This undated handout photo provided by the journal Science shows Iron oxides staining the snout of the Taylor Glacier, in the McMurdo Dry Valleys, Antarctica, forming a feature commonly referred to as Blood Falls. The iron originates from ancient subglacial brine that episodically discharges to the surface. Outflow collected at Blood Falls provides access to a unique subglacial ecosystem that harbors a microbial consortium which actively cycles iron, sulfur and carbon for growth. (AP Photo/ Science, Benjamin Urmston)Blogged last month; revisited today in order to show this great photo from Boston.com's Big Picture. Click to enlarge.