There was once a little grey planet that was very sad. The people living there hadn't looked after it, despite them having all the inventions and space ships you could ever need. They had contaminated the whole countryside so much with rubbish and pollution that there were no plants or animals left. One day, a little boy was walking on the planet, when he passed a cave and noticed a small red flower inside. The flower was very sick - almost dying - so the boy carefully dug up the flower, with roots, soil and everything. Then, he started looking for a place where he could look after it. He searched all over the planet, but everywhere was so contaminated that there was no place the flower could possibly live in. Then he looked up at the sky and noticed the moon. It seemed to the boy that maybe the plant could survive there. So the little boy put on his astronaut suit, and climbed into a space ship. He put the little red flower in the back, and off they went to the moon. Far away from all that pollution - and with the boy visiting it every day to tend it - the flower started to grow. The flower was so well cared for, that it had soon germinated, giving birth to others, and these other flowers spread onto other flowers. Before long, the whole moon was completely covered with flowers. That's why, whenever the little boy's flowers open up, for a few minutes the moon takes on a soft red sheen, like a warning light. Maybe it's telling us that if you don't look after your planet, a day will come when flowers will only be able to grow on the moon. 
If we don't actively care for the environment, it could seriously deteriorate. 