Proxima Centauri

Few things stir the imagination quite like the announcement of newly-discovered exoplanets. Within the space of a single lifetime, our understanding of our cosmos has grown so dramatically that it is hard to believe that the first true confirmation of extrasolar planets came in 1992–a mere twenty-four years ago–with the announcement of the three planets in orbit of the millisecond pulsar PSR1257+12 on February 25, 1992.

Since then, due to both the tremendous success of the Kepler Mission, launched by NASA in 2009, and the vast improvements in ground-based telescopes, the Exoplanet Catalog now boasts a remarkable 3,518 confirmed planetary bodies in orbit around alien suns. More than three thousand in twenty-four years! Each new discovery brings entirely novel and often unexpected stories: the so-called “carbon” or “diamond” exoplanet candidates like WASP-12b or 55 Cancri e; potential ocean planets, a la Star Wars’ Manaan or Venus in Perelandra, like Gliese 1214 b or Kepler-22b; or perhaps most dramatically, lonely rogue planets like PSO J318.5-22. Each of these discoveries results in a wave of euphoria, at least for me, as I realize that so much of what we’ve written in fiction over the past one hundred years is not overly imaginative, but if anything, fails to capture the unique drama of the billions of stars (and planets, as we now know!) that orbit just our own galaxy’s center.

But this news in particular has started a firestorm of excitement, because Proxima Centauri b is no ordinary exoplanet, (likely) doomed to be forever out of our reach. This planet, announced just last month in Nature, orbits the nearest star to our own sun. Think on it! This star is only four and a quarter light years from us–practically touching in astronomical terms–and this planet is not merely some super-Jupiter or garden variety ice giant, but somewhere around 1.25 Earth masses: an Earth-mass planet in the habitable zone–that is, the zone within which water can remain liquid. This planet orbits so close to her mother star–twenty times closer than we to our own sun!–that completes an orbit every eleven days, yet due to the dimness of the star, the surface temperature could still be quite comparable to our own planet–if, of course, this exoplanet has an atmosphere, for an atmosphere provides vital thermal inertia to stabilize daily temperatures.

Much is speculative at this point, but the news is still exciting. And what a boon for fiction writers! Although Proxima Centauri has already had its share of fiction relating to it over the years, I would not be surprised to see it rise to the forefront again in the next few years. And why not? Science fiction has always led the way in predicting the future, and helping us to wrap our minds around the discoveries of the present.

Come on, Breakthrough Starshot!