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Data from Perseverance confirms Jezero Crater once held a lake

figure 5 from paper showing ancient lake in Jezero Crater

According to a newly published paper, the data obtained by the rover Perseverance has confirmed and refined what orbital data has suggested, that Jezero Crater once held a lake. From the abstract:

We analyze images taken by the rover in the three months after landing. The fan has outcrop faces that were invisible from orbit, which record the hydrological evolution of Jezero crater. We interpret the presence of inclined strata in these outcrops as evidence of deltas that advanced into a lake. In contrast, the uppermost fan strata are composed of boulder conglomerates, which imply deposition by episodic high-energy floods. This sedimentary succession indicates a transition, from a sustained hydrologic activity in a persistent lake environment, to highly energetic short-duration fluvial flows.

In other words, the crater first held a lake, which as it slowly dried out was periodically renewed by flash floods. The distinct delta of material that made Jezero Crater the prime landing site was apparently formed during the period when the lake existed. The conditions that caused the subsequent flash floods is as yet not been determined, though it likely is related to the red planet’s long term evolution.

The image above, figure 5 from the paper, shows the inferred lake in that early history. The red cross marks Perseverance’s landing site.

This data reinforces the fundamental scientific mystery of Mars. It shows evidence that liquid water once flowed on the surface of Mars, even though other long term data of the planet’s history says the Martian atmosphere has been too thin and too cold to allow that to happen. There is evidence that the atmosphere might have once been thicker, but no computer model or theory has been able to produce a time when it was warm enough.

Conscious Choice cover

Now available in hardback and paperback as well as ebook!


From the press release: In this ground-breaking new history of early America, historian Robert Zimmerman not only exposes the lie behind The New York Times 1619 Project that falsely claims slavery is central to the history of the United States, he also provides profound lessons about the nature of human societies, lessons important for Americans today as well as for all future settlers on Mars and elsewhere in space.

Conscious Choice: The origins of slavery in America and why it matters today and for our future in outer space, is a riveting page-turning story that documents how slavery slowly became pervasive in the southern British colonies of North America, colonies founded by a people and culture that not only did not allow slavery but in every way were hostile to the practice.  
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“Zimmerman’s ground-breaking history provides every future generation the basic framework for establishing new societies on other worlds. We would be wise to heed what he says.” —Robert Zubrin, founder of founder of the Mars Society.


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  • John

    Not an astro geologist but put me down in the volcanism or impact camp of “rapid snowmelt episodes [from either a climatic origin (1, 3) or heating by volcanism or impact”. Be interesting if there’s any evidence of ancient volcano or other hydrothermal type of heating around Jezero.

  • pawn

    I wonder how big a collision would have to be to remove an atmosphere? Or stall the source of a magnetosphere., etc. .Ever since I was young, I thought it was odd that the biggest valley and the tallest volcano were on opposite sides of the planet.. It seems to me that something catastrophic could be responsible for things “not making sense”.

  • Max

    I agree, the impact that caused the Helena basin would be severe enough to “create” an atmosphere for hundreds of years.
    There is strong evidence it was the causation of the volcanoes as well. Also adding to the atmosphere.

    An older event has been speculated that the entire smooth “lower altitude” northern hemisphere of Mars is an “impact site” that deposited the debris on the higher rougher southern hemisphere. The only possible scenario that I can make work in my head, is if mars passed through the atmosphere of a gas giant, like passing through water, scrubbing the northern hemisphere and removing the atmosphere.

    The dust and debris from the Helenas impact would have covered any ice that existed at the time, in the same way ancient forest were covered during an event on earth, which are our coalbeds today. Places deeply covered could have melted and became ice volcanoes similar to the one just to the right and north of the Helena’s basin which shows a profound amount of erosion from one central point. (it looks different than the lava volcanoes)

    Although the pictures of physical evidence supports this. Even so, it’s still unclear. They do not have enough information for their models… As if those were ever right. I love a good mystery.
    (This feels like a game of Pictionary)

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