NASA | Seeing Photosynthesis from Space

Plants use light for energy, and excess light causes them to emit a fluorescent glow. This glow, invisible to the human eye, is detected by satellites. Chloroplasts in plant cells convert sunlight into energy, with a small fraction emitted as fluorescent light. Satellite data over five years has been used to visualize global plant fluorescence, helping scientists distinguish between healthy and stressed vegetation. This data is crucial for developing better vegetation models and predicting plant interactions with the environment in a changing climate.

What happens to plants when they receive an excess of light?

• They produce more seeds.

• They absorb more water.

• They emit a neon glow.

• They stop growing.

What percentage of absorbed light is emitted as fluorescent light by plants?

• 0.1%

• 1%

• 5%

• 10%

Why can't humans see the fluorescent light emitted by plants?

• It is blocked by chlorophyll.

• It is only visible at night.

• It is absorbed by the atmosphere.

• It is too dim for human eyes.

How do scientists detect the fluorescent light emitted by plants?

• Using ground-based telescopes.

• Through underwater cameras.

• With special sensors on satellites.

• By using infrared goggles.

What can changes in plant fluorescence intensity indicate?

• The age of the plant.

• The type of soil.

• The health status of the plant.

• The amount of water in the plant.