For the first time, astronomers have captured visual evidence of the existence of tubular plasma structures living in the inner layers of the magnetosphere that surrounds the Earth.

"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," explained Cleo Loi of the ARC Centre of Excellence for All-sky Astrophysics (CAASTRO) and the School of Physics at the University of Sydney.

 

"The discovery of the structures is important because they cause unwanted signal distortions that could, as one example, affect our civilian and military satellite-based navigation systems.

 

So we need to understand them," Loi, who is the lead author on this research, continued.

The plasma in the magnetosphere, which is the region of space around the Earth occupied by its magnetic field, is created by the atmosphere being ionized by sunlight.

The ionosphere is the innermost layer of the magnetosphere, and higher up is the plasmasphere.

These are implanted with many oddly shaped plasma structures, including the tubes.

"We measured their position to be about 600 km 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," Loi noted, who has been awarded the 2015 Bok Prize of the Astronomical Society of Australia for her work.

Loi used the Murchison Widefield Array, which is a radio telescope in the Western Australian desert, to discover that she could map large patches of the sky and harness the array's rapid snapshot setting to make a movie.

This resulted in real-time movements of the plasma.

"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 Loi's supervisor, Dr. Tara Murphy, also of CAASTRO and the School of Physics at the University of Sydney.