Water flowing over and eroding ancient rock exposed at the Superior Craton in Canada, represented here by the Scenic High Falls in Wawa, Ontario, holds clues to the development of Earth’s atmosphere 2.7 million years ago. A study led by Rice University showed the sulfur record held by the rock marked the dramatic change in the planet’s atmosphere that gave rise to complex life. (Credit: Tom Samworth/www.itsabouttravelling.com)

Return to article.