According to a study published in the Monthly Notices of the Royal Astronomical Society, the team also detected a huge tail of gas extending another 1.6 million light-years beyond the bridge, making it the largest feature of its kind ever recorded.

Lead researcher Professor Lister Staveley-Smith from ICRAR UWA explained that the finding provides an important new insight into how galaxies influence each other.

"Our modeling showed that the tidal forces acting between these galaxies, alongside their proximity to the massive Virgo cluster of galaxies, played a crucial role in the gas dynamics we observed," Professor Staveley-Smith said.

He added that as the galaxies orbited one another and moved toward the superheated gas cloud surrounding the Virgo cluster, which reaches temperatures about 200 times hotter than the Sun's surface, they experienced "ram pressure." This effect stripped gas from the galaxies and heated it as they passed through the dense environment.

"The process is akin to atmospheric burn-up when a satellite re-enters the Earth's upper atmosphere, but has extended over a period of a billion years," he said.

"The density of electrons and the speed at which galaxies are falling into the hot gas cloud are enough to explain why so much gas has been pulled away from the galaxies and into the bridge and surrounding areas."

The discovery was made as part of the Widefield ASKAP L-band Legacy All-sky Survey (WALLABY), a large-scale project that maps hydrogen gas throughout the Universe using the ASKAP radio telescope, owned and operated by CSIRO, Australia's national science agency.

Co-author Professor Kenji Bekki of ICRAR UWA said the team identified the enormous gas structures through high-resolution observations of neutral hydrogen, a key ingredient in star formation.

"Neutral hydrogen plays a crucial role in the formation of stars, making this finding fundamental to understanding how galaxies interact and evolve, particularly in dense environments," Professor Bekki said.

Professor Staveley-Smith said the system had strong similarities with our own Milky Way and Magellanic System, providing a unique opportunity to study such interactions in detail.

"Understanding these gas bridges and their dynamics provides critical insights into how galaxies evolve over time, how galactic gas is redistributed, and the varying conditions under which galaxies may or may not form stars," he said.

"This contributes to our broader understanding of the most massive structures in the Universe and their life cycles, which helps us grasp more about their vast complexities and history of star formation."