When Tajogaite erupted on La Palma in 2021, its lava flows left empty tubes underground. Scientists went inside 12 to 24 months later to watch life arrive. Wind, rain and animals such as birds and rodents carried microbes through skylights and cracks, along with decaying plant matter and guano. Early on, opportunistic microbes thrived where light or organic matter existed, but deep inside only specialists tolerant of extreme heat and dryness survived. These microbes formed biofilms and began dissolving rock, the first step toward soil. This matters for Mars, where lava tubes could shelter life.

Hampi is a UNESCO World Heritage Site in Karnataka, India, with more than 1,600 surviving remains spread over 4,100 hectares. It was the capital of the Vijayanagara Empire from 1336 to 1565. Travellers from Persia and Portugal described it as a prosperous, wealthy and grand city with temples, markets and farms along the Tungabhadra River. By 1500 it was estimated to be the world's second-largest city after Beijing, and probably India's richest at the time. In 1565 a coalition of Muslim sultanates defeated the Vijayanagara Empire, its capital was conquered and destroyed, and the city was left in ruins. Hampi remains a religious centre, with the active Virupaksha Temple at its heart.