Earth may have been a 'water world' 3bn years ago, scientists find

Related: Limited Archaean continental emergence reflected in an early Archaean 18O-enriched ocean (Nature Geoscience)

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Source: The Guardian

Earth may have been a 'water world' 3bn years ago, scientists find

Chemical signatures in ancient ocean crust point to a planet without continents

Ian Sample Science editor
@iansample
Mon 2 Mar 2020 16.19 GMT
Last modified on Mon 2 Mar 2020 18.21 GMT

Scientists have found evidence that Earth was covered by a global ocean that turned the planet into a “water world” more than 3bn years ago.

Telltale chemical signatures were spotted in an ancient chunk of ocean crust which point to a planet once devoid of continents, the largest landmasses on Earth.

If the findings are confirmed by future work, they will help researchers to refine their theories on where and how the first single-celled life emerged on Earth, and what other worlds may be habitable.

“An early Earth without emergent continents may have resembled a ‘water world’, providing an important environmental constraint on the origin and evolution of life on Earth, as well as its possible existence elsewhere,” the scientists write in Nature Geoscience.

Boswell Wing, of the University of Colorado, Boulder, and his former postdoctoral student Benjamin Johnson, now at Iowa State University, launched the project to break fresh ground in the debate over what ancient Earth might have looked like.

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Read more: https://www.theguardian.com/science/2020/mar/02/earth-may-have-been-a-water-world-3bn-years-ago-scientists-find