Since this journey started I was very much looking forward visiting the landable body with the highest gravity. But the record holder until recently was in a region too far away for a short stop. But that changed when this record
was broken.
So, here I am on
Kyloall CL-Y g1518 D 1 …
… that is not just the only planet in its system, but also holds the above mentioned record for all (landable) celestial bodies and for all Metal-rich bodies with a value of 11.009168647951414 g.
It is also the landable Metal-rich body with the largest mass (94.588409 Earth masses) and the largest radius (18,695.032 km).
Now for some additional thoughts.
On EDSM the colid composition is given as: 53.94% Rock, 42.61% Metal, 0.14% Ice.
This is confusing because neither does it say if it is mass or volume composition nor if this is just the surface composition (something I would guess is the only things our probes can measure).
Now the "ice" may point into the direction that this is mass. Why is that?
Well, the surface temperature is far too high to allow any liquid water (and there is also no atmosphere). We know, that a lot of
water is trapped in Earth's mantle.
Thus I take it that the word "ice" was chosen to go together with "solid composition". It is also just a different word for "solid water"
In absence of any other information am I assuming that I'm part of a totally average part of the cosmos (that must not be true), thus I assume that this is a rock-ish planet like Earth and that these develop all approximately the same.
The earth is made up of approx. 35 % Iron, 30 % Oxygen, 15 Silicon and 13 percent Magnesium. The only two of these that are metals are Iron and Magnesium. Thus Iron makes up ca. 73 % of the metal content of Earth.
Since this is just an estimation I go with these numbers and thus say that this planet's Iron content is ca. 29 Earth masses.
The vast majority of the Earth's iron is found in the core. NB: when I write "core" I mean the inner and the outer core and don't distinguish between these two (which seems to be OK since this is just an estimation).
According to the
Preliminary reference Earth model (looking at fig. 8 on page 310 keeps you from reading the whole article
) is the density of the core relativ constant and approx. 11 tons per cubic meter. Again: there are changes but within this estimation that doesn't really matter.
Earth itself has a mass of ca. 5.97 times 10 to the 24 kg. Assuming the core is pure iron and the complete 35 % are in the core (which is not too far from what is assumed) gives a mass of the core of ca. 2 times ten to the 24 kg.
This gives a volume of Earth's core of ca. 1.8 times ten to the 20 cubic meter. Assuming it is a sphere follows from this a radius of ca. 3,500 km. Despite all the assumptions and estimations is this pretty close to
the value we assume is correct. Thus we can continue with the planet I'm standing on.
29 Earth masses Iron content are approx. 1.7 times ten to the 26 kg. Assuming the same average density of 11,000 kg per cubic meter (which might not be too far from the truth, since the density of earth's inner core is even less dependent on the depth than the outer core, so more pressure seems not to compress the solid core a lot more) am I arriving at a radius of the core of approx. 15,500 km.
Mhmmm … The radius of earth's core is approx. half of its total radius. Here though the core radius is almost 83 percent of the total radius! That makes the following very very interesting.
With a core radius of 15,500 km and a total radius of ca. 18700 km it means that ca. 1.2 times ten to the 22 cubic meters of material are in the mantle of this planet. The core accounts for ca. 29 Earth masses of the total 94.588409 Earth masses of this planet. Thus we we need to cramp the remaining 65.6 Earth masses into these 1.2 times ten to the 22 cubic meters. Thus follows, that the average density of the mantle-material of this planet is 33,200 kg per cubic meter … … … ! … … … !!! … … … !!!oneoneeleven …
Well, this seems to be an inverted planet with a denser mantle than the core. I would be interested in the physics that can explain how such a planet can form.
It can't be that my assumptions are super wrong. Because I need to increase the density of the core by an order of magnitude to half the radius of the core which would lead to a halved density of the mantle material … this is still three times larger than Earth's mantle material density. BUT a ten times higher density … of Iron! … these physics would be equally interesting compared with an inverted planet.
Is "Metal" than not Iron? Looking at
densities of metals under normal conditions doesn't leave me a lot of room to wiggle here. A can maybe get a factor of approx 2.5 but not ten.
Something very different that is stable and behaves like metal? Well, we are back to very interesting physics.
Also: if I increase the core density towards infinity will the mantle density converge towards a value around 14,000 kg per cubic meter. So even with an infinitely dense core something must be very different.
Or Rock is not Rock (a.k.a. mostly silicon dioxide) but behaves like it … interesting physics at all corners … Thinking about it, is this planet truly fascinating
I'm open for suggestions to solve this riddle. And even though I've gone through the calculations several times may I have forgotten to divide by a thousand somewhere. So anybody please be my guest and check these numbers.
