Astronomers find hidden structures near Earth's surface

Melbourne: By observing galaxies billions of light-years away, a team of astronomers has detected tube-like structures mere hundreds of kilometres above the Earths surface.

"For over 60 years, scientists believed these structures existed but by imaging them for the first time, we have provided visual evidence that they are really there," said study lead author Cleo Loi from University of Sydney.

The astronomers made their observations with the Murchison Widefield Array (MWA)- a radio telescope in Western Australia designed to observe the early Universe and distant galaxies as well as stars and nebulae within our own Milky Way Galaxy.

The observations revealed that the tubes are 500 to 700 km above the surface and are aligned with the Earth's magnetic field. Mapping the variations in the positions of multiple radio sources over the course of a night revealed the shape and dimensions of the tube structures.

By exploiting the MWA's rapid "snapshot" capabilities, the researchers also created a movie -effectively capturing the real-time motions of the tubes.

"We were trying to understand if the motions of the ionosphere were random or had a pattern, both to see if the MWA could be used to study the ionosphere, and also to be able to correct for its effect and study the sources behind it," Bryan Gaensler University of Toronto in Canada noted.

"This work highlights the new frontier that the MWA is opening up. By operating at low radio frequencies and covering such an enormous field of view, we can study subtle and complicated processes that we had only ever caught fleeting glimpses of previously," Gaensler said.

The findings were detailed in the journal Geophysical Research Letters.