In the fall of 2016, Spitzer observed TRAPPIST-1 almost continuously for 500 hours. Jupiter's auroras are hundreds of times more powerful than Earth's, and they form a glowing ring around each pole that's bigger than our home planet.
TRAPPIST-1 is not very bright, so sunbathing on its planets could be a rather unsatisfying experience. Three of the planets lie within the "habitable zone", a theoretical range in which liquid water could exist. After being studied with telescopes for more than two centuries, Ceres became the first dwarf planet to be explored by a spacecraft, when NASA's Dawn probe arrived in orbit in March 2015. It's a bit cooler than Earth, but could be suitable with the right atmosphere and enough greenhouse gases.
Due to the low temperature of the star, all seven of the planets orbit closer to it than Mercury does to our Sun. Seven new planets! "Earthlike!". "It is like at the end of sunset", co-author Amaury Triaud, an astronomer at the University of Cambridge, said. Plus, generally speaking, just because a planet could be habitable doesn't mean humans would want to live there, even if we could leave behind Florida and make Obama president of humans and aliens alike. Today, we know of more than 3,500.
If they find traces of methane, oxygen and ozone simultaneously on one planet, then "that is a strong indication for life", Dillon said.
Presenters will include: NASA Science Mission Directorate Associate Administrator Thomas Zurbuchen, University of Liege astronomer Michael Gillon, NASA Spitzer Science Center manager Sean Carey, Space Telescope Science Institute astronomer Nikole Lewis, and Massachusetts Institute of Technology Professor of Planetary Science and Physics Sara Seager. "Answering 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 forward toward that goal". "Just imagine how many worlds are out there that have a shot at becoming a habitable system that we could explore".
Scientists have long believed that there are other Earthlike planets in the galaxy, and say the discovery of the TRAPPIST-1 system offers a unique opportunity for study, both because the system is so close to us and because the star's glow is dim enough that we can see the planets.
All seven of the TRAPPIST-1 planetary orbits are closer to their host star than Mercury is to our sun.
Even so, ultracool dwarf stars can be pretty hot places to look for potentially life-friendly planets.
Starting closest to the star and moving out, the planets have respective orbits from one and a half to almost 13 Earth days. The Sun has two: Earth and Mars, plus the dwarf planet Ceres in the asteroid belt. If a person were standing on one of the planet's surface, they could gaze up and potentially see geological features or clouds of neighboring worlds, which would sometimes appear larger than the moon in Earth's sky. And because of the red nature of the star, the light would be a salmon hue, the researchers speculate. "Still, the star is so small and cold that the seven planets are temperate, which means that they could have some liquid water - and maybe life, by extension - on the surface". But further observation is needed to know for sure. If TRAPPIST-1 were the Sun, all of them would be baked. Revolving outside this auroral oval are the glowing, electric "footprints" of Jupiter's three largest moons.
They were largely overlooked until Gillon made a decision to study the space around one of these dwarves.
The European Southern Observatory's TRAnsiting Planets and PlanetesImals Small Telescope (TRAPPIST for short) in Chile uses the transit method to hunt for planets. The team saw shadows, like little eclipses, periodically interrupting the steady pattern of starlight. These create what are called transit timing variations, where a planet may appear in front of its host star a few minutes earlier or later than would be expected if it is orbiting on its own. The shadows indicated planets, and further observation confirmed them.
So, they brought in the big guns: NASA's Spitzer space telescope.
Over the next decade, the researchers want to define the atmosphere of each planet, as well as to determine whether they truly do have liquid water on the surface and search for signs of life.
At about 40 light-years (235 trillion miles) from Earth, the system of planets is relatively close to us, in the constellation Aquarius. Some propose that it is the best place to search for life within the solar system. NASA's bleeding-edge James Webb Space Telescope, to be launched in October 2018, will make this search far easier.
The researchers are also searching for similar star systems to conduct more atmospheric research.