Group finds extrasolar planet habitable

World located 20.4 light years away could harbor life.
Scientists estimate that it is only slightly larger than Earth.

Artist's conception of habitable planet around Gliese 581. (Photo: ESO)

The search is finally over - or, in the words of the scientists themselves, it just got more interesting. A European group of researchers has discovered a planet outside our solar system that is much like Earth, with potential conditions to harbor life.

He is one of the three known planets orbiting a star called Gliese 581. This is a star of the most common of a class known as red dwarfs - smaller and cooler than the Sun The innermost planet is probably a gas giant, similar in size to Neptune, and completes an orbit around the star every 5.4 days on land. It was discovered two years ago.

The innovations are the other two planets, presented in a paper submitted to the journal "Astronomy and Astrophysics" (which was embargoed until this Tuesday 20h). The outermost one complete turn every 84 days and is about eight times the land mass. More interesting is that the middle planet. He has "only" five times the mass of the Earth (the smallest ever detected) and has a year that lasts a measly 13 days.

Although he is much closer to Gliese 581 than Earth's sun, as his star is much dimmer, its orbit falls into the so-called Zone of Habitability. It is the region in which a planet is not neither too hot nor too cold, and may harbor liquid water - essential to life main feature.

The group led by Michel Mayor of Geneva Observatory in Switzerland, estimates that the average temperature in this world is between 0 and 40 degrees Celsius - not unlike the Earth, whose average temperature is 15 degrees.

• Hunting data

The study of planets outside our solar system - there are more than the 200 known today - is still a delicate task. As they are very distant, it is impossible with current techniques, view the planet - the brightness of the star ends up overshadowing the parent. The most common strategy to detect them is to observe the star over time, trying to detect in its light, signs of movement.The idea is that while the planets revolve around the star, they draw from one side to the other, producing a stellar wobble. The detection of this wobble can be deduced that the planets would be needed to produce it.This was the technique used by Mayor and colleagues to detect the cousin closest to Earth today. The problem is that the data obtained with a telescope of ESO (European Southern Observatory) in Chile, do not say everything there is to know about this star. For example, it is possible to establish the mass, but the diameter (roughly the "width") of the world still depends on the chutômetro.Scientists estimate that the star has recently discovered about one and a half times the diameter of Earth (which would give a little less than 20,000 km).

• Cruel Questions

Everything else on this planet remains open. This includes, of course, the most essential features of this world. "We believe it is a rocky planet like Earth, with some oceans," said the G1, by telephone, Mayor. "However, some models suggest that it may be what is called 'ocean planet', with much more water than the Earth."

In the Solar System, there is no example of a planet-ocean. "But the theoretical models show that it could exist elsewhere," says Mayor. The key to this was that the planet to form farther away from the star, where there is more ice, and then migrate to the interior of the system. A nice portion of the total mass would create a global ocean, with many miles deep.Based on the information available, it is impossible to say whether the newly discovered star is most like Earth or a planet-ocean, but the fact is that in both cases, the presence of liquid water would be ensured. For most scientists, this is the basic precondition for the evolution of life.

Image shows the red dwarf star Gliese 581. (Photo: ESO)

• Good and bad news

Of course, between being able to have life and have it go a long distance. And astronomers say they will still need a few decades of research so that the instruments are capable of searching for "signatures" of life in the light of these objects.

The most eloquent conclusion, however, is that the discovery shows evidence that the universe must be full of planets like Earth. The star Gliese 581 is one of the hundred closest to the Sun It is 20.4 light years away - which is not so far away, in astronomical terms, is right there.

The fact that we found so similar neighbors already in the vicinity shows that they must be everywhere. Now it's just a matter of finding.

Via G1.

Newly discovered exoplanet has more water than Earth

composition shows the planet orbiting its star / / Credit: NASA via BBC

Astronomers have confirmed that the exoplanet GJ 1214b, found in 2009, consists largely of water, like the Earth. Called "Super Earth" by scientists, water and high temperatures of the surface can create an environment conducive to life.

The planet (it's outside our solar system) GJ 1214b is relatively close to Earth, located 40 light-years away. It is larger than the planet and less than giant as Jupiter. Through observations by the Hubble Space Telescope, researchers were able to study details.

The Hubble telescope can capture images of other galaxies / / Credit: NASA

It has been found, for example, that this planet is 2.7 times the diameter of the earth mass and an almost 7-fold. A complete órbitra around a dwarf red each 38 hours, at a distance of 2 million miles. By calculating the density of the planet, the scientists could also prove that he has more water than land and that its surface temperature is about 230 ° C.

"This planet is unlike anything we know. The high temperatures suggest that exotic materials can exist there, like 'hot ice' and 'superfluid water', "said astronomer Zachory Berta, the study coordinator.

Scientists speculate that the GJ1214b started to form far from its star, where the ice was abundant, and then approached, through the zone where surface temperatures would be similar to Earth.

Via BBC 

Earth-like planet is found around Sun-like star

Star may contain liquid water on its surface.
NASA has announced new data from the Kepler spacecraft on Monday (12/5).


U.S. space agency (NASA) announced on Monday (5) discovered the first planet similar in size to the Earth which revolves around a star like the Sun The planet is 600 light-years distance and was detected by Kepler spacecraft, launched in 2009 with the aim of discovering new "Earths" in space.


Another feature of the star is that it is at a distance from the star that could allow the development of liquid water and atmosphere, ideal conditions for the emergence of life as we know it. When a planet is under these conditions, it is said that he is in a "habitable zone" (also the common term "goldilocks").


The planet was named Kepler 22b. Their discovery is reported in the journal "Astrophysical Journal", a major scientific publications on astronomy.


In February, NASA astronomers had announced a list of 54 stars that could be habitable. Of these, only Kepler 22b was confirmed as a planet. The star has a radius 2.4 times larger than Earth and rotates around its star in 290 days. Scientists still can not say the planet is rocky or gaseous.



Illustration shows what the planet Kepler 22b. (Credit: Ames / JPL-Caltech / NASA)




Data from Kepler


The new balance of Kepler revealed the existence of 1,094 new planet candidates. Of these, 10 were in the "habitable zone" of the stars they orbit. Future observations should confirm that these bodies are planets or not.


Currently, only 600 stars are confirmed as planets by astronomers. The Kepler spacecraft is currently the main unveiled new worlds. The instrument scans the surrounding area of 150 000 stars, all located in a strip in the sky between the constellations Cygnus and Lyra.


To confirm that Kepler 22b was actually a planet, the probe had to check the signal coming from that region at least three times. The star it orbits is a little cooler than our Sun.


Since the last review in February, the number of candidate planets grew 89% and now reaches 2326. Of these, 207 have a size similar to Earth's 680 is larger than our planet, and 1181 are as big as Neptune. The list is completed by 203 stars with the same size as Jupiter and only 55 larger than the biggest star in the Solar System (after the Sun).


Other recent discoveries in astronomy point to the existence of places in space with conditions similar to those of our planet and may even contain life, such as Jupiter's moon Europa.


The yellow traces on the surface of Europa may indicate the presence of bacteria, the ice-covered world may have liquid water, energy, and organic compounds - all three of the ingredients necessary for life to survive, its surface is composed of ice and is one of the smoothest in the Solar System. Strong evidence that there is an ocean beneath the ice surface that will house life as well as early life on earth that would have begun in the oceans.

                                                      Europa.

Another discovery points to a planet with sufficient conditions to host life. The star with only three times Earth's mass was detected at 20 light years away from our Sun, orbiting a star in the constellation Libra known as Gliese 581, a red dwarf. Astronomers at the University of California and the Carnegie Institution of Washington say that the planet is the first to have real potential to support life.

The discovery was announced on Wednesday (29) by the National Science Foundation in the United States. The star called Gliese 581g, is in a region in which astronomers think that a planet may have liquid water to form oceans, rivers and lakes. On site, the distance from the star would allow an environment with a mild climate, neither too cold nor too hot.

A ilustração mostra um formato possível para o exoplaneta que orbita a estrela Gliese 581, a apenas 20 anos-luz de distância da Terra. (Crédito: AP / Zina Deretsky / National Foundation of Science)

The planet's orbit around the star Gliese 581 is just over one month on Earth, with the possible stations year lasting only days.

It is the first planet discovered in the "habitable zone" of the star. In 2007, another planet, located near the same star was cataloged, also with the potential to contain life.

Scientists also estimate that the average surface temperature varies from 31 to 12 degrees Celsius. The team also says that the planet orbits with one side always faces the star, similar to how the Moon always shows one face to Earth.

For astronomers, the planet can "sustain life", which means it has the potential to meet conditions of life. Living things can not necessarily be similar to humans.

According to Steven Vogt, coordinator of the study which included 11 years working in the Observatory W. M. Keck, located in Hawaii, the discovery is an indication that there may be many other similar bodies in the universe.

Results will be published in Astrophysical Journal, but are available online at arXiv.org. By September, 490 planets have been discovered outside our solar system.

Via G1.