Did life originate in space?
Did you know that you are made of star stuff? It’s true! Many of the atoms in your body were created in other stars. It’s one of the most exciting discoveries in science ever made.
When the Universe was very young, billions of years ago, there were only very simple atoms. Mostly hydrogen and helium. But today, there are many dozens of different atoms, like carbon, oxygen, calcium, iron, phosphor, gold, silver and uranium. For instance, there’s iron in your blood, calcium in your bones, carbon in your muscles, and phosphor in your DNA. Where did all these atoms come from?
For sure, the atoms in your body did not spontaneously appear when you were born. They were there all along. But shortly after the big bang, they were nowhere to be found. So when and where did they form?
We now know that new atoms are being forged in the interiors of stars, by nuclear reactions. When a star dies, it blows away huge amounts of gas, or it may even explode as a supernova. Thus, the new atoms end up in space. Later, they may find themselves in a cloud from which new stars and planets are born. Some of the atoms become part of the Earth, and some eventually end up in your body. So every single carbon atom in your body was once created in another star!
Without the nuclear reactions in the interiors of stars, there would be no life. But scientists still don’t know much about the origin of life. ALMA may help unravel this mystery. That’s because ALMA can detect the molecules that are important for the origin of life.
Molecules are combinations of atoms. They come in a wide variety of sizes and shapes. And some large molecules are important for the origin of life, like hydrocarbons, sugars, and amino acids. These molecules are really the building blocks of life.
Large molecules can only survive in cold and dark regions in the Universe. Precisely the regions that can be studied in detail by ALMA. Moreover, many molecules emit their own millimeter waves, so ALMA will be able to detect and identify them.
By peering into dark clouds of cold gas and dust, ALMA may discover when and where the first building blocks of life are created. And by studying the cool disks swirling around newborn stars, ALMA may discover that the ingredients of life are already present before planets are born. Finding out how life arose in the Universe would be one of the biggest scientific discoveries we can imagine.