TED-Ed: Earth's mysterious red glow, explained | Zoe Pierrat

Researchers discovered an unexpected red wavelength from Earth, linked to chlorophyll fluorescence in plants. This phenomenon, observed via satellite, allows real-time monitoring of photosynthesis and ecosystem health. Chlorophyll fluorescence provides a direct measure of photosynthetic activity, offering insights into plant health and environmental changes, such as droughts and phytoplankton blooms.

What was the unexpected wavelength observed from Earth associated with?

• Human-made structures

• Reflected sunlight

• Areas with dense human population

• Regions with abundant plant life

During photosynthesis, what happens to the electrons in chlorophyll molecules when they absorb light?

• They become grounded

• They are converted into water

• They become excited

• They are emitted as heat

How do plants manage excess light that they cannot use for photosynthesis?

• By transforming it into heat

• By storing it as glucose

• By converting it into oxygen

• By absorbing it into the roots

What is chlorophyll fluorescence?

• The conversion of light into chemical energy

• The emission of light by chlorophyll during photosynthesis

• The absorption of sunlight by chlorophyll

• The transformation of light into heat

Why is chlorophyll fluorescence considered a more reliable measure of plant health than greenness?

• It shows the color change in leaves

• It directly measures photosynthetic activity

• It measures the amount of water absorbed

• It indicates the amount of sunlight absorbed