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Scientists have found naturally occurring superconducting materials in extraterrestrial objects for the first time, embedded inside two distinct meteorites that crash-landed on Earth.
The discovery is just the latest to show that meteorites are much more than space debris that falls out of the sky. Recent investigations have turned up meteorite-borne deliveries of possible extraterrestrial proteins, minerals and materials older than the Solar System itself. But we have never seen anything quite like this before.
In the distant sky above, things could be very, very different with extreme environments in space creating exotic material phases which are not seen on Earth, via astronomical events that can unleash incredibly high temperatures and extremely high amounts of pressure.
Because of this, the thinking goes, meteorites could be good candidates for finding naturally formed superconducting materials forged in the strangeness of space. The only problem is, previous searches have never identified any such superconducting compounds. At least, not until now.
Superconductors are materials that can conduct electrical present without resistance, as well as they are longed for by scientists who research quantum computers as well as companies hoping to transfer power more efficiently. The superconductor inside the Australian meteorite is a well-known material, however, the exploration itself comes as a shock.
“The big takeaway is that there is superconductivity in the sky, naturally occurring,” Ivan Schuller, one of the study’s lead authors from the University of California, San Diego, told in an interview.
Six years ago, Schuller’s team debuted a technique called magnetic field modulated microwave spectroscopy (MFMMS). The MFMMS method starts with scientists putting tiny sample fragments into a cavity filled with microwaves and an oscillating magnetic field and then cooling it.
When samples transition from conductors to superconductors, the way they absorb microwaves dramatically changes. The MFMMS method allows scientists to quickly scan through lots of materials to determine whether or not they are superconductors.
They got two hits: one, in an iron meteorite called Mundrabilla, one of the largest meteorites ever found, which was discovered in Australia in 191. The other, a rare ureilite meteorite called GRA 95205, located in Antarctica a quarter-century ago.
This discovery was no glamorous EUREKA moment. Given that the superconductor was a material already known on Earth, the scientists immediately wondered whether they had accidentally contaminated the samples.
The team brought their samples to scientists Yimei Zhu and Shaobo Cheng at Brookhaven National Lab to inspect them using electron microscopes. Only after that confirmation could they feel confident they had actually discovered a naturally occurring superconductor from space.
According to the team’s measurements, which also drew upon Vibrating Sample Magnetometry (VSM) and Energy-Dispersive X-ray Spectroscopy (EDX) methods, both of these space rocks contain minute amounts of extraterrestrial superconductive grains.
That said, the fact that these superconducting grains were discovered in two separate meteorites and from such a small sampler overall of space rocks – means more of these superconducting phase materials are likely to exist in astronomical environments and their superconducting properties could, in turn, have all manner of effects on their extraterrestrial surroundings.
If these alloys took on superconducting properties in the cold of space, perhaps they could affect the magnetic fields surrounding them, producing phenomena potentially visible to telescopes on Earth. But these hypotheses will require a lot more evidence, modelling and research before they hold any water.
Just how substantial these phenomena would end up being is anybody’s guess, but there are lots of new questions to ask and now’s the time to get wondering.
The findings are reported in PNAS