JOE T. COXWELL --- Science Fiction Author & Astronomical Artist
Original Science Fiction and Space/Astronomical Art
Member Mississippi Writers Guild
Space News and Features
  • Home
    • Joe T. Coxwell -- A Brief Biography
    • Coxwell's Blog
    • Author Sci-Fi Recommendations
    • Author Interview with Sleepytown Press
  • FREE Story Teasers
    • Epsilon Wish Teaser
    • Third Contact Teaser
  • Purchase Book
    • Order On-line from Amazon.com and Others
    • Order a Kindle Download from Amazon.com
    • Order from the Author by Mail
  • Space News
    • Extraterrestrial Life Search >
      • ​Extraterrestrial Life Could Be Purple
      • ​Alien Life Could Thrive on 'Supercritical' CO2 Instead of Water
      • Alien Megastructure -- "Tabby's Star" -- KIC 8462852 >
        • ​Kepler's 'Alien Megastructure' Star Just Got Weirder
        • ​'Alien Megastructure' Star Keeps Getting Stranger
        • 'Alien Megastructure' Star Is at It Again with the Strange Dimming
      • Humans Will Hear from Intelligent Aliens This Century, Physicist Says
      • ​Could Methane on Saturn's Moon Enceladus Be a Sign of Life?
      • Superflare Blasts Proxima b, the Nearest Exoplanet, ​Dimming Hopes of Life
    • Exoplanets >
      • The Largest Alien Planet of TRAPPIST-1 Has an Atmosphere That Evolved Over Eons
      • First Exomoon Found? Neptune-Sized World Possibly Spotted Orbiting Alien Planet
      • ​Ringed, Rocky Alien Planets May Hide in Plain Sight
      • Kepler Space Telescope Discovers ​95 More Alien Planets
      • ​The Alien Planets of TRAPPIST-1 May Be Too Wet for Life
      • ​Exoplanets: Worlds Beyond Our Solar System
      • Current Potentially Habitable Exoplanets
      • That's No Moon? Proposed Exomoon Defies Formation Theories
      • KOI-500: A Crowded Little Solar System
      • Super-Earth HD 40307g in its Habitable Zone
      • New Earth-mass Planet Found in Nearby Alpha Centauri System
      • Super-Earth 55 Cancri e: Not So Earthlike
      • Newfound Alien Planet a Top Contender to Host Life
      • Planets in Multiple Star Systems -- Is Tatooine for Real?
      • Miniature Solar System Discovered
      • A Periodic Table of Exoplanets
      • Known Types of Alien Planets
      • How Planets in Alien Solar Systems Stack Up
      • Earth-sized Planets Discovered
      • Alien Planet HD 85512 b Holds Possibility of Life
    • Mars Exploration >
      • ​'Mars Ain't Gonna Be Easy': What Apollo 17 Leaders Are Saying About Future Space Exploration
      • The Curiosity Rover Just Drilled into a Rock on Mars for 1st Time Since 2016
      • Curiosity Mars Rover -- Image Gallery
      • Humans on Mars By 2039 -- The Long Delay is Mostly Lack of Political Will
      • Invasion of Mars: Landings and Crashes
    • US Space Program >
      • Pluto's Biggest Moon Could Give an Orbiter an (Almost) Free Ride
      • New Horizons Pluto Photo Gallery >
        • Pluto May Have a Gooey Carbon Layer Beneath Its Crust
      • Space Launch System: NASA's Giant Rocket Explained
      • NASA's New Multi-Purpose Crew Vehicle
    • Private Spaceflight Developments >
      • SpaceX's Dragon Capsule & Falcon-9 Booster
      • SpaceX Nails the Barge Landing!
      • Boeing's CST-100 Spacecraft
      • Sierra Nevada's Dream Chaser Spaceplane
      • Blue Origins >
        • Blue Origin's New Glenn Booster
    • The Solar System >
      • The Sun
      • Mercury
      • Venus >
        • NASA Wants to Send Humans to Venus, to Live in Airships Floating on Clouds
      • Earth's Moon
      • Mars
      • Asteroids / Vesta / Ceres >
        • Asteroid Sampling MIssion
      • Jupiter
      • Saturn / Titan
      • Uranus
      • Neptune
      • Pluto / Eris / Kuiper Belt Objects
  • Space Art & More
    • New or Recent Artwork
    • Space Art Gallery
    • Space Art Slideshow
  • Links & Contact Info
    • Author Contact
    • Links

​Extraterrestrial Life Could Be Purple

Picture
By Stephanie Pappas, LiveScience Contributor | October 22, 2018 12:51pm ET

      Alien life might be purple.
 
      That's the conclusion of a new research paper that suggests that the first life on Earth might have had a lavender hue. In the International Journal of Astrobiology, microbiologist Shiladitya DasSarma of the University of Maryland School of Medicine and postdoctoral researcher Edward Schwieterman at the University of California, Riverside, argue that before green plants started harnessing the power of the sun for energy, tiny purple organisms figured out a way to do the same.

      Alien life could be thriving in the same way, DasSarma said.  "Astronomers have discovered thousands of new extrasolar planets recently and are developing the capacity to see surface biosignatures" in the light reflected from these planets, he told Live Science. There are already ways to detect green life from space, he said, but scientists might need to start looking for purple, too. [7 Wild Theories on the Origin of Life]


Purple Earth

      The idea that the early Earth was purple is not new, DasSarma and his colleagues advanced the theory in 2007. The thinking goes like this: Plants and photosynthesizing algae use chlorophyll to absorb energy from the sun, but they don't absorb green light. That's odd, because green light is energy-rich. Perhaps, DasSarma and his colleagues reasoned, something else was already using that part of the spectrum when chlorophyll photosynthesizers evolved.

      That "something else" would be simple organisms that captured solar energy with a molecule called retinal. Retinal pigments absorb green light best. They're not as efficient as chlorophylls in capturing solar energy, but they are simpler, the researchers wrote in their new paper published Oct. 11.
Retinal light-harvesting is still widespread today among bacteria and the single-celled organisms called Archaea. These purple organisms have been discovered everywhere from the oceans to the Antarctic Dry Valley to the surfaces of leaves, Schwieterman told Live Science. Retinal pigments are also found in the visual system of more complex animals. The appearance of the pigments across many living organisms hints that they may have evolved very early on, in ancestors common to many branches of the tree of life, the researchers wrote. There is even some evidence that modern purple-pigmented salt-loving organisms calledhalophiles might be related to some of the earliest life on Earth, which thrived around methane vents in the ocean, Schwieterman said.


Purple aliens

      Regardless of whether the first life on Earth was purple, it's clear that lavender life suits some organisms just fine, Schwieterman and DasSarma argue in their new paper. That means that alien life could be using the same strategy. And if alien life is using retinal pigments to capture energy, astrobiologists will find them only by looking for particular light signatures, they wrote.  Chlorophyll, Schwieterman said, absorbs mostly red and blue light. But the spectrum reflected from a plant-covered planet displays what astrobiologists call a "vegetation red edge." This "red edge" is a sudden change in the reflection of light at the near-infrared part of the spectrum, where plants suddenly stop absorbing red wavelengths and start reflecting them away.

      Retinal-based photosynthesizers, on the other hand, have a "green edge," Schwieterman said. They absorb light up to the green portion of the spectrum, and then start reflecting longer wavelengths away.
Astrobiologists have long been intrigued by the possibility of detecting extraterrestrial life by detecting the "red edge,"Schwieterman said, but they may need to consider searching for the "green edge," too.
"If these organisms were present in sufficient densities on an exoplanet, those reflection properties would be imprinted on that planet's reflected light spectrum," he said. 
​ 

Originally published on Live Science.

Powered by Create your own unique website with customizable templates.