Ice Ages Make Outer Edge of 'Habitable Zone' a Tough Place for Life

But new research is showing a dramatically different scenario for planets at the outer edge of a star's habitable zone. This climate cycle, based on changes in the long-term carbon cycle, was examined as part of a NASA Habitable Worlds grant. Jacob Haqq-Misra, a research scientist at the Seattle-based nonprofit ‎Blue Marble Space Institute of Science, is leading the research to figure out where the limits of the habitable zone arise.