A team of planetary researchers led by Caltech has determined the chemical mechanisms by which the ancient Mars was able to sustain enough warmth in its early days to host water, and possibly life. Adams et al. estimate that Mars experienced episodic warm periods of an integrated duration of 40 million years, with each event lasting approximately 100,000 years. Image credit: M. Kornmesser / ESO / N. Risinger, skysurvey.org. “It’s been such a puzzle...