opportunity will spend a few more days in its small crater completing a survey of soil sites there, said Bethany Ehlmann, a science team collaborator from Washington University, St. Louis. One goal of the survey is to assess distribution of the spherules farther from the outcrop. After that, Opportunity will drive out of its crater and head for a much larger crater with a thicker outcrop about 750 meters (half a mile) away.

Halfway around Mars, NASA’s other Mars Exploration Rover, Spirit, has been exploring the rim of the crater nicknamed “Bonneville,” which it reached last week. A new color panorama shows “a spectacular view of drift materials on the floor” and other features, said Dr. John Grant, science team member from the National Air and Space Museum in Washington. Controllers used Spirit’s wheels to scuff away the crusted surface of a wind drift on the rim for comparison with drift material inside the crater.

A faint feature at the horizon of the new panorama is the wall of Gusev Crater, about 80 kilometers (50 miles) away, said JPL’s Dr. Albert Haldemann, deputy project scientist. The wall rises about 2.5 kilometers (1.6 miles) above Spirit’s current location roughly in the middle of Gusev Crater. It had not been seen in earlier Spirit images because of dust, but the air has been clearing and visibility improving, Haldemann said.

Controllers have decided not to send Spirit into Bonneville crater. “We didn’t see anything compelling enough to take the risk to go down in there,” said JPL’s Dr. Mark Adler, mission manager. Instead, after a few more days exploring the rim, Spirit will head toward hills to the east informally named “Columbia Hills,” which might have exposures of layers from below or above the region’s current surface.

The main task for both rovers is to explore the areas around their landing sites for evidence in rocks and soils about whether those areas ever had environments that were watery and possibly suitable for sustaining life. JPL, a division of the California Institute of Technology in Pasadena, manages the Mars Exploration Rover project for NASA’s Office of Space Science, Washington, D.C. Images and additional information about the project are available from JPL at http://marsrovers.jpl.nasa.gov and from Cornell University, Ithaca, N.Y., at http://athena.cornell.edu.

Original Source: NASA/JPL News Release

Posted on by Fraser Cain

Five Planets Visible in the Sky

Image credit: Sky and Telescope
For the next couple weeks, all five planets that are ever visible to the unaided eye shine at once during dusk. Moreover, the Moon and a prominent star cluster join the show as well, forming striking combinations in the early-evening sky.

“This is a special time for anyone who notices the sky,” says Alan MacRobert, a senior editor of Sky & Telescope magazine. “You don’t have to be any kind of great astronomer to enjoy this.”

Sky & Telescope offers news media the following guide to the changing celestial scenery. (All descriptions are for midnorthern latitudes, such as those in the United States and southern Canada.)

Every Evening, March 19?31: Spot All Five Planets
Look west as twilight fades on any clear evening, and there’s dazzling white Venus. You can’t miss it. Venus is the brightest point of light in the early-evening sky.

Look very far below Venus, and perhaps a bit to the right, to catch fainter little Mercury near the horizon. Be sure to look early (about 45 to 60 minutes after sunset) before Mercury gets too low and sets.

To the upper left of Venus, by roughly the width of your fist held at arm’s length, you’ll find fainter Mars, glimmering pale orange-red.

Three times farther to Mars’s upper left is pale yellow Saturn. It’s positioned high above the bright constellation Orion.

And Jupiter is the big, bright point of light shining high in the east-southeast. It’s second in brightness only to Venus.

One-Day Events
March 22: Crescent Moon and Mercury
Look low in the west (far below bright Venus) as twilight fades to pick up the beautifully thin crescent Moon. Look to its lower right ? and there’s Mercury. Binoculars give a fine view.

March 23: Moon under Venus
The crescent Moon shines below bright Venus in the west this evening, offering a foretaste of their beautiful conjunction (close pairing) tomorrow.

March 24: Crescent Moon and Venus Grab the Eye!
The Moon and Venus are closely paired in the western sky this evening, a strikingly beautiful sight. “This is going to be a real head-turner,” says MacRobert. “People will see this through their windshields driving home from work and say, ‘What’s that?'”

The Moon and Venus are the two brightest objects in the sky after the Sun. Binoculars will give an especially gorgeous view of them paired. This is also a good time to look for “earthshine” making the dark portion of the Moon glow dimly gray. Earthshine is sunlight reflected from the Earth onto the Moon’s nighttime landscape ? the same way a full Moon lights the ground on Earth at night.

As dusk deepens, look for fainter Mars to the upper left of the Moon and Venus, the star Aldebaran to the left or upper left of Mars (looking like its twin), and the Pleiades star cluster nearer to Mars’s right. The cluster is about as big as your fingertip held at arm’s length.

March 25: Moon with Mars
As a coda to yesterday’s Moon-Venus pairing, the Moon now pairs very closely with dimmer orange-red Mars ? while Venus blazes brightly to their lower right.

March 27: Saturn Left of the Moon
The Moon now pairs up with Saturn, the next planet east across the sky. Saturn is to the Moon’s left. Look below them for the bright constellation Orion.

March 28: Saturn under the Moon
Tonight you’ll find the pale yellow point of Saturn shining beneath the Moon, which is now at first-quarter phase (half lit).

April 1?4: Venus Meets the Pleiades
Meanwhile, action has been developing in the west. During and after nightfall in the first few days of April, you’ll see the little Pleiades star cluster positioned close to brilliant Venus. Again, binoculars give a wonderful view.

April 2: Moon Shines with Jupiter
Tonight the gibbous Moon shines close to bright Jupiter ? the last of the five naked-eye planets that it meets ? high in the southeast.

Original Source: S&T News Release

Posted on by Fraser Cain

NASA and Department of Energy Working on Nuclear Reactor

Image credit: NASA/JPL
NASA has a new partner in its mission to explore the universe and search for life.

The Department of Energy’s (DOE) Naval Reactors (NR) Program joins NASA in its effort to investigate and develop space nuclear power and propulsion technologies for civilian applications. These activities could enable unprecedented space exploration missions and scientific return unachievable with current technology.

NR brings 50-plus years of practical experience in developing safe, rugged, reliable, compact and long-lived reactor systems designed to operate in unforgiving environments. NR is a joint DOE and Department of the Navy organization responsible for all aspects of naval nuclear propulsion.

The partnership is responsible for developing the first NASA spacecraft, the Jupiter Icy Moons Orbiter (JIMO), that will take advantage of a nuclear-reactor energy source for exploring our solar system. JIMO will visit Jupiter’s three icy moons, Ganymede, Callisto and Europa. These icy worlds, in particular Europa, are believed to have liquid-water oceans, under a thick layer of ice on their surfaces, which could potentially harbor life.

The reactor system will provide substantially more electrical power. This will greatly enhance the capability of ion-drive propulsion, the number and variety of scientific instruments on the spacecraft, the rate of data transmission, and orbital maneuvering around Jupiter’s moons.

NASA sought this partnership because NR has an enduring commitment to safety and environmental stewardship that is a requirement for an undertaking of this magnitude, ” said NASA Administrator Sean O’Keefe.

“This partnership will help ensure the safe development and use of a space-fission reactor to enable unparalleled science and discovery as we explore the solar system and beyond. This work is an integral piece of the President’s exploration agenda,” Administrator O’Keefe said.

NASA, through its newly created Office of Exploration Systems, expects that several reactor modules of the same or similar design as that required for JIMO would be developed for use on future exploration missions. NR will direct and oversee the development, design and delivery of, and operational support for these civilian reactor modules.

The Office of Nuclear Energy, Science and Technology, another DOE organization with extensive nuclear-reactor development experience, will retain responsibility for supporting NASA’s other space nuclear technology efforts, including long-term space-reactor science and technology development not associated with NR’s responsibilities.

All activities in support of NASA will be conducted as part of NR’s civilian responsibilities for the National Nuclear Security Administration, a semi-autonomous agency of DOE. Activities in support of NASA are not part of NR’s Navy responsibilities or any Department of Defense activities. This partnership with NASA is consistent with NR’s history of supporting fission-reactor work for civilian applications, including the first U.S. commercial production of electricity from nuclear power at the Shippingport Atomic Power Station.

NASA will fund all work under the partnership. Specific roles and responsibilities will be defined in Memoranda of Understanding and Agreements currently being drafted by NASA and NR. NR and the DOE Office of Nuclear Energy will also review capabilities and facilities at DOE laboratories outside NR for consideration in support of JIMO and other Project Prometheus activities.

Established in 2003, Project Prometheus is developing radioisotope electric power sources for use in space and on planets or moons, as well as new fission-reactor power sources for advanced missions into deep space requiring higher power levels for science observations, propulsion, communications and life support systems.

More information on Project Prometheus is available at:
http://spacescience.nasa.gov/missions/prometheus.htm

More information on the Jupiter Icy Moons Orbiter is available at:
http://spacescience.nasa.gov/missions/JIMO.pdf

Original Source: NASA News Release

Posted on by Fraser Cain

Mars Express Finds South Pole Water Ice

Image credit: ESA
Thanks to ESA?s Mars Express, we now know that Mars has vast fields of perennial water ice, stretching out from the south pole of the Red Planet.

Astronomers have known for years that Mars possessed polar ice caps, but early attempts at chemical analysis suggested only that the northern cap could be composed of water ice, and the southern cap was thought to be carbon dioxide ice.

Recent space missions then suggested that the southern ice cap, existing all year round, could be a mixture of water and carbon dioxide. But only with Mars Express have scientists been able to confirm directly for the first time that water ice is present at the south pole too.

Mars Express made observations with its OMEGA instrument to measure the amounts of sunlight and heat reflected from the Martian polar region. When planetary scientists analysed the data, it clearly showed that, as well as carbon dioxide ice, water ice was present too.

The results showed that hundreds of square kilometres of ?permafrost? surround the south pole. Permafrost is water ice, mixed into the soil of Mars, and frozen to the hardness of solid rock by the low Martian temperatures. This is the reason why water ice has been hidden from detection until now – because the soil with which it is mixed cannot reflect light easily and so it appears dark.

However, OMEGA looked at the surface with infrared eyes and, being sensitive to heat, clearly picked up the signature of water ice. The discovery hints that perhaps there are much larger quantities of water ice all over Mars than previously thought.

Using this data, planetary scientists now know that the south polar region of Mars can be split into three separate parts. Part one is the bright polar cap itself, a mixture of 85% highly reflective carbon dioxide ice and 15% water ice.

The second part comprises steep slopes known as ?scarps?, made almost entirely of water ice, that fall away from the polar cap to the surrounding plains. The third part was unexpected and encompasses the vast permafrost fields that stretch for tens of kilometres away from the scarps.

The OMEGA observations were made between 18 January and 11 February this year, when it was late summer for the Martian southern hemisphere and temperatures would be at their highest. Even so, that is probably only ?130 degrees Celsius and the ice that Mars Express has observed is a permanent feature of this location.

During the winter months, scientists expect that carbon dioxide from the atmosphere will freeze onto the poles, making them much larger and covering some of the water ice from view.

Mars Express and OMEGA will now continue looking for water ice and minerals across the surface of the planet. In May, another Mars Express instrument, the Mars Advanced Radar for Subsurface and Ionospheric Sounding (MARSIS), will begin collecting data, looking for water underground.

It will be particularly exciting when MARSIS looks at the south pole because, once planetary scientists know how deep the ice reaches, they will be able to calculate exactly how much water there is. Knowing this is very important to understand how Mars evolved and if it ever harboured life.

Original Source: ESA News Release

Posted on by Fraser Cain

Near Miss Today By Asteroid 2004 FH

Image credit: NASA
A small near-Earth asteroid (NEA), discovered Monday night by the NASA-funded LINEAR asteroid survey, will make the closest approach to Earth ever recorded. There is no danger of a collision with the Earth during this encounter.

The object, designated 2004 FH, is roughly 30 meters (100 feet) in diameter and will pass just 43,000 km (26,500 miles, or about 3.4 Earth diameters) above the Earth’s surface on March 18th at 5:08 PM EST (2:08 PM PST, 22:08 UTC).

On average, objects about the size of 2004 FH pass within this distance roughly once every two years, but most of these small objects pass by undetected. This particular close approach is unusual only in the sense that scientists know about it. The fact that an object as small as asteroid 2004 FH has been discovered now is mostly a matter of perseverance by the LINEAR team, who are funded by NASA to search for larger kilometer-sized NEAs, but also routinely detect much smaller objects.

Asteroid 2004 FH’s point of closest approach with the Earth will be over the South Atlantic Ocean. Using a good pair of binoculars, the object will be bright enough to be seen during this close approach from areas of Europe, Asia and most of the Southern Hemisphere.

Scientists look forward to the flyby as it will provide them an unprecedented opportunity to study a small NEA asteroid up close.

Original Source: NASA News Release

Posted on by Fraser Cain

New Detail on Cometary Jets Seen By Stardust

Image credit: NASA/JPL
On 2 January 2004, NASA’s Stardust spacecraft successfully survived flying through the coma (dust and gas cloud) surrounding comet 81P/Wild 2, captured thousands of fresh cometary dust particles released from the surface just hours before, and is now on its way home for Earth return set for January 2006.

During the flyby, the highest resolution images ever taken of a comet’s nucleus were obtained and have been the subject of intense study since the flyby. A short exposure image showing tremendous surface detail was overlain on a long exposure image taken just 10 seconds later showing jets.

“This spectacular composite image shows a surface feature unlike any other planetary surface see to date in our solar system”, says Prof Donald Brownlee, the Stardust Principal Investigator from the University of Washington. “Other than our sun, this is currently the most active planetary surface in our solar system, jetting dust and gas streams into space and leaving a trail millions of kilometers long.”

“The overall shape of the nucleus resembles a thick hamburger patty with a few bites taken out”, says Thomas Duxbury, the Stardust Project Manager from JPL. “The surface has significant relief on top of this overall shape that reflects billions of years of resurfacing from crater impacts and out gassing”.

One mystery from the close-views of Wild-2 was its pockmarks. “I looked at the images in stereo view,” said Brownlee. “One large depression has a bottom that is flat, with very steep walls [400-500 meters deep]. While any scientific evidence is only two days old,” most impact craters are expected to be bowl-shaped with much shallower aspect ratios (0.1-0.2), meaning they are five times wider than they are deep. Some of these depressions are not round, but scalloped and much deeper (aspect ratio, 0.4).

“I am from Washington state”, said Brownlee, “and when the comet is viewed in stereo pairs like that, it reminds me of Grand Cooley, with its steep cliffs and run-out areas at the bottom. Like flood areas from the Columbia River, if you were standing at the bottom of one of these comet depressions. But the floor of these comet depressions are incredibly complicated, like balls of clay have been mashed together and then etched.”

“The mission scientists with Deep Space I,” which flew by comet Borrelly, found surprising “mesas”, said Brownlee. “They speculated that these walls can sometimes face sunwards, and volatiles like ice and methane may evaporate or etch that surface. But on Wild-2, we see pits, not mesas. The two comets are quite different. We may have [with Wild-2] a young comet that evolves towards Borrelly, or vice versa.”

Three large comet jets registered on one of Stardust’s instruments, its dust counter. Three distinct peaks appeared with thousands of particle strikes each. Slightly less than an ounce of comet dust, or about a thimbleful, were collected over the spacecraft’s 12 minute pass through these large jets. “The secret of our mission is that we sample only the volatile material, that which is evaporating into space,” said Brownlee. “That’s the way we avoid any contaminants that might have left those impact-like marks on the comet’s surface. So it was better in this case to fly-through the lighter dust stream, than to land on this comet. We’d have to drive around a bit to find just the comet stuff.” In just such a science-fiction scenario of landing on a comet, the European mission, called Rosetta, will launch next month and travel to comet Churyumov-Gerasimenko in November 2014.

Preliminary scientific results obtained from the Wild 2 encounter are being presented at the Lunar and Planetary Science Conference in Houston, Texas by the Stardust science team. Stardust will bring samples of comet dust back to Earth in January 2006 to help answer fundamental questions about the origins of the solar system.

Original Source: NASA Astrobiology Magazine

Posted on by Fraser Cain

Integral Solves a Gamma Ray Mystery

Image credit: ESA
ESA’s Integral gamma-ray observatory has resolved the diffuse glow of gamma rays in the centre of our Galaxy and has shown that most of it is produced by a hundred individual sources.

Integral’s high sensitivity and pointing precision have allowed it to detect these celestial objects where all other telescopes, for more than thirty years, had seen nothing but a mysterious, blurry fog of gamma rays…

During the spring and autumn of 2003, Integral observed the central regions of our Galaxy, collecting some of the perpetual glow of diffuse low-energy gamma rays that bathe the entire Galaxy.

These gamma rays were first discovered in the mid-1970s by high-flying balloon-borne experiments. Astronomers refer to them as the ‘soft’ Galactic gamma-ray background, with energies similar to those used in medical X-ray equipment.

Initially, astronomers believed that the glow was caused by interactions involving the atoms of the gas that pervades the Galaxy. Whilst this theory could explain the diffuse nature of the emission, since the gas is ubiquitous, it failed to match the observed power of the gamma rays. The gamma rays produced by the proposed mechanisms would be much weaker than those observed. The mystery has remained unanswered for decades.

Now Integral’s superb gamma-ray telescope IBIS, built for ESA by an international consortium led by Principal Investigator Pietro Ubertini (IAS/CNR, Rome, Italy), has seen clearly that, instead of a fog produced by the interstellar medium, most of the gamma-rays are coming from individual celestial objects. In the view of previous, less sensitive instruments, these objects appeared to merge together.

In a paper published today in Nature, Francois Lebrun (CEA Saclay, Gif sur Yvette, France) and his collaborators report the discovery of 91 gamma-ray sources towards the direction of the Galactic centre. Lebrun’s team includes Ubertini and seventeen other European scientists with long-standing experience in high-energy astrophysics. Much to the team’s surprise, almost half of these sources do not fall in any class of known gamma-ray objects. They probably represent a new population of gamma-ray emitters.

The first clues about a new class of gamma-ray objects came last October, when Integral discovered an intriguing gamma-ray source, known as IGRJ16318-4848. The data from Integral and ESA’s other high-energy observatory XMM-Newton suggested that this object is a binary system, probably including a black hole or neutron star, embedded in a thick cocoon of cold gas and dust. When gas from the companion star is accelerated and swallowed by the black hole, energy is released at all wavelengths, mostly in the gamma rays.

However, Lebrun is cautious to draw premature conclusions about the sources detected in the Galactic centre. Other interpretations are also possible that do not involve black holes. For instance, these objects could be the remains of exploded stars that are being energised by rapidly rotating celestial ‘powerhouses’, known as pulsars.

Observations with another Integral instrument (SPI, the Spectrometer on Integral) could provide Lebrun and his team with more information on the nature of these sources. SPI measures the energy of incoming gamma rays with extraordinary accuracy and allows scientist to gain a better understanding of the physical mechanisms that generate them.

However, regardless of the precise nature of these gamma-ray sources, Integral’s observations have convincingly shown that the energy output from these new objects accounts for almost ninety per cent of the soft gamma-ray background coming from the centre of the Galaxy. This result raises the tantalising possibility that objects of this type hide everywhere in the Galaxy, not just in its centre.

Again, Lebrun is cautious, saying, “It is tempting to think that we can simply extrapolate our results to the entire Galaxy. However, we have only looked towards its centre and that is a peculiar place compared to the rest.”

Next on Integral’s list of things to do is to extend this work to the rest of the Galaxy. Christoph Winkler, ESA’s Integral Project Scientist, says, “We now have to work on the whole disc region of the Galaxy. This will be a tough and long job for Integral. But at the end, the reward will be an exhaustive inventory of the most energetic celestial objects in the Galaxy.”

Original Source: ESA News Release

Posted on by Fraser Cain

Space Adventures Seeking a Spaceport Location

Image credit: Space Adventures
Space Adventures, the world’s leading space tourism company, is currently exploring several locations around the world for construction of a space tourism spaceport. Current sites being considered are located in Australia, The Bahamas, Florida, Japan, Malaysia, Nevada, New Mexico, Oklahoma, Singapore and Dubai in the United Arab Emirates. Operations at the spaceport will include sub-orbital flights, a space flight training center and other activities.

“This is an ideal economic scenario for local communities. The building and then operation of a Space Adventures’ spaceport will undoubtedly bring tens of millions of dollars in the short-term and hundreds of millions in the long-term to the local economy through the increase of jobs and of tourists to the area and the required ancillary support,” said Tim Franta, space business consultant and former director of business development, Florida Space Authority. “It will be a win-win for both Space Adventures and the selected region.”

“Securing the location of a spaceport will be a progressive step for Space Adventures in its evolution from a space experiences provider to an actual space flight academy,” said Eric Anderson, president and CEO of Space Adventures. “We are aggressively seeking a location and enthusiastically look forward to the launch of the first Space Adventures’ sub-orbital flight from our spaceport in the coming years.”

The next generation spacecraft vehicles that will be used for the sub-orbital flights are now being tested. Space Adventures is the marketing and experience operations partner for several of the leading space vehicle manufacturing companies and has already taken over 100 seat reservations for explorers from around the world.

Space Adventures’ sub-orbital program will consist of a detailed four-day flight preparation and training experience. The highly focused and inspiring pre-flight agenda will familiarize each passenger with the flight program, critical vehicle systems, flight operations, zero gravity conditions, in-flight accelerations, and space flight safety procedures. On launch day, flight specialists will assist the passengers in suiting up and guiding each through the final checklist. Each flight will be directed by both a skilled-pilot and a precise computer controlled system. As each vehicle reaches their maximum altitude, the rocket engines will shutdown and the passengers will experience up to five minutes of continuous weightlessness, all the while gazing at the vast blackness of space set against the blue horizon of the Earth below.

Original Source: Space Adventures News Release

Posted on by Fraser Cain

More Details on Water Vapour Feedback

Image credit: NASA
A NASA-funded study found some climate models might be overestimating the amount of water vapor entering the atmosphere as the Earth warms. Since water vapor is the most important heat-trapping greenhouse gas in our atmosphere, some climate forecasts may be overestimating future temperature increases.

In response to human emissions of greenhouse gases, like carbon dioxide, the Earth warms, more water evaporates from the ocean, and the amount of water vapor in the atmosphere increases. Since water vapor is also a greenhouse gas, this leads to a further increase in the surface temperature. This effect is known as “positive water vapor feedback.” Its existence and size have been contentiously argued for several years.

Ken Minschwaner, a physicist at the New Mexico Institute of Mining and Technology, Socorro, N.M., and Andrew Dessler, a researcher with the University of Maryland, College Park, and NASA’s Goddard Space Flight Center, Greenbelt, Md, did the study. It is in the March 15 issue of the American Meteorological Society’s Journal of Climate. The researchers used data on water vapor in the upper troposphere (10-14 km or 6-9 miles altitude) from NASA’s Upper Atmosphere Research Satellite (UARS).

Their work verified water vapor is increasing in the atmosphere as the surface warms. They found the increases in water vapor were not as high as many climate-forecasting computer models have assumed. “Our study confirms the existence of a positive water vapor feedback in the atmosphere, but it may be weaker than we expected,” Minschwaner said.

“One of the responsibilities of science is making good predictions of the future climate, because that’s what policy makers use to make their decisions,” Dessler said. “This study is another incremental step toward improving those climate predictions,” he added.

According to Dessler, the size of the positive water vapor feedback is a key debate within climate science circles. Some climate scientists have claimed atmospheric water vapor will not increase in response to global warming, and may even decrease. General circulation models, the primary tool scientists use to predict the future of our climate, forecast the atmosphere will experience a significant increase in water vapor.

NASA’s UARS satellite was used to measure water vapor on a global scale and with unprecedented accuracy in the upper troposphere. Humidity levels in this part of the atmosphere, especially in the tropics, are important for global climate, because this is where the water vapor has the strongest impact as a greenhouse gas.

UARS recorded both specific and relative humidity in the upper troposphere. Specific humidity refers to the actual amount of water vapor in the air. Relative humidity relates to the saturation point, the amount of water vapor in the air divided by the maximum amount of water the air is capable of holding at a given temperature. As air temperatures rise, warm air can hold more water, and the saturation point of the air also increases.

In most computer models relative humidity tends to remain fixed at current levels. Models that include water vapor feedback with constant relative humidity predict the Earth’s surface will warm nearly twice as much over the next 100 years as models that contain no water vapor feedback.

Using the UARS data to actually quantify both specific humidity and relative humidity, the researchers found, while water vapor does increase with temperature in the upper troposphere, the feedback effect is not as strong as models have predicted. “The increases in water vapor with warmer temperatures are not large enough to maintain a constant relative humidity,” Minschwaner said. These new findings will be useful for testing and improving global climate models.

NASA’s Earth Science Enterprise is dedicated to understanding the Earth as an integrated system and applying Earth system science to improve prediction of climate, weather and natural hazards using the unique vantage point of space. NASA plans to launch the Aura satellite in June 2004. Along with the Terra and Aqua satellites already in operation, Aura will monitor changes in Earth’s atmosphere.

Original Source: NASA News Release