Sunday 20 October 2019

Space dust recreated in laboratory


Stock picture
Stock picture

Douglas Barrie

The dust that forms the stars and planets of our galaxy has been recreated in a laboratory.

Professor Martin McCoustra and a team of scientists from Heriot-Watt University in Edinburgh have spent the last 12 years investigating how ice forms and behaves around tiny specks in the interstellar environment.

From that, new stars and planets are formed, as well as structures like the Eagle Nebula, providing a source of complex organic molecules from which life can originate.

The astrochemists recreated deep space in their lab.

They found the dust to be much more structurally complex than had first been thought.

Prof McCoustra compared it to a "badly baked cherry cake" instead of the widely held belief that the dust is structured like an onion.

"These tiny little snowballs have key roles to play in the evolution of the current universe, from controlling the process of star formation to providing an inventory of organic molecules from which biology might evolve," he said.

"If we understand their formation and evolution, then we can more fully appreciate those roles.

"We discovered that water is more mobile on the dust grain surface and tends to form little islands of ice as opposed to a uniform film," he added.

"This leaves parts of the grain surface free on which other species can adsorb," he said.

"So instead of an onion, picture a badly baked cherry cake, where the cherries of water have sunk to the bottom of the icy cake as it is baked."

A space dust proxy - copper plate coated in tiny silica particles, cooled to a few degrees above absolute zero and in an ultra-high vacuum - was used for the experiments on various species found in the environment.

The team now hopes other scientists will test out the ideas to help develop understanding.

Irish Independent

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