Water: it covers 70% of our own planet, it makes up 65% of our human bodies, and as far as we know, water seems to be essential for life. Water is also found in space, and in fact water ice is the most abundant solid material out there. But how did it get there, and how could water molecules possibly form in the freezing darkness of interstellar space? Japanese researchers trying to answer those questions say they have created water for the first time in conditions similar to interstellar space.
Water ice has been detected in our solar system on other planets and their moons, as well as in comets. A group of scientists at Japan’s Institute of Low Temperature Science at Hokkaido University say, “Since the solar system evolved from an interstellar molecular cloud, icy objects in the solar system originated from the water ice formed in the interstellar molecular cloud.” Their research was an attempt to gain an understanding of the origin of water molecules in interstellar clouds.
Water does form easily here in the warmth and abundance of Earth when oxygen and atomic hydrogen come together. But there’s not a lot of those elements floating around as gas in interstellar dust clouds. From their research, the group from Japan has concluded that water must form when atomic hydrogen interacts with frozen solid oxygen on a solid surface, such as dust grains in interstellar clouds.
They recreated this process by creating a layer of solid oxygen on an aluminum substrate at 10 degrees Kelvin and then added hydrogen. With infrared spectroscopy, they confirmed that both water and hydrogen peroxide formed, and in the right quantities to explain the abundance of water seen in interstellar clouds.
It’s interesting to note that the first water molecules in the universe must have started in this way, and that eventually led to water on Earth, then life, and then eventually people on Earth, who like to research, discuss and contemplate how it all began.