DeepSummary
This episode explores the question of where Earth's water came from, given that the planet was initially an extremely hot, molten object when it formed billions of years ago. Planetary scientist Lydia Halas describes various theories, including the classical idea that water was delivered by comets and asteroids after Earth cooled down, as well as her own hypothesis that primordial water may have been present in the rocks that formed Earth from the beginning.
Halas discusses her fieldwork in the Canadian Arctic, where she collected ancient rock samples containing olivine crystals that trapped water molecules billions of years ago. By analyzing the hydrogen signatures in these rocks, she found evidence suggesting that some of Earth's water may have originated from the solar wind of the Sun, rather than being delivered from outer space.
The implications of Halas' findings are significant, as they suggest that the presence of water, and thus the conditions for life, may be more common on rocky planets than previously thought. If water can survive extreme temperatures during a planet's formation, it increases the likelihood of finding water, and potentially life, elsewhere in the universe.
Key Episodes Takeaways
- Earth's water may have originated from primordial sources, rather than being delivered by comets and asteroids after the planet cooled down.
- Some of Earth's water may have come from the solar wind of the Sun, incorporated into the rocks that formed the planet.
- The presence of water, and thus the conditions for life, may be more common on rocky planets than previously thought.
- Analyzing the hydrogen signatures in ancient rocks can provide clues about the origins of a planet's water.
- The initial assumption that Earth was entirely dry when it formed may be incorrect.
- The wandering of Jupiter and Saturn in the early solar system may have been less crucial for delivering water to Earth than previously believed.
- Fieldwork and analysis of rock samples are essential for advancing our understanding of the origins of Earth's water.
- The search for water on other planets is closely tied to the quest for understanding the origins of life.
Top Episodes Quotes
- “I always thought that runners loved running, and that's not the case. Most runners hate running, but they choose.“ by Lydia Halas
- “And that supports the fact that early on in the solar system, those first solid minerals that formed in the solar system were irradiated by the sun and then were incorporated into the earth. So Earth wasnt formed completely dry.“ by Lydia Halas
- “Maybe its just that water is everywhere and that it sticks around in the rocks. And so wherever you form a rocky planet, youre likely to have some water content on that planet.“ by Lydia Halas
- “And I think thats the most important thing to kind of come from this theory, is that if you dont need delivery from the outer solar system of water, and Earth formed initially with its water, or at least some of its water, then anywhere that you form a rocky planet in any solar system, you may end up with a water content on that planet which could be supporting life.“ by Lydia Halas
- “The issue that scientists have always had is that when Earth formed really early during our solar system, Earth would have just been too hot to have any kind of condensation of liquid water.“ by Lydia Halas
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Episode Information
Unexplainable
Vox
4/24/24
Life as we know it needs water, but scientists can’t figure out where Earth’s water came from. Answering that question is just one piece of an even bigger mystery: “Why are we here?” (Updated from 2023)
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