Modeling suggests Uranus’s moon Ariel needed underground oceans to shape its known surface
Ariel as seen by Voyager-2 in 1986.
Click for original image.
The uncertainty of science: Using computer modeling based on our scant data of the surface features of the Uranus moon Ariel, scientists now posit that underground oceans, some of gigantic depth as much as 100 miles deep, were required to shape those features.
“First, we mapped out the larger structures that we see on the surface, then we used a computer program to model the tidal stresses on the surface, which result from distortion of Ariel from soccer ball-shaped to slight football-shaped and back as it moves closer and farther from Uranus during its orbit,” Patthoff said. “By combining the model with what we see on the surface, we can make inferences about Ariel’s past eccentricity and how thick the ocean might have been.”
The team found that, in the past, Ariel needed to have an eccentricity of about 0.04 [to create those surface structures]. This is about 40 times larger than its current value. While 0.04 may not sound dramatic, eccentricity can strengthen the effects of tidal stresses, and Ariel’s orbit would have been four times more eccentric than that of Jupiter’s moon Europa, which is wracked by the tidal forces that push and pull it to create its cracked and broken surface. Yet, to the eye, the orbit will still resemble a circle.
“In order to create those fractures, you have to have either a really thin ice on a really big ocean, or a higher eccentricity and a smaller ocean,” Patthoff said. “But either way, we need an ocean to be able to create the fractures that we are seeing on Ariel’s surface.”
This result does not prove an underground ocean now exists, or even if one existed in the past. The data is based on the few fly-by images taken by Voyager-2 when it passed close to Uranus in 1986. Coverage of the entire surface of Ariel was not complete, nor did the images have much resolution. The data is suggestive of this conclusion, but not conclusive by any means.
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
Ariel as seen by Voyager-2 in 1986.
Click for original image.
The uncertainty of science: Using computer modeling based on our scant data of the surface features of the Uranus moon Ariel, scientists now posit that underground oceans, some of gigantic depth as much as 100 miles deep, were required to shape those features.
“First, we mapped out the larger structures that we see on the surface, then we used a computer program to model the tidal stresses on the surface, which result from distortion of Ariel from soccer ball-shaped to slight football-shaped and back as it moves closer and farther from Uranus during its orbit,” Patthoff said. “By combining the model with what we see on the surface, we can make inferences about Ariel’s past eccentricity and how thick the ocean might have been.”
The team found that, in the past, Ariel needed to have an eccentricity of about 0.04 [to create those surface structures]. This is about 40 times larger than its current value. While 0.04 may not sound dramatic, eccentricity can strengthen the effects of tidal stresses, and Ariel’s orbit would have been four times more eccentric than that of Jupiter’s moon Europa, which is wracked by the tidal forces that push and pull it to create its cracked and broken surface. Yet, to the eye, the orbit will still resemble a circle.
“In order to create those fractures, you have to have either a really thin ice on a really big ocean, or a higher eccentricity and a smaller ocean,” Patthoff said. “But either way, we need an ocean to be able to create the fractures that we are seeing on Ariel’s surface.”
This result does not prove an underground ocean now exists, or even if one existed in the past. The data is based on the few fly-by images taken by Voyager-2 when it passed close to Uranus in 1986. Coverage of the entire surface of Ariel was not complete, nor did the images have much resolution. The data is suggestive of this conclusion, but not conclusive by any means.
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 only we had sent more than one solitary probe (using early 1970’s tech, no less) to the Ice Giants, our planetary scientist would not have to engage in so much speculative modeling….
I get it. Uranus and Neptune are really danged far away, and it’s not cheap or easy to send anything out there (you need nuclear power, for starters), and it takes a long time when you do. But these are planetary systems that have fallen into the low priority boxes, thanks in part to the energy and power of the Mars lobby and thanks in part due to those aforementioned costs and difficulties.
We’re left to hope that Starship is as successful as Elon Musk promises, such that it may open up more possibilities for exploring these strange distant worlds and their moons — and not all of them U.S. government possibilities.
The Uranus Orbiter and Probe is apparently on the list for the next Flagship-class probe. Launch date in 6 years if approved. I am an early and often kind of guy, but …. No such proposal exists for Neptune as yet. Cheers –
https://science.nasa.gov/wp-content/uploads/2023/10/uranus-orbiter-and-probe.pdf