Click for full image.
Cool image time! The photo to the right, cropped and reduced to post here, was taken on November 19, 2021 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows what the science team has labeled “Crescentic forms,” which in some ways resemble crescents that I featured in a cool image back in November 2020.
Unlike those earlier crescents, today’s are linked together to form a longer wavy line. Furthermore, today’s crescents include some positive relief, with some parts standing above the surrounding terrain. The earlier crescents were entirely carved out of the ground, forming depressions.
And yet, the method of formation for both must be somewhat similar. I say this based on their location, as shown in the overview map below.
The white cross marks the location of the today’s image, inside the westernmost section of Medusae Fossae Formation, about 250 miles east of the lander InSight and about 280 miles northeast of Curiosity in Gale Crater. The earlier crescents were also inside the Medusae Fossae, but in its eastern sections about 2,300 miles away.
Medusae Fossae is the largest volcanic ash deposit on Mars, and is believed to be the source of most of the planet’s ubiquitous dust. Thus, these crescents are thought to be created when the prevailing winds carve out scallops within the fossae’s thick dust layers as the wind is forced to bend around some more solid object buried in that dust. Think of the water in river rapids flowing around a boulder.
What makes today’s crescents intriguing are their two differing features, their positive relief and the linkage of several into a line. Apparently, there is not as much volcanic ash in this part of Medusae, and instead of carved depressions we’re are seeing the fossil remains of much older wind scallops. Once they were empty, but then became filled with material that ended up harder and more erosion resistant than the dust/ash that surrounded it. When the dust/ash blew away, it left behind that hardened material, the wavy ridges we see today.
At least, that’s my theory. And you should know, I wouldn’t bet a dime on it being correct.
NOTE: Posted late due to the site maintenance today.
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.
does more however. In telling the tragic history of the Virginia colony and the rise of slavery there, Zimmerman lays out the proper path for creating healthy societies in places like the Moon and Mars.
“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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