Tip:
Highlight text to annotate it
X
Dean Pesnell: Solar irradiance is the energy hitting
the earth from the sun. We have different kinds of solar irradiance. We have
heat solar irradiance, which is the infrared radiation. We have the
visible light, which is what we can use to see and what makes plants grow.
We also have ultraviolet light, which is absorbed by our ozone layer,
and we also have x-ray and extreme ultraviolet, which is quite
harmful and thankfully absorbed much higher up in our atmosphere.
EVE is the Extreme Ultraviolet Variability Experiment. It
will measure the solar irradiance in the extreme ultraviolet, which is very
short wavelengths that are absorbed completely by the Earth's atmosphere
and never make it to the surface. They also are quite deadly, and can
hurt people and electronics that are out in space. They cause the atmosphere
to heat up and expand and bring down spacecraft. And also,
it causes radio communications to be interfered with. EVE
will measure the solar irradiance at these wavelengths very rapidly--
about every ten seconds--allowing us to use that for warning people
about the dangers of flares, for putting them into the models that
tell us what's happening to the atmosphere, and to also allow people that are doing
radio communications and navigation to know that there could be a problem
with their system because of what the sun just did.