The universe just got a little smaller.
In a paper published in the journal Nature, astronomers have confirmed that they've discovered what they believe to be a rocky, Earth-like planet orbiting Promixa Centauri -- which, at 4.25 light-years away, is the closest star in the local neighborhood to our solar system.
The planet, dubbed for now Promixa B, was discovered by an international team led by astronomer Guillem Anglada-Escudé at Queen Mary University of London. The planet is around 30 percent larger than Earth, and while its orbit around its star is even closer than that of Mercury (it is less than 5 million miles away from the star), it could potentially sustain liquid water and life because Proxima Centauri is a red dwarf that is much cooler and smaller than the sun.
Scientists have not directly observed the planet yet, but discovered it through analyzing some 16 years of telescopic recordings of Promixa Centauri and noticing that it had a peculiar "wobble" every 11.2 days -- a shift in movement created by the gravitational pull between star and planet. Based on those readings, astronomers were able to determine that Promixa B is in the "habitable zone" -- the sweet spot where water can exist on its surface in liquid form and theoretically support life.
The one catch is that Promixa Centauri also generates a lot of solar flares and radiation that could possibly turn any life on the planet into toast. But if certain magnetic and atmospheric conditions exist there, so could life -- in the water or perhaps underground.
Now, we've been discovering thousands of planets, and quite a few Earth-like ones, for a few years now. But Promixa B is the closest one to date, and potentially one that we could visit even traveling below the speed of light. SETI astronomer Jeff Coughlin told Popular Mechanics, "There's nothing in physics that would keep us from sending a probe to Proxima B within the next few decades, even with just current-day technology."
Indeed, there are already plans afoot to someday launch an interstellar probe that could reach Promixa B and take pictures of it up close. According to Gizmodo, a $100 million venture called the Starshot Initiative is doing research and engineering on "nanocrafts" that can travel up to 20 percent the speed of light and could reach the Promixa Centauri system in 20 years. We could then observe if there is any life on Promixa B and what kind, or if there's anything on the surface at all.
Let's face it: Our sun is going to die in five billion years, so assuming we don't self-destruct as a species we're going to have to get off this rock at some point. And planets orbiting red dwarves -- like Proxima B -- offer the possibility of a nice new home since those stars can last trillions of years longer than our own. As Harvard's Abraham Loeb told Gizmodo, "A habitable rocky planet around Proxima would be the most natural location to where our civilization could aspire to move after the Sun will die, five billion years from now."
Ready to board that generation ship?