The theory of how planets form has been something of an enduring mystery for scientists. While astronomers have a pretty good understanding of where planetary systems comes from – i.e. protoplanetary disks of dust and gas around new stars (aka. “Nebular Theory“) – a complete understanding of how these discs eventually become objects large enough to collapse under their own gravity has remained elusive.
ETH researchers studying how stars are formed in distant galaxies have made an unexpected discovery: a correlation that exists today between the proportion of heavy chemical elements in a galaxy and the rate at which new stars are formed in this galaxy did not apply 10 billion years ago. This observation helps scientists understand how galaxies with their stars and planets were formed over billions of years.