Data from Perseverance suggests the delta in Jezero Crater was formed by a wide variety of different “fluvial” events
Jezero Crater delta
Using data from the Perseverance rover in Jezero crater, scientists now conclude that the delta that poured through a gap in the crater’s rim was formed by a wide variety of different “fluvial” events, not a steady flow as previously assumed.
From the paper’s conclusions:
The origin of this variability as well as that of the high discharge represented by the boulder conglomerate is still unknown. Realistic hypotheses include seasonal variations due to melting of snow, glacial input with possible episodic surges punctuating more regular fluvial input, or arid climate type of flows with intense storms and related flash floods.
We do not speculate further about the nature of fluvial activity in this study. However, the variability and the presence of high discharge rates have important implications on the lake evolution. Firstly, previous modeling of Jezero delta formation used steady-state discharge rates to estimate the time required to form the delta, an assumption that we can no longer justify according to our observations. Secondly, estimates of discharge rates … may be used as upper limits for some of the peak discharge rates, although the number of flood events is still difficult to determine from the sparse outcrops and the ubiquitous presence of scree.
In other words, the delta was not formed by a single event or a long stream of liquid flowing into the crater to form the lake that scientists believe once filled the crater. Instead, that flow varied, involved numerous distinct and different events over time, and likely included glacial ice transport as well.
Not that this is a surprise, but as always, the closer we get to a planet and the more detailed our data about it, the more complicated we find its nature and origins.
Readers!
Please consider supporting my work here at Behind the Black. Your support allows me the freedom and ability to analyze objectively the ongoing renaissance in space, as well as the cultural changes -- for good or ill -- that are happening across America. Fourteen years ago I wrote that SLS and Orion were a bad ideas, a waste of money, would be years behind schedule, and better replaced by commercial private enterprise. Only now does it appear that Washington might finally recognize this reality.
In 2020 when the world panicked over COVID I wrote that the panic was unnecessary, that the virus was apparently simply a variation of the flu, that masks were not simply pointless but if worn incorrectly were a health threat, that the lockdowns were a disaster and did nothing to stop the spread of COVID. Only in the past year have some of our so-called experts in the health field have begun to recognize these facts.
Your help allows me to do this kind of intelligent analysis. I take no advertising or sponsors, so my reporting isn't influenced by donations by established space or drug companies. Instead, I rely entirely on donations and subscriptions from my readers, which gives me the freedom to write what I think, unencumbered by outside influences.
You can support me either by giving a one-time contribution or a regular subscription. There are four ways of doing so:
1. Zelle: This is the only internet method that charges no fees. All you have to do is use the Zelle link at your internet bank and give my name and email address (zimmerman at nasw dot org). What you donate is what I get.
2. Patreon: Go to my website there and pick one of five monthly subscription amounts, or by making a one-time donation.
3. A Paypal Donation or subscription:
4. Donate by check, payable to Robert Zimmerman and mailed to
Behind The Black
c/o Robert Zimmerman
P.O.Box 1262
Cortaro, AZ 85652
You can also support me by buying one of my books, as noted in the boxes interspersed throughout the webpage or shown in the menu above.
Jezero Crater delta
Using data from the Perseverance rover in Jezero crater, scientists now conclude that the delta that poured through a gap in the crater’s rim was formed by a wide variety of different “fluvial” events, not a steady flow as previously assumed.
From the paper’s conclusions:
The origin of this variability as well as that of the high discharge represented by the boulder conglomerate is still unknown. Realistic hypotheses include seasonal variations due to melting of snow, glacial input with possible episodic surges punctuating more regular fluvial input, or arid climate type of flows with intense storms and related flash floods.
We do not speculate further about the nature of fluvial activity in this study. However, the variability and the presence of high discharge rates have important implications on the lake evolution. Firstly, previous modeling of Jezero delta formation used steady-state discharge rates to estimate the time required to form the delta, an assumption that we can no longer justify according to our observations. Secondly, estimates of discharge rates … may be used as upper limits for some of the peak discharge rates, although the number of flood events is still difficult to determine from the sparse outcrops and the ubiquitous presence of scree.
In other words, the delta was not formed by a single event or a long stream of liquid flowing into the crater to form the lake that scientists believe once filled the crater. Instead, that flow varied, involved numerous distinct and different events over time, and likely included glacial ice transport as well.
Not that this is a surprise, but as always, the closer we get to a planet and the more detailed our data about it, the more complicated we find its nature and origins.
Readers!
Please consider supporting my work here at Behind the Black. Your support allows me the freedom and ability to analyze objectively the ongoing renaissance in space, as well as the cultural changes -- for good or ill -- that are happening across America. Fourteen years ago I wrote that SLS and Orion were a bad ideas, a waste of money, would be years behind schedule, and better replaced by commercial private enterprise. Only now does it appear that Washington might finally recognize this reality.
In 2020 when the world panicked over COVID I wrote that the panic was unnecessary, that the virus was apparently simply a variation of the flu, that masks were not simply pointless but if worn incorrectly were a health threat, that the lockdowns were a disaster and did nothing to stop the spread of COVID. Only in the past year have some of our so-called experts in the health field have begun to recognize these facts.
Your help allows me to do this kind of intelligent analysis. I take no advertising or sponsors, so my reporting isn't influenced by donations by established space or drug companies. Instead, I rely entirely on donations and subscriptions from my readers, which gives me the freedom to write what I think, unencumbered by outside influences.
You can support me either by giving a one-time contribution or a regular subscription. There are four ways of doing so:
1. Zelle: This is the only internet method that charges no fees. All you have to do is use the Zelle link at your internet bank and give my name and email address (zimmerman at nasw dot org). What you donate is what I get.
2. Patreon: Go to my website there and pick one of five monthly subscription amounts, or by making a one-time donation.
3. A Paypal Donation or subscription:
4. Donate by check, payable to Robert Zimmerman and mailed to
Behind The Black
c/o Robert Zimmerman
P.O.Box 1262
Cortaro, AZ 85652
You can also support me by buying one of my books, as noted in the boxes interspersed throughout the webpage or shown in the menu above.
Readers: the rules for commenting!
No registration is required. I welcome all opinions, even those that strongly criticize my commentary.
However, name-calling and obscenities will not be tolerated. First time offenders who are new to the site will be warned. Second time offenders or first time offenders who have been here awhile will be suspended for a week. After that, I will ban you. Period.
Note also that first time commenters as well as any comment with more than one link will be placed in moderation for my approval. Be patient, I will get to it.