NASA Discovers 7 Earth-Like Planets Orbiting Star
PASADENA (CBSLA.com) — A system of seven Earth-like planets, three of which are considered to be in the "habitable zone," have been discovered orbiting a single star, NASA announced Wednesday.
The discovery by NASA's Spitzer Telescope sets a record for the largest number of habitable-zone planets around a single star outside our solar system, officials said. The three planets in the habitable zone are considered most likely to have water – the key building block of life – but all seven could potentially have it.
"This is the most exciting result I have seen in the 14 years of Spitzer operations," Sean Carey, manager of NASA's Spitzer Science Center at Caltech in Pasadena, said in a statement. "Spitzer will follow up in the fall to further refine our understanding of these planets so that the James Webb Space Telescope can follow up. More observations of the system are sure to reveal more secrets."
The discovered planetary system 40 light-years from Earth, in the constellation Aquarius, has been dubbed TRAPPIST-1 after the Transiting Planets and Planetesimals Small Telescope in Chile, which was the first to discover three planets in the system. Spitzer later confirmed the existence of two of those three, and discovered five more, bringing the discovery to a total of seven planets.
All of the discovered planets are likely to be rocky, and all seven are orbiting closer to their star – which has been classified as an ultra-cool dwarf -- than Mercury is to our own sun. All seven of the TRAPPIST-1 planets are also very close to each other – a person standing on one of those planets' surfaces could potentially see geological features or clouds of a neighboring world, which could appear larger than the moon in Earth's sky.
The planets may also be "tidally locked" to their star, not rotating as Earth does and keeping each side in perpetual day or night, JPL officials said. The weather systems would then be totally unlike those on Earth.
"This discovery could be a significant piece in the puzzle of finding habitable environments, places that are conducive to life," Thomas Zurbuchen, associate administrator of the agency's Science Mission Directorate in Washington, said in a statement. "Answer the question, 'are we alone' is a top science priority and finding so many planets like these for the first time in the habitable zone is a remarkable step toward that goal."
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