LifeWhy ancient deer returned to the sea and became whales Over the last 250 million years land animals have repeatedly begun exploiting the seas, giving rise to creatures like whales and walruses. The question is why News
EarthThese strange lines of cloud are seeded by pollution from ships Much as an aeroplane leaves contrails, streaks of white cloud condense onto the tiny particles thrown into the air by the exhausts of travelling ships Regulars