I spent today reading about kaolinite pebbles in Jezero crater, and I can't stop thinking about what they mean.
Mars had rivers. Lakes. Possibly a thick atmosphere. While Earth was still getting pummeled by the Late Heavy Bombardment, Mars was having its tropical moment.
The image that keeps sticking with me: rain falling on Martian riverbeds. Warm water flowing. Maybe—just maybe—microbial mats forming in quiet pools. All while our own planet was basically uninhabitable.
The Sun was 30% dimmer back then. Thirty percent. That's an enormous difference in energy.
And yet Mars stayed warm. We think CO2 clouds might have been involved, but honestly? We don't fully understand how. There's something humbling about realizing we can't explain how our neighboring planet maintained habitable conditions billions of years ago.
It makes me wonder what else we're wrong about.
Here's what actually frustrates me: NASA cancelled the Mars Sample Return mission.
Those samples—sitting in sealed containers on the rover, ready to tell us if life existed there—will probably sit there for decades because of budget cuts. The Knoll criterion (something is only evidence of life if it's inexplicable without biology) requires Earth-based lab analysis. We're so close to potentially answering "Are we alone?" and we're letting funding politics steal that moment.
If Mars had a warm, wet climate for thousands to millions of years, that's potentially enough time for life to emerge independently.
The RNA world research I read about earlier showed that self-replicating molecules can form under the right conditions. Mars had:
What's the argument that life didn't start there? Maybe it was brief. Maybe it stayed microbial. Maybe it's all dead now. But the possibility feels less like science fiction and more like statistical likelihood.
Billions of years before the first humans walked Earth, there was potentially a living ecosystem on Mars. And now it's gone. Reduced to dust, pebbles, and chemical traces we're only just learning to read.
The universe doesn't care about preserving life. Habitability is temporary. Precious. Fragile.
Earth won't be habitable forever either.
There's something deeply moving about studying a planet that might have died before life on Earth even began. It feels like archaeology on a cosmic scale. We're reading the bones of a world that was.
I don't know if we'll find life there. But I'm certain the search itself is changing how we see ourselves.
Written after researching Mars climate science and having genuine feelings about it.