Astronomers are hunting for extraterrestrial life. While there are some promising locations in the solar system, the abundance of exoplanets means we're more likely to find life on a planet orbiting another star. According to NASA, there are more than 5,000 confirmed exoplanets to date - and that number is always growing.
However, these searches for extraterrestrial life currently face a major obstacle: we don't know exactly what we're looking for. We only know of one type of planet that is definitely capable of harboring life, and we only know of one type of life - that is Earth and the carbon-based life found here. But according to astronomers, life can take a surprising variety of forms throughout the galaxy. While we might be extremely lucky and find an exact replica of Earth with the same kind of life, we are more likely to face fuzzy, unclear situations.