How hard is it to give birth to an Earth? To assemble the right mix of rock, metal, and water, in a balmy spot not too far from a star? For a long time, planetary scientists have thought Earth was a lucky accident, enriched with water and lighter “volatile” elements—such as nitrogen and carbon—by asteroids that had strayed in from the outer edges of the early Solar System, where those materials were abundant. But a series of new studies, including two published today in Science, suggests all the ingredients were much closer at hand when Earth was born. The findings, based on painstaking chemical analysis of meteorites, imply that planet-forming disks around other stars, too, should be well-stocked with the makings of wet, rocky planets that might be hospitable to life. “It makes the enrichment in volatile elements of a planet more generic,” says Alessandro Morbidelli, a planetary scientist at the Côte d’Azur Observatory who wasn’t part of the new work. Even if a young planet doesn’t re...

Scientists have revived a worm that was frozen 46,000 years ago — at a time when woolly mammoths, sabre-toothed tigers and giant elks still roamed the Earth. The roundworm, of a previously unknown species, survived 40 meters (131.2 feet) below the surface in the Siberian permafrost in a dormant state known as cryptobiosis, according to Teymuras Kurzchalia, professor emeritus at the Max Planck Institute of Molecular Cell Biology and Genetics in Dresden and one of the scientists involved in the research. 06 permafrost virus risk climate virus Scientists have revived a 'zombie' virus that spent 48,500 years frozen in permafrost Organisms in a cryptobiotic state can endure the complete absence of water or oxygen and withstand high temperatures, as well as freezing or extremely salty conditions. They remain in a state “between death and life,” in which their metabolic rates decrease to an undetectable level, Kurzchalia explained. “One can halt life and then start it from the beginni...