What is Stardust made of?

Everything you need to know about what is stardust made of begins with understanding what a Star is. Studying the origin of stardust astronomy points out it lies in star’s death. And just as everything else in the cosmos changes, death is the beginning of new galactic life.

Maybe that’s where the old saying came from: we are made of stardust. The explosive death of a star is the crucial process for the creation of the most complex elements in the universe… And life.

What is stardust made of? A life explosion

In a cosmos that’s getting bigger and bigger at an increasing speed, it’s essential to think about what causes this expansion and what it means. But, the only mystery we will solve today is: what is stardust made of?

According to science, stardust is made of particles remaining from a supernova explosion. Though we could wrongfully believe, Stars won’t shine forever. Like ourselves, and every other living being, the stars are born, they live, and they die. Of course, their lifespan is much longer than ours.

While the sun, which is also a star, has existed for billions of years, Homo erectus, our closest ancestor appeared just 1.8 million years ago. That means that the whole history of humankind comprises only a tiny part of the sun splendor.

How is a star born?

Stars are born in places called nebulae. Formed by gas and dust, a nebula is main element is hydrogen. Over time, due to gravity they begin to collapse forming a nucleus.

Through a process known as nuclear fusion, a course that can take millions of years to develop, the star nuclei increase its temperature transforming hydrogen into helium, the fuel that makes every star shine. And like so, in the midst of a cosmic spark, stars are born.

But let’s go back to the beginning, what is stardust made of? Helium?


Well, the first stars in the universe were formed only with hydrogen and helium. But, where do the other elements came from? That’s easy, from star’s transformation.

The creation of the other elements occurs inside of the stars, in their nuclei. For hundreds of billions of years, the hydrogen reacts until it is transformed into helium. Once all the hydrogen is consumed the star begins to die.

During this process the star synthesizes helium into beryllium through the triple Alpha reaction, in which the elements begin to deplete, giving way to new successive reactions, and with them to new elements formation.

These chemical reactions slowly make the nucleus to lose its balance until the star becomes a Red giant. However, to produce stardust astronomy indicates that it takes the explosion of a star 5 times bigger than the sun. A star this big will contain enough energy to generate all the elements, including iron.

When a star manages to transform its nucleus into iron, it’ll disintegrate, collapsing in an incredible explosion. One that can shine with the light of billions of stars together for several days, even weeks. This explosion is known as a supernova.

We are made of stardust:


In this explosion elements such as gold, copper, mercury, and silver are created. All of which end up floating in the space, forming a new nebula. That is what stardust is made of.

Then, the process will start again, and after millions and millions of years, a new star will be born, and it will contain all the elements of the previous one. Also, around this new star, the elements can come together forming planets and, for that reason, we can affirm that, without a doubt, we are made of stardust too.