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Let’s say this is the equivalent of the sun’s total energy output. 

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You can accumulate a hundred dollars a lot of different ways…

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But a hundred bucks…

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…is a hundred bucks!

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If energy from the sun were a hundred dollars,

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it would be important to know what kinds of currency was coming in—

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big groups of pennies …

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…whole dollar bills…

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…or combinations.

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The total amount of solar energy falling on Earth 

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generally doesn’t vary more than about 1 dime to $100 

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but the kinds of energy from the Sun can fluctuate.

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Remember that light we see with our eyes

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is actually a combination of many different colors, or wavelengths.

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That’s true also for the light we do NOT see. 

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The composition of that light matters to understanding Earth’s energy budget, 

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and that’s the reason NASA has a new instrument designed to study this question. 

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It’s called TSIS—

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—the Total and Spectral Solar Irradiance Sensor.

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It is important to know that the Sun supplies

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virtually all of the energy coming to Earth.

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But...inbetween the Earth and the Sun

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there is the atmosphere.

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In the atmosphere there are clouds, there are aerosols--

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that is particles--there are gasses

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that interefere with solar radiation reaching Earth.

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So, that's why we need to fly a satellite....

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to be above the atmosphere

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Mounted to the International Space Station, 

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TSIS will collect detailed assessments of solar energy.

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Those data will be vital for scientists

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to make more accurate forecasts about climate change

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and other interactions between our planet and our parent star.