“If I had to describe myself to an alien I’d say I was bigger than the average human, enjoy a drink or two with a good meal and have a bigger head than most. I’d also say I’m really handsome — especially if they were a female alien.” -Dwayne Johnson
The Earth, to the best of our knowledge, is the only inhabited world we have. The ingredients for life may be everywhere, from asteroids to nebulae to exoplanets and more, but so far, only Earth is confirmed to have life. While Earth-like planets around Sun-like stars at the right distance for liquid water on their surface might seem like the best place to look for life, we don’t necessarily need to go that far.
Right here in our own cosmic backyard, our own solar system boasts eight potential candidates for worlds with life on them today. Some of them are planets, like Mars and Venus; others are moons, like Europa and Titan; even asteroids like Ceres or Kuiper belt objects like Pluto get in on the action. The life that might be present might not look like most of life on Earth, but unless we look at the likely locations of biological activity in situ, we simply won’t know for certain.