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July 9, 2006, 7:51 PM CT

Where Craters Tell The Story Of Basalt

Where Craters Tell The Story Of Basalt This mosaic of three images, taken by the advanced Moon Imaging Experiment (AMIE)on board ESA's SMART-1 spacecraft, shows Mare Humorum on the Moon.
This mosaic of three images, taken by the advanced Moon Imaging Experiment (AMIE) on board ESA's SMART-1 spacecraft, shows Mare Humorum on the Moon.

AMIE obtained the top frame on 1 January 2006, from a distance of 1087 kilometres from the surface, with a ground resolution of 98 metres per pixel. The remaining two frames were taken on 13 January 2006, from a distance of about 1069 (centre) and 1050 kilometres (bottom) from the surface, with a ground resolution of 97 and 95 metres per pixel, respectively.

The area shown in the top image is centred at a latitude of 40.2º South and longitude 25.9 degree West; the centre image is centred at a latitude of 40.2º South and longitude 27.3 degree West; the bottom image is centred at a latitude of 40.2 degree South and longitude 28.8 degree West.

Mare Humorum, or 'Sea of Moisture', is a small circular mare on the lunar nearside, about 825 kilometres across. The mountains surrounding it mark the edge of an old impact basin which has been flooded and filled by mare lavas. These lavas also extend past the basin rim in several places. In the upper right are several such flows which extend northwest into southern Oceanus Procellarum.

Mare Humorum was not sampled by the Apollo program, so its precise age could not been determined yet. However, geologic mapping indicates that its age is in between that of the Imbrium and the Nectaris basins, suggesting an age of about 3.9 thousand million years (with an uncertainty of 500 million years).........

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July 4, 2006, 9:33 AM CT

Polar Year 2007-2008

Polar Year 2007-2008
Thousands of scientists from 60 countries will be conducting research during International Polar Year 2007-2008 and will, for the first time during an International Polar Year, be armed with satellite measurements offering complete coverage of the polar regions, which play a vital role in the Earth's climate and ecosystems.

Having access to near-continuous satellite data of these regions over long periods of time is important for scientists to identify and analyse long-term climatic trends and changes. ESA will provide current and historical data, dating back 15 years, from its ERS-1, ERS-2 and Envisat satellites as well as data collected from a number of non-ESA satellites.

Dr. David Carlson, Director of the International Programme Office for the Polar Year, predicts many uses of satellite data: "Many researchers use satellite data as part of their daily activities. During IPY those researchers will push to extract more and more information from the satellites, particularly to understand recent and current distributions of snow and ice. We will use every form of satellite data - passive visual, active microwave, and even sensitive gravity measurements - to understand changes in the global ice sheets".

Since their advent satellites have contributed to a greater understanding of polar regions, helped identify the strong links these regions have with Earth's terrestrial, ocean and atmospheric processes and made startling observations. For example, within days of its launch in 2002, ESA's environmental satellite Envisat captured the disintegration of the Larsen-B ice shelf in Antarctica, surprising scientists because of the rapid rate at which the shelf broke apart.........

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July 4, 2006, 9:23 AM CT

Jules Verne Passes Acoustic Test

Jules Verne Passes Acoustic Test
Acoustic testing of Jules Verne, the first Automated Transfer Vehicle (ATV), has successfully been completed at ESA's test facilities in Noordwijk, The Netherlands.

The 11-tonne test configuration of the ATV Flight Model (the actual flight launch mass is 20.5 tonnes) was transferred to the Large European Acoustic Facility (LEAF) with the help of an air cushion transfer pad.

The ATV, an unmanned vehicle that will deliver supplies to the International Space Station (ISS), will be put into orbit by the European Ariane-5 launcher. Acoustic testing is vital to ensure the ATV can withstand the vibrations caused by the extreme noise levels generated during launch.

Acoustic vibrations are been used to simulate the stress the ATV will encounter during the first three minutes of launch - due to aero dynamical forces - on top of the powerful European Ariane-5 launcher.

The whole structure of the ATV, which is the size of a double-decker London bus, will have to withstand an overall sound pressure level of 144 dB with main frequencies between 25Hz and 5kHz. The same amount of acoustic vibrations would be lethal for the human body.

Over several days different test runs were conducted in the special enclosed facility, LEAF. Dozens of sensors placed in different areas of the ATV have measured and checked its hardware behaviour. Two-dozen technicians and engineers from Prime Contractor EADS Launch Vehicles, EADS Space Transportation, Alcatel Alenia Space (former Alenia Spazio), Dutch Space (acquired by EADS Space), European Test Services (ETS) and ESA coordinated the test runs.........

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June 28, 2006, 11:46 PM CT

The Hooked Galaxy

The Hooked Galaxy ESO PR Photo
The Hooked Galaxy and its Companion
Because of the importance of exploding stars, and particularly of supernovae of Type Ia [1], for cosmological studies (e.g. relating to claims of an accelerated cosmic expansion and the existence of a new, unknown, constituent of the universe - the so called 'Dark Energy'), they are a preferred target of study for astronomers. Thus, on several occasions, they pointed ESO's Very Large Telescope (VLT) towards a region of the sky that portrays a trio of amazing galaxies.

MCG-01-39-003 (bottom right) is a peculiar spiral galaxy, with a telephone number name, that presents a hook at one side, most probably due to the interaction with its neighbour, the spiral galaxy NGC 5917 (upper right). In fact, further enhancement of the image reveals that matter is pulled off MCG-01-39-003 by NGC 5917. Both these galaxies are located at similar distances, about 87 million light-years away, towards the constellation of Libra (The Balance).

NGC 5917 (also known as Arp 254 and MCG-01-39-002) is about 750 times fainter than can be seen by the unaided eye and is about 40,000 light-years across. It was discovered in 1835 by William Herschel, who strangely enough, seems to have missed its hooked companion, only 2.5 times fainter.

As seen at the bottom left of this exceptional VLT image, a still fainter and nameless, but intricately beautiful, barred spiral galaxy looks from a distance the entangled pair, while many 'island universes' perform a cosmic dance in the background.........

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June 28, 2006, 0:32 AM CT

Double vortex at Venus South Pole

Double vortex at Venus South Pole Infrared views of south polar double-vortex
ESA's Venus Express data undoubtedly confirm for the first time the presence of a huge 'double-eye' atmospheric vortex at the planet's south pole. This striking result comes from analysis of the data gathered by the spacecraft during the first orbit around the planet.

On 11 April this year, Venus Express was captured into a first elongated orbit around Venus, which lasted 9 days, and ranged between 350 000 and 400 kilometres from Venus' surface. This orbit represented for the Venus Express researchers a unique opportunity to observe the planet from large distances. This made it possible to obtain first clues about the Venusian atmospheric dynamics on a global scale, before the spacecraft got closer and started observing the planet in greater detail.

During this first orbit - called the 'capture orbit' - some of the Venus Express instruments were used to perform the first observations at different distances from Venus, for a few hours per time on six different slots between 12 and 19 April 2006.

Amazing infrared, visible and ultraviolet images of the Venusian globe already reveal several atmospheric features of great interest. The most striking of these is a huge, double-eye atmospheric vortex over the south pole, not dissimilar from the equivalent structure present at the north pole - the only one previously studied in some detail.........

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June 28, 2006, 0:12 AM CT

Kidney Stone Prevention In Astronauts

Kidney Stone Prevention In Astronauts
As the space shuttle Discovery prepares to launch on July 1, scientists at the University of Minnesota have identified a way for astronauts to reduce their risk of developing kidney stones while in space.

Astronauts lose calcium in their bones and strength in their muscles while in space because of the zero-gravity environment. This calcium can end up in their kidneys, putting them at risk for developing kidney stones.

At least 14 American crew members have developed kidney stones in the last 5 years, and as missions become longer, the number is likely to grow. While astronauts have exercised in space to attempt to combat bone loss, the lack of gravity makes it difficult to achieve enough resistance to maintain their pre-flight fitness levels.

"This becomes a real health concern, as the time astronauts spend in space and living in the space station is extended," said Manoj Monga, M.D., professor of urologic surgery and lead investigator. The study would be reported in the July 2006 print issue of the Journal of Urology and is available online now.

Kidney stones are mineral deposits in the kidneys that can travel through the urinary tract, causing intense pain. One of the most common types of kidney stones is caused by the buildup of calcium oxalate.........

Posted by: Edwin      Permalink         Source


June 26, 2006, 8:36 PM CT

Vega's Second Stage Motor

Vega's Second Stage Motor Artist’s impression of the Vega launch vehicle climbing through the Earth’s atmosphere.
Credits: ESA - J. Huart
ESA's Vega small satellite launch vehicle has made a new step toward its maiden flight, late next year, with the success of the first firing test on its second stage motor, the Zefiro 23.

The static firing waccording toformed today, 26 June, at the Italian Ministry of Defence test centre in Salto di Quirra, Sardinia. The 7.5m tall, 2m diameter motor, featuring a carbon epoxy filament wound casing, delivered more than 100 metric tons of thrust (1,070 kN), burning some 24 metric tons of solid propellant in 75 seconds.

Numerous data were gathered during the test and are now under analysis to improve technical knowledge of the motor's behaviour and refine the launcher's future performance. Also tested during the firing were various subsystems, including a thrust vector control system that will steer the motor's nozzle to provide flight control. After this success, the motor will proceed with its critical design review, at which stage its technical characteristics will be finalised.

Built by Avio in Colleferro, near Rome, the Zefiro 23 motor will be the basis for the second stage of ESA's Vega launcher. The first firing test with the third stage motor - the Zefiro 9 - waccording toformed in December 2005. Conducted on behalf of ESA's Vega development programme, these two firing tests followed three static firings of the Zefiro 16 demonstrator in 1998, 1999 and 2000. Both the Zefiro 23 and Zefiro 9 will undergo an additional ground firing test each to complete their development and qualification.........

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June 24, 2006, 11:43 PM CT

Discovery Set For July 1 Launch

Discovery Set For July 1 Launch
The Space Shuttle Discovery and its crew are set for a July 1 flight to the International Space Station. The STS-121 mission will visit the International Space Station and continue evaluating new shuttle safety improvements. At least two spacewalks are planned during the 12-day mission, which also includes repair work to the station.

NASA managers gave the green light after a lengthy Flight Readiness Review held June 16-17, a traditional meeting in which top NASA managers and engineers set launch dates, determine whether the shuttle's complex array of equipment, support systems and procedures are ready for flight and assess any risks associated with the mission.

NASA senior managers on Saturday cleared the Space Shuttle Discovery for a July 1 flight to the International Space Station.

The decision was announced after a lengthy Flight Readiness Review, a traditional meeting in which top NASA managers and engineers set launch dates, determine whether the shuttle's complex array of equipment, support systems and procedures are ready for flight and assess any risks associated with the mission.

"We had two full days of an intensive Flight Readiness Review," said Administrator Michael Griffin. "It was spirited and one of the most open, yet non-adversarial meetings I've seen since returning to NASA".........

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June 22, 2006, 5:50 PM CT

Reason Behind Black Holes' Light Shows

Reason Behind Black Holes' Light Shows
A team of astronomers led by the University of Michigan may know how black holes are lighting up the Universe. New data from NASA's Chandra X-ray Observatory show, for the first time, that powerful magnetic fields are the key to these brilliant and startling light shows.

It is estimated that up to half of the total radiation in the universe since the Big Bang comes from material falling towards super-massive black holes, including those powering quasars, the brightest known objects. For decades, researchers have struggled to understand how black holes, the darkest objects in the Universe, can generate such prodigious amounts of radiation.

New X-ray data from Chandra give the first clear explanation for what drives this process: magnetic fields. Chandra observed a black hole system in our galaxy, known as GRO J1655-40 (J1655, for short), where a black hole was pulling material from a companion star into a disk.

"By intergalactic standards, J1655 is in our backyard so we can use it as a scale model to understand how all black holes work, including the monsters found in quasars," said Jon Miller, assistant professor at U-M, whose paper on these results appears in this week's issue of the journal Nature.

If gas in a disk around a black hole loses energy, it will swirl toward the black hole, generating light along the way. Researchers have long thought that magnetic fields may drive this energy loss by generating friction in the gas and driving a wind from the disk that carries momentum outward, in an example of conservation of momentum.........

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June 21, 2006, 11:24 PM CT

Saturnian Moon Ballet

Saturnian Moon Ballet Many denizens of the Saturn system wear a uniformly gray mantle of darkened ice, but not so for these two most fascinating of moons. The brightest body in the Solar System, Enceladus, is contrasted here against Titan's smoggy golden murk.
The cold, icy orbs of the Saturn system come to life in a slew of new movie clips showing the ringed planet's moons in motion.

In addition to their drama and visual interest, scientists use these movies to refine their understanding of the orbits of Saturn's moons. Engineers at NASA's Jet Propulsion Laboratory, Pasadena, Calif., use the same images, and the orbital positions of the moons, to help them navigate the Cassini spacecraft, which is nearing the halfway mark of its four-year tour.

Pictures capturing several moons in one frame are often strikingly beautiful, especially when deliberately imaged in red, green and blue spectral filters, which allow scientists to create a color photo. One recent color image shows two of Saturn's most fascinating moons, icy-white Enceladus and orange, haze-enshrouded Titan.

Ironically, what these two moons hold in common gives rise to their starkly contrasting colors. Both bodies are, to varying degrees, geologically active. For Enceladus, its southern polar vents emit a spray of icy particles that coats the small moon, giving it a clean, white veneer. On Titan, as-yet-undefined processes are supplying the atmosphere with methane and other chemicals that are broken down by sunlight, creating the thick yellow-orange haze that suffuses the atmosphere and, over geologic time, falls and coats the surface.........

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