Could life exist all across the universe?

There are many questions that we rarely think about in everyday life, such as: why are the stars shining, why people in horror movies are so stupid or are there any aliens. While we can answer the first question, the other two are much harder. Let’s skip the second question and go straight for the third. Whether aliens exist or not is not something we know right now, but we can still estimate, if the are out there or not. For these estimations we use the mighty power of science, more specifically astrochemistry. Astrochemistry does exists and believe me it is not some kind of dark magic.

Despite many people believing chemistry to be the mysterious thing that happens in the lab, or when the chemistry teacher detonates some strange chemicals during the painfully long chemistry lesson, it is actually happening in places where you wouldn’t expect. Chemistry happens in the sea, in the ground, in your dog(don’t hate the poor animal for it), and even in outer space. The chemistry that happens in space is actually quite important. When scientists looked into space, with their big ass telescopes, they found that there are actually organic molecules out there. Why is this important? Because these organic molecules might be very important in the origin of life.

Unfortunately, these molecules can’t just magically appear, like Jehovah’s witnesses at your door.  They need to form from the gas clouds that are in space. However, to form these molecules require energy. Unfortunately they don’t have a FRANK app, in which there is a discount for electricity.

 

When you look up to the night sky( or even the day sky) what you see is actually the energy source for the poor molecules: stars. For certain, big big molecules, to become the building blocks of life, need to react with water. By this I mean, they need to take the oxygen from the water, like a bully taking the lunch of the nerds, to become more complicated, more ‘lively’ molecules. For this to happen the light needs to be really energetic, by energetic I mean UV. This means that, around most stars, this kind of reaction couldn’t happen, because they are too dim and doesn’t produce enough UV light.

 

But recently, scientists actually proved that even visible light could start the reaction, if the starting molecules are inside ice crystals. This is actually quite possible, since space is extremely cold, even colder than your freezer or your ex. So, If the big organic molecule is surrounded by smaller water molecules, they can help him out a bit, and when the light attacks the molecule, and with a light smash it blasts one of its electrons away. Once the electron is away from the molecule, the surrounding ice can hold the tiny particle, like some pervert, keeping the molecule excited and ready to react with water.

 

That is actually beneficial for another reason. Since UV is ‘stronger’ than visible light, other molecules can more easily absorb it. And because of that, visible light can penetrate deeper and harder into the clouds of matter that exist in space.

 

This means that even around dimmer stars, so-called “red dwarves” , or “orange dwarves” , complex organic molecules could form and enable the birth of life around them. We already have some candidates, like Proxima B and Trappist-1 that have planets just the right distance away from them to potentially harbor life.

Source:

Lignell , A , Tenelanda-Osorio , L & Gudipati , M S 2021 , ‘ Visible-light photoionization of
aromatic molecules in water-ice : Organic chemistry across the universe with less energy ‘ ,
Chemical Physics Letters , vol. 778 , 138814 . https://doi.org/10.1016/j.cplett.2021.138814

Author:

Roland Vadász