ESA Envisat: Paraná River in Brazil As Seen From Space

The Paraná River cuts through this image of southern Brazil from the Envisat satellite.

Credit ESA/Envisat

In the area pictured, the river marks the borders of the Brazilian states of Mato Grosso do Sul to the north and west, Sao Paulo to the east and Paraná to the south.

The river along with its tributaries creates a massive watershed that spreads throughout much of the south central part of the continent. Agricultural structures are evident in the surrounding land. The area is known as a large producer of coffee.

Click here to play the ESA/Envisat video of Parana River

Near the centre of the image, smoke from a fire was captured blowing southwest from its source. Major fires are visible from space - satellites detect not only the smoke billowing from major conflagrations but also the burn scars left in their wake and even the fires themselves - appearing as hotspots when scanning Earth's surface in thermal-infrared wavelengths.

Envisat's Advanced Along-Track Scanning Radiometer was like a thermometer, measuring thermal-infrared radiation to take the temperature of Earth's land and sea surfaces.

Prior to the end of the Envisat mission in April, the radiometer data contributed to the ATSR World Fire Atlas.

Temperatures exceeding about 39oC were classed as burning fires by the instrument, which was capable of detecting fires as small as gas flares from industrial sites because of their high temperature. Fires are detected best during local night, when the surrounding land is cooler.

This image was acquired by the MERIS instrument on Envisat on 19 March.

The Image of the Week is featured on ESA Web-TV, broadcast online every Friday at 10:00 CEST.

Deep Depression over Britain

This MODIS weather satellite view of Britain, taken on 14 June 2012 at about 1.30pm, a shows a huge storm moving towards the south-west

Picture: MODIS

NASA EO-1 Images: Texas Fire Burn Scar

The Bastrop County Complex Fire in southern Texas started on September 4, 2011.

By September 13, 2011, the fire was 70 percent contained, but had scorched 34,068 acres (13,787 hectares). The Advanced Land Imager (ALI) on NASA’s Earth Observing-1 (EO-1) satellite captured these images of the affected region on September 12, 2011.

The false-colour image (top) shows a wide-area view of the fire. Vegetation is bright green, and sparsely vegetated or bare land is green-yellow.

The burn scar appears in shades of red and orange. The burn scar is far from uniform; burned areas are separated by unburned expanses.

The area outlined in white in the top image corresponds to the close-up view provided in the natural-color image (bottom). Land in and around the Circle D-KC Estates is charred to shades of brown and gray.

As of September 13, a re-entry plan had been established for residents of the region, the Incident Information System reported.

Residents were warned, however, that they might see vegetation still smoldering or burning.

Ongoing drought set the stage for severe fires in Texas in the slate summer of 2011. In early September, Tropical Storm Lee, which drenched other parts of the United States, brought strong winds to Texas, worsening the fires.

ESA ERS-2: Collision Avoidance manouvre

This multi-colour ERS-2 image shows the Strait of Messina, the narrow section of water separating the Italian Peninsula (seen on the right) from Sicily. 

It is a composite of three ERS-2 radar images acquired on different dates with different colours assigned to each date: red for 13 February 2002; green for 11 August 2004; blue for 5 May 1999.

Credits: ESA

ERS-2 was launched in 1995, four years after ERS-1, the first European Remote Sensing satellite.

With 20 years of continuous measurements, the two missions paved the way for the development of many new Earth observation techniques in the areas of atmosphere, land, ocean and ice monitoring.

ERS-2 also carried the first European high-precision instrument to measure stratospheric ozone concentrations. It was crucial for observing the evolution of annual ozone depletion over Antarctica.

ERS-2 travelled 3.8 billion km during its lifetime, providing data for thousands of scientists and projects.

NASA Image: Typhoon Muifa

NASA satellite image shows Typhoon Muifa to the east of Taiwan

Picture: REUTERS / NASA

NASA - A Snapshot of Sea Ice

The Arctic Ocean is covered by a dynamic layer of sea ice that grows each winter and shrinks each summer, reaching its yearly minimum size each fall.

While the 2010 minimum remains to be seen, NASA's Aqua satellite captured this snapshot on Sept. 3.

How does the Aqua satellite "see" sea ice? Microwaves. Everything on Earth’s surface -- including people -- emits microwave radiation, the properties of which vary with the emitter, thereby allowing the AMSR-E microwave sensor on Aqua to map the planet.

Ice emits more microwave radiation than water, making regions of the ocean with floating ice appear much brighter than the open ocean to the AMSR-E sensor. This difference allows the satellite to capture a sea ice record year-round, through cloud cover and the months of polar night. Continuous records are important because sea ice is dynamic. Besides melting and freezing, the ice moves with wind and currents which can cause it to split or pile up.

"The data from AMSR-E and other NASA satellites are critical for understanding the coupling between sea ice and the ocean and atmosphere," said Tom Wagner, Cryosphere program manager at NASA Headquarters in Washington. "It’s important for us to understand these connections to improve our predictive models of how the planet will change."

The Arctic sea ice is a major factor in the global climate system. The ice cools the planet by reflecting sunlight back into space. It also helps drive ocean circulation by converting the warm Pacific water that flows into the Arctic into the cold, saltier water that empties into the Atlantic. The sea ice also fundamentally shapes the Arctic; defining the organisms that make up its ecosystem and keeping heat from the ocean from melting the frozen tundra.

NASA Aqua Images: Greece from space

Greece: This picture taken by Nasa-Satellite 'Aqua' shows the devastating forest fires on the Peloponnese peninsula, on 26 August 2007

Picture: EPA / NASA

NASA ASTER Image: Argentine's Patagonia from space: NASA satellite pictures of the participating nations

Argentina: This image of a Patagonian glacier was aqcuired by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on May 2, 2000.

Patagonia is a mountainous region spanning the border between Chile and Argentina near the southern tip of South America.

Vegetation appears red in the image, which is a false-colour composite of near-infrared, red, and green light displayed as red, green, and blue, respectively

Picture: NASA / REX FEATURES