Meteorites

"This is a book I would recommend if you don’t have any geological background, if you’re like my mum. Very much like the book I’ve co-written, actually. Pitched at the same sort of level. It’s a fantastic book. It’s hardback and the illustrations are fantastic, the photography is fantastic and the way it is written makes it a pleasure to read. I’m very good friends with the lead author Alex Bevan, but I’d plug it even if I didn’t know him. I had to review it for The New Scientist when it came out in 2002 and I read it from cover to cover. What I like about it is that it will explain that meteorites are four and a half billion years old and we know this from doing radiometric dating, but instead of just saying that, there will be a whole page on radiometric dating and how it works and how you do it, which is why it’s a great book. Well, you know you have radioactive elements? You have your starting radioactive element and this is unstable so it will decay to form either another element or maybe the same element but with a different atomic mass. We call the starting element the parent isotope and the decayed one the daughter isotope. You can measure the rate of decay, and when half of your parent isotopes have decayed to the daughter isotopes we call this the half-life. So you know the half-life and you can look at the ratio of parent isotopes to daughter isotopes and you can do some maths and work out when the material formed. That’s the most basic way of describing a complicated technique that you can do in slightly different ways depending on what elements you are measuring and what you are trying to date. This book’s full of background information like that and a lot of interesting stories about early people recognising meteorite falls. In the Aboriginal communities in Australia there are stories about things falling from the sky and making a hole, and in fact there is research going on now which is tracking back meteorite craters which can be linked up to Aboriginal stories handed down for thousands of years. People would have seen this event and passed the stories down. It’s quite amazing. So it talks about the whole science of meteorites and why they’re interesting to study, why they’re important to study, what they tell us about our Solar System, but also you get the more personal aspects of it as well and the cultural importance."