Scientists spot traces of 10,000 miles of rivers in area where many believed ‘there wasn’t any evidence for water’

Thousands of miles of ancient riverbeds have been discovered in the heavily cratered southern highlands of Mars, suggesting the red planet was once a far wetter world than scientists thought.

Researchers spotted geological traces of nearly 10,000 miles (16,000km) of ancient watercourses, believed to be more than 3bn years old, in high resolution images of the rugged landscape captured by Mars orbiters.

While some of the riverbeds are relatively short, others form networks that stretch for more than 100 miles. The widespread rivers were probably replenished by regular rain or snowfall in the region, researchers said.