How Could Aliens Find Us?

Watch as Clara Sousa-Silva discusses how she uses light that passes through a planets' atmospheres to look for signs of life.

We've been sending signals into the universe for decades but what if we stopped - could aliens still find us? BBC Ideas' Universal Wonders series explores the universe and how we interact with it. In an animated video, EAPS postdoc and quantum astrochemist Clara Sousa-Silva discusses how we broadcast our signs of life out to the universe so others can locate us. But what if we went radiosilent, is there another way that others can detect Earth's lifeforms, and we can find life on other planets in the same way? Sousa-Silva's research examines how light passes through and interacts planetary atmospheres. She's looks at how the molecules in planetary atmospheres absorb and reflect light, and creates a spectral fingerprint of what molecules are present. This fingerprint will help tell us about the planet and if there's life there that's interacting with its atmosphere.

Sousa-Silva explains to Breakthrough what biosignatures are, what can tell us about potential life on other planets, and how she uses the properties of light to look for them.

Clara Sousa-Silva - How different could life be? (Credit: Breakthrough)

Clara Sousa-Silva – Does Alien Life Exist in the Universe? (Credit: Breakthrough)