Ancient city discovered deep in Amazonian rainforest, World 'must tackle space threat', Humans 80,000 Years Older Than Previously Thought?, Scientists Begin to Decode Whale Speak, Supersonic plumes of water erupt from Saturn's moon raising hopes of micro life under surface, Arthritis 'killing' Australia's cane toads, Amateur astronomer captures dawn of the universe from back garden observatory, Men's magazine loses 130,000 inflatable breasts, Ocean currents can power the world, say scientists, Thousands of New Species Discovered on Tiny Island