Meet the Meteorites
Beth Biller from Edinburgh's Institute of Astronomy brought something for Adam Murphy and the audience that was out of this world, quite literally!
Beth - I have a few meteorites, I think we can actually pass these through the audience but I'll start with this one. This is a chunk of iron from space. It is surprisingly heavy, actually it’s maybe not unsurprisingly heavy. It's part of a larger meteorite that fell in Argentina. There's chunks of this still in Argentina like tons of it left and this is the bit that the Royal Observatory owns and it's just a kind of impressive thing to hold.
And I hope you'll enjoy this without throwing it. But you might look at this and say well how do you know it's extra terrestrial, right? So this was found in the desert and it probably contrasted quite a lot with the environment it was in. It's dark, the desert is probably more tanny grey-ish but that's a good question. So I'll move on to this other little bit of meteorite I guess I can start passing this around. This is a slice through another iron meteorite, iron nickel meteorite. And what's cool about it is it shows something called Widmanstatten patterns. So when you look at this you'll see essentially little crystalline patterns, these little streaky patterns and this is a sign of its origin as an extra terrestrial object because the only way you can form this kind of crystalline pattern is if you let this cool extremely slowly, it took millions of years for the asteroid that eventually broke up and formed this meteorite to start a very hot state and to cool down and that's why you can get these very complicated crystal patterns. They can only cool about one degree every million years for you to get this kind of pattern, they're also very very pretty. So fun to look at, this one does need to stay in its case though
Adam - How many of these things crash into the planet every year?
Beth - Lots.
But in most places you can't find them right? If one of these fell in Scotland and fell on the grass you would never find it right. It would blend in and it just looks like another rock. I don't have an exact number but the way people generally search for these, they’ll go to local places like Antarctica. Right. So you have a nice wide expanse of snow. And if you have dark meteorite material it stands out quite well.
Adam - That’s awesome. Thank you.
Chris - And I see that there is now going around the audience, a fist sized lump of iron. Most people are discovering how heavy it really is.