Saturday, April 20, 2013

Two super-Earths discovered in habitable zone - THE WORLD

The space telescope ‘Kepler’ has already tracked down many exoplanets: But now it trumps with the sensational discovery of two super-Earths on. Both could be covered by oceans. From

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The success story dates back to the 80s of the last century. Even then, astronomers discovered the first exoplanet, but had not really understood what it was for worlds with them. They falsely classified as brown dwarfs or discarded their measurements completely equal.

before they reach the millennium, the advent of exosolaren planet was unstoppable. These objects are heavenly bodies that orbit other suns than ours. More than 800 such planets have now been detected.

And with each new exoplanets reduces the supposedly special position of the earth in space. Our planet is just one of many who happened to be in a so-called habitable zone of its solar system orbits around the parent star, our sun, attracts.

as astronomers call the habitable zone region in a planetary system where liquid water is possible. That liquid water is commonly referred to as the basis for the emergence of life considered, explains the term “habitable” zone so habitalbe

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In our solar system, it includes only the planet Earth and – possibly – Mars. Everything that is closer to the sun (Mercury and Venus), is too hot, everything beyond Mars’ (Jupiter, Saturn, Uranus, Neptune) is too cold to allow water on its surface

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for amateur telescopes invisible

It is therefore a great step forward that a 64-member international team of astronomers from the U.S., Denmark and now Germany has discovered a solar system for the first time, in the same two planets orbits its host star in the coveted habitable zone.

The headshot is the star “Kepler-62″, named after the U.S. space telescope “Kepler,” which is responsible for the discovery. For four years, this was named after the German astronomer Johannes Kepler telescope looking in its orbit around the sun by exosolaren planet.

In November, the U.S. space agency NASA has extended the mission for another four years. So far has tracked “Kepler” nearly 3000 candidates are now checked for their status as exoplanet out.

The Star “Kepler-62″ is just one of so far of 170,000 “Kepler” examined – as an arbitrary star like our Sun so. It is 1200 light years away from Earth. Of the “Kepler” trapped light from the star was so 1200 years long way to Earth, or more precisely to the lens of the Hubble Space Telescope

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An object at that distance is too faint to be seen from Earth with the naked eye in the night sky. Even those who aligns his Amateuer telescope precisely to the constellation Lyra, will not be successful.


Two planets at the right distance

Just like our sun, has also “Kepler-62″ a life-friendly zone. Since astronomers size, temperature and luminosity of this star thanks to “Kepler” know, they can then calculate at what distance this habitable zone is located, liquid remain in the water.

It so happens that the same two planets orbit in the “right” distance this star. You do not just wear the usual poetic but in astronomy called “Kepler-62e” and “Kepler-62f”.

The international team of astronomers has discovered even three more planets to “Kepler-62″. This system is thus a total of at least five planets. The three innermost However, it is likely to involve hot gas giants that are much too close to its sun to allow liquid water.

“Kepler-62e” but orbits its star at a distance that – native transferred to our solar system – about the orbit of the planet Mercury closest to the sun correspond. The orbit of the outermost planet Kepler-this system would be in approximately the area of ??Venus, the second planet from the Sun seen.

These planets spin their webs so extremely close to its parent star. The orbits of all five planets in our solar system would find inside the Venus orbit space. They are extremely close together, and also the habitable zone of this system is closer to the central star.


researchers suggest water on the planet

“Kepler-62e” and “Kepler-62f” are so-called super-Earths, terrestrial planets made of rock so that have an unknown multiple mass and size of the Earth. But because they are located in the habitable zone, the team of scientists suggest that liquid water exists on them.

And where there are oceans, there is also a water cycle: The water of the oceans heated by the sun, evaporates, rises and forms clouds. Thus, the atmosphere would also be enriched with hydrogen. From this, astronomers can even connect to the prospect of the two super-Earths.

“The sky is likely to be similar to blue as here on earth there,” said William Boruckis the reflections from NASA Ames Research Center in Moffett Field, Calif., the chief scientist of the “Kepler” mission. The H atoms in the atmospheres of “Kepler-62e” and “Kepler-62f” would provide a similar scattering of starlight as here on Earth.

“Sunrise and sunset on these worlds would, however, wrapped in a light rötlicheres as the earthly morning and evening twilights, because the parent star has a higher proportion of red light than our sun.”

possible life forms on both Kepler-super-Earths would turn into when looking up a different picture than the people here on earth. Because both planets are so close to their star, the sun appears on this “Kepler-62e” half as large in the day sky.

When more distant “Kepler-62f”, however, takes the stellar disk only about 90 percent of the size of the Sun in Earth’s sky. Even the lighting conditions are different: The Star “Kepler-62″ appears on the nearby planet about 20 percent brighter than the sun, on the other hand, more outlying, less than half as bright

five planets revolve around host star

Even if the planetary system around the star is “Kepler-62″ pushed relatively dense and all the five planets orbit their stars in relatively close orbits, this would be the individual members of the solar system At night, no more than dots in the sky.

Who looks of one of the two outer super-Earths in the adjacent, that is from the planet “Kepler-62e” on its neighbors, “Kepler-62f” – or vice versa – , the planet is visible in the sky only in star size -. earthly astronomers appear as the two inner and outer neighbors of the Earth, Venus and Mars, with the naked eye even as stars

Hydrogen is the most abundant element in the universe. And experience shows that where water is possible, there is also available. On Earth, it exists in liquid and frozen form, there is water ice on the shady inner sides of lunar craters at the poles of Mars, under the ice sheets of Saturn’s moon Enceladus and Jupiter’s moon Europa.

Also comets are not for nothing known as “dirty snowballs”: They transport water – in the form of ice – from one end of the solar system to another. Thus, the chance is even liquid water on the two exoplanets now so big.

Open is the probability of the next step: Are water-oceans synonymous with life? This question is William Borucki, on behalf of his international experts prefer unanswered: “At the moment we can not say anything about the existence of life on these planets,” the U.S. astronomer. According to the latest discoveries, however, speaks more likely than not.

It is no longer the mere number of planets in other solar systems that astronomers fascinated – more and more telescopes in space are able to describe such worlds even more accurate . The space telescope ‘Kepler’ has become doubly successful.

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