Why we can't go to Mars (yet)

"R F L Henley" skrev i en meddelelse
...

unless and until we have robotically established conclusively that there
is or is not life on Mars, we can't put humans on the planet because
they will inevitably bio-contaminate it.

To a degree, I agree. The absence of life on Mars can never be
established conclusively, and certainly not by softlanding a number of
robotic probes. There may be subsurface life in a few locations. But a
rather thorough survey by robotic landers may at least conclude that the
surface and near-surface of Mars is very probably without life. Or find it,
of course.

Jon Lennart Beck.