Alien Connections

Hubble Telescope image of a star cluster. Credit: NASA, ESA, STScI.

Have you ever gazed up at the night sky and wondered if living beings like us were out there somewhere, also searching the skies for others? If so, you are certainly not the first one to do so! Through the centuries, scientists, philosophers, and many other curious minds have pondered this.

Our galaxy, the Milky Way, has over 100 billion stars, and recent discoveries show that most of them have exoplanets, with many being earth-like. So why haven't we connected with any aliens yet?

This is a key question, the answer to which lies in the Drake Equation, which has been called the second-most important equation in science. Named after Frank Drake, an astronomer who in 1960 led the first official search for extraterrestrial radio signals, this equation attempts to quantify the probability of finding other civilizations in our galaxy (the same concept can be extended to the whole universe):

Credit: NOIRLab/AURA/NSF/P. Marenfeld

As you can see, it is not enough to have habitable planets, or even for life to emerge on them. This life would have to be capable of developing intelligence and interstellar communication, and also communicate during a time span that overlaps with our interstellar communication here on earth. Given all this, the odds of detecting and connecting with alien life seems slim indeed!

However, there are numerous efforts underway to detect and connect with alien civilizations, such as those by the SETI (Search for Extraterrestrial Intelligence) Institute. So the day may not be far-off when we will be able to engage in other-worldly communications from earth!