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It’s autumn

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and things are changing.

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Cool air,

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hot cider,

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and leaves!

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As humans

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we can see this striking change

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in our neighborhoods

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or even on a trip.

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Fall foliage tourism brings

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in tens of billions of dollars

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in the U.S. alone.

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But there’s more to it

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than just a

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pretty scene.

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The fall colors

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signal changes with our food,

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our air, our ecosystems.

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Photosynthesis ends,

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carbon and water balance change,

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and leaf color changes

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how much sunlight is absorbed.

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Now with the PACE satellite,

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we’re seeing

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seasonal fall foliage

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in a whole new view.

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PACE can see more information

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in leaf color changes

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than our eyes can detect,

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especially in leaf pigments.

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These pigments

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protect plants

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and allow them to thrive

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in changing conditions

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and seasons.

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Before PACE, we’d

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have to infer the timing

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of seasonal changes

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by how much “green-ness”

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has decreased.

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By looking at how PACE’s

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pigment indices change

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relative to one another,

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it can give us a view

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into the health of ecosystems.

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For instance,

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a shift in the start of fall colors

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could mean drier or colder years.

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And data on leaf pigments

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could help answer

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other science questions.

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Like why do trees even turn red?

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Is it sun protection

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in colder temperatures?

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Or warning against

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insect damage?

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Or something else entirely?

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As PACE repeatedly covers

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both the land and ocean,

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we’ll gather more data

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to help us decode

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these colors.