This is really exciting: an international team of astronomers has discovered that Tau Ceti, the closest single star like our Sun, has planets just like our solar system. But more importantly, one of these planets orbits in the habitable zone around the star.
Tau Ceti is very close to Earth. It's only 12 light-years away, which is cosmic terms is just around the corner. It's so close that, even while it's like our Sun, we can see it with the naked eye at night.
The most exciting news is about the Earth-ish planet found in this solar system's goldilocks region, the circumstellar zone area in which, theoretically, life would develop.
The artist's impression above shows its five planets with masses that vary between two to six times the mass of Earth. The astronomers, who used more than six-thousand observations and three different instruments, say that this is "the lowest-mass planetary system yet detected."
This is an important discovery, as it shows once again that almost every star has planets. According to UC Santa Cruz professor of astronomy and astrophysics Steve Vogt — one of the authors of the study that is going to be published in the scientific journal Astronomy & Astrophysics — "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."
The sightly bad news is that the universe seems to prefer systems that have planets with orbits less than 100 days. According to Vogt, "this is quite unlike our own solar system, where there is nothing with an orbit inside that of Mercury. So our solar system is, in some sense, a bit of a freak and not the most typical kind of system that Nature cooks up."
Still, the evidence seems pretty overwhelming. With an estimated 100 thousand million stars in the Milky Way alone, and millions and millions and galaxies in the universe, the statistical probability of planets full of life just like ours is overwhelming. We now just need to visit. And 12 light years away is a perfect place to star, just in our own neighborhood. [UCSC]