Braai4Heritage Tour Day 11: Vredefort Dome

World Heritage Site number 3 of the tour.

Shooting stars as we know them aren’t really shooting starts at all. They are pieces of rock entering the earth’s atmosphere. As they enter the atmosphere at an average speed of about 10km per second the resultant friction with the air causes them to burn. And that is the light we see. These pieces of flying rock are called asteroids. And sometimes when they are big enough they get all the way down to earth without completely burning out before they arrive. In those cases they are called meteorites.

With our tour guide for the day. His name is also Jan.

Give or take a few million, about 2023 million years ago one such meteorite arrived on earth hitting the surface at previously mentioned speeds. What made this particular meteorite special is that is was about 10km in diameter. So a 10km wide rock struck the earth at 10km per second 2023 years ago at Vredefort and due to the magnitude of the impact the whole thing exploded so there is nothing left of that meteorite today. The question then is, how do we know the story is true? And this is how: There is a 90km wide bowl (or upside down dome) in the earth at the site of impact, and a larger 300km wide crater around that. You obviously need to look at this from the air to actually see it and that is why we went flying over it in a light aircraft. Scientists could use the size of this dome and crater and their knowledge of the speed that meteorites travel at to calculate the size of said meteorite. The impact is believed to have been bigger than the biggest atom bomb ever set off on earth. The good news is that distressing yourself over the consequences of such a meteorite arriving again is not necessary, as there would be no consequence for you at all. We’d all die instantly.

It's Sunflower season in that part of the Free State. Photo also indented to relax you after the ending of last paragraph.

As this is the biggest crater and dome caused by a meteorite anywhere on earth ever, it teaches scientists many valuable lessons about the history and development of earth and civilization. As I’m not a scientist I have no idea what those lessons are.  But nonetheless, due to this scientific value, the Vredefort dome was declared a Unesco World Heritage Site in 2005.

Despite bad signal, Helderberg FM tracked me down for an update interview on the tour. Chris captured it on camera.

The only remaining mystery is the following: If shooting stars allows us to make wishes and the biggest shooting star in living and un-living memory occurred in the Free State, then why does their rugby team consistently fail to win trophies?

Due to the impact of the meteorite, gold deposits are close to the earth surface and there are old gold mines at Vredefort. The camera crew was exited about lighting up the whole place and shooting there for a while. As I could not walk upright I was less exited about it. Here's two of TV crew members, Faan and Timmy about to film me "walking out of a gold mine".

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