Astronomers make real-time, 3D movies of plasma tubes drifting overhead: CAASTRO
AN AUSTRALIAN scientist has discovered that giant, invisible, moving plasma tubes fill the skies above Earth.
It’s a finding that was initially met with a considerable degree of scepticism within the field of astrophysics, but a University of Sydney undergraduate student Cleo Loi, 23, has proven that the phenomenon exists.
By using a radio telescope in the West Australian outback to see space in 3D, Ms Loi has proven that the Earth’s atmosphere is embedded with these strangely shaped, tubular plasma structures. The complex, multilayered ducts are created by the atmosphere being ionised by sunlight.
“For over 60 years, scientists believed these structures existed, but by imaging them for the first time, we’ve provided visual evidence that they are really there,” said Ms Loi, of the Australia Research Council Centre of Excellence for All-sky Astrophysics (CAASTRO).
“We measured their position to be about 600km above the ground, in the upper ionosphere, and they appear to be continuing upwards into the plasmasphere.
“This is around where the neutral atmosphere ends, and we are transitioning to the plasma of outer space.
“We saw a striking pattern in the sky where stripes of high-density plasma neatly alternated with stripes of low-density plasma. This pattern drifted slowly and aligned beautifully with the Earth’s magnetic field lines, like aurorae.
“We realised we may be onto something big.”
An artist’s impression of tubular plasma structures in the Earth’s magnetosphere. Source: Supplied
The breakthrough came when Ms Loi used the remote telescope, the Murchison Widefield Array (MWA), to map large patches of the sky in a new way.
By separating the signals from tiles in the east from the ones in the west, the astronomers gave the MWA — a set of 128 antenna tiles spread over 9sq km in the desert — the power to see in 3D.
“This is like turning the telescope into a pair of eyes, and by that we were able to probe the 3D nature of these structures and watch them move around,” Ms Loi said.
“We were able to measure the spacing between them, their height above the ground and their steep inclination. This has never been possible before and is a very exciting new technique.”
Ms Loi told news.com.au that her research was initially dismissed as being based on imperfections in the telescope images.
“They had never seen this type of thing before. No one had looked at the data in this way before,” she said.
“A lot of the people were pretty convinced is was some problem with the imaging, that it was nothing to get excited about.
“But, I guess being a student and being a bit stubborn, I was so curious, so mystified.
“I was careful about what had happened, and that’s how everyone came to be convinced that it had to be something else.
“We found that the ionisation patterns in the ionosphere are quite structured. They flow in these tubular structures that are aligned with the Earth’s magnetic field. And they can then move of their own accord.”
University of Sydney astrophysics student Cleo Loi has made a remarkable discovery. Source: Supplied
Ms Loi said the drifting plasma tubes could distort astronomical data, especially satellite-based navigation systems. It may also mean we need to re-evaluate our thinking about how galaxies, stars and clouds of gas behave and what they look like.
Ms Loi’s supervisor Tara Murphy said her work was impressive.
“It is to Cleo’s great credit that she not only discovered this but also convinced the rest of the scientific community. As an undergraduate student with no prior background in this, that is an impressive achievement,” said Dr Murphy, also of CAASTRO and the School of Physics at the University of Sydney.
“When they first saw the data, many of her senior collaborators thought the results were literally ‘too good to be true’ and that the observation process had somehow corrupted the findings, but over the next few months, Cleo managed to convince them that they were both real and scientifically interesting.”
Ms Loi’s research has been published in Geophysical Research Letters.
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