In the beginning...
… there were lots of tiny specks of dust left over from a star exploding. Specks that happened to be close to other tiny specks of dust started to clump together by gravitational attraction. These slightly larger clumps in turn began to attract and stick to each other. Pretty soon a maelstrom of bigger and smaller clumps started whizzing around as things were accelerated towards each other (same physics as the whizzing involved when you accidentally knock your iPhone off your hotel balcony) and much larger bodies (“planetisimals”) began to form. I say pretty soon. I mean probably less than 10 million years - which is not all that long when you consider a) that we’re talking about forming the whole solar system and b) how long it takes buses to arrive in rush hour. As these rocky objects smashed into each other the energy released upon impact began to heat them to melting point. The heavy things like iron sank, and the relatively light rocks actually floated on top, producing a “stratified” planet, with concentric spherical shells that are actually made of different stuff. If you could travel to the centre of Earth, or Mars, today, you’d find almost pure metal, while if you look out the window on your way down you’d mainly be looking at the silicon-rich stuff we handily call rock.
This is, in essence, how planets are thought to form. At some point things like water and various gases enter the picture (either fizzing out of the rock like CO2 escaping from an opened coke bottle or ferried in by icy comets) and there was a good long time when material was steadily added by smaller bodies smashing into us and getting embedded. Here’s a funny thing: this process is still ongoing. The Earth is still growing - each meteorite impact adds a little bit of mass. Now they are relatively infrequent, so it looks like we’re mostly done, but in theory it’s precisely the same process as built the whole planet, back in the day. And by back in the day, we’re talking 4,540,000,000 years ago.
If this story interests you and/or if you’re fascinated by any and all subjects that fall beneath the broad purview of Earth science, then I hope you’ll like this blog. I do Earth science research and often find myself frustrated at how bad the Earth science community is at communicating the incredible results of our work to non-specialists. You shouldn’t have to wade through the jargon that is often applied by people who are just trying to make themselves sound clever and esoteric. Many concepts in Earth science are intuitive and captivating and perfectly accessible.
So my intention with this blog is to expand the general knowledge of Earth science. I don’t want to dumb down the science, although simplifications have to be made to get the concepts across - by the way, if the scientific community doesn’t think we already do this internally then we are kidding ourselves; 90% of extremely well-informed scientists understand the finest details of only 10% of the science they read about*. With some effort on the part of the specialists, as well as healthy interest on the part of the reader, I think we can open up the engaging world of Earth science to anyone that cares to take a look at, or down into, it.
* approximate statistics. Based on an estimation of the experiences of a sample of size N=me.