Thousands of people gathered across Arctic regions, Siberia and China to see a total eclipse of the sun, despite Chinese warnings that it could augur bad luck.

People have been recording solar eclipses for perhaps 4,000 years, and they typically inspire a combination of dread, fascination and awe. According to NASA, the next total eclipse will occur July 22, 2009, starting in India and moving across Nepal, Bangladesh, Bhutan, Myanmar, China and over the Pacific Ocean.

The Space Shuttle Discovery successfully launched last week, becoming the 154th manned US space mission.

One of the best features of the space program has always been astronaut photography.

It would be really unbelievable if we can just fly around and view it ourselves. 8)

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Mysterious Night-Shining Clouds.

It's got the same climate as Earth, plus water and gravity. A newly discovered planet is the most stunning evidence that life - just like us - might be out there. The discovery was announced today by a team of European astronomers, using a telescope in La Silla in the Chilean Andes.

The Earth-like planet that could be covered in oceans and may support life is 20.5 light years away, and has the right temperature to allow liquid water on its surface.

The new planet, which orbits a small, red star called Gliese 581, is about one-and-a-half times the diameter of the Earth. It is the first exoplanet (a planet orbiting a star other than our own Sun) that is anything like our Earth. Gliese 581 is among the closest stars to us, just 20.5 light years away (about 120 trillion miles) in the constellation Libra. It is so dim it can be seen only with a good telescope.

It has a mass five times that of Earth, probably made of the same sort of rock as makes up our world and with enough gravity to hold a substantial atmosphere.

Astrobiologists - scientists who study the possibility of alien life - refer to a climate known as the Goldilocks Zone, where it is not so cold that water freezes and not so hot that it boils, but where it can lie on the planet's surface as a liquid. This new planet lies bang in the middle of the zone, with average surface temperatures estimated to be between zero and 40c (32-102f). Lakes, rivers and even oceans are possible.

The surface gravity is probably around twice that of the Earth and the atmosphere could be similar to ours.

Although the new planet is in itself very Earth-like, its solar system is about as alien as could be imagined. The star at the centre - Gliese 581 - is small and dim, only about a third the size of our Sun and about 50 times cooler. The two other planets are huge, Neptune-sized worlds called Gliese 581b and d (there is no "a", to avoid confusion with the star itself).

The Earth-like planet orbits its sun at a distance of only six million miles or so (our Sun is 93 million miles away), travelling so fast that its "year" only lasts 13 of our days. The parent star would dominate the view from the surface - a huge red ball of fire that must be a spectacular sight. Its sun is an ancient star - in fact, it is one of the oldest stars in the galaxy, and extremely stable. If there is life, it has had many billions of years to evolve.

This makes this planet a prime target in the search for life. According to Seth Shostak, of the Search for Extraterrestrial Intelligence Institute in California, the Gliese system is now a prime target for a radio search.

The real importance is not so much the discovery of this planet itself, but the fact that it shows that Earth-like planets are probably extremely common in the Universe. There are 200 billion stars in our galaxy alone and many astronomers believe most of these stars have planets.

Related: Star System 'Just Right' for Building an Earth.

An Earth-like planet is likely forming 424 light-years away in a star system called HD 113766, say astronomers using NASA's Spitzer Space Telescope.

Scientists have discovered a huge belt of warm dust - enough to build a Mars-size planet or larger - swirling around a distant star that is just slightly more massive than our sun. The dust belt, which they suspect is clumping together into planets, is located in the middle of the system's terrestrial habitable zone. This is the region around a star where liquid water could exist on any rocky planets that might form. Earth is located in the middle of our sun's terrestrial habitable zone.

"The timing for this system to be building an Earth is very good," said Carey Lisse, of the Johns Hopkins University Applied Physics Laboratory, Baltimore, Md. "If the system was too young, its planet-forming disk would be full of gas, and it would be making gas-giant planets like Jupiter instead. If the system was too old, then dust aggregation or clumping would have already occurred and all the system's rocky planets would have already formed."

According to Lisse, the conditions for forming an Earth-like planet are more than just being in the right place at the right time and around the right star - it's also about the right mix of dusty materials.

Lisse says that HD 113766 does not contain any water ice, carbonates, or fragile organic materials; stuffs that makes up infant solar systems and comets.

Studies tell us that metals began separating from rocks in Earth's early days, when the planet's body was completely molten. During this time, almost all the heavy metals fell to Earth's center in a process called "differentiation." Lisse says that, unlike planets and asteroids, the metals in HD 113766 have not totally separated from the rocky material, suggesting that rocky planets have not yet formed.

"The material mix in this belt is most reminiscent of the stuff found in lava flows on Earth. I thought of Mauna Kea material when I first saw the dust composition in this system - it contains raw rock and is abundant in iron sulfides, which are similar to fool's gold," said Lisse. Mauna Kea is a well-known volcano in Hawaii.

"It is fantastic to think we are able to detect the process of terrestrial planet formation. Stay tuned - I expect lots more fireworks as the planet in HD113766 grows," he adds.

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Mars Once Had Large Oceans.

Since Sky in Google Earth debuted two weeks ago to let the public explore the heavens from their computers, two University of California, Berkeley, astronomers have jumped in to populate Google's sky with the most recently discovered heavenly objects.

This week, Google posted on its Web site another layer of information users can add to their personal sky: real-time updates on new objects that flash in the heavens.

"Right out of the gate, Google Sky has become a powerful tool for the public and in the classroom," said Bloom, an assistant professor of astronomy who employed Sky in his opening lecture last week to an introductory astronomy class at UC Berkeley. "And if it works well and gets more and more of these transient events into the system, we as researchers will be using it."

Bloom and his colleagues at the California Institute of Technology and Los Alamos National Laboratory build the "cyber"-infrastructure, called VOEventNet, that allows satellites and telescopes to send astronomers, and Google, real-time information on these newly discovered transients in the sky. VOEvent is an important backbone for the Large Synoptic Survey Telescope, which should detect thousands of interesting transients every night. The LSST is a proposed ground-based 8.4-meter telescope that will image faint astronomical objects across the entire sky. (Targeted for completion by 2017)

"LSST answers the question, How do you do 21st century astronomy?" Bloom said. "The cutting edge won't be people going to telescopes and taking data, but terabytes and terabytes of data coming in every day, and astronomers sifting though the data for new discoveries."

VOEventNet, which allows these disparate data to be fed to Sky, was developed with funding from the National Science Foundation as a way to automate astronomy so that new observations are relayed within seconds or minutes to robotic telescopes that can quickly and automatically swivel to observe them.

Bloom expects more astronomers to take advantage of the ease of adding mash-ups to Sky in Google Earth in order to layer interesting astronomical objects over the viewing area and create personalized tours of the cosmos.

It's beautiful! 8)

The noctilucent clouds form in the upper layer of the Earth's atmosphere in summer and are made of tiny ice crystals.

Scientists don't know much about how the clouds form, or why they have been appearing more often at lower latitudes and glowing brighter. Some scientists suspect their proliferation is related to increasing greenhouse gases, which can actually cause the upper reaches of the atmosphere to cool.

The amount of water vapour in the upper atmosphere has increased in the past 50 years, perhaps as a result of increased methane in the atmosphere from farming and other human activities. Methane can react with oxygen in the atmosphere to create water molecules.

To find out, NASA has employed a satellite, named AIM (Aeronomy of Ice in Mesosphere) to observe two cloud seasons over both of Earth's Poles. On June 11, AIM captured its first images of night shining clouds. The satellite will also provide scientists with data on the size and shape of the particles that make up the clouds.

Related: Satellite snaps first images of mysterious glowing clouds.