The European Space Agency's Envisat is the largest Earth Observation spacecraft ever built, and on March 1st, it celebrated its tenth anniversary in low Earth orbit.
In the past decade, the massive, 8-ton satellite has coursed its way around our planet over 50,000 times, capturing tens of thousands of pictures of everything from hurricanes to volcanic eruptions in the process. Here are a few of our favorites.
In recognition of Envisat's ten years in space, Wired's Betsy Mason took to the ESA image archives to pick out some of the satellite's most breathtaking images, and we suggest you do the same. We've included a few of Mason's picks here, along with a number of our own.
All images and captions via ESA
Von Karmen Vortices
This false-color Envisat image, acquired on June 6, 2010, highlights a unique cloud formation south of the Canary Island archipelago, some 95 km from the northwest coast of Africa (right) in the Atlantic Ocean. Seven larger islands and a few smaller ones make up the Canaries; the larger islands are (left to right): El Hierro, La Palma, La Gomera, Tenerife, Gran Canaria, Fuerteventura and Lanzarote. [Hi res available here]
This Envisat image captures Asia's diverse topography, altitude and climate with the snow-sprinkled Himalayan Mountains marking the barrier between the peaks of the Tibetan Plateau (top) in Central Asia and the plains of Nepal, Buthan and India in the Indian subcontinent. In this false-color image, lush or green vegetation appears bright red. This image was acquired by Envisat's Medium Resolution Imaging Spectrometer (MERIS) instrument on Feb. 20, 2009, working in Full Resolution mode to provide a spatial resolution of 300 m. [Hi res available here]
Volcanic eruptions in Japan
Acquired on 4 February 2011 at 01:25 GMT by the MERIS instrument carried on ESA's Envisat satellite, this image shows smoke pouring from Mount Shinmoedake, a volcano in the Kirishima mountain range on Japan's southern island of Kyushu. Shinmoedake started erupting on 27 January after being quiet for 52 years. [Hi res available here]
West Coast of Africa
The first MERIS observation captured the huge phytoplankton patch produced by the 'upwelling' mechanism along the west coast of Africa near Mauritania. The unprecedented resolution allows fine-scale structures to be detected. In such upwelling areas, northeast trade winds bring deep and nutrient-rich water to the surface, feeding phytoplankton. Changes in climate affect the intensity of the upwelling with important consequences for marine ecosystems, fisheries and local economies. [Hi res available here]
This Envisat image features the Galapagos Islands, an archipelago situated some 1,000 km to the west of Ecuador in the Pacific Ocean. Galapagos's largest island is Isabela (visible). The five volcanoes seen on the island are (from north to south): Wolf Volcano, Darwin Volcano, Alcedo Volcano, Sierra Negra Volcano and Cerro Azul Volcano. The bigger island to the right of Isabela is Santiago Island.
The image was obtained by combining three Advanced Synthetic Aperture Radar (ASAR) acquisitions (March 23, 2006, Aug. 14, 2008 and Jan. 1, 2009) taken over the same area. The colors in the image result from variations in the surface that occurred between acquisitions. Apart from mapping changes on the land surface, radar data can also be used to determine sea surface parameters like wind speed, wind direction and wave height. Different wave types and wind speeds are visible in the image as ripples on the water surface. [Hi res available here]
Fissure on the massive A53A iceberg
On 1 March 2008 Envisat's Advanced Synthetic Aperture Radar (ASAR) instrument spotted a huge fissure running south to north through the massive A53A iceberg [A53A measured close to 50 kilometers by 22 kilometers, about seven times the area of Manhattan Island] located just east of the South Georgia Island (visible at image bottom) in the southern Atlantic Ocean. ASAR is able to produce high-quality images of icebergs and ice sheets and is capable of differentiating between different types of ice because it is able to see through clouds and local darkness – conditions often found in polar areas. [Hi res available here]
This image, acquired by Envisat's Medium Resolution Imaging Spectrometer (MERIS) instrument on Nov. 12, 2009, captures the rugged and remote Kamchatka Peninsula on Russia's East Coast. The 1,250-km long peninsula lies between the Pacific Ocean to the east and the Sea of Okhotsk to the west. [Hi res available here]