 |
| The Himalayas, as seen by Envisat: Tthe barrier between the peaks of the Tibetan Plateau (top) in Central Asia and the plains of Nepal, Bhutan and India in the Indian subcontinent. In this false-color image, lush or green vegetation appears bright red |
The largest civilian Earth-observing satellite has celebrated its tenth 'birthday' in space - having orbited our planet more than 50,000 times.
The eight-tonne Envisat had a planned lifetime of five years, but has doubled that - and the European Space Agency has celebrated the anniversary with a gallery of the unforgettable imagery captured by Envisat's eight sensors.
More than 2,000 scientific publications have been based on Envisat data.
 |
| Clouds south of the Canary Islands: A unique cloud formation was captured by Envisat in this false-colour image |
With ten sophisticated optical and radar sensors, the satellite continuously observes and monitors Earth’s land, atmosphere, oceans and ice caps.
Envisat’s largest instrument is the Advanced Synthetic Aperture Radar, which can be used day or night because it sees through clouds and darkness.
This is particularly useful over polar regions, which are prone to long periods of bad weather and extended darkness.
Other instruments include the Radar Altimeter, which measures surface topography to an accuracy of a few centimetres, revealing the changes in sea-surface height over time.
Envisat provides crucial Earth observation data not only to scientists, but also to many operational services such as sea ice mapping or oil spill monitoring..
In 2010, the satellite’s orbit was changed to allow Envisat to continue operating for at least another three years.
This is ensuring the continuity of crucial Earth-observation data until the next generation of satellites – the Sentinels – are fully operational in 2013.
 |
| The Ganges Delta, the world s largest river delta, captured in three separate radar images by Envisat: Radar images are black-and-white - this image is made superimposing three radar images on top of one another and highligting slight variations between the three in different colours |
 |
| A phytoplankton bloom in the South Atlantic Ocean east of the Falkland Islands |
|
 |
| The Tanezrouft Basin in the Algerian Sahara in a radar image showing the roughness of the planet surface: Rough areas are bright, sandy areas are darker |
 |
| The McClure Strait, one end of the route through the Northwest Passage |
 |
| The Indus River in India and southern Pakistan - a seasonal salt marsh shows up in red, as the image is created by scans from three 'passes' of Envisat, coloured to show differences in the terrain over time |
 |
| Sea ice around the North Magnetic Pole in the Canadian Arctic |
 |
| The islands of Hawaii captured in a composite radar image |
 |
| The Strait of Gibraltar, showing wave patterns on the surface of the sea, detected using high-powered radar instruments |
 |
The Galapagos Islands, captured in a radar view that highlights minute changes in sea surface level
|
 |
| California and Nevada as captured by Envisat: the Sierra Nevada mountains form a barrier between two very different types of terrain |
 |
| Kamchatka in Russia, as seen by Envisat's Medium Resolution Imaging Spectrometer (MERIS) instrument |
0 Comments