Using our current technology, it would take 180,000 years to reach Zarmina. But our resident physicist Dave Goldberg has a more optimistic estimate – thanks to antimatter and time dilation, astronauts could get there in just a few years.
Dave calculates that, if we could build a stellar drive that gets its fuel from matter-antimatter explosions, then it would be possible to travel to Zarmina at 92% the speed of light. Since the planet is about 20 light-years away, that means the starship would get there in 22.4 years as far as mission control back on Earth is concerned, but thanks to such serious time dilation at such near-light speeds, it would only be 6.1 years for the astronauts on board. All this assumes the ship would accelerate (and then decelerate) at Earth gravity throughout its voyage to give the astronauts a little comfort.
All that sounds pretty amazingly manageable, but we’re not out of the woods yet. To carry all the fuel necessary for such a journey, the ship’s fuel stores would have to be at least 530 times as massive as everything else on board the ship. That isn’t exactly impossible, but let’s just say we’re going to have to jump up a few levels on the Kardashev scale before we can seriously plan on heading to this second Earth.
For a more complete explanation of Dave’s math, check out his post at A User’s Guide to the Universe. For a rather less optimistic view on traveling to Zarmina, check out Discoblog.