The Key to Finding Life Elsewhere in the Universe: Purple Planets?!?

The video explores the color of exoplanet HD 189733B and Earth's historical color changes. It discusses chlorophyll's role in photosynthesis and its inefficiency in absorbing green light. The video introduces the hypothesis that Earth might have been dominated by purple, retinal-using organisms before chlorophyll became prevalent. This idea is significant for astronomers searching for extraterrestrial life, as a purple planet could exist. The video also highlights the potential of future telescopes like HabEx to detect such planets.

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