China: samples from the near and far sides of the Moon are different
Scientists studying the lunar samples brought back from China’s Chang’e-6 mission to the far side of the Moon have determined that the different environments create differences in the surface material.
The study found that the solar wind exposure time of the Chang’e-6 samples was close to the minimum observed in the Apollo 11 samples, lower than that of the other Apollo samples, and slightly shorter than that of the Chang’e-5 samples. However, surprisingly, the npFe⁰ grain sizes in the Chang’e-6 samples were larger. “This might suggest that solar wind radiation in this region leads to more pronounced segregation and aggregation of iron,” she noted. These exciting new results add to the growing evidence that space weathering on the lunar farside may differ from that on the nearside, and, contrary to previous findings from Apollo and Chang’e-5 samples, solar wind radiation plays a more dominant role in the space weathering process on the lunar farside.
There are differences in the solar wind’s influence on different regions of the Moon. During each synodic month, the near side of the Moon enters Earth’s magnetotail, where the protection afforded by Earth’s magnetic field reduces its exposure to the solar wind; in contrast, the farside is continuously exposed to direct solar wind radiation. Moreover, due to orbital dynamics, different locations on the Moon experience varying impact velocities from cometary and asteroidal meteoroids. The relative velocity between the Moon’s surface and impacting meteoroids changes with the lunar phase: during a full moon, when the Moon and meteoroids move in the same orbital direction, the relative velocity increases; the opposite occurs during a new moon.
That there are differences between samples from the Moon’s two hemisphere should not a surprise. Confirming and characterizing those differences however is good.
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
Scientists studying the lunar samples brought back from China’s Chang’e-6 mission to the far side of the Moon have determined that the different environments create differences in the surface material.
The study found that the solar wind exposure time of the Chang’e-6 samples was close to the minimum observed in the Apollo 11 samples, lower than that of the other Apollo samples, and slightly shorter than that of the Chang’e-5 samples. However, surprisingly, the npFe⁰ grain sizes in the Chang’e-6 samples were larger. “This might suggest that solar wind radiation in this region leads to more pronounced segregation and aggregation of iron,” she noted. These exciting new results add to the growing evidence that space weathering on the lunar farside may differ from that on the nearside, and, contrary to previous findings from Apollo and Chang’e-5 samples, solar wind radiation plays a more dominant role in the space weathering process on the lunar farside.
There are differences in the solar wind’s influence on different regions of the Moon. During each synodic month, the near side of the Moon enters Earth’s magnetotail, where the protection afforded by Earth’s magnetic field reduces its exposure to the solar wind; in contrast, the farside is continuously exposed to direct solar wind radiation. Moreover, due to orbital dynamics, different locations on the Moon experience varying impact velocities from cometary and asteroidal meteoroids. The relative velocity between the Moon’s surface and impacting meteoroids changes with the lunar phase: during a full moon, when the Moon and meteoroids move in the same orbital direction, the relative velocity increases; the opposite occurs during a new moon.
That there are differences between samples from the Moon’s two hemisphere should not a surprise. Confirming and characterizing those differences however is good.
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
In Larry Niven’s INCONSTANT MOON, he had a character that speculated the far side would get the most of any abuse from a superflare.