The BBC nature documentary has become a cultural institution, beloved, but overly familiar. To sated 1990s audiences there seemed to be little left for the cameras to capture. We had seen all kinds of animals doing all kinds of things, over the years, and though always interesting, these films were beginning to be less than amazing. Then David Attenborough, who has become almost synonymous with these programmes, came up with The Private Life Of Plants (World, 9pm) and the genre underwent a renaissance. Attenborough manages to make the struggles of a sapling to hold on to its place in the forest, as thrilling as his close-ups with gorillas, or the internal politics of an ant colony. Some have claimed this six part series is actually as great in its way as the legendary Life On Earth series. It is certainly Attenborough at the peak of his powers, and not to be missed. In the opening episode, Growing, he explains how plants make sure they get enough light and moisture to survive. The Other Side Of The Moon (World, 10pm) is not another documentary about space travel, it is about the men who have experienced space travel, which is much more interesting. In particular, it is about eight American astronauts who have walked on the moon, and how the experience changed them. Some, it should be said, don't think it changed them at all. Pete Conrad blinks into the screen and insists he had a good long think about it all in his car on the way home from hearing he had made it into the final group of astronauts. About 30 kilometres later he decided it was just a job. Jim Irwin and Edgar Mitchell saw God. Strictly speaking, only Irwin actually admits that, and spends his days hunting for Noah's ark in the mountains of Eastern Turkey. Mitchell dismisses conventional religions, but was so shaken by what he saw, so sure that the universe had to be the result of some great intelligence, that he went on to found a new science he calls Nonetics. Another, Stuart Roosa, simply determined that landing on the moon wasn't going to be his only achievement, and went on to found a successful beverage company. 'We are all out trying to relieve everyone's thirst.' It may seem prosaic compared with his former colleagues (Conrad sells arms to foreign powers, and is proud of it) but in many ways Roosa has been the most successful of them all. He is certainly the only one whose first marriage has survived, thanks in great part to his excellent wife Joan, who also appears all too briefly, to acknowledge it hasn't always been easy. Others have trailed broken marriages in their wake, and most have opted in the end for yes-women. Buzz Aldrin lectures his new wife on astronomy: 'How far is it to the moon?' he grills her. 'Er . . . I never can remember.' And another, Al Woldren, appears to have paired off with a blonde who looks as if she wasn't even alive when he flew to the moon.