Weathering by the solar wind creates a small hair iron crystals in the Asteroid perplexed by the “iron-lash” – scinexx


Surprising discovery: In the samples from the asteroid Itokawa, researchers have identified a previously unknown phenomenon – that of the powder granules are coated with a small amount of iron in the hair. This is the metal from the hair, and is apparently caused by the solar wind, leaving the space station, and the area of the time, and the sulfur-containing iron ores are broken down. That is such an iron, hair can be the result is a completely new aspect of space weather, as the researchers explained.

The inclusion of the asteroid Itokawa, the Hayabusa spacecraft. © Burke et al. /PNAS

If asteroids, comets or the moon and All the heavenly bodies, which have neither an atmosphere nor a magnetic field are exposed to the solar wind almost defenceless, – and it has consequences. On the moon, and the constant barrage of energy particles, color of the Regolith, in the course of time, in the dark, and left only a few protected Points of light. In addition to this, the surface of the asteroid and a comet is modified by this space weathering and chemistry.

The grain of dust, with metallic “eyelash”

But now, researchers at the Toru Matsumoto of Kyushu University has discovered a new Form of space weathering processes in the dust samples from the asteroid Itokawa. It was visited in 2005 by a space probe the Japanese Hayabusa, the samples collected in 2010, returned to the earth, has brought to us. Since that time, the asteroid samples will be studied in an extensive way.

All the more it surprised scientists were when they discovered a new phenomenon in the dust samples: The surface of most granules was covered with glass from the small hair in the shape of an Iron. These lashes are at their peak, the thin, folded longitudinally showing grooves”, according to Matsumoto and his Team. “The length varies from several tens of nano-meters up to 2.8 microns.” A lot of these “lashes” which were made out of a number of small hairs.

The hair is made up of almost pure iron

Further analysis revealed that these little hairs were made of almost pure iron – Nickel ratio less than about 0.7% by weight. “All of the diffraction patterns indicates that a lot of fine hair is composed of a single crystal of iron, or of a few slightly differently-oriented crystals,” report the researchers.

However, as this iron is designed for the hair? The scientists suspect that they have developed in the Mineral Troilite (FeS) – a sulfide of iron, which is commonly found in iron meteorites. After in-depth investigation of the possible chemical reaction paths that They and their Team have come to the conclusion that the bombardment with high-energy ions from the solar winds have on the railway in and from the Troilite to the surface of the asteroid Itokawa to be removed.

“The Cosmic dimensions of the scary-fast”

“As a result of the weathering of the area, the iron and the Troilite is free, and is deposited in the Form of the now uncovered needle on the surface,” says co-author Falko Langenhorst of the University of Jena. As for the sulphur from the sulphide of iron is volatilized, and the iron, and the hair-like crystals. Growth takes place very quickly in a way surprising: at the End of the additional two-and-a-half microns in length, and are in need of the iron for the hair, probably about 1,000 years ago. “In the process, that is, in order for the “cosmic” dimensions, very quickly,” says Matsumoto.

According to the researchers, this iron and the hair is not just a completely new phenomenon of space weathering, their existence also throws light on the behaviour of the Minerals Troilite, under the conditions of the space: “In contrast to the above-mentioned assumptions, the sulphides of iron are, therefore, highly susceptible to degradation by the ion-current of All,” concluded the researchers.

How widespread is this Form of space weathering, that is, one can show, among other things, the spacecraft Hayabusa-2. They’ve taken out the dust samples from the asteroid, Ryugu, and it is up to you it is already again on the way back down to earth. By the end of 2020, all the samples are on the way. The international Team looks forward to. “The Occurrence of iron lashes by ion bombardment has never been previously observed in the Mineralogy, material research and more research will bring new insights into the growth mechanisms and the processes of etching, ion-irradiation.” (Nature Communications, 2020; doi: 10.1038/s41467-020-14758-3)

Source: Nature Communications, Friedrich-Schiller-University Of Jena