Underground channels point to Mars flooding  The face of Mars is
dotted with a maze of channels, pointing to possible ancient
megaflood episodes. Now scientists peering below the surface
have uncovered the first evidence of underground channels
apparently created by flooding – a finding that’s expected to
further illuminate the role of water in Mars’ history.   Besides
the contributions from rovers and landers, “our view of the red
planet has largely been restricted to looking at the surface”
from orbiting spacecraft, said lead researcher Gareth Morgan, a
planetary scientist at the Smithsonian Institution. The
research, published this month in the journal Science, offers a
new perspective below the Martian surface and hints of past
flooding at a time when the planet was mostly thought to be cold
and desert-like. The channels remained hidden because the once
volcanically active region had been filled in by lava flows
hundreds of millions of years ago.  Dry channels on the Martian
surface were first spied by Ma