Antarctica data adds weight to hypothesis that glaciers shaped Mars
New data from an Antarctica ice core strengthens the hypothesis that the flow of glaciers, not liquid water, helped shape the meandering canyons on Mars.
The data was the discovery of the mineral jarosite deep within the south pole ice-cap. Jarosite needs water to form. Previously it was generally believed it formed in conjunction with liquid flowing water. On Mars, which appears to have lots of jarosite, scientists have struggled for decades to figure out how enough liquid water could have existed on the surface of Mars to produce it.
The discovery of jarosite deep inside the Antarctic ice cap now suggests that it can form buried in ice, not liquid water. According to the scientists,
the jarosite was born within massive ice deposits that might have blanketed [Mars] billions of years ago. As ice sheets grew over time, dust would have accumulated within the ice—and may have been transformed into jarosite within slushy pockets between ice crystals.
From the paper’s conclusions:
The occurrence of jarosite in TALDICE [in Antarctica] supports the ice-weathering model for the formation of Martian jarosite within large ice-dust deposits. The environment inside the Talos Dome ice [in Antarctica] is isolated from the Earth atmosphere and its conditions, including pressure, temperature, pH and chemistry, provides a suitable analogue for similar Martian settings. Dust deposited at Talos Dome is also similar to Martian atmospheric dust, being both mostly basaltic. Within thick ice deposits it is likely that the environment would be similar at Talos Dome and under Mars-like conditions since both settings would contain at cryogenic temperatures basaltic dust and volcanogenic and biogenic (for Antarctic only) sulfur-rich aerosols. … Considering this context, it is reasonable that the formation of jarosite on Mars involves the interaction between brines and mineral dust in deep ice, as observed in TALDICE. This mechanism for Martian jarosite precipitation is paradigm changing and strongly challenges assumptions that the mineral formed in playa settings.
Playa settings are places where there is standing liquid water, slowing drying away.
This result is another piece of evidence that ice and glaciers were the cause of the Martian terrain that to Earth eyes for decades was thought to have formed by flowing water. It also continues what appears to be a major shift on-going in the planetary science community, from the idea of liquid water on Mars to that of a planet dominated by glacial and ice processes.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The print edition can be purchased at Amazon or from any other book seller. If you want an autographed copy the price is $60 for the hardback and $45 for the paperback, plus $8 shipping for each. Go here for purchasing details. The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
New data from an Antarctica ice core strengthens the hypothesis that the flow of glaciers, not liquid water, helped shape the meandering canyons on Mars.
The data was the discovery of the mineral jarosite deep within the south pole ice-cap. Jarosite needs water to form. Previously it was generally believed it formed in conjunction with liquid flowing water. On Mars, which appears to have lots of jarosite, scientists have struggled for decades to figure out how enough liquid water could have existed on the surface of Mars to produce it.
The discovery of jarosite deep inside the Antarctic ice cap now suggests that it can form buried in ice, not liquid water. According to the scientists,
the jarosite was born within massive ice deposits that might have blanketed [Mars] billions of years ago. As ice sheets grew over time, dust would have accumulated within the ice—and may have been transformed into jarosite within slushy pockets between ice crystals.
From the paper’s conclusions:
The occurrence of jarosite in TALDICE [in Antarctica] supports the ice-weathering model for the formation of Martian jarosite within large ice-dust deposits. The environment inside the Talos Dome ice [in Antarctica] is isolated from the Earth atmosphere and its conditions, including pressure, temperature, pH and chemistry, provides a suitable analogue for similar Martian settings. Dust deposited at Talos Dome is also similar to Martian atmospheric dust, being both mostly basaltic. Within thick ice deposits it is likely that the environment would be similar at Talos Dome and under Mars-like conditions since both settings would contain at cryogenic temperatures basaltic dust and volcanogenic and biogenic (for Antarctic only) sulfur-rich aerosols. … Considering this context, it is reasonable that the formation of jarosite on Mars involves the interaction between brines and mineral dust in deep ice, as observed in TALDICE. This mechanism for Martian jarosite precipitation is paradigm changing and strongly challenges assumptions that the mineral formed in playa settings.
Playa settings are places where there is standing liquid water, slowing drying away.
This result is another piece of evidence that ice and glaciers were the cause of the Martian terrain that to Earth eyes for decades was thought to have formed by flowing water. It also continues what appears to be a major shift on-going in the planetary science community, from the idea of liquid water on Mars to that of a planet dominated by glacial and ice processes.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The print edition can be purchased at Amazon or from any other book seller. If you want an autographed copy the price is $60 for the hardback and $45 for the paperback, plus $8 shipping for each. Go here for purchasing details. The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
And yet, the rovers show that there were definitely fluvial processes on Mars, for quite a while. I’m suspicious of these satellite-based observations. A single ground-truth can upend piles of distant observations.
ChairAgainstWall: The data clearly requires the presence of water where the rovers Spirit, Opportunity, and Curiosity have roamed. The assumption is that it must be fluvial, or flowing water. It is that assumption that the new data, both from this study and the widespread evidence of glaciers on Mars from the orbiters, is questioning.
Glaciers flow like rivers, though obviously much slower. Because on Earth we see glaciers in much more limited settings, scientists have not considered them as a major factor on Mars.
That appears to be now changing. On Mars glaciers have been in the past very widespread, and for a very long time, based on all recent data. Scientists are now increasingly considering it possible that those ice processes might be the source of much of Mars’ geology.
None of this is proven. I merely report what I have been observing within the planetary science community.
So I Googled ‘jarosite ‘ and Wikipedia informs me that that is the substance that stopped the rover, Spirit. It seems it doesn’t have a lot of cohesion and acted like quicksand when the rover broke through a thin crust of ordinary looking Martian soil. No amount of, literally, spinning its wheels could get the poor thing out of this trap.