Water can form on planets as they develop, not just from comets or asteroids. This new finding shakes up what we thought we knew about where Earth’s water comes from.
For years, scientists have debated two main ideas about Earth’s water. One suggests that icy bodies from the solar system delivered water after Earth formed. The other argues that the building blocks of our planet had what it takes to create water on their own. Until recently, there wasn’t any concrete evidence to support the second idea, especially under real-world conditions.
In ground-breaking tests, researchers created high-pressure and high-temperature environments that mimic the early days of a young planet. They found that liquid water can actually form naturally as planets are being born. This study, published in Nature, opens up new possibilities for where water—and potentially life—might exist in the universe.
Anat Shahar, one of the scientists behind the research, stated, “This work shows that large amounts of water are made during planet formation. It’s a major step in understanding how we search for worlds that could support life.”
Researchers are particularly interested in sub-Neptunes—exoplanets larger than Earth but smaller than Neptune. Although our solar system doesn’t have these planets, they are common elsewhere in the galaxy. Scientists believe that these planets have rocky cores enveloped in thick hydrogen-rich atmospheres, making them good candidates to study how water can form during planetary evolution.
To investigate this, Shahar and her team created a mini version of a sub-Neptune in the lab. They used a device called a diamond anvil cell to simulate extreme conditions by compressing molten iron-rich rock to nearly 600,000 times Earth’s atmospheric pressure while heating it to over 7,200 °F (4,000 °C)—conditions found deep within a molten planet.
Under these intense conditions, hydrogen easily mixed with molten rock, leading to significant water production. This means water can emerge from rock-and-gas interactions without needing to be brought in from external sources.
These new insights suggest that water may not be a rare cosmic phenomenon but instead a common result of planet formation. This finding could change how we view the potential for life beyond Earth, making researchers optimistic about identifying more habitable worlds in the universe.
In summary, the research not only alters our understanding of where planets might get their water but also helps clarify the likelihood of finding life-supporting conditions elsewhere in the cosmos. For more details, you can read the study here.
