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Data sent by Huygens probe indicate that the physical processes shaping Titan are much the same as those shaping Earth. There were precipitation, erosion, mechanical abrasion and other fluvial activity on Titan.Images have shown a complex network of narrow drainage channels running from brighter highlands to lower, flatter, dark regions. These channels merge into river systems running into lakebeds featuring offshore ‘islands’ and ‘shoals’ remarkably similar to those on Earth.
While many of Earth’s familiar geophysical processes occur on Titan, the chemistry involved is quite different. Instead of liquid water, Titan has liquid methane, a simple organic compound that can exist as a liquid or gas at Titan’s sub-170°C temperatures, rather than water as on Earth. Instead of silicate rocks, Titan has frozen water ice. Instead of dirt, Titan has hydrocarbon particles settling out of the atmosphere, and instead of lava, Titanian volcanoes spew very cold ice.
Titan’s rivers and lakes appear dry at the moment because when it rains the liquid rapidly sinks into the soil leaving behind dry river and lakebeds. But methane rain may have occurred not long ago. Images show small rounded pebbles in a dry riverbed. Spectra measurements (colour) are consistent with a composition of dirty water ice rather than silicate rocks.
Titan’s soil appears to consist at least in part of precipitated deposits of the organic haze that shrouds the planet. This dark material settles out of the atmosphere. When washed off high elevations by methane rain, it concentrates at the bottom of the drainage channels and riverbeds contributing to the dark areas seen in Huygens images.
The material beneath the surface’s crust has the consistency of loose sand, possibly the result of methane rain falling on the surface over eons, or the wicking of liquids from below towards the surface.
Heat generated by Huygens warmed the soil beneath the probe and bursts of methane gas boiled out of surface material, reinforcing methane’s principal role in Titan’s geology and atmospheric meteorology — forming clouds and precipitation that erodes and abrades the surface.
Newly released imagery from NASA spaceborne instruments sheds valuable insights into the Indian Ocean tsunami on December 26 2004.
The Multi-angle Imaging SpectroRadiometer imagery includes the only known animations produced by a remote sensing instrument to capture tsunami waves in motion as they make landfall. The image set and animations were collected December 26 as Terra spacecraft passed over the eastern Indian coast about an hour and a half after the first waves hit shore. Together with measurements of ocean depth, these data can be used to refine models of how tsunamis originate and travel. Better understanding of how tsunamis interact with coastal areas is one factor needed to improve near-real-time forecasts of tsunami arrival times and effects, and to reduce damage from such waves in the future.
To access the new images available on the Web, visit:
http://www.nasa.gov/vision/earth/lookingatearth/tsunami-images.html .
.On 14 January 2005 Huygens space probe has finally landed on Titan, ending a seven-year, 3.5 billion-kilometer voyage. As Titan, Saturn’s largest moon, is enveloped in thick orange clouds past observations failed to reveal what is on the surface. To solve "Titanic" puzzle and to study Saturn NASA and the European and Italian space agencies have collaborated on the $3.3 billion Cassini/Huygens mission for two decades. After circling Saturn for more than 5 months Cassini mothership lets Huygens to seperate and descend to Titan’s surface.
The first haze-free glimpse of Titan’s surface, seen from 10 miles up, showed canyons and riverbeds in a wrinkled, hilly terrain, bordering what looked like a shoreline of a dark sea, possibly of liquid methane.
Huygens was designed to float in case it landed in a river or lake—but it didn’t. After descending by parachute for two and a half hours, the saucer-shaped probe landed in mud at a speed of 4.5 meters per second (10 mph), experiencing a brief jolting deceleration of 15 Gs. Huygens survived the impact and continued transmitting data for more than one hour revealing a smog-shrouded landscape of boulder-strewn plains, winding drainage channels, and dark pools that may contain liquid hydrocarbon.
Among the measurements sent back to Earth were air temperature, pressure, composition and wind speed sampled at points ranging from the top of Titan’s atmosphere to the ground. The temperature of the landing site itself was minus 291 degrees F. A "penetrometer" on the bottom of the probe poked into the ground. The soil, it found, has the consistency of wet sand or clay and is covered by a thin crust ... of something. Scientists are still analyzing all these data. There are enough photos, sounds and other measurements to keep researchers busy for years
The Cassini mothership will continue to study Saturn and its more than 30 moons from orbit until at least 2008.
European Space Agency (ESA) staff are planning future research into the possibility of inducing a hibernation-like state in humans.ESA believes hibernation would help astronauts to cope with the psychological demands of decades-long return journeys to destinations such as Saturn. And because less space and food would be needed on such missions, the spacecraft would be lighter and easier to launch.
Inquiry centres on DADLE (D-Ala,D-Leu-enkephalin), a substance with opium-like properties. An injection of DADLE is known to trigger hibernation in ground squirrels during the summer season, when the animals would normally be awake. It also seems to send cultures of human cells to sleep: the cells divide more slowly and their gene activity drops when the molecule is applied.
Researchers are following up other leads too. One downside of hibernation is that it leads to loss of muscle strength, a problem that also afflicts patients confined to bed after an operation. Such bedridden patients retain more strength if they receive dobutamine, a drug used to boost the strength of heart muscles, so a similar treatment might work during hibernation.
But practical hibernation mechanisms are at least a decade away.
Satellites have observed and measured the Indian Ocean tsunami on December 26.This is the first observation of major tsunami event in open ocean from space .The satellites flew over the Bay of Bengal about 150 kilometers (93 miles) apart approximately two hours after the quake.
The satellites recorded a maximum sea surface elevation gain of 50 centimeters (1.6 feet) on the open ocean about 1,200 kilometers (746 miles) south of Sri Lanka at the leading crest of a tsunami wave raging out of the Bay of Bengal. It was followed by a trough of sea surface depression of 40 centimeters (1.3 feet) below normal. The distance from one wave crest to the next was about 800 kilometers (500 miles). The first wave was followed by a second with a crest height of 40 centimeters (1.3 feet) above normal. Near the northern end of the Bay, two waves with crest heights of 40 centimeters (1.3 feet) and 20 centimeters (0.66 feet) above normal were approaching the coasts of Myanmar. Spreading across the Bay of Bengal from the earthquake zone offshore from Western Sumatra, these tsunami waves eventually reached shallow waters along the coasts of Sumatra, Sri Lanka, Thailand and Southern India. Their open ocean speeds reduced from that of a jet plane, 800 kilometers (500 miles) per hour, to about 32 kilometers (20 miles) per hour, building the open ocean wave heights of 0.5 meters (1.6 feet) or less to walls of water up to 10 meters (33 feet) high with great destructive power.
NASA scientists have calculated that the Indonesian earthquake of Dec. 26, 2004it slightly changed our planet’s shape, shaved almost 3 microseconds from the length of the day, and shifted the North Pole by centimeters. According to latest calculations, the Dec. 26th earthquake shifted Earth’s "mean North Pole" by about 2.5 centimeters (1 inch) in the direction of 145 degrees east longitude, more or less toward Guam in the Pacific Ocean.
The quake also affected Earth’s shape. Earth’s oblateness (flattening on the top and bulging at the equator) decreased by a small amount—about one part in 10 billion. This continues the trend of earthquakes making Earth less oblate. Less oblate means more round.
It is also found the earthquake decreased the length of the day by 2.68 microseconds. (A microsecond is one millionth of a second.) In other words, Earth spins a little faster than it did before. This change in spin is related to the change in oblateness. It’s like a spinning skater drawing arms closer to the body resulting in a faster spin.
But please note that none of these changes have yet been measured—only calculated. But scientists hope to detect the changes when Earth rotation data from ground based and space-borne sensors are reviewed.
The Swift space telescope, launched in November 2004, has seen its first gamma-ray bursts (GRBs). GRBs are the most powerful explosions in the Universe, releasing more than one hundred billion times the energy our Sun emits in a year.
The mission aims to understand what GRBs are. Scientists know there are two types of burst which could be caused by entirely different types of event. In one scenario, bursts occur when a star collapses in on itself, giving birth to a black hole. Another possibility could be that bursts come from the collision between two neutron stars. Click here for more informations.
In 1980 John Anderson, Jet Propulsion Laboratory physicist, was looking over data from two Pioneer spacecraft that had been speeding through the solar system for nearly a decade. He noticed the crafts weren’t where they were supposed to be. In fact, rather than traveling at a constant velocity of more than 25,000 mph toward the edge of the solar system, Pioneer 10 and 11 were inexplicably slowing down. Even factoring in the gravitational pull of the sun and the other planets couldn’t explain what he was seeing.
Since then the observed deviation from expectations of the trajectories of various unmanned spacecraft visiting the outer Solar system is called The Pioneer Anomaly’’.Attempts to test the anomaly using other spacecraft such as Galileo and the Voyager probes have proved unsuccessful, and the deep-space missions that are currently being developed will not be designed to test the properties of the Pioneer anomaly.
In October 2004, a European Space Agency panel recommended a space mission to test the Pioneer anomaly directly and determine whether Anderson had found something that could rewrite physics textbooks. Such a mission could also be an excellent opportunity to develop and test new technologies for spacecraft design, in-space propulsion, on-board power and many other developments that may ultimately find their way into many other space and terrestrial applications.
1. There was water
Photos snapped from orbit suggested dry lakes and riverbeds on Mars. However, until NASA’s Opportunity rover examined Eagle Crater, its landing site in Meridiani Planum, there had been no proof.
The evidence: round rocks dubbed "blueberries," which formed in water; small holes formed by crystals that dissolved; rich sulfur content attributed to water; cross-bedding or rock formations formed by flowing water currents; and salt deposits typical of evaporation.
2. Life was possible
The rovers’ discoveries offer both a promising target for future missions and enticement to investigate whether life can arise in hostile environments.
Experiments suggest that deposits like those on Mars may create an environment where the components of nucleic acids, the building blocks of genetic material, are made and stabilized.
3. Impressive performances of robots
Spirit and Opportunity were supposed to last three months. Spirit is at 12 with Opportunity not far behind, highlighting the impressive capabilities of robots.
As they come out of winter, they’re getting more power than expected. Dust on the solar panels has leveled off and even was cleaned off on Opportunity, perhaps by wind or a dust devil.
Instead of traveling a third of a mile as expected, Spirit has rolled about 2.5 miles.
4. Methane mystery
Europe’s Mars Express orbiter has found water vapor concentrated in three equatorial regions that correspond to where NASA’s Odyssey saw a layer of water ice below the surface.
Intriguingly, concentrations of methane overlap with the water vapor. Though more analysis is needed, the discovery raises the question of whether geothermal processes bring water vapor and methane to the surface, or whether bacterial life might be a source of the methane.
5. Meteorites find match
Opportunity found that the volcanic rock has a strong similarity to some meteorites discovered in Antarctica and other locations on Earth, giving credence to the theory that they came from Mars.
Click here for more about Mars
Mars rovers
NASA’s rovers Spirit and Opportunity each turned up evidence that water had altered the planet’s surface in the past. Recent discoveries of atmospheric methane suggest life could be thriving on the Red Planet even now, belching out the gas from scattered oases. Click here for details
Cassini-Huygens mission to Saturn
Saturn got its close-up as the joint US-European Cassini spacecraft reached orbit in July after a seven-year voyage. The craft revealed the planet probably captured its outermost large moon, Phoebe, from the Kuiper Belt, a belt of icy bodies beyond Neptune. And it turned up a delicate new ring and mysterious knife-sharp edges in Saturn’s famous rings. Click here for details
SpaceShipOne
SpaceShipOne became the first commercial vehicle to fly to the brink of space and back and won the $10 million Ansari X Prize in October. Click here for details
Mo'nonymous on New companion of Nep...
Mo'nonymous on New companion of Nep...
Mo'nonymous on New companion of Nep...
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