Bright core of a Mars south polar 'Spider' dark fan vent streak source. Both ice and dark powder emit from these in seasonal eruptions. View on marsroverblog.com, as the topic " 'Mars Polar Event'...," the Open Forum. Image credit:NASA/JPL/University of A

Bright core of a Mars south polar 'Spider' dark fan vent streak source. Both ice and dark powder emit from these in seasonal eruptions. View on marsroverblog.com, as the topic " 'Mars Polar Event'...," the Open Forum. Image credit:NASA/JPL/University of A