Cruising to Proxima d
2-27-22 by Carol Baxter
Raise your water bottle and toast Proxima Centauri’s Proxima d, the newest habitable zone planet.
Imagine the excitement of astronomers from the European Southern Observatory’s Very Large Telescope studying Proxima b’s mass using radial velocity data in 2020 (the universe spin on, indifferent to Covid) finding a new planetary signal — d.
They published “A candidate short-period sub-Earth orbiting Proxima Centauri” this year. I wonder if they wanted to title it, “Hell yeah! We discovered a new extrasolar planet with the potential for water.” I hope finding new planets brings a thrill even as the number of discoveries approaches 5,000.
At 4.246 light-years away the Proxima Centauri system is our nearest starry neighbor and that made me wonder how long it would take to get there using current technology — 6,300 years.
Alas, suspended animation is not available so any spaceship making the attempt would be multigenerational, about 229. Your family tree would be easy to track.
How many people would you need in the gene pool to make the trip?
Timewarp back to 1996 when, as part of a team-building exercise at work this scenario was posed to the group:
You have a bomb shelter capable of sheltering 40 people from a pool of 100. These 40 folks are the only humans that will survive to repopulate the planet.
The team-building exercise must have been around since the 1960s because the pool of folks included a go-go dancer amongst the lawyer, homemaker, physician, and physicist. During a psychology class in 1984, we had argued the balance of 40 that would leave Earth in a spaceship — male versus female, their ages, health, and professions
In 1984 and 96 the go-go dancer in my mind was culled from a picture in a family album of a petite woman with a head of cascading red curls, full of energy and fun, in shiny, tall, white boots and a brick-colored mini dress that showed more skin than my grandfather thought appropriate.
In the 12 years between, I’d read that to viably relocate and grow elsewhere the gene pool would need to be 10 times larger — a 50/50 split of 400 people. Did I read this in a science magazine or a science fiction novel, Heinlein maybe? I don’t recall. But it made sense.
Conversation ensued. I listened. The dancer was one of the first individuals my coworkers agree was out.
My hand up from the back, reminiscent of LDS seminary questions I’d asked, except this time my boss Hank had no idea what was coming.
“The gene pool is too small to sustain life. You are all going to die. Why not take the dancer, at least she will be entertaining?”
Swiveled heads. Big eyes, all looking at me. Mouths closed or open but silent.
I confess. I enjoy shock value.
If Hank saw this as an opportunity to out me as a realist or even the class clown he did not. He managed after a few moments to get the session back on track and I went home to my four-year-old daughter named after a constellation.
Back to the present. It turns out I am vindicated by a number more than double 40 but less than 400.
French astronomers Frédéric Marin and Camille Beluffi have come up with an algorithm that indicates a minimum of 49 pairs of settlers would be needed for the 63-century-trip assuming radiation did not interfere with birth rates and all those children had the same dream of their parents.
Hmmm. Do you want to make a bet on which will cause the most mayhem—the toll of radiation or children with divergent dreams?
Shall I argue the merits of being the writer on that mythical ship? I’d be there when technological progress brought a new ship to dock with the old and continue the trip to Proxima d with colossal speed.
Human beings have been stargazing for several hundred thousand years. I’d like to think that 229 generations from now those twinkling lights in the sky will still lead to wonder, as human beings look up from our solar system or others.
Sources:
Proxima a and b by NASA Goddard , Photo Credit: https://images.nasa.gov/details-GSFC_20171208_Archive_e000214
https://astronomy.com/news/2022/02/third-planet-found-around-proxima-centauri
https://www.eso.org/public/archives/releases/sciencepapers/eso2202/eso2202a.pdf
