Nasa’s Curiosity rover has detected organic molecules on Mars, including chemicals widely considered building blocks for the origin of life on Earth.

Five of the seven molecules identified in a dried lakebed near the equator had never previously been observed on the red planet. The analysis performed by the robotic rover cannot establish whether the organic compounds are linked to potential ancient life on Mars or were delivered by meteorites or formed through geological processes. However, the finding implies that if microbial life once thrived on Mars, chemical fingerprints should remain there today.

“We think we’re looking at organic matter that’s been preserved on Mars for 3.5bn years,” said Prof Amy Williams, an astrogeologist at the University of Florida and a Curiosity mission scientist, who led the experiment. “Is it life? We can’t tell, based on this information.”

“It had all the conditions for life to start there when life was starting on Earth,” said Prof Andrew Coates, a planetary scientist at University College London’s Mullard Space Science Laboratory, who was not involved in the latest findings. “There’s no known reason why it shouldn’t have started on Mars as well.”