Stars such as the Sun and planets such as the Earth are born from a cloud of gas floating between stars called molecular clouds.In the molecular cloud, volatile elements (hydrogen, carbon, nitrogen, oxygen) form various molecules at a low temperature of about -263 degrees, and they also exist as ice.This ice, called interstellar ice, has various molecules formed on its surface, and the bonds of the molecules in the ice are broken by irradiation with ultraviolet rays, and these molecules are used as materials to form complex organic matter. Is known, and these complex organic matter are thought to be the origin of macromolecular organic matter found in comets and extraterrestrial substances.
A research team at Hokkaido University created simulated interstellar ice by irradiating a mixed gas of water, ethanol, and ammonia with ultraviolet rays in order to investigate the properties of interstellar ice, which can be said to be a "cradle" for the formation of organic molecules in space.As a result of observation, it was discovered that this ice behaves liquidly at a low temperature of -220 to -120 degrees Celsius, instead of the solid state previously considered.
Furthermore, it was discovered that ice made of pure water also becomes liquid at -220 to -130 degrees when irradiated with ultraviolet rays.This suggests that ice containing water may have the property of liquefying when exposed to ultraviolet light.
The liquid behavior of interstellar ice may help the effective formation of complex organic matter in the universe, which is also related to biomaterial organic matter, as it is expected to promote organic molecule formation reactions in liquids. be.The presence of liquid ice may also help the efficient accretion and growth of dust in space, and is expected to lead to an understanding of the dust accumulation process, which is the first step in planet formation.
Paper information:[Science Advances] Liquid-like behavior of UV-irradiated interstellar ice analog at low temperatures
