1. Forum
  2. USENET
  3. talk.origins

  • Earth had life for roughly 3 bn years before it produced enough oxygen to be detectable from space

    From Pro Plyd@invalide@invalid.invalid to talk-origins on Sun Jul 26 23:35:43 2026
    From Newsgroup: talk.origins


    https://spacedaily.com/t-early-earth-oxygen-hwo-biosignature-false-negative/ Published July 26, 2026

    Earth had life for roughly three billion years before
    it produced enough oxygen to be detectable from space,
    which means NASA's new planet-hunting telescope could
    be staring directly at an inhabited world and see
    nothing

    The search for alien life relies on a cosmic red
    herring: Earth itself remained invisible to the very
    biosignatures astronomers now use to hunt for
    habitable worlds.

    For most of EarthrCOs inhabited history, an astronomer
    on another world could have studied our atmosphere
    and missed the most important fact about it.

    Life was present by at least 3.5 billion years ago,
    yet oxygen and ozone became reliable remotely
    detectable signs only during roughly the past 500
    million years. That leaves an approximate
    three-billion-year interval in which Earth was
    inhabited but could have failed a search built
    mainly around oxygen.

    An oxygen search would have missed it.
    ...
    The Great Oxidation Event began around 2.4 billion
    years ago, but oxygen remained far below present
    levels through much of the Proterozoic. A distant
    telescope could therefore have encountered a living
    Earth without finding the oxygen-rich atmosphere
    familiar today.
    ...

    --- Synchronet 3.22a-Linux NewsLink 1.2
  • From RonO@rokimoto557@gmail.com to talk-origins on Mon Jul 27 09:14:09 2026
    From Newsgroup: talk.origins

    On 7/27/2026 12:35 AM, Pro Plyd wrote:

    https://spacedaily.com/t-early-earth-oxygen-hwo-biosignature-false- negative/
    Published July 26, 2026

    Earth had life for roughly three billion years before
    it produced enough oxygen to be detectable from space,
    which means NASA's new planet-hunting telescope could
    be staring directly at an inhabited world and see
    nothing

    The search for alien life relies on a cosmic red
    herring: Earth itself remained invisible to the very
    biosignatures astronomers now use to hunt for
    habitable worlds.

    For most of EarthrCOs inhabited history, an astronomer
    on another world could have studied our atmosphere
    and missed the most important fact about it.

    Life was present by at least 3.5 billion years ago,
    yet oxygen and ozone became reliable remotely
    detectable signs only during roughly the past 500
    million years. That leaves an approximate
    three-billion-year interval in which Earth was
    inhabited but could have failed a search built
    mainly around oxygen.

    An oxygen search would have missed it.
    ...
    The Great Oxidation Event began around 2.4 billion
    years ago, but oxygen remained far below present
    levels through much of the Proterozoic. A distant
    telescope could therefore have encountered a living
    Earth without finding the oxygen-rich atmosphere
    familiar today.
    ...


    One the positive side any atmosphere that we detect as being rich in
    molecular oxygen would be a very good sign that water splitting
    photosynthesis had evolved on that planet. It is believed that
    anaerobic photosynthesis evolved first. This type of photosynthesis
    still exists, but relies on hydrogen, sulfur containing molecules and
    iron for electrons.

    The issue with evolving oxygen generating photosynthesis is that oxygen
    is toxic to anaerobic lifeforms, and life had to evolve ways to deal
    with the oxygen pollution. The photosynthetic organism producing the
    oxygen had to evolve the means to deal with the poison.

    Ron Okimoto

    --- Synchronet 3.22a-Linux NewsLink 1.2