What's the origin of water on Earth?

With more than 70% of its surface covered in water, Earth is rightly known as the "blue planet". But where did this water - so essential to life - originate? While some theories suggest that hydrogen was delivered to Earth from space via asteroids, new research indicates that the building blocks for water may have been present on our planet all along. We chat to Tom Barrett from Oxford's Department of Earth Sciences to find out more.

You can listen to What's the origin of water on Earth? online on Radio and Podcast. Open the player on this page to stream the available audio.

What's the origin of water on Earth? is an episode from Oxford Sparks Big Questions by Fiona Jones.

This episode is 14:31 long.

This episode was published on May 14, 2025.

Yes. Use the heart button on the episode page to add it to your favorite episodes list.

Yes. This page shows related episodes from Oxford Sparks Big Questions when more episodes are available from the podcast feed.