Biological particles reach for the stars

High-speed winds in space blow biological particles into higher altitudes than previously thought.

For many decades large vertical winds have been observed at high altitudes of the Earth's atmosphere, in the mesosphere and thermosphere layers. These winds are not reproduced by weather models and the mechanism by which they are occurring is not fully understood.

Professor Arjun Berera and PhD student Daniel Brener, from the School’s Particle Physics Theory Group, have shown using theoretical estimates that particles similar in size to viruses could be projected by these strong vertical winds to higher altitudes than previously discovered.

Their studies found that biological particles could be carried more than 120km above the Earth’s surface by such high-speed vertical winds, and may even reach as high as 150km. This is much higher than the 77km altitude that bacteria spores have previously been discovered at.

If biological particles can be found at such high altitudes, it is also suggested that the hypervelocity space dust, which continuously impacts the atmosphere, can propel such particles into deep space. Over aeons, some of these micro-organisms may have landed on other planets, or may have travelled from other planets to Earth.

In their paper published in the Proceedings of the Royal Society A, the researchers discuss the numerous applications of these results in astrobiology and climate science. 

This work further advances the space dust interplanetary atmospheric exchange mechanism theory which was initially proposed by the Particle Physics Theory Group.