[Reading Science] Discovery of 'Eoreum' Never Seen Before... Could It Lead to Finding Extraterrestrial Life?

London College Research Team
Discovers 'Medium-Density Amorphous Ice'
"Breaks Common Sense That Water Density > Ice, Water = Ice"
"May Provide Clues for Extraterrestrial Life Search"

[Asia Economy Reporter Kim Bong-su] Water is a physically very unique substance. Most materials have a higher density in solid form than in liquid form. However, water is the opposite: ice has a lower density and larger volume than liquid water. Recently, scientists have discovered a solid ice with the same density as liquid water. This finding is analyzed to provide clues for predicting the existence of life when exploring extraterrestrial planets with ice, such as Jupiter's moon Europa.

An experimental model devised by a research team at University College London (UCL) to create medium-density amorphous ice. Photo by UCL

A research team from University College London in the UK reported these findings on the 2nd (local time) in the international academic journal Science. The team named this ice "medium-density amorphous ice." At minus 200 degrees Celsius, they placed regular ice and stainless steel balls in a small container and shook it 20 times per second, creating a previously unseen variant of ice.

Ordinary water crystallizes as it freezes, with molecules arranged in a hexagonal, rigid structure. The unique aspect is that ice has a lower density than water. This is a special property of water, unlike most substances that have higher density in solid form. Additionally, water exhibits 24 different forms depending on freezing speed and pressure. However, amorphous ice has no fixed structure because its molecules bond randomly. It was already known decades ago that when water freezes on very cold metal surfaces below minus 150 degrees Celsius, low-density amorphous ice forms. Under the same conditions but with high pressure, high-density amorphous ice forms. Both types are rare on Earth but are frequently found in space, such as in comets (low-density amorphous ice).

The research team used stainless steel balls, tools commonly used for grinding or mixing mineral materials, to crush crystallized ice. At an ultra-low temperature of minus 200 degrees Celsius, they placed a small amount of ice in a container with stainless steel balls and shook it at about 20 times per second. The stainless steel balls applied shear force to the ice, turning it into a white powder. Using X-ray diffraction, the team examined the structure of this white ice powder. They confirmed that this white ice powder has the same density as liquid water. The molecular structure was amorphous without the characteristic hexagonal order of ice.

Further research is needed, but if this discovery is confirmed, scientists point out that it could significantly change existing research and common knowledge about water. Although amorphous ice has been discovered before, its density was either much lower or much higher than that of liquid water, showing a clear difference.

Martin Chaplin, a professor at London South Bank University in the UK, said, "Liquid water is a unique substance that we still do not fully understand. If medium-density amorphous ice is actually connected to liquid water, it means existing theories are incorrect, opening a new chapter in ice research."

An artist's concept of the Europa moon exploration jointly planned by the National Aeronautics and Space Administration (NASA) and the European Space Agency (ESA). Photo by NASA

This discovery is also expected to impact extraterrestrial planet exploration. Within our solar system, Jupiter’s Europa and Saturn’s Enceladus have surface ice, raising the possibility of life. Due to tidal forces on these moons, ice sheets collide and generate shear forces, which could produce medium-density amorphous ice like that discovered by the research team. If the density of the ice increases, the surface cracks and fractures, causing large-scale collapses that significantly affect the surface terrain of these moons. Therefore, scientists view the presence of such medium-density amorphous ice on these moons’ surfaces as a positive sign for the potential existence of life.

Marius Millot, a researcher at the Lawrence Livermore National Laboratory in the US, said, "One of the key factors in determining whether life can exist on moons like Europa or Enceladus is whether there is an intermediate zone between seawater and rock where life can emerge. The presence of amorphous ice could be a clue."