Monday, 3 February 2014

We are all star stuff..

The famous quote from Carl Sagan's Cosmos (look out for the new edition with Neal Degrasse Tyson), was one of the things that made me first interested in Astronomy. So today I thought I'd explain what it actually means.

When the Universe was a baby, and the first stars were forming the only elements that were around were simple ones like Hydrogen and Helium. But when the first stars began to form what scientists think was around 13 billion years ago the were hot enough at the centre for more complicated elements, as heavier elements such as gold and iron need both high temperatures and pressures to form. So the stars have started to form and maybe some of these elements that you need to make a human are at the heart of a star, but how to they become us?

When a star has used up it's power source, it causes a massive explosion called a Supernova (I'll go into these in more details in another post), but basically the star goes BOOM. These supernova's aren't only really pretty to look at (see below), but they are one of the only reasons we are here on Earth!

When these stars explode they scatter the heavy elements into space, and then nebula left over from the star's old atmosphere can then go onto be the base of new stars forming. One of the theories of how our own Star formed is that a supernova happened nearby creating a shockwave that rippled through a cloud of dust and other elements.  This creates sections that are denser than others, causing star formation (this will be another blog post soon).

So think about what makes a human.. If you look at the picture above, it is so clear that we aren't just made of Hydrogen and Helium, we are Carbon and Oxygen and a whole host of other things! This is stuff that is only synthesised in Stars. So technically that makes us Star stuff.

Think about that when you are making your tea tonight, you are made of Star stuff, pretty special eh? I can't wait for you to read the blog post coming soon about every fundamental particle in your body is as old as the Universe.
So how does it feel to be a star?


  1. I love reading deep thoughts <3

  2. interesting post dear ! xx

    1. Awww thank you! I really love your blog, all your posts are so lovely! xx