I have seen many articles that talk about a star's "habitable zone" as the ring around it which is just the right temperature for planets to have liquid water, which is necessary for life. My question ...
What is the lowest pressure at which plants can survive? How the plants behave in a Martian-type atmosphere? Is there any plant that can survive such atmosphere? Can a lichen grow at Martian pressure?...
Inspired by an answer to a previous question. It's hypothesized that extraterrestrial life could be based on silicon rather than carbon as its main structural element. Are there similar theories ...