Thursday 25 December 2014

Watch how one NASA satellite has changed how we see Earth in the 21st century

The western hemisphere of the Blue Marble, created in 2002.

In December 1999, NASA launched Terra, the flagship satellite of the Earth Observing System, outfitted with a whole rig of sophisticated instruments for collecting data on our planet.


Terra was meant to last six years when launched. A decade and a half later, its still alive and kicking, along with the 17 other NASA Earth-observing satellites, a small but important subset of the over 1,200 satellites that orbit the planet.


In 15 years, the Earth Observing System has collected some amazing data, enabling some fascinating images and visualizations of the Earth—and how humans impact it.


Here are the most striking and informative visuals released by NASA.


Arctic heating


Since 2000, solar radiation absorption in the Arctic has increased 5%. In this image, red represents absorption increase, while blue represents solar ice decrease.



Arctic ice shrinkage


Ice caps in the Arctic fluctuate seasonally, growing in winter and shrinking in summer. Summer ice has also decreased overall over the past several yeas. This image shows the changing Arctic ice caps from September 2009 to January 2011.



US Air quality


Measuring by levels of one pollutant, nitrogen dioxide, air quality in the US has improved due to emissions restrictions and technologies that decrease pollution. This image shows the decrease of nitrogen dioxide—especially in urban areas. One wonders what China’s nitrogen dioxide map might look like.



Global vegetation coverage


In winter, not much grows in the higher latitudes of the planet. In temperate seasons, though, vegetation covers much of Earth, save several large, conspicuous desert regions. Scientists can determine vegetation coverage by measuring carbon-dioxide absorption from the atmosphere. In this image, which shows the vegetation cycle over the course of a year, green indicates more carbon absorption from the atmosphere.



Greenhouse gas coverage


In addition to measuring absorption of carbon dioxide—a chief ingredient of what we mean when we talk about greenhouse gasses—the Earth Observing System also measures carbon dioxide distribution. This image shows that distribution changing over the course of the year. In the winter and spring, it accumulates in the north, and then in the summer and fall its is absorbed by plants as part of photosynthesis.



The complete images released for the 15th birthday of the Earth Observing System are available on NASA’s website.




Watch how one NASA satellite has changed how we see Earth in the 21st century

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