Hey neighbors! Nearest sun-like star hosts 4 Earth-sized planets

Tau Ceti has been a staple of science fiction for decades. Now we know a little more about the real worlds around the bright star.

Eric Mack Contributing Editor
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Eric Mack
2 min read
Watch this: 4 Earth-sized exoplanets found orbiting our nearest sun-like star

Last year we learned the nearest star beyond our sun has a planet about the size of Earth, but it's very different than our solar system and not an ideal candidate for finding alien life.

So what about the closest star that would actually remind us of our own beloved sun? We now know that it probably hosts a handful of Earth-like planets, including a pair that might be able to support life.

Tau Ceti is the center of the nearest solar system that's similar to ours, an assumption made stronger by the discovery of four rocky super-Earths orbiting the star just 12 light years away. 


A comparison of the rocky planets around Tau Ceti and our sun.

Fabo Feng

Two of the four planets are in the habitable zone around the star where temperatures could be just right for liquid water, and perhaps alien life, to be present. 

An international team of scientists devised a new, more accurate and sensitive method of detecting planets by looking for "wobbles" in the star's movement caused by the minute gravitational tug of orbiting planets, while also better ruling out false positives coming from activity on the star itself.

"But no matter how we look at the star, there seem to be at least four rocky planets orbiting it," said Mikko Tuomi of the University of Hertfordshire, in a release. "We are slowly learning to tell the difference between wobbles caused by planets and those caused by stellar active surface. This enabled us to essentially verify the existence of the two outer, potentially habitable planets in the system."  

Tuomi is one of the co-authors on a paper detailing the discovery, which has been accepted for upcoming publication in the Astrophysical Journal.

Tau Ceti is particularly prevalent in science fiction that imagines future civilizations visiting the relatively nearby star system. Unfortunately, the odds of life on the potentially habitable rocky planets in the system might not be great after all. A massive disc of debris around the star means that the planets are likely being bombarded by asteroids and comets, making it hard for life to emerge.

Then again, certain life forms are known to be pretty tough, so perhaps we'll discover one day that a civilization of Tau Cetian tardigrades thrives on the system's planets.

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