I was born in Nigeria and grew up there; I married and came over to Britain in 1982. I knew it was going to be cold, but no-one had prepared me for the winter. Because it was all dead, no leaves, I thought, ‘scientists, they’ve killed the trees’. I couldn’t understand why everyone walking around didn’t seem to care that the trees were dying. Then spring came along and I realised that everything was coming alive, being reborn. I kept saying to my friend, ‘look at those beautiful flowers’, and jumping up and down as if I’d won the lottery. At last she said, ‘you should get a camera, and stop bothering us. So I said I’d see if there were adult education classes in photography. She thought I was mad, but something had connected deep down. I enrolled in a photographic training centre in Earls Court; it was expensive and full of rich foreign students. When I finished I hadn’t decided what to do, but I went on a visit to Nigeria and took some photos when I was there. When I came back, everyone said, ‘oh, they’re beautiful!’ So that’s how it started. I gave up the business management course I was doing, because I knew I was home with the photography. I began by taking photos for newspapers, then in 1991 I began to write as well. I’d always written things down, but I’d hidden what I called my scribbles because I had an uncle in Nigeria who was a very well-known and I hadn’t wanted to compete in his arena.

I find it difficult to label myself. I’ve done a lot of things. If I have to sum myself up in one word, I either say ‘astronomer’ or ‘writer’. Astronomy was something I wanted to do from a very early age, 7 or 8. I’ve always regarded it as not so much a job or a profession as a calling. I remember being quite small, outside at night in the dark, looking at the stars. One of books I still have in the bookcase is my treasured first book about stars, the Giant Golden Book of Astronomy, which my parents bought for me at that time, a real luxury in the post-war years. I still get most delight out of seeing a completely black night sky, so dark that you can see every possible star – most of us have never seen the sky with no other lights. Built up environments and the light pollution they make lessen our awareness; our ancestors’ experience of the sky was totally different.

I remember when I was quite young thinking that I didn’t have any opinions, and wondering where people got them from. I could see both sides of every case, and I wondered how people acquired convictions. Now I’m a hotbed of convictions. Injustice gets me fired up, whether it’s at a tiny level, like a parking ticket for an offence not committed, or a global scale. It makes me a good children’s writer, because children always say, ‘it’s not fair’; it really gets their goat if they’re accused of something they didn’t do. I like right to triumph. I like there to be a definite ending, not necessarily happy, but satisfying.