Layered volcanic vent on Mars
Click for original image.
Cool image time! The picture to the right, rotated, cropped, reduced, and sharpened to post here, was taken on August 31, 2023 by the high resolution camera on Mars Reconnaissance Orbiter (MRO), and shows what the science team labels as a “vent near Olympica Fossae.”
The grade within the fissure is downhill to its center. Outside the vent the grade is downhill to the north and south, with the overall grade sloping to the west as well. Note the layers on each side of the depression. Each indicates another volcanic flood event that laid down another layer of lava. At some point this vent either blew up through those layers, or it had remained opened during all those many events, the lava flowing out and acting like water to erode the layers on the north and the south.
As always, the scale of Martian geology is daunting, as shown by the overview map below.
The little white box on the map to the right marks the location, about forty miles north of a 250-mile-long fissure called Olympica Fossae, not visible on the overview map. That big fissure appears to have been caused by a combination of faulting and lava venting, as it also does not have a clear downward grade.
Look however at the inset, created from a mosaic of MRO’s global context camera images. In the lower right can be seen a crater that is almost completely covered by lava, with only its western half still exposed. This location, surrounded by Mars’ biggest volcanoes, clearly was formed largely by volcanic events. Furthermore, its location inside the dry tropics of Mars means water/ice has probably played little part in its formation, or if it did, subsequent lava events have buried all evidence.
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
Click for original image.
Cool image time! The picture to the right, rotated, cropped, reduced, and sharpened to post here, was taken on August 31, 2023 by the high resolution camera on Mars Reconnaissance Orbiter (MRO), and shows what the science team labels as a “vent near Olympica Fossae.”
The grade within the fissure is downhill to its center. Outside the vent the grade is downhill to the north and south, with the overall grade sloping to the west as well. Note the layers on each side of the depression. Each indicates another volcanic flood event that laid down another layer of lava. At some point this vent either blew up through those layers, or it had remained opened during all those many events, the lava flowing out and acting like water to erode the layers on the north and the south.
As always, the scale of Martian geology is daunting, as shown by the overview map below.
The little white box on the map to the right marks the location, about forty miles north of a 250-mile-long fissure called Olympica Fossae, not visible on the overview map. That big fissure appears to have been caused by a combination of faulting and lava venting, as it also does not have a clear downward grade.
Look however at the inset, created from a mosaic of MRO’s global context camera images. In the lower right can be seen a crater that is almost completely covered by lava, with only its western half still exposed. This location, surrounded by Mars’ biggest volcanoes, clearly was formed largely by volcanic events. Furthermore, its location inside the dry tropics of Mars means water/ice has probably played little part in its formation, or if it did, subsequent lava events have buried all evidence.
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