The essence and origins of life. What is it? Yes, we can define characteristics that differentiated the living from the non-living. The building blocks of life are still not the same as a simple virus. Do you think new forms of life "become living" these days?. Do you think that the conditions to form new life simply do not exist anymore? Evolution can not even begin until something (still yet unknown to us) happens first. Do you think we will ever discover the recipe?
The Manned Mars mission is now being discussed as a one-way deal.
Making it a colonization deal instead of round trips.
The major expense is escaping the planet with all that life support weight, a one-way trip means you don't have the cost of a launch off the Martian surface. No need to carry extra launch system and fuel, turn all that excess weight into stuff to build a colony with.
Once a successful colony is established all you need to do is send supply drones (no need for life support).
It's a more practical plan, it's just a one-way trip for the people.
There is no reason not to send all the materials for the colony up first.
Not exactly what people mean by "colonizing," though. So, I wonder who is willing to sign up for a one-way trip, never to be physically present with their family ever again.
A penal colony, perhaps. A kind of Devil's Island in space.
They already have volunteer astronauts for the job.