It’s a common saying that elephants never forget. But the more we learn about elephants, the more it appears that their impressive memory is only one aspect of an incredible intelligence that makes them some of the most social, creative, and benevolent creatures on Earth.
The last episode deals with the future of conservation. It begins by looking at previous efforts. The 'Save The Whales' campaign, which started in the 1960s, is seen to have had a limited effect, as whaling continues and fish stocks also decline.
Venture into the danger zone of two volcanic craters posing widely divergent threats. Hawaii's Kilauea is a shield volcano that threatens communities with its slow-but-relentless lava flow, while the Sumatran Sinabung is a stratovolcano delivering carnage via a sudden and explosive surge of superheated gas and rock.
Between the blue sky above and the infinite blackness beyond lies a frontier that scientists have only just begun to investigate. In "At the Edge of Space," NOVA takes viewers on a spectacular exploration of the Earth-space boundary that's home to some of nature's most puzzling and alluring phenomena: the shimmering aurora, streaking meteors, and fleeting flashes that shoot upwards from thunderclouds, known as sprites.