The seasonal cloud over Arsia Mons on Mars
The cloud as seen in 2018.
Scientists have now documented the seasonal nature of the strangely elongated cloud that was first spotted in 2018 above the giant volcano Arsia Mons (the southernmost volcano of the three volcanoes east of Olympus Mons).
From their abstract:
We find that the AMEC [Arsia Mons Elongated Cloud] repeated regularly each morning for a number of months, and that it is an annually‐repeating phenomenon that takes place every Martian Year around the southern hemisphere spring and summer. The AMEC follows a rapid daily cycle: it starts to expand from Arsia Mons at dawn at an altitude of about ∼45 km, and for ∼2.5 hours it expands westward as fast as 170 m/s (around 600 km/h). The cloud then detaches from Arsia Mons and evaporates before noon. In previous Martian Years, few observations of this phenomenon are available because most cameras orbiting Mars are placed in orbits where they can only observe during the afternoon, whereas this cloud takes place in the early morning, when observational coverage is much lower.
They also state that they will outline their theories as to the cause of the cloud in a follow-up paper.
I can’t help wondering if it is related to other evidence that suggested past glacial activity on the western flanks of Arsia Mons. There are many pits surrounding this volcano, and many might contain residue ice. One wonders if, during the warm spring and summer months at dawn the arrival of the sun might cause this cloud to form, and then vanish as the day passes, just like the dew does on Earth.
That is my uneducated guess, and likely wrong. We shall have to wait for their theoretical paper for a more educated guess.
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The cloud as seen in 2018.
Scientists have now documented the seasonal nature of the strangely elongated cloud that was first spotted in 2018 above the giant volcano Arsia Mons (the southernmost volcano of the three volcanoes east of Olympus Mons).
From their abstract:
We find that the AMEC [Arsia Mons Elongated Cloud] repeated regularly each morning for a number of months, and that it is an annually‐repeating phenomenon that takes place every Martian Year around the southern hemisphere spring and summer. The AMEC follows a rapid daily cycle: it starts to expand from Arsia Mons at dawn at an altitude of about ∼45 km, and for ∼2.5 hours it expands westward as fast as 170 m/s (around 600 km/h). The cloud then detaches from Arsia Mons and evaporates before noon. In previous Martian Years, few observations of this phenomenon are available because most cameras orbiting Mars are placed in orbits where they can only observe during the afternoon, whereas this cloud takes place in the early morning, when observational coverage is much lower.
They also state that they will outline their theories as to the cause of the cloud in a follow-up paper.
I can’t help wondering if it is related to other evidence that suggested past glacial activity on the western flanks of Arsia Mons. There are many pits surrounding this volcano, and many might contain residue ice. One wonders if, during the warm spring and summer months at dawn the arrival of the sun might cause this cloud to form, and then vanish as the day passes, just like the dew does on Earth.
That is my uneducated guess, and likely wrong. We shall have to wait for their theoretical paper for a more educated guess.
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.
I am reminded of a presentation by Dr Michael Malin long ago where he remarked on observations from the Mars Global Surveyor where dust devils would appear on mars at the same place and in the same time as they had a martian year before. It hints of a peculiarly stable system of weather activity.
David Telford: Speaking of dust devils returning to the same spot, you might find this BtB article of interest: The dark splotches on Mars: Magnets for dust devils.
Thank you Bob, an interesting phenomenon around Olympus Mons. I could wonder if there are prevailing and steady winds that hit the Mons and maybe there are large wavelength resonances that cause the dust devils to concentrate, and subsequently expose the darker stuff underneath. I recall years ago crossing eastern Washington in the early summer. Stopped to see some dust devils going, and noticed there were dozens formed in a large grid slowly moving across the open plane. Would be nice to know that science has this figured out. Or maybe not yet?
I wonder if its simple uplift like we have in mountain rangers on Earth.
Water laden air hits a mountain and its pushed up till it gets cold enough to condense into clouds and eventual rain.
On Earth its normally a mountain range and the rain falls on the same side of the mountains that the wind hits,
But since Olympus Mons is singular wouldn’t the clouds travel around it and re-converge on the other side?
And because of the unique Mars atmosphere and the hight of the mountain the rain would be coming from way to high to ever actually hit the ground and show up as a wet spot.
It goes from super high ice crystal clouds to low level falling clouds and right into sublimated water vapor to thin to see.