The challenge for finding life OutThere is the chances of it looking like “Life As We Know It” is vanishingly small. That is because only a small portion of the life on Earth timeframe has been “Life as We Know It.” (And I am going to ignore the life at the bottom of the ocean which isn’t even part of the photosynthesis cycle in a parallel existence with “real” life for this discussion.)
Earth formed somewhere around 4.5 billion years ago, give or take 15 minutes. Single-celled life started in the 4.2 billion years ago. Photosynthesis, creating oxygen, somewhere around 3 billion years ago. (A lot of the search for life on other planets is looking for oxygen.) Multicellular life somewhere around 1.5 billion years ago. The first edge of “Life as We Know It” with plants and animals is around 600 million years ago. Mammals 220 million years go; something close to human 20 million years ago; humans as we know them between 300,000 and 800,000 years ago. (Wikipedia)
The expression “not in a million years” doesn’t even apply to all of Homo sapiens existence yet.
So how do we find life OutThere? How will we recognize the blueprint? Not just of intelligent life, but any life…a planet with the potential to function as a second Earth. We are talking about landing on and exploring a planet in the “life zone” orbit and not in the perfect 10% window where we would have a chance of recognizing “Life As We Know It.” We are much more likely to find a planet in the 1.5 to 4.5 billion year window where there might be single-celled life, or photosynthesis, or (if we are very lucky) the start of multicellular life.
Equally important from an exploring point of view is not only finding life, but taking a planet that doesn’t have a mature biosphere with plants and animals and develop it from life-not-as-we-know-it to life-as-we-know-it so it can be settled – the gold standard of “terraforming”.
Well, we might be one step closer. A group of scientists working together from
(See Rucker et.al)
dialed back the clock billions of years (yes, B as in billions) to get the modern nitrogenases precursors. Nitrogenases are organisms that take atmospheric nitrogen (N₂) and make it into something which plants and animals can use.
If you work with plants, you are familiar with their need for nitrogen. A lot of modern nitrogenases exchangers live in the root systems of plants, other just free-wheel through life without the symbiotic partnerships. (Gronstal) For nitrogen to be a building block for “Life as We Know It” it needs to be broken apart into singular nitrogens (modernly we (the plants and animals of Earth) like it attached in stuff like hydrogen; ammonia – NH3 is very tasty.)
“Because nitrogen fixation is critical for life as we know it, scientists believe that nitrogenase must have evolved early in life’s history, at a time when only single-celled microorganisms existed.” (Gronstal)
If we ever terraform, we will need these early nitrogen fixers to set up the building blocks for “Life as We Know It.” And until then, looking at rocks from other planets (like, say Mars and its leopard spots (see Geeking Science: A Leopard Never Changes Its Spots, but Life Might (1/15/2026)) to find signs of life.
I’m ready to find signs of life. How about you? Ready to Geek some Science?
Gronstal, Aaron. “Resurrecting Ancient Enzymes in NASA’s Search for Life Beyond Earth.” nasa.gov. 30 January 2026. https://science.nasa.gov/science-research/planetary-science/astrobiology/resurrecting-ancient-enzymes-in-nasas-search-for-life-beyond-earth/ – Previously viewed 2/6/2026.
Rucker, Holly R.; Kunmanee Bubphamanee, Derek F. Harris, Kurt Konhauser, Lance C. Seefeldt, Roger Buick & Betül Kaçar. “Resurrected nitrogenases recapitulate canonical N-isotope biosignatures over two billion years.” nature communications. 22 January 2026. https://www.nature.com/articles/s41467-025-67423-y – Previously viewed 2/6/2026.
Mahon, Elise. “Resurrected ancient enzyme offers new window into early Earth ad the search for life beyond it.” phys.org. 22 January 2026. https://phys.org/news/2026-01-resurrected-ancient-enzyme-window-early.html – Previously viewed 2/6/2026.
Wikipedia. “Timeline of Human Evolution.” https://en.wikipedia.org/wiki/Timeline_of_human_evolution – Previously viewed 2/9/2026.
Wikipedia. “Timeline of Life.” https://en.wikipedia.org/wiki/Timeline_of_life – Previously viewed 2/9/2026.