Meet the neighbours.
Confirmed yesterday was the discovery of a planet orbiting our closest stellar neighbour; Proxima Centauri. That's big news in itself, but the fact that the world is both earth-sized, and within the star's habitable zone where water can exist in liquid form on the surface, means that we'll never find a closer exoplanet than this. That's a big deal in terms of technology.
Normally with our news stories we say 'hey, look at this awesome thing you can buy. Soon,' but today we really wanted to marvel at this scientific discovery and theorise about how it will change the way we think about space exploration. In the past when an exoplanet is discovered it tends to be hundreds or thousands of light years away. Those discoveries garner excited yet realistic responses, because lets face it; we're probably never going to be able to visit them. But Proxima b is just 4.25 light years away.
But that is still a looooong way away. If they aimed New Horizons, the probe that passed Pluto late year, toward Proxima b, under it's current, admittedly very fast, speed it would still take 78,000 years to get there. The huge distance, coupled with a desire to see what the planet is actually like close-up, will no doubt encourage space agencies to find new ways of getting there. For example, a laser-based system for probe propulsion suggested by NASA, which uses a huge solar sail to catch the laser beam and be propelled at speeds approaching light speed, could make the journey in 12 years. It would be a fast fly-by however, with no way to slow down at the other end.
But the most crucial thing about the discovery is that we now have a definite target to aim for. Before, when missions to Alpha Centauri (around which Proxima Centauri orbits) have been proposed, it has always been a shot in the literal dark; a hope that there is something more than stars out there. Now we know for sure that a world exists, and a world that possibly might harbour earth-like conditions - maybe even life. Hopefully one day soon we actually will get to meet the neighbours.