From the farthest planet to the nearest star, the entire firmament is observed by Miraestels.

With no help other than his sight and a privileged floating position in the Mediterranean Sea, the guardian of the waters watches the sky impassively. You may wonder if we will ever be able to understand the stars and even if we will be able to visit them on an interstellar journey unthinkable today.

No doubt, after years of seeing the stars shining over the port of Barcelona, Miraestels will have appreciated that the stars closest to us are in Alfa Centauri, the stellar system closest to our Sun and, therefore, the first stop on our interstellar journey. But what else do we know about this fate?

Alpha Centauri: three stars, one system

Alpha Centauri is the closest star system to us and yet it’s a whopping 4.37 light years away. It may not sound like that, but we are talking about more than 40 billion kilometres.

The star system of Alfa Centauri is composed of three stars: Alfa Centauri A, Alfa Centauri B and… guess which is the third?

If you have answered Alpha Centauri C, you have failed; since the third component of Alpha Centauri is what we know as Proxima Centauri, a red dwarf known to be the closest star to our Sun, only 4.2 light years from us.

One of the main curiosities of Alfa Centauri is that we cannot know for sure what happens to the planets of that system, nor how many exist as such. At the moment, we know of the existence of at least a couple of planets: Alpha Centauri Bb and Proxima Centauri b; but it is very complex to calculate the situation of other bodies in the system due to the problem of the three bodies.

If you don’t know what the problem of the three bodies is, just imagine if you had to calculate the situation of something that is affected by three different gravitational effects. 

Do you have any idea how you’d do it? Well, that’s what the problem of the three bodies consists of, which has all the mathematicians of our time in check.

Anyway, the most important stop of a possible interstellar trip to Alfa Centauri would be the mentioned Proxima Centauri, not only for its closeness, but also for being a star full of mysteries and curiosities that, surely, has fascinated Miraestels and all humanity.

Proxima Centauri: the star closest to us

Of the three stars that make up Alfa Centauri, the most peculiar of them is Próxima Centauri.

First, its distant position from the other two stars in the system invites suspicion that it may not even be part of the system. In addition, being so far away, it is not possible to fully know its orbit, as it would take hundreds of thousands of years to complete it.

A second curiosity of Proxima Centauri is that the planet most similar to the Earth orbits around it, and is none other than Proxima Centauri b. As far as we know so far, it is an ocean planet, rocky in formation, with an atmosphere and a temperature that would make life on it possible.

Finally, and unfortunately, it is a rather dark star for what we are used to, with a luminosity much less than 1% of that of our Sun.

Faced with all these curiosities and the impossibility of knowing them from the Earth, the question is simple: could we make an interstellar journey to verify them?

Interstellar trip to the nearest star

Traveling to a star doesn’t sound very safe and, of course, traveling to a three-star system doesn’t make it much more appetizing. But would we even be able to get there?

The truth is, it would be terribly complicated. Today, the fastest object we have launched is the famous Voyager 1 probe, which reaches just under 18 kilometers per second, leaving our interstellar journey to this star system in just under 80,000 years.

The reality is that interstellar travel would be practically ruled out for us until we reached 25,000 kilometers per second, and it would still take 50 years to reach Alfa Centauri.

To this should be added that we cannot use any fuel. It would take planetary-sized fuel tanks to get a little closer to Alpha Centauri. Even other types of energy, such as nuclear thermal energy, would still involve thousands of years of travel.

The reality is that if we want to approach other stellar systems, we must make our interstellar journey with the oldest of the propulsion techniques: sailing. However, in this case it would not be a wind candle, but solar, able to take advantage of the pressure of solar light radiation.

Still, NASA estimates that we may be launching the first missions to Alpha Centauri in 2069. As always, it is possible that in the end everything will be delayed by a few decades, and that none of us will ever see them.

Nevertheless, there is something comforting about thinking that our Miraestels will continue to be there, as always, looking up to the sky, shedding invisible tears with each step we take towards the sky that it searches tirelessly.