Scientists locate lunar impact crater produced by LCROSS in 2009
Taken from figure 2 of the paper. Click for
original image.
Using orbital radar and opitcal images scientists finally believe they have identified the small crater on the Moon produced when — as part of the 2009 LCROSS mission — an abandoned rocket stage crashed in a permanently shadowed section of Cabeus crater near the lunar south pole.
LCROSS was designed to study the ejecta thrown up by that impact, and found “a significant amount of water, estimated at 5.6 ± 2.9% by mass, as well as minor amounts of other volatile species.” Because the impact was in that permanently shadowed region, however, locating the new crater required new instrumentation.
Using a radar instrument on Lunar Reconnaissance Orbiter (LRO) as well as the Shadowcam instrument on South Korea’s Danuri orbiter — designed to take optical images in very low light — the scientists pinpointed that impact crater, as shown in the image to the right, overlaying both the radar and optical images. The crater is estimated to be about 22 meters across, about 25% smaller than predicted. From this the scientists conclude that the water in the ejecta plume came from close to the surface, and thus could only have been placed there in the past billion years. Before that, the location was not in shadow, and volatiles like water could not have survived if they were near the surface.
From this data the scientists believe the water was likely placed there by the “recent delivery by comets or the solar wind, rather than as a paleo-reservoir from an early volcanic atmosphere.” If so, the amount of material can be reasonably predicted, and is likely less than hoped for because it only exists in the top two meters.
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
Taken from figure 2 of the paper. Click for
original image.
Using orbital radar and opitcal images scientists finally believe they have identified the small crater on the Moon produced when — as part of the 2009 LCROSS mission — an abandoned rocket stage crashed in a permanently shadowed section of Cabeus crater near the lunar south pole.
LCROSS was designed to study the ejecta thrown up by that impact, and found “a significant amount of water, estimated at 5.6 ± 2.9% by mass, as well as minor amounts of other volatile species.” Because the impact was in that permanently shadowed region, however, locating the new crater required new instrumentation.
Using a radar instrument on Lunar Reconnaissance Orbiter (LRO) as well as the Shadowcam instrument on South Korea’s Danuri orbiter — designed to take optical images in very low light — the scientists pinpointed that impact crater, as shown in the image to the right, overlaying both the radar and optical images. The crater is estimated to be about 22 meters across, about 25% smaller than predicted. From this the scientists conclude that the water in the ejecta plume came from close to the surface, and thus could only have been placed there in the past billion years. Before that, the location was not in shadow, and volatiles like water could not have survived if they were near the surface.
From this data the scientists believe the water was likely placed there by the “recent delivery by comets or the solar wind, rather than as a paleo-reservoir from an early volcanic atmosphere.” If so, the amount of material can be reasonably predicted, and is likely less than hoped for because it only exists in the top two meters.
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
If the site is permanently shadowed how can the solar wind be a factor. I guess there’s been some precession.
pawn: That is an excellent question. I suspect the theory is that the solar wind follows a rougher course than light, and since some light reaches the pole the spread of the wind can get it into areas the light does not reach.
Then again, maybe not. Like I said, an excellent question.
pawn asked: “If the site is permanently shadowed how can the solar wind be a factor.”
Remember that the solar wind is ionized and follows magnetic field lines rather than travel in straight lines from the source. Parker saw an interesting phenomenon when it was especially close to the Sun: the solar wind sometimes turning back toward the Sun (switchbacks) before streaming outward again:
https://behindtheblack.com/behind-the-black/scientists-confirm-parker-entered-suns-corona-in-april-2021/
Link:
https://skyandtelescope.org/astronomy-news/humanity-has-touched-the-sun/
The solar wind travels a different path than the sunlight, so it is still possible and maybe likely that the wind gets into shadowed areas of the Moon, even permanently shadowed areas.