Nasa's new global map shows seasonal changes on Earth over two decades

Nasa has captured 20 years of seasonal changes in a striking new global map of the home planet.

The data visualisation, released this week, shows Earth's fluctuations as seen from space.

The polar ice caps and snow cover are shown ebbing and flowing with the seasons. The varying ocean shades of blue, green, red and purple depict the abundance or lack of undersea life.

Nasa oceanographer Jeremy Werdell, who took part in the project, says it's like watching Earth breathe. He says the visualisation shows spring coming earlier and autumn lasting longer in the Northern Hemisphere. Also noticeable to him is the Arctic receding over time and, though less obvious, the Antarctic, too.

Researchers compiled the visualisation from satellite imagery.