Wow! NASA discovered seven Earth sized planets that could possibly harbor life
स्रोत: News Bharati English      तारीख: 23-Feb-2017

Washington, February 23: On Wednesday NASA surprised the whole world with live announcement about new space discovery which said that the astronomers have discovered another solar system which is 40 light years away consisting of seven Earth sized planets orbiting a star called TRAPPIST-1. The findings were announced at a news conference at NASA Headquarters in Washington.
Among those seven planets three of them in the TRAPPIST-1 system are in the habitable zone which lets us assume that could have water on their surfaces and therefore it could possibly support life. These planets orbit a dwarf star named Trappist-1 about 40 light years or 235 miles from Earth which is closer in cosmic terms. It will be easy to study these planets in detailed manner due to their orientation in orbits.

Astronomers led by Michaël Gillon from the University of Liège in Belgium first detected three exoplanets around the star back in May 2016, using Earth-based telescopes. “This is the first time so many planets of this kind are found around the same star,” said Michael Gillon. These planets appear to be made of rock, have life-friendly surface temperatures ranging between a life-friendly 0 to 100°C (32 to 212°F), and some could potentially host liquid water.

“You can just imagine how many worlds are out there that have a shot to becoming a habitable ecosystem,” said Thomas Zurbuchen, associate administrator of NASA’s science mission directorate. “Are we alone out there? We’re making a step forward with this a leap forward, in fact towards answering that question.”

During the NASA news conference, Dr. Gillon gave a simple analogy: If our sun were the size of a basketball, Trappist-1 would be a golf ball. Some of the scientists expected a deep red, but with most of the star’s light emitted at infrared wavelengths and out of view of human eyes, perhaps a person would “see something more salmon-y,” Dr. Triaud said.

The whole system is compact as the closest planet only takes 1.5 days to orbit its star. The sixth planet takes 13 days. The planets are so close together, if you were to stand on the surface of one, you'd see the other six looking as large as or larger than our moon. NASA also believes the planets are locked into their home star's gravity in such a way that they don't rotate, but have permanent night and day sides.
According to NASA, that means "they [might] have weather patterns totally unlike those on Earth, such as strong winds blowing from the day side to the night side, and extreme temperature changes." All of the planets are very close to the dim star they orbit, which means they are tidally locked like our Moon and so have one side in permanent darkness, Gillon said.

“I think that we have made a crucial step toward finding if there is life out there,” said Amaury H. M. J. Triaud, an astronomer at the University of Cambridge in England and another member of the research team. “Here, if life managed to thrive and releases gases similar to that we have on Earth, then we will know.”

“You can just imagine how many worlds are out there that have a shot to becoming a habitable ecosystem,” Thomas Zurbuchen, associate administrator of NASA’s science mission directorate, said during a NASA news conference on Wednesday. “Are we alone out there? We’re making a step forward with this — a leap forward, in fact — towards answering that question.”

What’s next?

With the NASA James Webb Space Telescope scheduled to come online next year, researchers should be able to get a better idea of the composition and atmosphere of this sister solar system. And when the European Space Organization’s Extremely Large Telescope goes live in 2024, it should actually be able to detect water on the distant worlds from right here on Earth.