30. Planet Needs To Be Made Of Rock
One of the most common issues when searching for a habitable planet is finding one made of rock. What we mean by this is that a planet’s main make-up is rock-based like that of Earth. While we may have a lot of things within this, rock overall is always at the bottom of it.
This is different from that of gas planets like Jupiter and Neptune. These places are not possibly habitable for human life, and we’re unsure if any life can live on these planets either. We do know we can never really live here, so these places are off-limits to consider.