Posted on Jan 6, 2021
APOD: 2021 January 6 - Striped Sand Dunes on Mars
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Good morning, Rallypoint. Today's Astronomy Picture of the Day (APOD) is titled "Striped Sand Dunes on Mars." This image was captured by the Mars Reconnaissance Orbiter (MRO) looking down into Kunowsky Crater. Scientists suspect that frozen carbon dioxide (dry ice) may be the cause of these features. When thawed, carbon dioxide does not become liquid; it sublimates directly from a solid to a gaseous state. This reveals darker sand beneath what was once covered. The dry ice can also trap heat, causing it to melt from the bottom up. That may be one cause of the 'stripes'...geyser-like eruptions occur when pressures build sufficiently to break through the overlying ice sheet. From high above, MRO can see the results.
APOD: 2021 January 6 - Striped Sand Dunes on Mars
Posted from apod.nasa.gov
NASA
Space
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Astronomy
Posted 4 y ago
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Provided to YouTube by BWSCD, Inc.Sand Dunes · Erin DurantIslands 2019 Keeled ScalesReleased on: 2019-06-28Mixer: Gabriel GalvinProducer: Kyp MaloneComposer...
Thank you my friend Maj William W. 'Bill' Price for posting the NASA Astronomy Picture of the Day (APOD) is titled "Striped Sand Dunes on Mars."
Image: Striped Sand Dunes on Mars - Image Credit - HiRISE, MRO, LPL (U. Arizona), NASA; Processing - WĹ‚odek GĹ‚aĹĽewski; Text - Alex R. Howe (NASA/USRA, Reader's History of SciFi Podcast)
APOD Background
"Explanation: Why are these sand dunes on Mars striped? No one is sure. The featured image shows striped dunes in Kunowsky Crater on Mars, photographed recently with the Mars Reconnaissance Orbiter’s HiRISE Camera. Many Martian dunes are known to be covered unevenly with carbon dioxide (dry ice) frost, creating patterns of light and dark areas. Carbon dioxide doesn’t melt, but sublimates, turning directly into a gas. Carbon dioxide is also a greenhouse material even as a solid, so it can trap heat under the ice and sublimate from the bottom up, causing geyser-like eruptions. During Martian spring, these eruptions can cause a pattern of dark defrosting spots, where the darker sand is exposed. The featured image, though, was taken during Martian autumn, when the weather is getting colder – making these stripes particularly puzzling. One hypothesis is that they are caused by cracks in the ice that form from weaker eruptions or thermal stress as part of the day-night cycle, but research continues. Watching these dunes and others through more Martian seasons may give us more clues to solve this mystery."
Sand Dunes · Erin Durant
https://www.youtube.com/watch?v=DA-zUgM1ofo
FYI Maj Robert Thornton COL Mikel J. BurroughsPO1 William "Chip" Nagel Maj Bill Smith, Ph.D. Lt Col John (Jack) Christensen Sgt Vance Bonds MAJ Dale E. Wilson, Ph.D. TSgt David L. SPC Nancy GreenePO2 (Join to see) SSG Michael Noll SMSgt David A Asbury SMSgt Lawrence McCarter SPC Michael Terrell MSG Andrew White SFC Chuck Martinez CPT (Join to see) SPC Randy ZimmermanSGT John " Mac " McConnell
Image: Striped Sand Dunes on Mars - Image Credit - HiRISE, MRO, LPL (U. Arizona), NASA; Processing - WĹ‚odek GĹ‚aĹĽewski; Text - Alex R. Howe (NASA/USRA, Reader's History of SciFi Podcast)
APOD Background
"Explanation: Why are these sand dunes on Mars striped? No one is sure. The featured image shows striped dunes in Kunowsky Crater on Mars, photographed recently with the Mars Reconnaissance Orbiter’s HiRISE Camera. Many Martian dunes are known to be covered unevenly with carbon dioxide (dry ice) frost, creating patterns of light and dark areas. Carbon dioxide doesn’t melt, but sublimates, turning directly into a gas. Carbon dioxide is also a greenhouse material even as a solid, so it can trap heat under the ice and sublimate from the bottom up, causing geyser-like eruptions. During Martian spring, these eruptions can cause a pattern of dark defrosting spots, where the darker sand is exposed. The featured image, though, was taken during Martian autumn, when the weather is getting colder – making these stripes particularly puzzling. One hypothesis is that they are caused by cracks in the ice that form from weaker eruptions or thermal stress as part of the day-night cycle, but research continues. Watching these dunes and others through more Martian seasons may give us more clues to solve this mystery."
Sand Dunes · Erin Durant
https://www.youtube.com/watch?v=DA-zUgM1ofo
FYI Maj Robert Thornton COL Mikel J. BurroughsPO1 William "Chip" Nagel Maj Bill Smith, Ph.D. Lt Col John (Jack) Christensen Sgt Vance Bonds MAJ Dale E. Wilson, Ph.D. TSgt David L. SPC Nancy GreenePO2 (Join to see) SSG Michael Noll SMSgt David A Asbury SMSgt Lawrence McCarter SPC Michael Terrell MSG Andrew White SFC Chuck Martinez CPT (Join to see) SPC Randy ZimmermanSGT John " Mac " McConnell
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LTC Stephen F.
The song of the dunes introduced by Stéphane Douady. Since Marco Polo this strange sounds that can be heard in some deserts fanscinates. Here Stéphane Douady...
The song of the dunes introduced by Stéphane Douady. Since Marco Polo this strange sounds that can be heard in some deserts fanscinates. Here Stéphane Douady shows the different sounds that can be made, as soon as this singing sand it is sheared, with the hand, the feet, or in avalanches. Recorded on a singing dune in Morocco. A movie from Etienne Chaillou and Mathias Thery
https://www.youtube.com/watch?v=4yFaMsUawi4
FYI SSG Franklin BriantSgt John H.SGT (Join to see)SSG Jeffrey Leake SPC Matthew Lamb CPT Gurinder (Gene) Rana SSG Samuel Kermon LTC Wayne Brandon Sgt (Join to see) PO2 (Join to see) MSgt Robert "Rock" Aldi SP5 Geoffrey Vannerson LTC (Join to see) LTC (Join to see) Maj William W. 'Bill' Price Lt Col John (Jack) Christensen SFC Don Vance Maj Marty Hogan SCPO Morris Ramsey MAJ Dale E. Wilson, Ph.D.
https://www.youtube.com/watch?v=4yFaMsUawi4
FYI SSG Franklin BriantSgt John H.SGT (Join to see)SSG Jeffrey Leake SPC Matthew Lamb CPT Gurinder (Gene) Rana SSG Samuel Kermon LTC Wayne Brandon Sgt (Join to see) PO2 (Join to see) MSgt Robert "Rock" Aldi SP5 Geoffrey Vannerson LTC (Join to see) LTC (Join to see) Maj William W. 'Bill' Price Lt Col John (Jack) Christensen SFC Don Vance Maj Marty Hogan SCPO Morris Ramsey MAJ Dale E. Wilson, Ph.D.
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MSgt Paul Connors LTC Tom McNew LTC Stephen C. SSG Michael Noll SGT Steve McFarland LTC Stephen F. 1SG Steven Imerman Cpl (Join to see) Sgt Kelli Mays MSgt Robert "Rock" Aldi PO3 Lynn Spalding LTC (Join to see) SSG Gordon Holmes SMSgt Lawrence McCarterSGT Mark Anderson SPC Nancy Greene 1SG (Join to see) PO2 (Join to see) SGT Denny Espinosa SSG C.V. Shaw
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