It's the second potentially habitable planet astronomers found in our backyard in just a couple of months, after the discovery of an Earth-sized planet around Alpha Centauri, astronomers now say they have found a planet that has similarities to Earth around Tau Ceti, a star just 12 light years away and visible to the naked eye.Tau Ceti is almost identical to our sun, so the theory goes that a planet similar in size to the Earth positioned at around the same distance from its star should have favorable conditions to life similar to the one on our own planet.
Generally, this region, the habitable zone, where water can exist in liquid form is dubbed the "Goldilocks Zone," not too hot and not too cold.
Astronomers now believe there are five planets circling Tau Ceti, the closest sun-like star, and that one of those planets is situated in the star's habitable zone. The planet is only five times larger than our planet, making it a Super Earth.
Still, it's the smallest planet found in the habitable zone around a star similar to the sun, so it's the likeliest candidate we have for a life-bearing planet.
Detecting extrasolar planets is no small feat and has only been possible in the past couple of decades, with most discoveries happening in the past few years.
What's more, the techniques used make it easier to spot giant planets, like our gas giants Jupiter or Saturn, rather than small rocky ones like the Earth or Mars.
But as techniques become more precise, smaller and smaller planets are discovered. Already, planets lighter than the Earth have been found.
In this particular case, astronomers perfected the radial velocity method, which detects planets by looking at the wobble of the star, caused by the gravity of the planets circling around it. Their improvements made it possible to detect signals half the size of what was previously possible.
Also interesting about this discovery is that, once again, the team found a lot of planets circling very close to their parent star. This has been the case in most discoveries so far, indicating that our solar system may not be the norm in the galaxy. Granted, there's too little data to make a prediction like that just yet.