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Alien planets might teem with purple — yes, purple — life

Alien planets might teem with purple — yes, purple — life

NASA Having already seen the diversity of rock, Earth-like worlds. In the universe but unlike our green planet, many of these worlds can thrive. purple Life – If life is there, it is.

It is easy to imagine organisms resembling the colors of trees, algae, grasses and beyond dominating our earthly reality. It absorbs some of the light waves from green life. the sun to fuel the energy-generating photosynthesis, and the green compound chlorophyll helps drive this profoundly successful process. New research from Astronomers And microbiologists, however, suggest that life elsewhere may have produced energy from a different type of light than the sun, and may have used compounds with purple pigments instead of green.

This is not far-fetched. After all, some microbes do Earth It's just that on Earth, in our now oxygen-rich atmosphere, green life (using “oxygenic photosynthesis”) predominates in most ecosystems.

“But that's not necessarily the case on other planets,” microbiologist Legia Fonseca Coelho of Cornell University's Carl Sagan Institute told Mashable.

gave research It was recently published in the peer-reviewed journal Science. Monthly Notices of the Royal Astronomical Society. A major goal was to demonstrate how Space observatories When observing distant planets beyond the Sun – and should – look for telltale signs of purple life, called exoplanets. Very powerful, upcoming telescopes, such as the Very Large Telescope in the High Mountains of Chile and the Habable World Observatory (which will orbit the location) will consider. Environments of such distant worlds and determine their composition and habitat.

“Stop looking at the green. Look at the purple too.”

The scientists extracted more than 20 purple bacteria from different ecosystems, such as lakes and marshes in Massachusetts and New York, measured their dynamic pigments and how they emit light. Then, they simulated “light signatures” — the unique color and chemical fingerprints that would be visible in the reflected light of an alien planet — and found that the purple bacteria would produce a clear, recognizable signature.

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“Stop looking at just the green. Look at the purple too,” Coelho emphasized. “We can miss the sign of life because of our prejudice.”

Lígia Fonseca Coelho holds a sample full of purple pigmented bacteria.
Credit: Ryan Young / Cornell University

NASA's concept of an Earth-like exoplanet.

NASA's concept of an Earth-like exoplanet.
Credit: NASA Scientific Visualization Studio

Purple life might not exist. It can also be normal.

Our most abundant stars. The Milky Way Galaxy There are small red stars called red dwarf stars. (The closest star to Earth is a red dwarf called Proxima Centauri.) They are only a fraction of the size of the Sun, and are excellent stars in temperature. Accordingly, most of the light a red dwarf emits is low-energy (in the infrared or red lightwaves), so any nearby organisms would need this infrared light (which our eyes can see) to power their cells. is hidden from) will need to be used. “If life exists on the planet, it will use this (infrared) energy,” Coelho explained. Importantly, on Earth, purple bacteria thrive in these low-energy environments.

On a planet where green microbes and organisms cannot live, or are not fit to live, purple ones Strange life Can fight them, and dominate.

“It may be that the earth was purple.”

It is also possible for such purple bacteria to thrive on a bar. EARLY EARTH. After all, our planet has only had oxygen for about half of its 4.5 billion year lifespan. There was a time when green, oxygen-releasing, photosynthesizing plants took over the world. Different bacteria, which survive on different chemical reactions, would have flourished.

“The earth might be purple,” Coelho said.

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