Can private-sector space business be profitable, or is it just an exciting way for billionaires to live out their fantasies?

NASA knows there are billions of Earth-sized exoplanets out there, many of which could (for better or worse) host life. But until we can travel faster than the speed of light, we’ll never actually be able to reach most of them.

With the discovery of Proxima b, an Earth-like planet just 4.2 light years away, that could change.

There’s a lot of research that remains to be done before we know whether it’s worth planning a trip. It would take many millennia using current technology, although better options could change that. Watch the video above to see why scientists are so excited about the discovery, and what are the next steps.