Earth is a less volatile version of the Sun, study finds

Scientists at The Australian National University (ANU) have found that Earth is made of the same elements as the Sun but has less of the volatile elements such as hydrogen, helium, oxygen and nitrogen.

Lead author of the study, Dr Haiyang Wang, said they made the best estimate of the composition of Earth and the Sun with the aim of creating a new tool to measure the elemental composition of other stars and rocky planets that orbit them.

“The composition of a rocky planet is one of the most important missing pieces in our efforts to find out whether a planet is habitable or not,” said Dr Wang from the ANU Research School of Astronomy and Astrophysics (RSAA).

Other rocky planets in the Universe are devolatised pieces of their host stars, just like Earth.

Co-author and RSAA colleague Associate Professor Charley Lineweaver said every star had some kind of planetary system in orbit around it.

“The majority of stars probably have rocky planets in or near the habitable zone,” he said.

Co-author Professor Trevor Ireland, from the ANU Research School of Earth Sciences, said the team conducted the study by comparing the composition of Earth rocks with meteorites and the Sun’s outer shell.

“This comparison yields a wealth of information about the way the Earth formed. There is a remarkably linear volatility trend that can be used as a baseline to understand the relationships between meteorite, planet and stellar compositions,” he said.

The research will be published in the journal Icarus.

The paper can be downloaded from here:


Associate Professor Charley Lineweaver
Research School of Astronomy and Astrophysics
Research School of Earth Sciences
ANU College of Science
T: +61 2 6125 6717 or +61 2 6125 0822
M: +61 457 550 577

Dr Haiyang Wang
Research School of Astronomy and Astrophysics
ANU College of Science

Professor Trevor Ireland
Research School of Earth Sciences
ANU College of Science

For media assistance, contact Will Wright on +61 2 6100 3486, the ANU Media Hotline on +61 2 6125 7979 or at

About The Australian National University

ANU is a world-leading university in Australia’s capital city, Canberra. Our location points to our unique history, ties to the Australian Government and special standing as a resource for the Australian people.

Our focus on research as an asset, and an approach to education, ensures our graduates are in demand the world-over for their abilities to understand, and apply vision and creativity to addressing complex contemporary challenges.

The Australian National University
East Road, Acton
2601 Canberra