From Mica
Water on Mars - Again
a talk by Giuseppe Longo, University Federico II in Naples Department of Physical Sciences, Italy
The existence of water on Mars was proved by Vesto Slipher in 1906 through the detection of water vapor in the atmosphere. Since then, water on Mars has been re-discovered at least 25 times. A fact which hits against the common sense statement that something can be discovered only once.
Media
Slides (PDF Format)
Audio recording