Habitable planets | | | | | |
| | | | | | |  Automatic translation | | | | | | Planets in the habitable zone of stars | | Updated May 20, 2012 | | Category: Planets |  | | | | | Six planets the size of the Earth have been discovered in the habitable zones of stars.
The mission of NASA's Kepler discovered his first planets the size of the Earth candidates to life, that is located in the habitable zone of the star, a region where liquid water can exist on the surface of a planet.
Five of these planets are about the size of Earth and orbits are in the habitable zone of stars cooler than our sun. These candidates for life are the subject of observation and monitoring to verify their real lives. Kepler confirmed the observation of six planets around a sun-like star.
This is the largest group of transiting planets observed around a single star outside our solar system.
"In one generation we went from alien planets, the pillars of science fiction to reality and has allowed Kepler science fiction turns into reality today," said NASA Administrator Charles Bolden.
Several hundred new planets have been identified in the data from the Kepler Mission Science, published Tuesday, February 1, 2011.
Among the 1235 candidates identified by Kepler planets in early 2011, 68 are about the size of the Earth, 288 are super-Earth, 662 are about the size of Neptune, 165 are about the size of Jupiter and 19 are larger than Jupiter. 54 new planets in the habitable zone 5 which, in size of the Earth. The 49 remaining candidates in the habitable zone, are super-Earths, 2 times the size of the Earth at a height greater than that of Jupiter.
These conclusions are based on the results of observations made between May 12 and September 17, 2009, over 156,000 stars in the Kepler field of view. | | This covers only about 1/400 of the sky.
"This large number of planets discovered, in a short time and a tiny fraction of the sky, shows that there must be countless planets orbiting Sun-like stars in our galaxy."
Said William Borucki of Ames Research Center of NASA in Moffett Field, California.
"We went from zero to 68 planets the size of the Earth and from zero to 54 candidates in the habitable zone, some of which may have moons and liquid water."
The results of Kepler were published in February in the journal Nature.
Six planets are orbiting Kepler 11, a star very similar to the sun being at about 2,000 light-years away in the constellation Cygnus.
This discovery, due to the data of exoplanet hunter NASA's Kepler, Kepler's is 11, the system Exoplanetary the most comprehensive to date. 6 inner planets are mixtures of rock and gas, which may include water. The rock materials are the mass of the planets, while the gas occupies most of their volume.
The Kepler space telescope, looking for signatures of planets by measuring the slight decrease in the brightness of stars caused by planets passing in front of the star (mini eclipse). This is called a transit.
Transits of planets in the habitable zone of stars like the Sun, occurring about once a year and it takes three transits to check it, so it takes 3 years of observation for planets the size of Earth.
The scientific team also uses Kepler, ground-based telescopes and the Spitzer Space Telescope to observe planetary candidates. | | 
* All the planets orbit Kepler-11 are larger than the Earth, comparable in size to Uranus and Neptune.
The closest planet, Kepler-11b, is ten times closer to its star than Earth.
The other planets are Kepler-11c, 11d, Kepler, Kepler-11th, Kepler-11E, and the outermost planet, Kepler-11g, is only half as far from its star than Earth. | | | | | | | | The proper place to live near the stars | | | | | | | | | | The circumstellar habitable zone is a sphere or ecosphere theory surrounding a star where the temperature at the surface of planets orbiting them would allow the appearance of liquid water.
Scientists believe that liquid water is vital, because of its role in biochemical reactions.
Frank Drake calculate the distance of this area in his equation in 1961. This equation takes into account the size, the brightness of the star and the brightness of the sun. A star that has 25% of the brightness of the sun will habitable zone centered at about 0.50 AU.
A star that has twice the brightness of the Sun will have a habitable zone centered at 1.41 AU.
A habitable zone does not mean it houses within it life but there is a possibility depending on many factors that a terrestrial planet is home life: the Earth is home life, but the Moon, located in the same area is sterile. The planet candidate in the development of life, must be massive enough to prevent water from escaping.
The habitable zone is not a fixed area, it changes depending on the temperature of the star, as in their evolution the stars becoming brighter and more hot, the habitable zone moves logically from the star.
A planet will therefore remain as long as possible in this area to develop all the molecules necessary for life form. | | We must not, in determining the habitability of a planet, put all the conditions that met our Earth, if no other planet in the universe could not support life, each planet is unique.
Only if they have liquid water seems necessary, it is considered an essential element for a viable ecosystem because it helps tremendously transporting materials for biochemical activity.
Water is a perfect material to dissolve and store very well the chemical elements.
Life can be present outside the living areas, simply that there is liquid water, a source of energy and chemicals whose life needs to build its materials.
The astrobiologists think that life forms may exist on other objects in our solar system as Europe, a Galilean moon of Jupiter at 500 million km from Earth.
Europe is a ball covered with ice the size of our Moon and has a sea of tens of km deep, kept liquid by the energy of tidal forces of Jupiter.
The friction caused by this stretching causes sufficient heat to maintain liquid water below the frozen surface.
The discovery of exoplanets began in 1990 and 2010, 490 exoplanets were referenced. | |  * The ecosphere or habitable zone of a solar system in terms of its luminosity (mass).
Life can still be present outside the living areas, simply that there is liquid water, a source of energy and chemicals whose life needs to build its materials. |
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