A minor rill on the Moon
Click for full image.
Cool image time! The image above, reduced to post here, is a colorized digital terrain model produced from Lunar Reconnaissance Orbiter (LRO) data. On top of the original mosaic of photos the LRO science team has overlaid the elevation data obtained by LRO’s laser altimeter. It shows a tadpole shaped pit dubbed Kathleen, with its tail trailing off to the southeast. As they note:
Kathleen is a pyroclastic vent with a sinuous rille (colloquially known as Rima Mozart [Not IAU confirmed]) that extends from the southeast end of the vent. Rilles are large channels formed by sustained channelized lava flows. This vent is a great location to investigate ancient volcanism on the Moon.
The elevation data reveals one interesting feature: The lowest part of the vent pit is not at its western end, where one would think at first glance, based on the general dip that produced the rill flowing to the east. That the lowest point is at the widest section of the pit instead suggests that this pit no longer looks as it did when it was venting. In the almost four billion years since it is thought all volcanic activity here ceased, there has been plenty of time for the slow erosion processes on the Moon, caused by radiation, micrometeorites, and the solar wind, to partly fill this pit and round out its cliff walls.
The two overview maps below provide some context.
This volcanic vent sits inside the large mare basin dubbed Mare Imbrium, or in English the Sea of Showers. The Apennine Mountains form the mare’s southeast margin, with Hadley Rille, the landing site of Apollo 15 tucked just inside the mare. The white box is the area shown in the closer overview below that focuses on the entire rill and nearby similar vents.
According to this paper, the origin of Kathleen and the surrounding vents is explained as follows:
Construction of Rima Mozart began with an explosive eruption at Kathleen Crater. A limited amount of pyroclastic debris was emplaced around this source vent. Lava erupted at Kathleen, carved a channel to the southeast, and spread out in the low-lying region now occupied by Lacus Mozart … Lava from this first eruption may have formed a tube along the channel. If so, almost all of this tube is now collapsed.
…Kathleen erupted at least one more time to form the second channel. … This eruption may have also had an explosive phase which contributed to the blanket of pyroclastic material surrounding the crater.
All of this occurred a long time ago. Since then nothing much has really happened except for those slow erosion processes, interrupted violently and abruptly by the impact of a larger asteroid at random times.
Now available in hardback and paperback as well as ebook!
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.
Conscious Choice 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.
All editions are available at Amazon, Barnes & Noble, and all book vendors, with the ebook priced at $5.99 before discount. The ebook can also be purchased direct from my ebook publisher, ebookit, in which case you don't support the big tech companies and I get a bigger cut much sooner.
Autographed printed copies are also available at discount directly from me (hardback $24.95; paperback $14.95; Shipping cost for either: $5.00). Just email me at zimmerman @ nasw dot org.
Click for full image.
Cool image time! The image above, reduced to post here, is a colorized digital terrain model produced from Lunar Reconnaissance Orbiter (LRO) data. On top of the original mosaic of photos the LRO science team has overlaid the elevation data obtained by LRO’s laser altimeter. It shows a tadpole shaped pit dubbed Kathleen, with its tail trailing off to the southeast. As they note:
Kathleen is a pyroclastic vent with a sinuous rille (colloquially known as Rima Mozart [Not IAU confirmed]) that extends from the southeast end of the vent. Rilles are large channels formed by sustained channelized lava flows. This vent is a great location to investigate ancient volcanism on the Moon.
The elevation data reveals one interesting feature: The lowest part of the vent pit is not at its western end, where one would think at first glance, based on the general dip that produced the rill flowing to the east. That the lowest point is at the widest section of the pit instead suggests that this pit no longer looks as it did when it was venting. In the almost four billion years since it is thought all volcanic activity here ceased, there has been plenty of time for the slow erosion processes on the Moon, caused by radiation, micrometeorites, and the solar wind, to partly fill this pit and round out its cliff walls.
The two overview maps below provide some context.
This volcanic vent sits inside the large mare basin dubbed Mare Imbrium, or in English the Sea of Showers. The Apennine Mountains form the mare’s southeast margin, with Hadley Rille, the landing site of Apollo 15 tucked just inside the mare. The white box is the area shown in the closer overview below that focuses on the entire rill and nearby similar vents.
According to this paper, the origin of Kathleen and the surrounding vents is explained as follows:
Construction of Rima Mozart began with an explosive eruption at Kathleen Crater. A limited amount of pyroclastic debris was emplaced around this source vent. Lava erupted at Kathleen, carved a channel to the southeast, and spread out in the low-lying region now occupied by Lacus Mozart … Lava from this first eruption may have formed a tube along the channel. If so, almost all of this tube is now collapsed.
…Kathleen erupted at least one more time to form the second channel. … This eruption may have also had an explosive phase which contributed to the blanket of pyroclastic material surrounding the crater.
All of this occurred a long time ago. Since then nothing much has really happened except for those slow erosion processes, interrupted violently and abruptly by the impact of a larger asteroid at random times.
Now available in hardback and paperback as well as ebook!
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.
Conscious Choice 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.
All editions are available at Amazon, Barnes & Noble, and all book vendors, with the ebook priced at $5.99 before discount. The ebook can also be purchased direct from my ebook publisher, ebookit, in which case you don't support the big tech companies and I get a bigger cut much sooner.
Autographed printed copies are also available at discount directly from me (hardback $24.95; paperback $14.95; Shipping cost for either: $5.00). Just email me at zimmerman @ nasw dot org.
Somewhere I’ve missed something in all my reading. I didn’t think the moon had a molten core? How do these form if so? I thought, supposedly, it’s just a dead rock. Although the “ringing” sound the astronauts mentioned is a little mystifying.
Ruth: The Moon’s core is today believed to be solid. At one time however (4 billion years ago) the surface was being heavily reshaped by volcanic activity, linked to internal matters as well as the heavy bombardment from objects within the solar system. Mare Imbrium is believed to have been caused by a big impact, and was then flooded with impact melt.
What is the temperature at the center of the moon at present thought to be?