Terraces within one of Mars’ giant enclosed chasms
Cool image time! The picture to the right, rotated, cropped, reduced, and sharpened to post here, was taken on January 27, 2025 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows the terraced layers descending down a 7,000-foot-high ridgeline within Hebes Chasma, one of several enclosed chasms that are found to the north of Mars’s largest canyon system, Valles Marineris.
The white dot on the overview map above marks this location, inside Hebes. The rectangle in the inset indicates the area covered by the picture, which only covers the lower 5,000 feet of this ridge’s southern flank.
The ridgeline might be 7,000 feet high and sixteen miles long, but it is dwarfed by the scale of the chasm within which it sits. From the rim to the floor of Hebes is a 23,000 foot drop, comparable to the general heights of the Himalaya Mountains. Furthermore, this ridge is not the highest peak within Hebes. To the west is the much larger mesa dubbed Hebes Mensa, 11,000 feet high and 55 miles long.
The terraces indicate the cyclical and complex geological history of Mars. Each probably represents a major volcanic eruption, laying down a new bed of flood lava. With time, something caused Hebes Chasm to get excavated, exposing this ridge and these layers.
The excavation process itself remains unclear. Some scientists think the entire Valles Marineris canyon was created by catastrophic floods of liquid water. Others posit the possibility of underground ice aquifers that sublimated away, causing the surface to sink, eroded further by wind. Neither theory is proven, though the former is generally favored by scientists.
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Cool image time! The picture to the right, rotated, cropped, reduced, and sharpened to post here, was taken on January 27, 2025 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows the terraced layers descending down a 7,000-foot-high ridgeline within Hebes Chasma, one of several enclosed chasms that are found to the north of Mars’s largest canyon system, Valles Marineris.
The white dot on the overview map above marks this location, inside Hebes. The rectangle in the inset indicates the area covered by the picture, which only covers the lower 5,000 feet of this ridge’s southern flank.
The ridgeline might be 7,000 feet high and sixteen miles long, but it is dwarfed by the scale of the chasm within which it sits. From the rim to the floor of Hebes is a 23,000 foot drop, comparable to the general heights of the Himalaya Mountains. Furthermore, this ridge is not the highest peak within Hebes. To the west is the much larger mesa dubbed Hebes Mensa, 11,000 feet high and 55 miles long.
The terraces indicate the cyclical and complex geological history of Mars. Each probably represents a major volcanic eruption, laying down a new bed of flood lava. With time, something caused Hebes Chasm to get excavated, exposing this ridge and these layers.
The excavation process itself remains unclear. Some scientists think the entire Valles Marineris canyon was created by catastrophic floods of liquid water. Others posit the possibility of underground ice aquifers that sublimated away, causing the surface to sink, eroded further by wind. Neither theory is proven, though the former is generally favored by scientists.
Readers!
My annual February birthday fund-raising drive for Behind the Black is now over. Thank you to everyone who donated or subscribed. While not a record-setter, the donations were more than sufficient and slightly above average.
As I have said many times before, I can’t express what it means to me to get such support, especially as no one is required to pay anything to read my work. Thank you all again!
For those readers who like my work here at Behind the Black and haven't contributed so far, please consider donating or subscribing. My analysis of space, politics, and culture, taken from the perspective of an historian, is almost always on the money and ahead of the game. For example, in 2020 I correctly predicted that the COVID 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. Every one of those 2020 conclusions has turned out right.
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.
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