Scientists and extra-terrestrial researchers have been looking for signs of life all over our Universe, and in others, however a newly published study in the journal Monthly Notices of the Royal Astronomical Society indicates that atmospheric components may make finding alien life on other planets more difficult than previously thought.
Unusual air flow patterns could hide atmospheric components from telescopic observations, with direct consequences for formulating the optimal strategy for searching for such as bacteria or plants on exoplanets. These forms of life would indicate others that are similar to “life as we know it.”
Scientists currently measure the likelihood of finding alien life outside of our own Solar System by identifying chemical compounds that would suggest living things – oxygen, and ozone being paramount. These are trace elements which allow us to detect life from afar.
In Earth’s atmosphere, ozone protects us from the Sun’s harmful ultraviolet (UV) radiation, thus allowing all forms of life to thrive. Though life, different to how we have defined it here may exist elsewhere, the presence of oxygen-producing elements make it more likely that life somewhere in deep space exists.
Researchers from the Max Planck Institute for Astronomy in Germany, led by Ludmila Carone now suggest that those traces – ozone or oxygen – could be hiding in planets like Proxima b, TRAPPIST-1d, and others that are very Earth-like because of the air-flow that happens within their atmospheres.
Modelling the flow of air within the atmospheres of these planets, Carone and her colleagues found that changes which happen from day to night caused a marked effect on the distribution of ozone across the atmosphere.
For some planets, the major air flow may lead from the poles to the equator, systematically trapping the ozone in the equatorial region.
“Absence of traces of ozone in future observations does not have to mean there is no oxygen at all. It might be found in different places than on Earth, or it might be very well hidden.”
Such unexpected atmospheric structures may also have consequences for habitability, given that most of the planet would not be protected against UV radiation.
UV radiation that is higher even within Earth’s atmosphere cause all kinds of trouble for humans and our technological equipment, but this doesn’t mean that life elsewhere couldn’t have evolved to handle higher UV exposure.
Carone explained further,
“In principle, an exoplanet with an ozone layer that covers only the equatorial region may still be habitable. Proxima b and TRAPPIST-1d orbit red dwarfs, reddish stars that emit very little harmful UV light to begin with. On the other hand, these stars can be very temperamental, and prone to violent outbursts of harmful radiation including UV.”
The combination of advances in modelling and much better data from telescopes like the James Webb Space Telescope is likely to lead to significant progress in this exciting field.
“We all knew from the beginning that the hunt for alien life will be a challenge,” says Carone. “As it turns out, we are only just scratching the surface of how difficult it really will be.”
Or, it could mean that scientists have to change the way that they look for the “cues” of life (such as expecting that all life must be preceded by the presence of oxygen or ozone), along with a dismantling of presuppositions that life cannot be supported in atmosphere’s we, here on Earth, would consider extremely hostile.
Even in Earth’s own high atmosphere, it has been posited that alien life already exists. University of Houston students found that microbes do just fine there.
Image: Daily Galaxy