What is TRAPPIST-1?
TRAPPIST-1 stands for Transiting Planets and Planetesimals Small Telescope. The discovery is a small, dim star in the constellation Aquarius, less than 40 light-years from Earth, or 235 trillion miles away, according to Nasa and the Belgian-led research team who announced its discovery on Wednesday.
An artist's conception of what the surface of the exoplanet TRAPPIST-1f may look likeSeven planets circle Trappist-1, with orbits ranging from one and a half to 20 days. If Trappist-1 were our sun, all these planets would fit inside the orbit of Mercury. That's how close they are to their star and why their orbits are so short. The planets have no real names. They're only known by letters, "b" through "h." The letter "A" refers to the star itself.
Can this newly discovered solar system support life?
Six of TRAPPIST-1's "exoplanets" lie in a temperate zone where surface temperatures range from zero to 100C.Of these, at least three are thought to be capable of having watery oceans, greatly increasing the likelihood of life.No other star system known contains such a large number of Earth-sized and probably rocky planets.All are about the same size as Earth or Venus, or slightly smaller. Because the parent star is so dim, the planets are warmed gently despite having orbits much smaller than that of Mercury, the planet closest to the sun.Scientists said they need to study the atmospheres before determining whether these rocky, terrestrial planets could support some sort of life.
From the viewpoint of someone standing on the surface of one of the planets, some of the other worlds would appear larger than the moon in the Earth's sky.Gazing up, it would be possible to see the geological features, oceans and clouds of your planetary neighbours.The ultracool star at the heart of this system would shine 200 times dimmer than our sun, a perpetual twilight as we know it. And the star would glow red - maybe salmon-colored, the researchers speculate.
No other star system known contains such a large number of Earth-sized and probably rocky planets.All are about the same size as Earth or Venus, or slightly smaller. Because the parent star is so dim, the planets are warmed gently despite having orbits much smaller than that of Mercury, the planet closest to the sun.Scientists said they need to study the atmospheres before determining whether these rocky, terrestrial planets could support some sort of life. But just because a planet is in this sweet spot, doesn't mean life exists or ever did.
The first exoplanet was confirmed to have been discovered in 1992, since when a total of 3,577 have been found. Of these, less than a dozen are thought to be well suited to supporting life, and Nasa said only three previously known exoplanets were as ideal as those in the new solar system.
the sourcehttp://www.telegraph.co.uk/technology/2017/02/23/seven-earth-sized-exoplanets-discovered-does-nasa-announcement/
http://www.telegraph.co.uk/science/2017/02/22/nasa-announcement-live/