# Basic Math Reveals How Many Advanced Alien Species Live in Our Galaxy

Tuesday, 27 March 2018 - 1:17PM
Tuesday, 27 March 2018 - 1:17PM
The Milky Way galaxy is a big place.

With well over a hundred billion stars and plenty of planets in orbit around them, it makes sense that somewhere out there in the vast cosmic noise, there must be evidence of some other advanced life forms.

Surely, in a space this big, humanity can't possibly be alone, right?

A new article from NBC takes a look at the math behind alien life forms and suggests that, in the grand scheme of things, we might not be that far away from our nearest intelligent cousins.

This speculation comes from the Drake Equation, which factors in the number of habitable planets in the galaxy, the fraction of these that will go on to develop life forms, and in turn, the fraction of these species that will develop sentience.

There are a lot of ifs and maybes within this formula. At present, we have no way of knowing how frequently life occurs throughout the universe, nor can we tell how often a species will achieve human-levels of intelligence.

That said, by crunching the numbers with our best possible estimates for these factors, it seems that intelligent alien life might be present in as many as a hundred million star systems throughout the Milky Way.

This is a fairly big chunk of stars, but it's worth noting that the galaxy is not a small place. Based on this estimate, you can kiss the possibility of ever meeting an intelligent alien goodbye—modern rocket technology would take 20 million years to reach the nearest planet that would contain sentient life, as the distance involved would be over a thousand light-years.

The best we can hope for is to see some evidence that alien creatures might exist somewhere out in space, but even factoring in the time it'd take for messages to pass between these two planets, it'd take a thousand years to respond to any communication in either direction.

This is assuming that our current estimates are correct, which they almost certainly are not at present. All of our speculation is based on guesswork, as without any real numbers to work from, we're essentially shooting darts into a cosmic map when it comes to working out where aliens might live.

There's also the little matter of the Fermi Paradox; the theory that if intelligent aliens do exist, we probably should have spotted their communications already.

As for the explanation as to why our galactic neighbors are so quiet, there's a pretty good explanation already: they just don't want to deal with us.