It’s Time to Seed Life on Mars, Scientist Says

It’s been nearly 25 years since NASA sent biological experiments to Mars. Chris McKay, a planetary scientist at NASA’s Ames Research Center and a member of the NASA Astrobiology Institute, thinks it’s time to try again. McKay helped organize a NASA conference last year on terraforming — that is, what it might take to make Mars fit for human habitation. In a presentation at the conference, McKay proposed an intriguing experiment.