[X] My Assistant

[SFJCody]

Nick Hoffman's 'white Mars' [partially] vindicated?

http://www.bbc.co.uk/news/science-environment-22869184

http://www.sciencedirect.com/science/artic...019103513001668

Long thin grooves - called gullies - on the surface of Mars may have been made not by water but by blocks of frozen carbon dioxide - dry ice.

Funny how old hypotheses can come back again. We've had a decade+ in which the consensus has been that the gullies are formed by liquid water, but now CO2 is a possible instigator again, albeit in the form of solid blocks rather than liquid flows. What with this and other things (such as Edwin Kite's hypothesis for the formation of Aeolis Mons), is the pendulum of scientific opinion swinging away from 'warm, wet, Earth-like Mars' and back in the direction of an alien, colder, only sporadically active world? At least in terms of the overall picture of the planet, admittedly the ground truth from Oppy and Curiosity to date is evidence for a benign, pleasant environment at some points and times in Martian history.

EDIT: Original commentary in the topic title moved to comments section above - ADMIN