More evidence of life on Mars but still no life
Bob McDonald looks back at the many times scientists previously thought they'd found life on the Red Planet
Scientists are excited over the latest geological evidence for the existence of life on Mars. But as we have seen many times in the past, the Red Planet guards its secrets closely with the possibility of non-life explanations for the formations.
As geologist Joel Hurowitz said in our recent conversation on Quirks & Quarks, the rock in question was found by the Perseverance rover that has been exploring what was once a river delta that drained into an ancient Martian lake.
Two chemicals found in the delta, vivianite and greigite , are most often formed on Earth by microbial activity in the soil — hence the excitement. But under certain conditions, they can also be formed by chemical reactions. In other words, we have potential evidence for life on Mars, but no conclusive proof.
Mars has been tantalizing us with the possibility of life on its surface since American astronomer Percival Lowell looked through his telescope in 1894 and thought he saw straight lines crisscrossing the planet.
He called them canals, which are artificial, not naturally formed channels. Lowell believed these enormous features were engineered like the Panama or Suez Canals, but on a much larger scale. To him it suggested there was a civilization on Mars with amazing technical skills.