Scientists can string out things. It is a means of securing funding for long periods.
I think there has been evidence of life in the Venusian atmosphere since the 80s and on/in Mars since the 70s.
I think there has been evidence of life in the Venusian atmosphere since the 80s and on/in Mars since the 70s.
The public believe we should be looking for cities and skeletons, when in fact we should be looking for extremophiles. It is possible that some of these are due to cross-contamination within the solar system (before human intervention), but that is another matter.
However, I think the bulk of life on Mars – if it exists – is probably underground. Conditions there are much less hostile than the immediate surface. Since Viking, we continue to find Earth life in extreme environments including high altitudes and deep underground. Microbes can be much tougher than animals.
However, we have found life in some very hostile environments on Earth, notably high up in the atmosphere. Planococcus halocryophilus can exist on Earth at -20' C, well within Martian surface temperature ranges, and is tolerant of very salty water. Microbes need a fraction of the resources we do, and some can exist in very small numbers for long periods before better conditions come along. Surface temperatures on Mars have been observed to go over 20' C during the day in some places which may allow for some warmth to penetrate rock and dust. A very hostile environment, to be sure.