Thursday, July 30, 2009

Planets from Hell - 51 Peg




2005 - 2006









Sometime in the future a spaceship from earth will explore the far reaches of our galaxy billions of miles from home.The pioneering space experiences will be the ultimate voyage to encounter new planets around distant stars. Theirs will be the journey into the extraordinary. On distant planets are incandescent storms big enough to swallow the earth. Bolts of lightning thousands of miles long. Raging infernos of toxic gas. Inconceivable violence and terrifying extremes. These are the planets from hell.





Also perhaps extremophiles burried deep within the sands or the rocks. We hardly understand the extremopihles in our own earth. Would we recognize life on another planet regardless how extreme, nevertheless still classified as life.






Planets from Hell 51Pegasi

December 2005

true masked wabbit

excerpts / National Geographics

NASA





Our sun is only one of two hundred billion stars that make up our galaxy, the Milky Way. Like our sun each star could be orbited with its own system of planets. Today astronomers are piecing together incredible new evidence in the search for distant worlds. Theirs is the ultimate scientific quest, they are the planet hunters. “There’s an absolute explosion going on right now, this is by far the most amazing time in astronomy that could ever be imagined.” Said Jeff Massey. These astronomers have discovered planets of frightening proportions that would dwarf any in our own solar system.
“Every once in a while a field in science will crack open and you get a peek at something that’s never been seen before.” Said Deborah Fisher Theirs’ a remarkable story in discovery, a scientific revolution that has changed our view of who and what we are. Now a race is on to find what planets lie beyond our solar system, will the all be planets from hell or could any of them be like earth? Hawaii, where astronomers head to gain an unparallel view of the heavens. On top of the 14,000-foot high summit of Mauna Kea, high above the obscuring clouds stand the two might Keck telescopes. Inside these enormous twin domes are the biggest telescopes in the world. So powerful, they could see a candle flame on the moon. Each of the two telescopes has a vast mirror over 30feet across. Essential for capturing the faintest starlight. This is the hunting ground of the world’s most successful planet hunting team. And King of the planet hunters is Geoff Marcy.“I think the most important thing we’re learning here in our search for planets around other stars is, we’re learning about how our solar system fits in to the grand cosmic scheme of planetary systems. Is our solar system unique? Special, or is it some common run of the mill type of planetary system?”Marcy and fellow astronomer Paul Butler use the Keck Telescopes to hunt for planets billions of miles from earth. But even with the power of the world’s most advanced technology a planet circling a distant star is too small and too faint to be seen directly. Instead they have perfected an ingenious technique to find these invisible worlds.“Finding planets in principle is actually easy”; says Geoff Marcy “We watch the star itself and look for the planet which we actually can’t see at all it’s blocked out by the glare of the star, so we watch the star itself to see if it wobbles in space due to the gravitational pull on the star by the planet. So simply we’re watching to see if stars are stationary or wobbling.”When a planet orbits a star, its gravitational force will pull the star off centre making it wobble from side to side. The largest planet in our solar system is Jupiter and so vast it can swallow 1300 earths. Five hundred million miles out from the sun it takes 12 years to complete each orbit. As it travels round Jupiter pulls our sun off centre by as much as half a million miles. The planet hunters believed that if they could find another star performing the same cosmic dance as our sun then it too would be orbited by a Jupiter sized planet.
When I heard of the discovery of the first planet outside our solar system my first reaction was amazement.” Said Geoff Marcy. And their research opened a whole new chapter in the study of astronomy.

Marcy and Butler began their search in 1987; they chose a hundred of our closest stars, many visible in our night sky and familiar constellations. The two astronomers were convinced they would soon find a wobbling star and detect their first planet. For year after year they could find no sign for the wobble they had expected. They began to doubt if there were any planets out there at all. The two astronomers were convinced they’d find their wobbling star and detect the first planet. For year after year they’d find no sign of the wobble they had expected. They began to doubt if there were any planets out there at all. “It was an extraordinary trying and stressing time, day after day coming into the office, leaving at the end of the day, realizing that not yet we have the ability to detect planets. I was worried that we were wasting telescope time and frankly wasting our whole lives.” Said Marcy
In 1995 came a break through but not from Marcy and Butler. Half a world away a rival Swiss team of planet hunters was working in southern France. One of them was D. Queloz; he was still a student studying for his PHD. Like the Americans Kello was sure that planets must exist through out the galaxy. “I was pretty much convinced that there are planets there. You know in science you never really start something unless you really believe you will find something, or you go crazy, we were pretty much convinced there were planets. That’s why decided to look for them.” Said QuelozAt a telescope in Province Queloz searched for wobbles in stars that might have been overlooked by other astronomers.

Three hundred trillion miles from earth in the constellation of Pegasus is one of the stars he was observing. Visible to the naked eye is 51Pegasi called 51Peg for short. Even traveling at a hundred and eighty six thousand miles per second the light from this star has taken nearly 50years to reach earth.After just a few weeks of measurements Queloz found the first hint that 51Peg was wobbling. But the way the star was moving was very different from anything anyone had ever expected.
“I was very puzzled”, said Queloz “and I though oh my god something is very wrong with the instrument.” The rapid movement Queloz had recorded suggested that something was orbiting 51Peg inconceivably fast. The astronomers had all been looking for a planet like our own Jupiter that would take many years to orbit its star. Here was something entirely different. The planet that was orbiting 51Peg was almost the size of our own Jupiter but the big surprise was the length of its orbit. Rather than orbiting every 12 years it was racing round in less than a week. After double-checking its wobble data Queloz knew there could be no doubt. “The only interpretation we are left with,” said Queloz “ that this is a planet there is no other way to explain what we are seeing except that this is a planet and that’s the beginning of the whole story.”The news of the discovery of the first planet beyond our solar system reverberated around the world. Marcy and Butler swung their telescopes round 51Peg and independently confirmed the discovery. There was indeed a planet racing around the star. “We were so shocked that we didn’t believe that it was a planet at first, and we had to go to the telescopes ourselves to confirm it, And the reason it was a shock is that this planet goes around its star 51Pegasi taking only 4 days.” Said Massey.

Not only was the planet orbiting fast, but also it was orbiting just 4 million miles away from its star. No one had ever dreamt that a planet could exist so terrifying close to the fiery surface of a star. In their search to find the distant world like our own the planet hunters had found the universe to far more frightening and hostile than they’d ever imagined. With the discovery of the first planet orbiting the star 51Peg they had stumbled across a world of violent extremes. The American team returned to their old data to see if they had missed other fast orbiting planets.Says Marcy “Here we were for the first time realizing that there might be planets that would take only a few weeks or months to go around their star, and it’s like finding a gold vein in a mine. We now knew where to look for planets. Some might be in fairly close. And we looked and sure enough we found dozens of them.”

A disturbing trend began to emerge. Many of the stars in our galaxy have giant super hot planets in close fast orbits. One planet a hundred and seventy bigger than our planet earth races around its star in just three days. The quickest ever found. Another is eleven hundred times larger than earth and orbits eight times closer. On the surface of the hottest planet ever found is scorched at more than 12000oc. It was a mystery how such large planets could be orbiting so fast and so close to their star. How did they fit in into the original astronomers’ theories the way planetary systems are formed?

On the west coast of America one man who thought he had the answer was Professor Doug Lynn.“The general reaction at that time was that there’s got to be a mistake in the data or the interpretation of the data, this could not be due to a planet.” Said Professor Lynn. “Because it looks so different from our solar system.Orbiting close to our sun are four small rocky planets including the earth. Beyond them, hundreds of millions of miles out lay the gas giants. Jupiter larger than all the other planets put together is made almost entirely of hydrogen and helium. And Saturn eight hundred times the size of the earth is mostly hydrogen. Based on this pattern the astronomers have built a theory of how planetary systems are born and how they evolve.
They believe young proto planets are created from a giant spinning disc of gas and dust that swirls around on the nuclear fires of the newborn star. Over millions of years the fines grains of dust clustered together. Their gravity grows and attracts more material until a planet is formed. The lighter elements such as hydrogen and helium are blown to the edge of the disc where they collect to form giant gas planets. The heavier substances, silica and iron remain close to the star where they eventually form small rocky planets. This was a theory that couldn’t explain the presence of a gas giant so close to a star like 51Peg.Lynn soon realized a radical idea was needed to explain the existence of a gas giant in close orbits. He used a computer to construct a new mathematical model of how large planets grow and evolve from a spinning disc of gas and dust. “I worked very quickly to develop a theory to account for how these planets may have formed at very far away from the star and then gradually migrate to the neighbourhood of the star. “ Lynn said.
Lynn’s breakthrough was to realize that a giant planet could be born far from its parent star and then spiral inwards finishing in a tight circular orbit. But Lynn’s theory also dashed any hopes that stars like 51Peg might also harbour more rocky earth like planets. If any of these young proto planets had existed they would have been bulldozed into oblivion as the gas giants spiralled in towards the star.The star 51Peg and its newly discovered planet lie in an almost unimaginable distance from earth. Today’s fastest space probe would take half a million years to get there. But if thousands of years into the future an interstellar spaceship on a scientific mission reached 51Peg, what would it find?Physicist Andrew C. Cameron thinks he knows the kinds of conditions we could expect to find. Far ahead any interstellar probe, he’s using spectral analysis of distant starlight to understand what these gas giants are made of.Says Cameron;” Every once in a while in astronomy a new phenomenon is discovered which you can’t actually see. It all begins with an act of imagination. You would have to imagine what it would have to be like on this world and then you use science to flesh in the numbers. The temperatures, the pressures, the kinds of material which would likely be present. And eventually you finish up with a complex picture of what the atmosphere of a planet might be like even before you’ve seen it.”Cameron is trying to confirm preliminary observations of some of these gas giants have atmospheres containing sodium and potassium. And the atmosphere of any planet so close to its star must be super heated.“They’re incredibly hot because they’re twenty times closer to their parent stars than the earth is to the sun so you can imagine that these planets being twenty times closer are actually being spit roasted.” In this inferno even solid metal would be vaporized.“Here on earth you would think of most metals as being solids.” Cameron continued,” however you can imagine that if you heated the earth up to say 11000c some metals would melt and boil and then they would then become as gases in the atmosphere, and this is the situation we have so hot that some of the metals exist in the atmosphere as gases.”

With such extreme conditions the planet 51Peg would challenge any space ship even with the most advanced technology. On its scientific mission, the interstellar space ship finally reaches its destination, the planet orbiting 51Peg. The gravitational grip of the star is so great that one side of the planet is permanently faces the searing heat well over a thousand degrees Celsius. The far side freezes in permanent darkness. The space ship dispatches a probe down into the atmosphere. It enters a millstream of super heated noxious gases where winds top a thousand miles per hour. The probe is bombarded by lethal radiation. The poisonous clouds of methane, sodium and potassium envelope the probe, giant bolts of lightning upwards to a thousand miles long strike all around it. The probe plummets down to a hailstorm of rock particles.

Down here nothing can survive.


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