NASA's ECOSTRESS Mission Sees Plants 'Waking Up' From Space

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Although plants don't sleep in the same way humans do, they have circadian rhythms — internal clocks that, like our own internal clocks, tell them when it's night and when it's day. And like many people, plants are less active at night. When the Sun comes up, they kick into gear, absorbing sunlight to convert carbon dioxide they draw from the air and water they draw from the soil into food, a process called photosynthesis. They also "sweat" excess water through pores on their leaves to cool themselves down, a process called evapotranspiration. 

NASA's ECOsystem Spaceborne Thermal Radiometer on Space Station (ECOSTRESS) can see when plants "wake up" and begin these processes from space. The image above shows plants waking up (as evidenced by evapotranspiration) west of Lake Superior near the U.S.-Canada border. Plants in the red and pink areas began to awake at around 7 a.m. local time. Those in green areas awoke closer to 8 a.m., and those in blue areas, closer to 9 a.m....Read More