A team of scientists just published a paper where they explained how the recently launched
James Webb Space Telescope is capable of finding alien worlds with developed agriculture.
Isn't that fascinating?
You can find the link to that paper in the description below.
The only life we know so far is here on Earth.
But people have always tried to find it somewhere else, be it in the form of microscopic organisms
or intelligent civilizations.
Our ancestors have been around for about six million years, but modern Homo sapiens evolved
about 200,000 years ago in Africa.
However, the true civilization of humankind began about 10,000 years ago, when for the
first time ever farming appeared on Earth and humans switched from hunter-gatherers
to agriculture.
Humans learned to use natural resources to produce commodities that maintain life, and
cities started to emerge.
This, in turn, changed the way Earth looked.
The same might happen in other worlds out there, but we never had the technology to
witness something like that, at least until now.
Scientists are optimistic that we might soon detect "exofarms" on distant planets, and
now that Webb telescope has been successfully deployed, it will help aid the search.
The space observatory contains cutting-edge technologies such as the gigantic mirror and
ultra-sensitive detectors which will help us examine many unexplored exoplanets moving
around their parent stars.
If something like photosynthesis is occurring on a particular exoplanet, then the farming
of plants would produce recognizable signatures as it does on our planet.
According to the new paper, the cultivation of plants requires a planet with active hydrological
and carbon cycles and depends on the availability of nitrogen in the soil.
About 78% of Earth's atmosphere is made up of nitrogen.
But since atmospheric N2 is a very stable molecule, it's kinda hard to give plants access
to it.
That's why the use of nitrogen fertilizers is crucial in agriculture to increase production.
It helps plants get more access to nitrogen, and this process leads to the release of greenhouse
gases such as ammonia and nitrous oxide.
The new study suggests Webb telescope could detect the presence of these gases in the
atmosphere of an exoplanet which could serve as a remotely detectable spectral signature
of technology.
Since ammonia falls back to the ground in a matter of days on an Earth-sized planet,
this would indicate an ongoing agricultural activity.
But unlike ammonia, nitrous oxide can continue to exist in the atmosphere for more than a
hundred years.
This greenhouse gas is also a byproduct of combustion, but the authors of the study assume
that other civilizations may discover, just like us, that combustion is not sustainable
and phase it out.
So this can also be an indicator of agricultural activity.
But there's another greenhouse gas, methane, emitted by agriculture, rice agriculture and
ruminant ranching in particular, as well as from biomass burning, landfills, and energy
use.
And this could be another signature worth looking for.
About 70% of methane comes from human activities, and it just keeps increasing.
That's extremely bad for our climate, as methane has accounted for about 30% of global warming
since pre-industrial times.
All in all, possible signatures of agriculture could only occur on a planet that already
supports photosynthesis.
And Webb's sharp infrared eyes are powerful enough to scan exoplanet atmospheres with
enough sensitivity to confirm water, oxygen, and carbon dioxide, along with traces of ammonia
and nitrous oxide, all of which are technosignatures for extraterrestrial agriculture.