Now we know, That’s the way Big stars born

A new discovery has the potential to answer the long-standing question of how massive stars are born -- and hints at the possibility that planets could form around the galaxy's biggest bodies.
"Astronomers have long been unclear about how the most massive stars form," said Stefan Kraus, a NASA Sagan Exoplanet Fellow and astronomer at the University of Michigan, Ann Arbor. "Because they tend to be at very large distances and surrounded by dusty envelopes, it's very hard to separate and closely observe them."
To get a better look, Kraus' team used the Very Large Telescope Interferometer of the European Southern Observatory in Chile to focus on IRAS 13481-6124, a star located at a distance of 10,000 light-years away in the constellation Centaurus, and about 20 times more massive than our sun. "We were able to get a very sharp view into the innermost regions around this star by combining the light of separate telescopes," Kraus said, "basically mimicking the resolving power of a telescope with an incredible 85-meter [280-foot] mirror."
The team's observations yielded a jackpot result: the discovery of a massive disk of dust and gas encircling the giant young star. "It's the first time something like this has been observed," Kraus said. "The disk very much resembles what we see around young stars that are much smaller, except everything is scaled up and more massive."
The presence of the disk is strong evidence that even the very largest stars in the galaxy form by the same process as smaller ones -- growing out of the dense accumulation of vast quantities of gas and dust, rather than the merging of smaller stars, as had been previously suggested by some scientists. The results were confirmed by NASA's Spitzer Space Telescope. "We looked at archival images of the star taken by Spitzer, and confirmed that the star is flinging disk material outward from its polar regions, just as we see with smaller stars and their dust disks," Kraus said.
The discovery also opens up the possibility that planets, perhaps even Earth-like ones, may be able to form around massive stars like IRAS 13481-6124, in the same way that they formed around our sun when it was much younger. "In the future, we might be able to see gaps in this and other dust disks created by orbiting planets, although it is unlikely that such bodies could survive for long." Kraus said. "A planet around such a massive star would be destroyed by the strong stellar winds and intense radiation as soon as the protective disk material is gone, which leaves little chance for the development of solar systems like our own."

The daylight star - Tycho's Supernova

Tycho's Supernova, the red circle visible in the upper left part of the image, is SN 1572 is a remnant of a star explosion is named after the astronomer Tycho Brahe, although he was not the only person to observe and record the supernova. When the supernova first appeared in November 1572, it was as bright as Venus and could be seen in the daytime. Over the next two years, the supernova dimmed until it could no longer be seen with the naked eye. In the 1950s, the remnants of the supernova could be seen again with the help of telescopes.When the star exploded, it sent out a blast wave into the surrounding material, scooping up interstellar dust and gas as it went, like a snow plow. An expanding shock wave traveled into the surroundings and a reverse shock was driven back in toward the remnants of the star. Previous observations by NASA's Spitzer Space Telescope indicate that the nature of the light that WISE sees from the supernova remnant is emission from dust heated by the shock wave.To the right is a star-forming nebula of dust and gas, called S175. This cloud of material is about 3,500 light-years away and 35 light-years across. It is heated by radiation from the young, hot stars within it, and the dust within the cloud radiates infrared light.

Mars Down to Earth, Through the E-Telescope

Microsoft Research and NASA are providing an entirely new experience to users of the WorldWide Telescope, which will allow visitors to interact with and explore our solar system like never before. Viewers can now take interactive tours of the red planet, hear directly from NASA scientists, and view and explore the most complete, highest-resolution coverage of Mars available. To experience Mars up close, Microsoft and NASA encourage viewers to download the new WWT , Mars experience at http://www.worldwidetelescope.org. Dan Fay, director of Microsoft Research’s Earth, Energy and Environment effort, works with scientists around the world to see how technology can help solve their research challenges. Since early 2009, he’s been working with NASA to bring imagery from the agency’s Mars and Moon missions to life, and to make their valuable volumes of information more accessible to the masses. “We wanted to make it easier for people everywhere, as well as scientists, to access these unique and valuable images,” says Fay. “NASA had the images and they were open to new ways to share them. Through the WorldWide Telescope we were able to build a user interface at WWT Mars that would allow people to take advantage of the great content they had.”

Planets parade on 14th July

Five of the sky's brightest and most dazzling lights will make appearances in the western sky on several nights this month in a promising celestial show for skywatchers with clear skies.
Venus, the dazzling evening star, is currently creeping past Regulus, the brightest star of Leo, the lion. At the beginning of July, Venus was well to the lower right of Regulus, but now the planet stands side by side with the bright star.
Being the brightest object in the night sky other than the moon, Venus is impossible to miss. People often mistake it for an airplane or UFO, and calls to local police and sheriff departments are not uncommon when Venus graces the evening sky.
The slim crescent moon will dance close to this bright duo on July 14, making an equilateral triangle with the moon at left, Venus on top, and Regulus on the right.
The orange-hued planet Mars and the golden gas giant Saturn will be a little higher to the group's upper left.
The display of these five bright cosmic objects provides a good look at the ecliptic – the path that the sun traces across the sky.
In ancient times, the ecliptic was thought to hold special significance. In fact, the first major constellations ever drawn were those of the zodiac – the 12 constellations that lie along the ecliptic.

Amazing world of many craters !

Asteroid Lutetia has been revealed as a battered world of many craters. ESA’s Rosetta mission has returned the first close-up images of the asteroid showing it is most probably a primitive survivor from the violent birth of the Solar System.The flyby was a spectacular success with Rosetta performing faultlessly. Closest approach took place at 18:10 CEST, at a distance of 3162 km.
The images show that Lutetia is heavily cratered, having suffered many impacts during its 4.5 billion years of existence. As Rosetta drew close, a giant bowl-shaped depression stretching across much of the asteroid rotated into view. The images confirm that Lutetia is an elongated body, with its longest side around 130km.
The pictures come from Rosetta’s OSIRIS instrument, which combines a wide angle and a narrow angle camera. At closest approach, details down to a scale of 60 m can be seen over the entire surface of Lutetia.

Where would the Rosewell Aliens come from ?

A reader reminded me that today is the 63rd anniversary of the so-called Roswell UFO Incident. Even if you know nothing else about the UFO phenomenon, you certainly have heard about what supposedly happened in Roswell, New Mexico in July, 1947: a crashed flying saucer, autopsies on alien bodies, Government cover-ups. It ushered in the 1950’s kitsch of bubble-headed little green space jockeys inside silvery saucers flitting across our skies.
This space-age mythology, embellished over the years, tells of an alien interstellar vehicle simply falling out of the sky near a desert town. The only tangible evidence is scraps of wood and metal foil and other mundane debris that suspiciously look like they came from a crashed U.S. military balloon. That is, unless you believe the Government has been hiding all the goodies -- including alien corpses -- inside an Indiana Jones style warehouse all these decades.

This leads me to wonder that if flying saucers are supposedly real, why haven't we learned where the visitors come from among the stars? Didn't the Roswell aliens leave a driving map in their glovebox?
If someone who claimed to be in contact with space aliens could give us just a few simple numbers they’d unequivocally prove their case to skeptics. Simply send me (1) the celestial coordinates of the home star, (2) the number of planets orbiting it, (3) their distances from the parent star, (4) and their relative masses. Then all we’d have to do is look at the star and see if the planets were there. Viola!
This has never happened in UFO history. Well, almost never.
A search on the Internet comes up with one particularly legendary place, the double star system Zeta Reticuli. It's nearby, only 39 light-years away in the southern sky.
The naked-eye double star burst into UFO culture in the mid -1970s. An Ohio school teacher, Marjorie Fish, claimed to have decoded a star map from a 1961 UFO abduction case. It pointed to Zeta Reticuli as the aliens' place of origin.
The alleged extraterrestrial kidnapping, described in journalist John Fuller’s book “Incident at Exeter: The Interrupted Journey,” tells how a New England couple was taken aboard a flying saucer and medically examined. Under hypnotic regression the wife, Betty Hill, sketched a star map she said she saw while inside the spaceship.
In the pre-home computer days of the early 1970s, Fish actually constructed a wireframe cube and positioned beads on strings for the nearby stellar neighborhood। She viewed the model from different angles until a match was found with the Hill map. It pinpointed Zeta Reticuli.

This map is legendary but meaningless. First, the Hill drawing contains 25 dots for stars. If you flew around a computer database of the local stellar neighborhood you’d come up with more than one match that roughly “looked” similar to her sketch.
Secondly, Hill described the map as showing alien exploration and trade routes to other stars. The notion of trade between extraterrestrial civilizations is patently absurd. There is nothing worth trading that would justify the transportation costs (at least nothing short of Star Trek’s Green Orion Slave Women). And, clearly the Zeta Reticulans aren’t trading with us, unless they’re getting modeling fees and a cut from Roswell UFO souvenir stands.
Finally, in the Fuller book Hill described the map as a flat pull-down chart (later she changed her account and described it vaguely to me, in a hesitant voice, as some sort of 3D display). BTW the UFO also carried paperbound books with “Chinese looking printing” according to Hill. This is as nonsensical as Neil Armstrong carrying stone tablets to the moon. Didn't the aliens at least have something like an iPad?
Today, the Hill map even has a link to the Roswell incident. According to one website the Roswell aliens supposedly set up a secret exchange program with the U।S। military. Apparently 12 humans were sent to the home planet, named Serpio, in the Zeta Reticuli system. The write-up describes a “10-month journey” with poor food (what do you expect from an interstellar airliner?)

The reality is that the Zeta Reticuli system is a fascinating place where I’d expect to find advanced life. The two stars are similar to our sun and separated by 800 billion miles. This would leave plenty of elbowroom for inhabited planets to exist around both stars.
The stars are estimated to be as much as 3 billion years older than our Sun. Any intelligent life that originated there would be far too advanced for the shenanigans reported in Roswell. What's more, you could not place a sentient entity a billion years more evolved than us onto a dissection table. And, it definitely would not be humanoid, or perhaps even biological.
Therefore, it's simply ludicrous to imagine that there really was such a wayward craft over Roswell with pilots of flesh and blood. Over the past 50 years our newbie space civilization has reconnoitered the entire solar system with a pretty nimble and savvy armada of robots. They self-navigate into stable orbits and landings on hostile worlds. At least when one of them crashes, nobody gets killed.
Similarly, a native technological intelligent species certainly would be enticed to explore any inhabited planets orbiting the companion star in the Zeta Reticuli system. They would rapidly become and “extra-terrestrial” space-faring civilization. They would be motivated to develop far-advanced propulsion systems needed to hop over to the companion star. Such a trip would take close to 2,000 years with our present generation space vehicles.
In this star system UFOs could become reality. That’s because a less advanced civilization on the companion star might be able to see manifestations of a visiting advanced intelligence from the neighboring binary companion. Eventually they could decide to send a living emissary for a face-to-face contact between civilizations, assuming a similar astrobiology. It could be a scene straight out of the sci-fi classic film “Avatar.”
To date, no planets have been found around either star. NASA’s Spitzer Space Telescope did find the telltale glow of a dusty disk that would indicate planets are present.
As our survey techniques improve it’s probably only a matter of time before we discover a family of worlds in the Zeta Reticuli system. And, follow-up observations will seek out the biosignatures of life on any planets in habitable zones. This is a far more enthralling future narrative than the unimaginative fantasy of some space hot rodders totaling their vehicle in the middle of nowhere.
Now, Roswell UFO believers can save us a lot of time and effort by simply telling us exactly what the planetary system looks like . . .

Don’t Worry about Aliens

STEPHEN HAWKING is worried about aliens. The famous physicist recently suggested that we should be wary of contact with extraterrestrials, citing what happened to Native Americans when Europeans landed on their shores. Since any species that could visit us would be far beyond our own technological level, meeting them could be bad news.
Hawking was extrapolating the possible consequences of my day job: a small but durable exercise known as SETI, the Search for Extraterrestrial Intelligence.
Although we have yet to detect an alien ping, improvements in technology have encouraged us to think that, if transmitting extraterrestrials are out there, we might soon find them. That would be revolutionary. But some people, Hawking included, sense a catastrophe.
Consider what happens if we succeed. Should we respond? Any broadcast could blow Earth's cover, inviting the possibility of attack by a society advanced enough to pick up our signals.
On the face of it, that sounds like a scenario straight out of cheap science fiction. But even if the odds of calamity are small, why gamble?
For three years, this issue has been exercising a group of SETI scientists in the International Academy of Astronautics. The crux of the dispute was an initiative by a few members to proscribe any broadcasts to aliens, whether or not we receive a signal first.
In truth, banning broadcasts would be impractical - and manifestly too late. We have been inadvertently betraying our presence for 60 years with our television, radio and radar transmissions. The earliest episodes of I Love Lucy have washed over 6000 or so star systems, and are reaching new audiences at the rate of one solar system a day. If there are sentient beings out there, the signals will reach them.
Detecting this leakage radiation won't be that difficult. Its intensity decreases with the square of the distance, but even if the nearest aliens were 1000 light years away, they would still be able to detect it as long as their antenna technology was a century or two ahead of ours.
This makes it specious to suggest that we should ban deliberate messages on the grounds that they would be more powerful than our leaked signals. Only a society close to our level of development would be able to pick up an intentional broadcast while failing to notice TV and radar. And a society at our level is no threat.
The flip side is that for any alien society that could be dangerous, a deliberate message makes no difference. Such a society could use its own star as a gravitational lens, and even see the glow from our street lamps. Hawking's warning is irrelevant.
Such considerations motivated the SETI group at the International Academy of Astronautics to reject a proscription of transmissions to the sky. It was the right decision. The extraterrestrials may be out there, and we might learn much by discovering them, but it is paranoia of a rare sort that would shutter the Earth out of fear that they might discover us.
- Seth Shostak
(The writer is a senior astronomer at the SETI Institute, and chair of the International Academy of Astronautics' SETI Permanent Study Group)

Beware ! Cartosat-2B is watching you

India's advanced, high-resolution remote-sensing satellite Cartosat-2B would be launched July 12 at 9.23 am from the Sriharikota spaceport in Andhra Pradesh, giving a boost to the country's infrastructure and urban planning.The Indian Space and Research Organisation's (ISRO) rocket Polar Satellite Launch Vehicle (PSLV) will carry into space the 690 kg Cartosat 2B and an Algerian satellite, Alsat (117 kg).The rocket will blast off carrying also three nano satellites - NLS 6.1 and NLS 6.2 from Canada and Switzerland, and StudSat developed by students of engineering colleges in Bangalore and Hyderabad.'The launch is fixed for July 12 at 9.23 a.m. The rocket will carry five satellites,' S.Sathish, director (Publications and Public Relations) said from Bangalore over phone.The rocket's main cargo Cartosat-2B is a remote sensing satellite carrying a sophisticated panchromatic camera on board to photograph specific spots closely. The pictures are useful for cartographic applications such as mapping, land information and geographical information system.Cartosat 2B will join the other two cartography satellites Cartosat 2 and 2A launched earlier. With three satellites ISRO's satellites can cover the country effectively.ISRO has been carrying out multiple launches for several years and in 2008 it set a world record launching 10 satellites at one go.Originally scheduled for launch May 9, ISRO decided to postpone the launch as it found 'a marginal drop in the pressure in the second stage of the vehicle during mandatory checks'.Though the pressure drop was marginal, ISRO wanted to be sure as it does not want to risk a failure since PSLV is a major revenue earner, carrying satellites for others for a fee.The 44 metre tall PSLV is a four stage (engine) rocket powered by solid and liquid propellants alternatively.The first and third stages are fired by solid propellant and the second and fourth stages are fired by liquid propellant.At that time the rocket was almost ready except for the loading of the satellites that had arrived at the launch centre in Sriharikota around 80 km from here.As the faulty valve was in an inaccessible area with the rocket stages having been fully assembled, the second stage had to be dismantled to take corrective action.Even after the replacement of the faulty valve at Sriharikota the problem continued to persist and ISRO sent the second stage (engine and other systems) to Liquid Propulsion System Centre at Thiruvanthapuram in Kerala where it was originally assembled.'The second stage was refurbished and sent back to Sriharikota,' Satish said