First thing you need to know for this story is that Ray Bradbury wasn’t stupid.

The thing that’s most fascinated humanity about Mars, since we figured out what Mars was, is the idea that there might be life there. There’s a yearning, a deep longing that we not be alone in the universe, and a nextdoor neighbor might be nice.

So, when Ray Bradbury was writing his stories about humans meeting Martians and discovering ancient Martian civilizations in The Martian Chronicles and other works, it wasn’t because Ray Bradbury was some dumb guy that didn’t know that old speculation about Martian canals had been debunked and the current science showed Mars to be a cold dead world.

It was because he was a smart guy that understood that people needed and wanted the dream more than truth, the wonder of finding another intelligence just a cosmic cross-town bus away. Hey, even when they sometimes turn out to be hostile in science fiction, there’s still sort of a relief at knowing we’re not all alone.

I always keep that in mind when someone finds evidence of life on Mars. We really, really want it to be there on some deep unconscious level.

So take this news with the requisite caution, but a scientist has found that Martian soils from 3.7 billion years ago were much more Earthlike and more conducive to life.

Oregon geologist Gregory Retallack has studied images and data collected from the Martian surface by NASA’s Curiosity Rover, and his analysis of the impact Gale Crater shows soil similar to soil found on Earth, specifically the Antarctic Dry Valleys and Chile’s Atacama Desert.

Exploring the crater allowed a peek at soil much older than the current Martian topsoil, allowing Retallack, an expert on fossilized earth “paleosoils” to look back at what the soil might have been like nearly four billion years ago.

Curiosity rover image of Martian soil.
Curiosity rover image of Martian soil.

“The pictures were the first clue, but then all the data really nailed it,” Retallack said. “The key to this discovery has been the superb chemical and mineral analytical capability of the Curiosity Rover, which is an order of magnitude improvement over earlier generations of rovers. The new data show clear chemical weathering trends, and clay accumulation at the expense of the mineral olivine, as expected in soils on Earth. Phosphorus depletion within the profiles is especially tantalizing, because it attributed to microbial activity on Earth.”

In other words the ancient Martian soil looks a lot like ancient Earth soil, modified by microscopic organisms in the same way Earth soil was.

Retallack isn’t saying for sure that there is or was life on Mars, of course. Just that it might have been more likely before Mars transitioned from “an early benign water cycle on Mars to the acidic and arid Mars of today.”

“We can’t prove that Mars was alive, but this really does take us along the road to thinking that very likely it was,” Retallack said in the video embedded above.

Malcolm Walter of the Australian Centre for Astrobiology, was a little less cautious, saying the research shows “There is a real possibility that there is or was life on Mars.”

So there you go. If Retallack’s suggestions are heeded Curiosity and other missions will be steered toward the older soils to give us a better look at ancient conditions, and maybe to finally see if this old dream is true.

[Source: University of Oregon]

Images: Michael Whelan’s The Martian Chronicles Cover artwork and NASA Curiosity Rover image of Martian Soil

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