I have to admit I’m brought up a little short by things presupposed by this article by the European Space Agency about AMEC, a cloud in the Martian atmosphere that forms daily (by Martian reckoning) over a certain mountain, then stretches over 1,000 miles before dissipating until the next sunrise. First of all: Mars has clouds? By which I mean: Mars has water, or anyway water vapor in its atmosphere? I guess it does?? OK!