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.
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
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.
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