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Scientists Observe Rare Plastic Ice, A Hybrid Form of Ice and Water, Under Extreme Pressure and Heat
Researchers have observed plastic ice, a phase where water molecules rotate while staying in a solid structure. The discovery, made under extreme pressure and heat, could provide new insights into the composition of icy exoplanets and moons. The findings suggest plastic ice VII may have existed in Europa and Titan's interiors and could influence nutrient exchange in deep oceans on exoplanets. This breakthrough offers valuable data on planetary evolution and habitability beyond Earth.
A rare phase of ice, believed to exist deep within icy exoplanets and moons, has been observed in laboratory conditions for the first time. Scientists have identified a hybrid form of water called plastic ice, which exhibits characteristics of both solid ice and liquid water under extreme pressure and temperature. The discovery is expected to provide new insights into the internal composition of celestial bodies such as Neptune and Jupiter's moon Europa, potentially influencing studies on planetary habitability.
Properties of Plastic Ice Identified Under Extreme Conditions
According to a study published in Nature, plastic ice forms when ice is subjected to temperatures above 177 degree Celsius and pressures exceeding 30,000 bars. This phase retains a cubic crystal lattice, similar to Ice VII, but allows water molecules to rotate while remaining fixed in position. Livia Bove, a physicist at Sapienza University of Rome, explained to Science News that the material exhibits plasticity, meaning it can be deformed while maintaining its structure.
Experiments were conducted at the Institut Laue-Langevin in France, where a neutron beam was used to measure molecular motion under extreme conditions. Water samples were exposed to high-pressure environments, and the scattered neutrons provided data confirming the existence of plastic ice VII. Unlike previous theoretical predictions, researchers found that the molecules rotated in a jerky manner rather than moving freely.
Potential Role in Planetary Evolution
Baptiste Journaux, a planetary scientist at the University of Washington in Seattle, stated to Science News that plastic ice VII may have played a role in shaping the internal structures of moons like Europa and Titan during their early formation. The presence of this phase could have influenced the retention of water within their interiors.
Beyond the solar system, plastic ice VII may exist within deep exoplanetary oceans, potentially affecting nutrient exchange between seabeds and overlying waters. Research into its ability to incorporate salts could enhance understanding of ocean chemistry on distant worlds.
