Pluto 8 months after fly-by
The New Horizons science team today published five papers summarizing what they have so far learned from the data obtained during last year’s July 14 fly-by and since downloaded.
Two of the many discoveries are to me the most interesting: The first illustrates Pluto’s strange and very active geology:
Age-dating of Pluto’s surface through crater counts has revealed that Pluto has been geologically active throughout the past 4 billion years. Further, the surface of Pluto’s informally named Sputnik Planum, a massive ice plain larger than Texas, is devoid of any detectable craters and estimated to be geologically young – no more than 10 million years old.
Moreover, the materials that cause Pluto to be geologically active are much more complicated than anything on Earth:
Scientists studying Pluto’s composition say the diversity of the planet’s landscape stems from eons of interaction between highly volatile and mobile methane, nitrogen and carbon monoxide ices with inert and sturdy water ice. “We see variations in the distribution of Pluto’s volatile ices that point to fascinating cycles of evaporation and condensation,” said Will Grundy, from Lowell Observatory in Flagstaff, Arizona, and lead author of the composition paper. “These cycles are a lot richer than on Earth, where there’s really only one material that condenses and evaporates – water. On Pluto, there are least three materials, and while they interact in ways we don’t yet fully understand, we definitely see their effects all across Pluto’s surface.”
The second discovery that fascinates me has to do with the formation of Pluto and all its moons:
The high albedos (reflectiveness) of Pluto’s small satellites are entirely different from the much lower albedos of the small bodies in the general Kuiper Belt population (which range from about 5 to 20 percent). This difference lends further support to the idea that these satellites were not captured from the general Kuiper Belt population, but instead formed by agglomeration in a disk of material produced in the aftermath of the giant collision that created the entire Pluto satellite system.
In other words, Pluto and its moons are not a collection of different Kuiper Belt objects brought together over time. Instead, they formed together.
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
The New Horizons science team today published five papers summarizing what they have so far learned from the data obtained during last year’s July 14 fly-by and since downloaded.
Two of the many discoveries are to me the most interesting: The first illustrates Pluto’s strange and very active geology:
Age-dating of Pluto’s surface through crater counts has revealed that Pluto has been geologically active throughout the past 4 billion years. Further, the surface of Pluto’s informally named Sputnik Planum, a massive ice plain larger than Texas, is devoid of any detectable craters and estimated to be geologically young – no more than 10 million years old.
Moreover, the materials that cause Pluto to be geologically active are much more complicated than anything on Earth:
Scientists studying Pluto’s composition say the diversity of the planet’s landscape stems from eons of interaction between highly volatile and mobile methane, nitrogen and carbon monoxide ices with inert and sturdy water ice. “We see variations in the distribution of Pluto’s volatile ices that point to fascinating cycles of evaporation and condensation,” said Will Grundy, from Lowell Observatory in Flagstaff, Arizona, and lead author of the composition paper. “These cycles are a lot richer than on Earth, where there’s really only one material that condenses and evaporates – water. On Pluto, there are least three materials, and while they interact in ways we don’t yet fully understand, we definitely see their effects all across Pluto’s surface.”
The second discovery that fascinates me has to do with the formation of Pluto and all its moons:
The high albedos (reflectiveness) of Pluto’s small satellites are entirely different from the much lower albedos of the small bodies in the general Kuiper Belt population (which range from about 5 to 20 percent). This difference lends further support to the idea that these satellites were not captured from the general Kuiper Belt population, but instead formed by agglomeration in a disk of material produced in the aftermath of the giant collision that created the entire Pluto satellite system.
In other words, Pluto and its moons are not a collection of different Kuiper Belt objects brought together over time. Instead, they formed together.
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