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July 26, 2006, 5:02 PM CT

Global Coral Reef Assessment

Global Coral Reef Assessment
A first-of-its-kind survey of how well the world's coral reefs are being protected was made possible by a unique collection of NASA views from space.

A team of international scientists using NASA satellite images compiled an updated inventory of all "marine protected areas" containing coral reefs and compared it with the most detailed and comprehensive satellite inventory of coral reefs. The global satellite mapping effort is called the Millennium Coral Reef Mapping Project and was funded by NASA. The study was reported on recently in the journal Science.

The assessment observed that less than two percent of coral reefs are within areas designated to limit human activities that can harm the reefs and the sea life living in and around them. Countries around the world have created these protected ocean and coastal zones where human activities such as shipping, fishing, recreation and scientific research are restricted to varying degrees.

"The contribution of NASA images to this project was crucial," says study lead author Camilo Mora, a marine biologist at Dalhousie University, Canada. "The satellite images allowed us to pinpoint where coral reefs are actually located within coastal marine ecosystems."

The Millennium Project collection of global satellite images of coral reefs was first released in 2003; maps derived from these images were released in 2004. The images are now publicly available from NASA's Goddard Space Flight Center, Greenbelt, Md. Landsat 7 was designed by NASA and launched in 1999. The Landsat Program is a series of Earth-observing satellite missions jointly managed by NASA and the Department of the Interior's U.S. Geological Survey.........

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July 25, 2006, 6:54 PM CT

Red Spots of Jupiter

Red Spots of Jupiter
A high-resolution image just released by the Gemini Observatory shows two giant red spots brushing past one another in Jupiter's southern hemisphere.

The image was obtained in near infrared light using adaptive optics which removed most of the distortions caused by turbulence in Earth's atmosphere. The result is a view from the ground that rivals images from space.

"It was tricky getting this picture," said Gemini astronomer Chad Trujillo who helped lead the effort to capture the image. "Since we used adaptive optics we needed a star-like object nearby to guide on, so we had to find a time when Jupiter's moon Io would appear close enough to Jupiter and the red spots would be optimally placed on Jupiter's disk. Fortunately it all worked out on the evening of July 13th and we were able to capture this relatively rare set of circumstances," said Trujillo.

Professor Steve Miller of University College London is a keen Jupiter-watcher and said The latest images from Gemini are truly amazing in the detail that they show of these two major storm systems on Jupiter. It is now clear that they are lined up more or less "on top" of each other, with the smaller storm further south, closer to the South Pole.

Both red spots are massive storm systems. The larger one, known for a long time as the Great Red Spot, lies about 8 kilometres (5 miles) above the neighbouring cloud tops and is the largest hurricane known in the solar system. The smaller storm (officially called Oval BA, but informally known as Red Spot Junior) is another hurricane-like system. Since it appears nearly as bright as the Great Red Spot in near-infrared images, Red Spot Junior may be at a similar height in the Jovian atmosphere as the Great Red Spot.........

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July 21, 2006, 7:12 AM CT

Nuclear explosion on a dead star

Nuclear explosion on a dead star

A team of astronomers from the UK and Gera number of have observed that a nuclear explosion on the surface of a star 5,000 light years from Earth resulted in a blast wave moving at over 1,700 km per second (one thousand miles per second or almost four million miles per hour!). The discovery, published in the 20 recent issue of Nature, was made by bringing together a number of of the world's radio telescopes into arrays capable of seeing the aftermath of the explosion in incredible detail.

During the night of 12 February this year Japanese astronomers reported that a star called RS Ophiuchi had suddenly brightened and become clearly visible in the night sky. Eventhough this was the latest in a series of such outbursts that have been spotted over the last hundred years or so, it was the first since 1985 and therefore an opportunity to bring to bear new, more powerful, telescopes in an effort to understand the causes and consequences of these eruptions.

Dr Tim OBrien of The University of Manchesters Jodrell Bank Observatory requested urgent observations with the VLBA (the Very Long Baseline Array of radio telescopes extending from Hawaii to the Caribbean). Our first observations, made only two weeks after the explosion was reported, showed an expanding blast wave already comparable in size to Saturns orbit around the Sun. However, we needed to use the worlds most powerful radio telescopes because, from a distance of 5,000 light years, its apparent size on the sky was only 5 millionths of a degree the size of a football seen from 2,700 km (1,700 miles) away.........

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July 19, 2006, 11:23 PM CT

Cluster Hits The Magnetic Bull's-eye

Cluster Hits The Magnetic Bull's-eye Credits: Dr. Xiao/Chinese Academy of Sciences (Beijing)
ESA's spacecraft constellation Cluster has hit the magnetic bull's-eye. The four spacecraft surrounded a region within which the Earth's magnetic field was spontaneously reconfiguring itself.

This is the first time such an observation has been made and gives astronomers a unique insight into the physical process responsible for the most powerful explosions that can occur in the Solar System: the magnetic reconnection.

When looking at the static pattern of iron filings around a bar magnet, it is difficult to imagine how changeable and violent magnetic fields can be in other situations.

In space, different regions of magnetism behave somewhat like large magnetic bubbles, each containing electrified gas known as plasma. When the bubbles meet and are pushed together, their magnetic fields can break and reconnect, forming a more stable magnetic configuration. This reconnection of magnetic fields generates jets of particles and heats the plasma.

At the very heart of a reconnection event, there must be a three dimensional zone where the magnetic fields break and reconnect. Scientists call this region the null point but, until now, have never been able to positively identify one, as it requires at least four simultaneous points of measurements.........

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July 18, 2006, 10:34 PM CT

Xploring Mars With Mini Probes

Xploring Mars With Mini Probes An artist's rendering shows the baseball-sized probes
Illustration / Gus Frederick
MIT engineers and scientist colleagues have a new vision for the future of Mars exploration: a swarm of probes, each the size of a baseball, spreading out across the planet in every direction.

Thousands of probes, powered by fuel cells, could cover a vast area now beyond the reach of today's rovers, including exploring remote and rocky terrain that large rovers cannot navigate.

"They would start to hop, bounce and roll and distribute themselves across the surface of the planet, exploring as they go, taking scientific data samples," said Steven Dubowsky, the MIT professor of mechanical engineering who is leading the research team.

Dubowsky's team plans to test prototypes on Earth this fall and estimates that a trip to Mars is about 10 years away. He is now working with Penelope Boston, director of the cave research program at the New Mexico Institute of Mining and Technology, to create probes that can handle the rough terrain of Mars.

Researchers think that lava tubes usually seen on Mars are a promising location to search for signs of water. Lava tubes are tunnels left behind by underground lava flows. Signs of these tubes, which are also present in a number of locations on Earth, can be seen above ground.

The tubes could be entered through holes that formed on the Mars surface where sections of the tubes have collapsed, but these formations are too treacherous for today's rovers to explore. However, tiny bouncing probes could make their way inside the caves.........

Posted by: Edwin      Permalink         Source


July 17, 2006, 8:19 PM CT

Next-generation High-altitude Airships

Next-generation High-altitude Airships
"Paint-on" antennas, designed to establish new high-altitude communications and surveillance platforms, successfully transmitted voice and data links as well as teleconferencing capabilities during test flights in the Nevada desert June 21 on board an SA-60 spherical airship.

RTI International and its research partners at Unitech, Applied EM, the International Communications Group, and TechSphere Systems International, a wholly owned subsidiary of Cyber Defense Systems, successfully tested the antennas from several positions on the airship. The experiment provided the first opportunity to test and evaluate the electrical, electromagnetic and mechanical properties of the "paint-on" antenna technology during an actual flight.

"The successful airship test flights demonstrate exciting possibilities for 'paint-on' antenna technologies," said David Myers, vice president of RTI's Engineering and Technology Unit. "This new technology can be used to assist with hurricane disaster relief, provide enhanced security of ports and borders, perform science observation missions and improve military communications".

High-altitude airships can be used for both defense and homeland security purposes including surveillance of battlefields and domestic borders and ports. The airships are intended to serve as economical station-keeping communications and/or ground-sensing platforms that will augment both ground-based and more expensive satellite systems. The airships will operate well above commercial air traffic and the jet stream and beyond the range of most ground-to-air missiles.........

Posted by: Edwin      Permalink         Source


July 17, 2006, 8:16 PM CT

Sub-millimetre Astronomy In Full Swing

Sub-millimetre Astronomy In Full Swing The APEX-Telescope
The Atacama Pathfinder Experiment (APEX) 12-m sub-millimetre telescope lives up to its ambitions of providing access to the "Cold Universe" with unprecedented sensitivity and image quality. As a demonstration, no less than 26 articles based on early science with APEX are published this week in the research journal Astronomy & Astrophysics. Among the a number of new findings, most in the field of star formation and astrochemistry, are the discovery of a new interstellar ion and the detection of CO radiation at 0.2 mm and of H2D+ radiation.

Using both APEX and the IRAM 30-metre telescope the first astronomical detection of a charged molecule composed of carbon and fluorine - the 'CF+ ion' - was made. Previous to this discovery, only one fluorine-containing molecular species had been found in space so far, the HF molecule ('hydrogen fluoride'), consisting of one atom of hydrogen and one of fluorine. The newly discovered molecule, produced through a reaction between carbon and the HF molecule, was found in a region adjoining the Orion Nebula, one of the nearest and most active stellar nurseries in the Milky Way. This detection provides support to the astronomers' understanding of interstellar fluorine chemistry, suggesting that hydrogen fluoride is ubiquitous in interstellar gas clouds.........

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July 12, 2006, 11:55 PM CT

Flying over the cloudy world

Flying over the cloudy world Global dynamics of Venus northern hemisphere
On 20 April 2006, after its first 9-day, elongated orbit around Venus, ESA's Venus Express started to get closer to the planet, until it reached its final 24-hour long orbit on 7 May. During this time, and up to today, the spacecraft has been working relentlessly: the new data coming in are already providing first glimpses on planetary features never seen before.

If taking the first ever clear images of the double-eye vortex at Venus' south pole - imaged by Venus Express during its very first orbit - was already a first in the history of planetary exploration and a very pleasant surprise for the scientists, nobody could expect that the vortex had a structure even more complicated than possibly foreseen.

Infrared images taken by the Ultraviolet/Visible/Near-Infrared spectrometer (VIRTIS) on board the spacecraft not only provided the first clear view of the vortex, but also gave a much closer insight into it when Venus Express flew over the south pole at the end of May this year.

VIRTIS is an instrument that can operate at different wavelengths. Each infrared wavelength provides a view of the Venusian atmosphere at a different altitude, like a 'cross-section'. "When we looked at this gigantic vortex at different depths, we realised how much its shape is varying over altitude," said Pierre Drossart, VIRTIS co-Principal Investigator, from the Observatoire de Paris, France. "It is like if we were looking at different structures, rather than a single one. And the new data we have just started gathering and analysing reveal even stronger differences".........

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July 12, 2006, 11:45 PM CT

View Of Crater Sulpicius Gallus

View Of Crater Sulpicius Gallus This mosaic of three images, taken by the advanced Moon Imaging Experiment (AMIE) on board ESA's SMART-1 spacecraft, shows the area around the Sulpicius Gallus crater
This mosaic of three images, taken by the advanced Moon Imaging Experiment (AMIE) on board ESA's SMART-1 spacecraft, shows the area close to the Sulpicius Gallus crater on the Moon.

AMIE obtained this sequence on 18 March 2006, from a distance of 1200 kilometres from the surface, with a ground resolution ranging from 110 to 114 metres per pixel.

The area shown in the top image is centred at a latitude of 19.7º North and longitude 12.2º East; the image in the middle is centred at a latitude of 18.2º North and longitude 12.3º East; the bottom image is centred at a latitude of 16.7º North and longitude 12.5º East.

The prominent crater on the upper left area of this mosaic is called Sulpicius Gallus. It is a fairly fresh, bowl-shaped crater with a diameter of roughly 12 kilometres. The flat lava plains surrounding it belong to the Mare Serenitatis (the 'Sea of Serenity') on the north-eastern side of the Moon facing Earth. The mountains going diagonally through the middle part of the mosaic are called Montes Haemus. They are denoting the edge of the huge impact crater which formed the Mare Serenitatis.

The area around Sulpicius Crater is very interesting for lunar researchers - it is one of the most geologically and compositionally complex areas of the nearside of the Moon. The geologic history of this region has been shaped by impacts of different scales and epochs, by volcanism of variable style and composition with time, and by limited tectonics. Specific findings (Bell and Hawke, 1995) include the detection of relatively fresh highlands materials in the crater.........

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July 9, 2006, 7:56 PM CT

Supernova And A Mysterious Object

Supernova And A Mysterious Object Puzzling pulsation from the heart of RCW103
Thanks to data from ESA's XMM-Newton satellite, a team of researchers taking a closer look at an object discovered over 25 years ago have found that it is like none other known in our galaxy.

The object is in the heart of supernova remnant RCW103, the gaseous remains of a star that exploded about 2 000 years ago. Taken at face value, RCW103 and its central source would appear to be a textbook example of what is left behind after a supernova explosion: a bubble of ejected material and a neutron star.

A deep, continuous 24.5-hour observation has revealed something far more complex and intriguing, however. The team, from the Istituto di Astrofisica Spaziale e Fisica Cosmica (IASF) of the Istituto Nazionale di Astrofisica (INAF) in Milan, Italy, has found that the emission from the central source varies with a cycle that repeats itself every 6.7 hours. This is an astonishingly long period, tens of thousands of times longer than expected for a young neutron star. Also, the object's spectral and temporal properties differ from an earlier XMM-Newton observation of this very source in 2001.

"The behaviour we see is particularly puzzling in view of its young age, less than 2 000 years," said Andrea De Luca of IASF-INAF, the lead author. "It is reminiscent of a multimillion-year-old source. For years we have had a sense that the object is different, but we never knew how different until now." .........

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