How on Earth are we made of stardust? I just don’t get it. We, humans, are made of something that has been ushered off of star’s shoulders. I mean, really.

3 Answers
Apr 19, 2018

It begins with the creation of matter in general: stars are what created the elements we are made of.


When the universe was created, it was a swarm of subatomic particles. Once they finally formed into Hydrogen and Helium, they gravitated together into starts, generating an incredible amount of energy, thereby creating new elements, one of which just so happens to be our base material: Carbon.

Some more things happened, stars exploded, new elements were made with the explosion of energy there, and eventually all of those elements became things like Earth, asteroids, etc. From there, once Earth become an actually habitable planet, life was born from the elements through a process that would likely consume the entire page, and if you want the rundown on that you should head to the biology section.

Actually, I was really dumbfounded by this concept when I was first introduced to Astronomy.


However, I got my head around that fact when I learnt one fact - that is, we are not the first thing to exist in the universe.

In fact, the Earth is only estimated to be around 4.5 billion years old. The Universe is estimated to be around 13.7 billion years.

A lot can happen in 9 billion years, my friend. But on a more serious note, in those 9 billion years, gravity, collisions between space rock and a whole lot of other factors gradually formed the Earth that we stand on now.

So what created you and me? Atoms. The same (well, not really) atoms that created the Earth, in a different arrangement can form humans!

However, based on the fact that almost #7×10^27# atoms consist one human being of around 70kg. Can you imagine how many possible permutations and arrangements that can bring? Now imagine the earth. How many atoms would that need? About #1×10^50# atoms. Then think about the sun. A staggering #1.2×10^57# atoms. Because we know that stars can die (our sun is, by the way, a star), a star can explode violently when its time is up and the number of atoms that can be ejected is literally uncountable.

Once we can get our heads around the literal impossibleness of the number of possible combinations atoms can do, it starts to become possible that we can be made of stardust, right? Well, not star dust. More like star atoms.

Hope this helps!

Apr 19, 2018

The important elements for life can only be made in stars.


The important elements for life are Carbon, Nitrogen, Oxygen and heavier elements. These elements can only be made in stars through fusion reactions. Only Hydrogen, Helium and traces of Lithium and Beryllium were present in the early universe.

When a large star dies it explodes forming a cloud of gas containing these important elements. These clouds of gas form new star systemss.

Our solar system was formed from a gas cloud which was the remnants of a large star. All of the elements in our bodies, except for Hydrogen were created in the core of a long dead star.

We are truly made of stardust!