Close Sun-like Star Tau Ceti Could Have Two Habitable Planets | Out Of This World Weekly

A new technique has been used to filter out noise in data to reveal that Tau Ceti may have one or two habitable planets.  Tau Ceti is only 12 light years away (70 Trillion miles) and is the second nearest star that closely resembles our own sun.  Recently, the closest star to resemble our Sun in the Alpha Centauri system was found to have an Earth sized planet.  Tau Ceti is slightly smaller, cooler, and less bright than our own Sun, which means that the habitable zone is closer to Tau Ceti.  The two planets that could be habitable are Tau Ceti e and f, with e being at the near edge of the habitable zone and f being at the outer edge of the habitable zone.  The discovery of yet another star that is similar to the Sun having planets in the habitable zone reinforces our chances of ultimately finding another planet to settle that is like our own.  

While these planets may be habitable, mostly meaning that water could exist in liquid form, these are not planets like Earth.  Tau Ceti e has a year that is only 168 days long and more importantly, it is about 4.3 times the mass of Earth.  While this could be a rocky or water world, the excess mass means that it would likely have a much greater gravity at the surface.  Tau Ceti f is farther out with a year that is 642 days long.  It has a greater mass of 6.67 times that of Earth and it may be much cooler as it roughly orbits in the same area that Mars orbits in our own solar system.  While these higher mass planets might suggest unfriendly conditions, it is possible that they could be larger and less dense which could allow for similar gravity at the surface.  There is always the possibility of moons around these planets that could even be Earth sized, although current techniques do not allow for the detection of moons. (Tau Ceti is yellow star near the bottom of the picture on left)

Tau Ceti is similar to our Sun but there are some interesting differences between the Tau Ceti system as a whole and our solar system.  The amount of dust, gases, and material seems to be about 10 times greater in the Tau Ceti system than our own.  This could mean that they have a much larger amount of asteroids and comets.  While this could mean that the planets are under continuous bombardment, it could also mean that it is likely that comets have spread water to any planet that can support it.  The Tau Ceti system seems to have a lower metallicity than our own system.  Lower metallicity means that the original gas cloud that the system formed from contained less heavy elements like Iron, Nickel, Lead, and Uranium and more light elements like Hydrogen, Helium, Oxygen, and Carbon.  This lower metallicity could mean both lower density of planets and a greater abundance of water.  The age of Tau Ceti is 5.8 Billion years, which is about 1.3 Billion years older than our own sun.  Hopefully, this means that the early bombardment of planets by comets and asteroids is over and everything has reached some sort of stable equilibrium. 

The amount of planets being found continues to rise.  The total at this point is 854 confirmed planets, with many more unconfirmed planets needing only more data for confirmation.  Not all of these planets are in the habitable zone of the star, yet recent discoveries finding water on the Moon and Mercury could provide many places we could live that aren’t in the habitable zone as long as we have the help of technology.  Tau Ceti is the closest system discovered that could have habitable planets and that could one day mean that we could colonize it.  Even so, we have a long way to go with establishing colonies in our own solar system and learning to travel the vast distances between stars in a reasonable amount of time. 

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