In what is being hailed as "the story of the decade" by some scientists, the discovery of a new planet was announced two weeks ago.
So what? Astronomers have now discovered 843 planets (exoplanets) in star systems other than our own. What is so darn special about this one?
It is so special it almost makes me giddy.
Alpha Centauri Bb (not B-flat) orbits our closest neighbour star in the entire universe.
Okay, Alpha Centauri is actually a binary star, Alpha Centauri A and Alpha Centauri B. Alpha Centauri Bb orbits Alpha Centauri B (hence the rather awkward name) so sometimes when A is closer to us, B is actually our second closest neighbour, but what's a few million kilometres between friends? And just to add a bit more complexity, there is a third tiny star (Proxima Centauri) that orbits the other two.
Nevertheless, if our closest neighbour binary/tertiary star, out of all the hundreds of billions of galaxies in the universe, each containing millions to hundreds of billions of stars, has planets, then planets are surely as common as grains of sand on a beach.
And if planets are that common, surely life exists almost everywhere.
Not on Alpha Centauri Bb, probably, because it orbits so close to its sun-about one-tenth the distance Mercury is from our sun-the temperature on the surface is estimated at approximately 1,200 degrees Celcius.
Still, the prospect of a life-bearing planet in the system is tantalizing. "Statistical studies of exoplanets suggest that low-mass planets are preferentially formed in multi-planetary systems," says the paper released in the prestigious journal Nature on October 17. "There is therefore a high probability that other planets orbit Alpha Centauri B, perhaps in its habitable zone."
There is a big difference between discovering planets in the "Goldilocks Zone" and discovering life. For the latter, we would pretty much have to go there.
Unfortunately, even though Alpha Centauri is our closest neighbour, it's still 4.37 light years away (40 trillion kilometres. That is, something traveling at the speed of light would still take more than four Earth years to get there and it would take at least that long again to get data back here.
And that's at light speed. With current technology, we're talking tens of thousands of years even to get a probe out there. It's kind of disheartening.
Yet it seems absurd, even to a space exploration buff like me, that we would ever launch such a mission.
One argument against the prospect is the old "Interstellar travel time and technological progress paradox." This basically goes along the lines that if we were to launch a mission today to the nearest star, by the time it got there it would probably be greeted by humans living there because in the interim our technology would have progressed to the point that we could get there in years instead of thousands of years.
Of course, if we applied this logic to everything, there would be no technological progress. If Europeans had never risked sailing for months to the Americas because they foresaw technology that would get them there in hours (say, airplanes), what are the chances we would have airplanes today?
Even so, it's tough to advocate for a tens of thousands of years mission strictly on practical terms, especially when there is currently research that could deliver a much faster solution on the near horizon.
The most exciting of these is warp drive. Yes, like in Star Trek. Scientists have now proven the math works and are designing experiments to prove the concept. I'm not holding my breath, though. As inclined as I am to hope, this seems like an extreme long shot, at least within the next few generations.
The most promising is nano space probes. Funded by the United States Air Force, researchers at the University of Michigan are building tiny devices that rely on a kind of miniature particle accelerator to propel them. In the near vacuum of space they will be small and light enough to accelerate to near light speed making interstellar travel highly plausible, perhaps even within our lifetime.
Furthermore, they should be cost-effective enough that we could launch thousands of them so even if some, or most, get lost, damaged or destroyed along the way, the rest could be sending back data from Alpha Centauri within a few years.
All we need now is someone with the will to say, "make it so."
