New technique enables mineral ID of precious Antarctic micrometeorites

July 28, 2020

The composition of Antarctic micrometeorites and other tiny but precious rocks such as those from space missions--is really hard to analyze without some sample loss. But a new technique should make it easier, cheaper and faster to characterize them while preserving more of the sample. The findings were published on the peer reviewed journal Meteoritics & Planetary Science on May 21.

Some 40,000 tons of micrometeorites, less than a millimeter in diameter, bombard the earth every year. Analyzing the composition of this type of cosmic dust can potentially reveal many secrets about the evolution of our solar system. They land everywhere on the planet, but we can't tell them apart from regular dust. Antarctic micrometeorites (AMMs) are special because this cleaner environment makes them easier to distinguish--but because Antarctica is such a remote and challenging place, AMM samples are very precious.

One of the main techniques used to identify the composition of a material, X-ray diffraction, mainly depends upon the use of X-rays produced at laboratories with synchrotrons, a type of particle accelerator, which is expensive and not always convenient.

This method is also challenging if, as is common in the case of AMMs, researchers only have a very small sample of the material needed to be investigated and want to avoid significant sample loss.

However, researchers with Japan's National Institute of Polar Research have now applied a different--and actually quite old--technique to such objects, which opens up the opportunity of much more convenient and cheaper identification of them than has previously been available, while also conserving more of the sample.

In the late 1960s, a Gandolfi x-ray diffraction camera that could rotate on two axes began to be used within X-ray crystallography, the experimental science of investigating materials via determining the molecular structure of the crystals many materials are made out of.

"There are a handful of different X-ray diffraction techniques, including using a vacuum tube that converts electrical energy into X-rays," says Naoya Imae Ph.D., a researcher who worked on applying the Gandolfi x-ray diffraction method to micro-samples, "but a Gandolfi set-up is just much easier to use and much faster."

Until now, the Gandolfi set-up had not been widely used for identification of micrometeorites.

The researchers attached a Gandolfi system to an X-ray diffractometer that had recently been delivered to the National Institute of Polar Research, and tested their set-up on very small rock samples (0.2-0.8 mm) that contained olivine and pyroxene, two minerals that are important for the identification of rocky meteorites.

The set up worked best with rock samples in the form of powders rather than "bulk" agglomerations of grains of mineral crystals.

With the test on known rock samples proven to be successful, the researchers now want to apply the technique on actual AMMs and samples taken by the Hayabusa 2 mission from near-Earth asteroid 162173 Ryugu expected to return to Earth later this year.
-end-
About National Institute of Polar Research (NIPR)

The NIPR engages in comprehensive research via observation stations in Arctic and Antarctica. As a member of the Research Organization of Information and Systems (ROIS), the NIPR provides researchers throughout Japan with infrastructure support for Arctic and Antarctic observations, plans and implements Japan's Antarctic observation projects, and conducts Arctic researches of various scientific fields such as the atmosphere, ice sheets, the ecosystem, the upper atmosphere, the aurora and the Earth's magnetic field. In addition to the research projects, the NIPR also organizes the Japanese Antarctic Research Expedition and manages samples and data obtained during such expeditions and projects. As a core institution in researches of the polar regions, the NIPR also offers graduate students with a global perspective on originality through its doctoral program. For more information about the NIPR, please visit: https://http://www.nipr.ac.jp/english/

About the Research Organization of Information and Systems (ROIS)

The Research Organization of Information and Systems (ROIS) is a parent organization of four national institutes (National Institute of Polar Research, National Institute of Informatics, the Institute of Statistical Mathematics and National Institute of Genetics) and the Joint Support-Center for Data Science Research. It is ROIS's mission to promote integrated, cutting-edge research that goes beyond the barriers of these institutions, in addition to facilitating their research activities, as members of inter-university research institutes.

Research Organization of Information and Systems

Related Polar Research Articles from Brightsurf:

Plane travel destroys polar bear habitat
A group of polar bear researchers wants you to do more than worry about the fate of these beautiful animals.

First evidence of feathered polar dinosaurs found in Australia
A cache of 118 million-year-old fossilized dinosaur and bird feathers has been recovered from an ancient lake deposit that once lay beyond the southern polar circle.

A polar-bear-inspired material for heat insulation
For engineers, polar bear hair is a dream template for synthetic materials that might lock in heat just as well as the natural version.

Academic journal Polar Science features polar science in India
The National Institute of Polar Research (NIPR) published a special issue 'Recent advances in climate science of polar region (to commemorate the contributions of late Dr.

POLAR experiment reveals orderly chaos of black holes
An international consortium of scientists studying gamma-ray bursts (GRBs) as part of the POLAR (GRB polarimeter) experiment has revealed that high-energy photon emissions from black holes are neither completely chaotic nor completely organized, but a mixture.

Can artificial intelligence tell a polar bear from a can opener?
How smart is the form of artificial intelligence known as deep learning computer networks, and how closely do these machines mimic the human brain?

The secret contamination of polar bears
Using a new approach to measure chemical contaminants in polar bears, scientists from Canada and the United States found a large variety of new chlorinated and fluorinated substances, including many new polychlorinated biphenyl metabolites.

'True polar wander' may have caused ice age
Earth's latest ice age may have been caused by changes deep inside the planet.

Walking is more efficient than thought for threatened polar bears
Polar bears are under increasing risk and one of the threats was thought to be an inefficient walking style, which could drive them to starvation as they are forced to walk further to find food as the summer sea ice retreats.

Polar vortex defies climate change in the Southeast
Overwhelming scientific evidence has demonstrated that our planet is getting warmer due to climate change, yet parts of the eastern US are actually getting cooler.

Read More: Polar Research News and Polar Research Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.