Els científics creen un gel exòtic de l'”espai exterior”, a diferència de qualsevol a la Terra


Il·lustració de la nau espacial Europa Clipper

Els científics de l’ORNL i del Jet Propulsion Laboratory de la NASA van estudiar la formació de gel amorf com el gel exòtic que es troba a l’espai interestel·lar i a la lluna de Júpiter, Europa. Crèdit: NASA/JPL-Caltech

La recerca de vida més enllà de la Terra normalment se centra a buscar primer l’aigua, la base de la vida tal com la coneixem. Tant si l’aigua és un gas, un líquid o un sòlid, la seva presència i composició poden dir molt als investigadors sobre el planeta, la lluna, el cometa o l’asteroide on es detecta i si podria donar suport a la vida.

Com que l’espai interestel·lar és tan fred i és principalment un buit, l’aigua que detectem de la Terra sol tenir forma de gel amorf, és a dir, la seva estructura atòmica no està ordenada en una xarxa cristal·lina com el gel a la Terra. Com es produeix la transició entre les fases de gel cristal·lí i amorf en cossos gelats com Europa o en objectes del cinturó de Kuiper més enllà[{” attribute=””>Pluto, is difficult to study—unless you can mimic the cold, dark vacuum of outer space, under intense radiation, in a laboratory.

That’s exactly what scientists from the US Department of Energy’s (DOE’s) Oak Ridge National Laboratory (ORNL) and Exotic

Scientists created this exotic “outer space” ice by freezing a stream of heavy water (D2O) molecules
on a sapphire plate that is cooled to about -414° F in a vacuum chamber. Credit: ORNL/Genevieve Martin

“The experiment produced a layer of amorphous ice similar to the ice that makes up most of the water throughout the universe,” said Chris Tulk, ORNL neutron scattering scientist. “This is the same type of ice that could have formed on the extremely cold permanently shadowed regions of the Moon, on the polar regions of

Disrupted Ice Crust on Jupiter's Moon Europa

Enhanced image of a small region of the thin, disrupted ice crust on Jupiter’s moon Europa
taken in 1996 by NASA’s Galileo spacecraft. Credit: NASA

The scientists hope to answer questions such as how much of the ice on the surface of Europa, Jupiter’s second smallest moon, could be amorphous ice as a result of the surface being irradiated by charged particles produced by Jupiter’s magnetic field.

“This information could help us better interpret the science data from the Europa Clipper spacecraft and also provide some clues about how water ice evolves in various parts of the Universe,” said Murthy Gudipati, senior research scientist at

The research is supported by the DOE’s Office of Science and NASA’s Jet Propulsion Laboratory’s internal funding.

This research is partly carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration.

SNS is a DOE Office of Science user facility. UT-Battelle LLC manages ORNL for the DOE Office of Science. The Office of Science is the single largest supporter of basic research in the physical sciences in the United States and is working to address some of the most pressing challenges of our time.