Scientists posit that Neptune and Uranus might be rockier than previously theorized
Scientists doing new computer modeling of the known data now posit that Neptune and Uranus might not be as icy as previously believed and instead could be more like the inner terrestrial planets like Earth, much rockier in their interior.
According to the work carried by the UZH scientific team, Uranus and Neptune might actually be more rocky than icy. The new study does not claim the two blue planets to be one or the other type, water- or rock- rich, it rather challenges that ice-rich is the only possibility. This interpretation is also consistent with the discovery that the dwarf planet Pluto is rock-dominated in composition.
…With their new agnostic, and yet fully physical model, the University of Zurich team found the potential internal composition of the “ice giants” of our Solar system, is not limited at all to only ice (typically represented by water). “It is something that we first suggested nearly 15 years ago, and now we have the numerical framework to demonstrate it,” reveals Ravit Helled, a professor at the University of Zurich and initiator of the project. The new range of internal composition shows that both planets can either be water-rich or rock-rich.
This new hypothesis might also help explain the multi-polar magnetic fields of both planets.
All is uncertain of course, as this is just a computer model based on limited data. Nor is it a surprise that an alternative conclusion appears to work. We know so little about these distant worlds that it is likely that multiple theories could fit the data, and all could be wrong when we finally learn more.
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 doing new computer modeling of the known data now posit that Neptune and Uranus might not be as icy as previously believed and instead could be more like the inner terrestrial planets like Earth, much rockier in their interior.
According to the work carried by the UZH scientific team, Uranus and Neptune might actually be more rocky than icy. The new study does not claim the two blue planets to be one or the other type, water- or rock- rich, it rather challenges that ice-rich is the only possibility. This interpretation is also consistent with the discovery that the dwarf planet Pluto is rock-dominated in composition.
…With their new agnostic, and yet fully physical model, the University of Zurich team found the potential internal composition of the “ice giants” of our Solar system, is not limited at all to only ice (typically represented by water). “It is something that we first suggested nearly 15 years ago, and now we have the numerical framework to demonstrate it,” reveals Ravit Helled, a professor at the University of Zurich and initiator of the project. The new range of internal composition shows that both planets can either be water-rich or rock-rich.
This new hypothesis might also help explain the multi-polar magnetic fields of both planets.
All is uncertain of course, as this is just a computer model based on limited data. Nor is it a surprise that an alternative conclusion appears to work. We know so little about these distant worlds that it is likely that multiple theories could fit the data, and all could be wrong when we finally learn more.
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
I posit they might be made of cream cheese.
It’s really a shame that we’ve only ever sent one probe out to the ice giants, er rocky giants?, so far. And that was launched back in 1977.
I grok that it’s really far away, really expensive, and takes a really long time and all that — and even Starship won’t fully eliminate these difficulties. It would need to be nuclear powered, for starters. But if there’s something that I want NASA to do, science was, that’s really hard and really unlikely that the private sector will do, an ice giants orbiter is very high on that list. We might even get a good lead on answering questions like the one this study poses.
pzatchok,
Gonna need to find a Jovian-scale bagel somewhere to spread all of that on if so.
Richard M,
Entirely agree. Such a mission would be a good first use of the nuclear-electric drive Jared I. wants NASA to develop. I hope he manages to get such a project going during his tenure as NASA Administrator. 48 years and counting between missions does seem a tad neglectful.
That would mean the impactor that knocked Uranus on its side was larger?
”It’s really a shame that we’ve only ever sent one probe out to the ice giants…”
NASA is doing outer-planet orbiters and atmospheric probes one at a time interspersed among other science priorities. First came Galileo at Jupiter. Then Cassini at Saturn. Next up is the Uranus Orbiter and Probe (UOP), the second-highest scientific priority after Mars Sample Return. Neptune and Pluto will probably follow.
But as you say, those planets are very far away, it takes a long time to get there, and conducting world-class science at those distances is expensive, so NASA has to do them sequentially.
Jeff Wright,
There likely never was such an impactor. Mars’s axis of rotation nutates quite a bit relative to the ecliptic over periods of millennia, for example. Its current tilt of 25 degrees was, in the past, 60 degrees or more. In Mars’s case this all happens absent any consequential impactors. The same is likely true of Uranus. The dynamics of spinning objects – especially those of planetary or stellar size – are not simple.
Ice giants?
Both are as hot as the Photosphere of the sun (surface).
https://en.wikipedia.org/wiki/Uranus
“Uranus’s core density is around 9 g/cm3, with a pressure in the centre of 8 million bars (800 GPa) and a temperature of about 5000 K.[86][87] The ice mantle is not in fact composed of ice”
“The extreme pressure and temperature deep within Uranus may break up the methane molecules, with the carbon atoms condensing into crystals of diamond that rain down through the mantle like hailstones.[89][90] This phenomenon is similar to diamond rains that are theorised by scientists to exist on Jupiter, Saturn, and Neptune.”
“Neptune, which is Uranus’s near twin in size and composition, radiates 2.61 times as much energy into space as it receives from the Sun,[24] but Uranus radiates hardly any excess heat at all.”
Hello mkent,
Well, I think your summary has hit the problem: The sequence has had a far larger gap this time around. Voyagers were built in the 70’s. Galileo was built in the 80’s. Cassini was built in the 90’s. But here it is 2025 and we are still waiting for a greenlight on on a UOP.
I think the problem is that the Mars lobby sponged up too much of the planetary science budget since Goldin’s era. Yes, we did get two flagship-level missions to the Outer Solar System this century, but one took some heavy lifting by an unusually interested congressional committee chairman, and the other was sneaked through as a New Frontiers mission whose cost only exploded, probably inevitably, to flagship levels later. And of course, neither has even reached its destination yet.
Again, though, I get it: the ice giants are very far away, and naturally expensive. It really has to be flagship levels funding to get something out there (TRIDENT’s valiant effort notwithstanding), and it’s a harder sell to the SMD and appropriators on the Hill when you have to wait a decade for the science and the pretty pictures to come in.
P.S. if Dwayne Day were here, he would say that we are remiss for not discussing how the Decadal review process shapes the decisions for what missions get funded. A Uranus orbiter has been moving up the Decadal flagship priority list over the last two Decadals, but there’s always been something ahead of it.
But the Decadal is shaped by the scientists who sit on it. And the career paths have just been a lot more frequent for those studying Mars than those studying ice giants, (And, frankly, even ocean worlds get more attention.) Those careers are not helped, in turn, when it takes something close to two decades from conception to getting actual data back for any mission you send out that far.