Green ice, Ravens, Ice Caves and the Movie “Contact”

By SpaceRef Editor
July 23, 2006
Filed under
Green ice, Ravens, Ice Caves and the Movie “Contact”

Towards the end of our summer expedition while flying back to Eureka from our camp on Axel Heiberg, I spotted a lake with what appeared to be green ice on it.

Seeing ice this color is particularly interesting since the color green tends to make an aquatic ecologist think of life – microbial life with chlorophyll. It also reminded me of a question I first heard posed by Chris McKay, a scientist at NASA’s Ames Research Center in California. During one of his presentations, Chris asked the question “why isn’t Greenland green? Why is the ice-cap of Greenland, or the Antarctic for that matter, not covered with photosynthetic organisms tinting the snow and ice green despite the abundant availability of summer sun and 90% of the planet’s fresh water?”

This observation points out a profound ecological reality for life on Earth – just having water available is not enough – it must be liquid water in order for life to carry out the chemistry of life. The snow and ice on the ice-caps do not support an abundance of photosynthesizers mainly because the water is present as a solid (ice) and for all practical purposes is not available for life to use. Despite the cubic kilometers of water within these ice-caps, they are vast frozen deserts. I did not have time to drop down to get a sample of the bright green ice, but as green as it was, I suspect that the tint must have been a result of the presence of chlorophyll. The difference between this lake ice and the ice-caps of Greenland and Antarctica being the abundance of liquid water on and within the small ice-cover as it melted away.

This full story is online at Astrobiology.net

SpaceRef staff editor.