When news broke last year that an Earth-like planet was found orbiting the habitable zone of our nearest star neighbor, Proxima Centauri, scientists began to dream that we might visit it within our lifetimes. After all, Proxima Centauri is only 4.24 light-years away, and according to some experimental methods that might make it reachable in just over 20 years, using probes.
The only problem? To reach Proxima Centauri so quickly, those probes wouldn't be able to slow down. So it would have to be a very brief fly-by mission, with barely more than a few seconds to study the star system up-close.
For those who want to stick around for a while in an alien star system, it would take a different sort of technology. The good news is, that technology is currently possible to develop, thanks to work presented by researchers René Heller and Michael Hippke. They recently showed how light from the very stars we want to visit could be used to slow down a solar-sail powered spacecraft, reports New Scientist.
There's one catch, though. Proxima Centauri won't do. It might be our nearest neighbor, but it's a very faint star. Using Heller and Hippke's method to slow down a probe using the light available in that system would require a 140-year mission. That's still reasonable, but it's not within the lifetime of any scientist working today.
So Heller and Hippke began to look elsewhere, and what better place to look than the brightest star in the night sky? Sirius, sometimes called the "Dog Star," is about twice as far away as Proxima Centauri, but because it's so much brighter, it can better help to both speed up and decelerate a visiting probe. That extra brightness means that it would only take 69 years to get to Sirius using Heller's and Hippke's method.
For their method to be viable, only one thing to happen: the development of an extremely thin solar sail to keep the mass of the probe light. “We need a very light, solid, temperature-resistant, and highly reflective sail material that can span an area of several hundred meters squared,” explained Heller.
He suggests that material could possibly be built from graphene, with a metamaterial coating. Once that is developed — a project that's well within reach — all we'll need is the will to put it into action.
Imagine that in 69 years (and, presumably, another eight years to get the pictures sent back to us), we could have an up-close view of a whole other star. How might that change the way we look at the universe around us?