Call it exoplanet fatigue. The historic detection of an exoplanet just 4.2 light-years from Earth, featured on our cover, was big news. It attracted a lot of media buzz. But outside the office, I heard little about it. No questions from other parents at the playground, including those who had been eager to chat about gravitational waves and the Zika virus. Even my significant other, a science fiction fan, didn’t probe for any details or wonder aloud about the chances for alien life on Proxima b.
I was a bit surprised. Because, as astronomy reporter Christopher Crockett writes in “Signs of planet detected around sun’s nearest neighbor star” (SN: 6/17/16, p. 6), this nearby world might well be the one we’ve been searching for. Proxima b orbits its star within a zone where temperatures permit liquid water to exist on its surface. In terms of intriguing exoplanets that could possibly harbor life, this one seems to be in the sweet spot (SN: 4/30/16, p. 32). Proxima b may be just a tad bigger than Earth and it’s also just next door, astronomically speaking. It orbits Proxima Centauri, the closest star to the sun and a member of the triple-star Alpha Centauri system.
There’s plenty we still don’t know. Proxima Centauri is quite different from the sun: A dim red dwarf, its planet is huddled up close, leaving the world vulnerable to stellar outbursts. And although the artist illustrated Proxima b with a rocky surface (and a news release announcing the discovery called it “rocky” as well), no one yet knows what the planet is really like. And, in this case, close-by is still dreadfully far — a trip there would take 80,000 to 90,000 years with current spacecraft technology. (In a post on his Context blog on the Science News website, managing editor Tom Siegfried discusses alternate technologies, such as a proposed scheme to use alpha radiation decay to power a ship that might cut the journey down to something like a mere 5,000 years.) Superfast, nano-sized spacecraft sent to investigate might make it in just 20 years, but development of that idea is just beginning.
Even with these caveats, though, this is a story that appeals to the imagination. The star system where the exoplanet was found has a long history as a potential destination in science fiction, from Avatar and Doctor Who to an Isaac Asimov short story and a Robert Heinlein novella. The TV show Babylon 5 even featured an Earth colony orbiting Proxima Centauri. So why so little chatter among the people I know?
I have a few hypotheses, pretty much all untestable. One is that Donald Trump and Hillary Clinton are hogging all of the news-related conversations. Another is that it was back-to-school week. Maybe, after the thousands of exoplanets already found, folks have become blasé about exoplanets, even one that is so close. Perhaps some were so disappointed by the false alarm in 2012, when another group claimed to have found an exoplanet in the Alpha Centauri system, no one wanted to get their hopes up. Or, it could be that my acquaintances have taken the mature and reasonable approach that, while intriguing, more evidence is needed before we can say anything definitive about Proxima b.
I, for one, was excited about Proxima b. Now we know of at least one destination suitable for our first interstellar voyage.