Detailed Instructions: You are given a passage. You need to construct a question about the information present in the passage. Construct a question in such a way that (i) it is unambiguous, (ii) its answer is the whole paragraph. Avoid creating questions that can be answered correctly without actually understanding the paragraph.
Q: The answer to your question is no. There is no absolutely definitive evidence to date. We do have very strong evidence that significant amounts of water once existed on the Martian surface, and some recent results show that Martian water may still exist below ground, and under heavy packs of ice. There are many scientists who believe that Mars once had a thicker atmosphere, which would have made it a considerably wetter and warmer place. Given this, and the ability for solar system bodies to seed each other via ejecta from large impacts, Mars could very possibly have been seeded by Earth or vice versa many billions of years ago. Still, we're not sure if life exists or every existed there. The most recent chapter was the recent discovery of methane there. Methane can be created by non-biological processes, but we have not observed the right conditions for this on Mars. Another possible explanation would be a biological origin for the gas, potentially from colonies of microscopic organisms in the soil. Given our current rate of deepening understanding, we will likely solve this mystery sometime in the next 50 years, but as of now we simply don't have enough evidence to constitute "proof"
A:
Is there any proven evidence that Mars at some point in the past had microscopic life?