Astronomers are finding potential new planets out in the cosmos all the time now, and though it seems more and more of those planets are turning out to possibly be habitable, they're all so far away that it seems humanity will never reach them. But now another possibly habitable planet has popped up, and though it's still far away, it's the closest one to our solar system that we've ever seen.
Studying data from three different spectrometers, a team of astronomers has found five possible planets orbiting Tau Ceti, a sun-like star only 12 light-years from Earth. One of those planets, a body with at least 4.3 times the mass of Earth, is located well within Tau Ceti's "habitable zone," the zone in which liquid water can exist.
If the findings are confirmed by further analysis, the planet would be the smallest yet found inside the habitable zone of a sunlike star, as well as the closest potentially habitable planet to our solar system found so far.
"This discovery is in keeping with our emerging view that virtually every star has planets, and that the galaxy must have many such potentially habitable Earth-sized planets," said Steve Vogt of the University of California, who co-authored a paper on the findings. "They are everywhere, even right next door."
Researchers have searched for signs of planets around Tau Ceti before, but Vogt and his colleagues were able to see what others couldn't through new analysis methods. The spectrometer data used in the study is supposed to detect the small gravitational fluctuations that indicate large, possibly planet-sized bodies, but until now those signals weren't detected around Tau Ceti.
"We pioneered new data modeling techniques by adding artificial signals to the data and testing our recovery of the signals with a variety of different approaches," said lead author Mikko Tuomi of England's University of Hertfordshire. "This significantly improved our noise modeling techniques and increased our ability to find low-mass planets."
Apart from finding the signal of the habitable-zone planet, scientists don't know much about it yet, but the research team believes that it is not a rocky world like Earth.
"It is impossible to tell the composition, but I do not consider this particular planet to be very likely to have a rocky surface," Tuomi said. "It might be a 'water world,' but at the moment it's anybody's guess."
Though 12 light-years is still a long way to travel if we actually want to visit, the planets orbiting Tau Ceti are close enough that we can examine them more closely than other more distant exoplanets, and that's got astronomers excited.
"Tau Ceti is one of our nearest cosmic neighbors, and so bright that we may be able to study the atmospheres of these planets in the not-too-distant future," said James Jenkins of the Universidad de Chile and the University of Hertfordshire. "Planetary systems found around nearby stars close to our sun indicate that these systems are common in our Milky Way galaxy."
You might recognize the name Tau Ceti from various works of science fiction, including the works of Isaac Asimov. According to his fictional universe, humanity's first settlement outside of our solar system was on a planet orbiting the star. Could it be fate, or is this just another cool discovery?
(Via Huffington Post)