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A spruced-up Hubble Space Telescope has been released back into space after five days of spacewalks to repair and upgrade the ageing observatory.

The space shuttle Atlantis will now make its way back to Earth, ending the $1.1 billion mission, which aimed to extend Hubble's life to at least 2014 and vastly improve its vision.

Six days after grabbing hold of the telescope with the shuttle's 15-metre-long robotic arm, astronaut Megan McArthur lifted the telescope from the shuttle's payload bay and placed it back in its own orbit at 1257 GMT.

Now, the 19-year-old telescope will undergo an intensive testing period, in which astronomers and engineers will calibrate and assess the health of the newly-installed and repaired instruments. NASA hopes Hubble science operations will reach "full stride" by September, Hubble programme manager Preston Burch told reporters on Monday.
Two-day trip

It took Atlantis two days to rendezvous with Hubble after a morning launch last week. A series of five back-to-back spacewalks began the next day.

Day one: Spacewalk virgin Andrew Feustel and veteran Hubble mechanic John Grunsfeld battled a stuck bolt to replace Hubble's "workhorse" camera, which since 1993 has taken some of the scope's most iconic images. In its place, the duo installed a modern set of eyes – the $132 million Wide Field Camera 3. The team also replaced a faulty data router. The Hubble upgrade mission was delayed six months to prepare the spare.

Day 2: New gyros, needed to stabilise the telescope, were the top priority of the mission. Rookie spacewalker Michael Good and Hubble veteran Mike Massimino installed the gyros and replaced three of Hubble's six batteries.

Day 3: Astronauts Grunsfeld and Feustel took their second spacewalk on Saturday to install a new instrument, the Cosmic Origins Spectrograph, and repair Hubble's Advanced Camera for Surveys. The delicate repair job was mostly successful, restoring the camera's wide-field channel, which is responsible for some stunning images, including the Ultra Deep Field, the deepest visible light image of the universe yet taken. However, the camera's high-resolution channel, which can block the bright light from a star to image fainter objects around it, could not be restored.

Day 4: The second day of camera repair work became the longest spacewalk of the mission, at 8 hours 2 minutes. A handrail with one recalcitrant fastener stood between astronaut Massimino and the Space Telescope Imaging Spectrograph, which can be used to measure the composition and motion of celestial objects. Massimino eventually used brute force to remove the handrail, then removed more than 100 screws to access the camera. Burch says initial tests suggest the camera, which was downed by power problems in 2004, has been restored.

Day 5: Eager to get the most out of the last day of spacewalks, Grunsfeld and Feustel started Monday's work an hour early. The astronauts exceeded expectations for the spacewalk, replacing the remainder of Hubble's old batteries and some degraded insulation, as well as replacing a sensor used to hold the telescope steady.
Museum pieces

Atlantis is set to land at NASA's Kennedy Space Center at Cape Canaveral, Florida on Friday.

It will touch down with two Hubble relics – the Wide Field and Planetary Camera 2 and COSTAR, a corrective optics box that was used to blurring caused by a flaw in Hubble's primary mirror. All Hubble instruments now have built-in corrective optics, so the box is no longer needed. Both devices are destined to become museum specimens at the Smithsonian Institution.

By : Rachel Courtland

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Stonehenge is one of the world ancient mistery. Archaeologists who carried out a dig in April say new radiocarbon dating evidence suggests the first stones brought to Stonehenge were erected around 2300BC - around 300 years earlier than previously believed.

The findings will be featured in the Timewatch documentary Stonehenge Deciphered to be broadcast on both BBC2 in the UK and the Smithsonian Channel in the US on Saturday.

Previous Stonehenge theories include it having been a prehistoric observatory, a temple, a giant calendar or a royal burial ground.

What is known is that the monument was built in stages between 3000BC and 1600BC. Prior to the erection of a double circle of bluestones brought 140 miles from south Wales and the subsequent placing of the larger famous Sarsen stones, was the building of a circular earthwork and placing of timber posts within the enclosure.

Darvill and Wainwright's team inferred the arrival of the bluestones as between 2400BC and 2200BC, from the positions of 14 samples of organic material such as carbonised plant remains and bone in their trench. This is precisely the date range for the Amesbury Archer, a man believed to have originated in the Alps, who was buried five miles from Stonehenge, and whose remains show evidence of an infected kneecap and a serious tooth abscess - potentially backing their healing hypothesis.

The new bluestone dates could undermine the main rival theory proposed by Mike Parker Pearson of the University of Sheffield, namely that the monument was primarily a burial ground for a Neolithic elite and a place at which people paid their respects to their ancestors.

Darvill says the monument was an important place of burial but only up until 2500BC or 2400BC - before the erection of the stones.

Archaeologists are split on the issue and dismiss each other's explanations. Asked about the elite cemetery theory, Wainwright said people must back up their ideas with "hard evidence", adding "the time has passed for mysticism to play a large role".

On the other side of the debate, Mike Pitts, editor of British Archaeology, describes the healing centre theory as "a fairy story".

Radiocarbon dating in the 1990s on samples from earlier digs places the erection of the Sarsens at 2500 - 2400BC, yet Darvill places them at 2100BC. Pitts said: "There is no evidence for that at all. These dates are completely baffling. They have to say that because we know from archaeological evidence that the first bluestones in the centre were there before the Sarsens were put up. I'm suspicious as to why this dating comes out so fortunately as fitting their theory."

Still, the stonehenge remains as a mistery...

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It can't be denied that stress can easily occurs in this globalization era. It is important to move away the stress from our daily activity.

For decades, medical researches are strenuously working to sum up the ways, to protect our health .Few of the suggestions being concluded by the practitioners are to control weight, blood pressure, cholesterol, sugar levels, etc.

Scientists believe that stress is a fundamental issue which leads to death of maximum people around the globe. They believe that stress releases or leaves a bad effect in the body's Endocrine system. This process starts in the hypothalamus (a part of the brain), which sends a message to the body's master gland which is known as the pituitary gland. It signals the adrenal glands to release abnormally high amounts of the stress hormone cortisone. This will result in abdominal fat storage and raised insulin levels (which have been linked to heart attacks, diabetes and stroke), high sugar level and blood pressure and other problems.

Tips to live a healthier life

Living a healthier life is a wish of every one. But it can only be achieved when we follow certain guidelines strictly.

1 LIMIT YOUR EATABLES:

Scientists have suggested that people with an uncontrollable diet are the victims of stress. Due to the excess in eatables, the metabolism rate of the person decreases. Nutritionists recommend a diet rich in whole grains, fruit land vegetables and low in saturated fat, cholesterol, salt and refined sugar. This proper diet is the basic way to live a healthy life.

2) REGULAR EXERCISE:

For year, depression is linked to an increased risk of heart attack. Exercise is an often overlooked antidepressant and helps the stressed person to live a free and healthier life. 30 minutes of brisk walk at least three times w week help person to be fit and fine.

3) CONTROL YOUR BAD HABITS:

Heavy drinking will lead the person to complete dizziness and then the fat body will lead to death. Smoking is very dangerous for many reasons besides lung cancer and emphysema. The study showed that after sixty minutes smoking, smokers still showed increased levels of cortisone, promotes abdominal fat storage.

Moderate caffeine consumers don't seem to be harmed. But the recent studies suggest that the person who has high blood pressure and the family history of hypertension and drinks a lot of caffeinated coffee while under stress, he may experience a dangerous rise in the blood pressure.

4) SLEEP WELL:

Sleeping for about seven hours will help the person to stay fit and fine and the stress will be released.

If you follow a better lifer style, then doubtless, you will be able to reduce the risk of your life. Be happy and follow good diet is the secret to healthier life style.

Hope this article helps you .....

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We already knew that Windows 7 is almost certain to be with us in all its finished, Microsoft-saving glory in the summer, but had you cottoned on to the fact that you can get the release candidate next week and run it for free for a year anyway?

Microsoft has confirmed that the 5 May RC of the new OS will not expire until 1 June 2010, which means more than a year of free play for anyone installing it next week. It hasn't explained why.

Previously, Windows Vista's candidate releases remained fully functional only for around eight months, nominally for testing purposes, but there was no shortage of cracks available online to keep them going indefinitely.

So far, the Windows 7 RC has been available to professional subscribers to Microsoft's MSDN and TechNet sites, although both have been reporting early hitches as download requests overwhelmed their servers.

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Molecules of CO2 are very stable, so processes that convert the gas to methanol normally require high temperatures and pressure. They also use catalysts containing toxic metal ions. "Our catalyst isn't toxic, and the reaction happens rapidly at room temperature," says team leader Jackie Ying.

The catalyst used by Ying's team is a type of chemical called an N-heterocyclic carbene (NHC). The mechanism by which the NHC speeds up the conversion is uncertain, but it appears to change the shape of the CO2 molecule, "activating" it in a way that makes it easier for hydrogen to bond with its carbon atom, says team member Yugen Zhang.

The catalyst may also help to release hydrogen from hydrosilane molecules, which are the source of hydrogen in the new process. Hydrosilane is an expensive chemical usually used to make computer chips, so the team wants to find a cheaper source.

"Potentially, it's a means for taking carbon dioxide out of the air and making it into something useful," says Dongke Zhang, director of the Centre for Petroleum, Fuels and Energy at the University of Western Australia in Perth. As well as being a fuel, methanol can be used as a feedstock for the chemical industry.Zhang's team is developing a technique for converting CO2 into methanol using high-frequency electromagnetic fields or plasmas to activate the gas.

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