User:Stecklen/sandbox

Outline Of Entire Wiki Article (With potential edits)
italics = pre-existing section

bold = new section


 * 1) Discovery
 * 2) Earth's core
 * 3) Link to Earth's Core wiki page
 * 4) Seismological methods
 * 5) Moon and Rocky Planet cores
 * 6) Formation
 * 7) Accretion
 * 8) Differentiation
 * 9) Magma oceans (need it's own section?)
 * 10) Core merging/impacts
 * 11) Earth-Moon system
 * 12) Mars
 * 13) Chemistry
 * 14) Determining primary composition - Earth
 * 15) Talk about light elements in the core
 * 16) Link to mineral physics and experiments
 * 17) Weight deficit components - Earth
 * 18) Isotopic composition - Earth
 * 19) Pallasite meteorites
 * 20) Dynamics
 * 21) Dynamo
 * 22) Stability and instability
 * 23) Heating of cores
 * 24) primordial heat/secular cooling
 * 25) Rocky planets: more massive planets = longer cooling
 * 26) Cores in the Solar System
 * 27) Observed Types
 * 28) Within the Solar System
 * 29) Mercury
 * 30) Venus
 * 31) Moon
 * 32) Earth
 * 33) Mars
 * 34) Ganymede
 * 35) Jupiter
 * 36) Saturn
 * 37) Remnant Planetary Cores
 * 38) Psyche mission
 * 39) Extrasolar
 * 40) Chthonian planets
 * 41) Planets derived from stellar cores and diamond planets
 * 42) Hot ice planets
 * 1) Hot ice planets

Edits section by section
Again, italics is text that is already a part of this article. Non-italicized text is my contribution.

I will switch the sections Dynamics and Chemistry, as Dara suggested.

(Discovery) Moon and Rocky planet cores
The core of the moon was determined using moonquakes measured by the Apollo measurements.

Mass and size can give us a first-order idea of the components that make up the interior of a planetary body. The structure of the rocky planets can be derived using average density of a planet and its moment of inertia. The composition or structure of the core can be inferred using conservation of energy calculations as well as magnetic field measurements.

(Dynamics) Heating of the Core
Planetary cores are a heat source for the planetary body. A core’s initial accretion energy, the primordial heat, leads to secular cooling of the core as energy radiates into the rest of the planet. Lord Kelvin tried to calculate this primordial heat as a way to calculate the age of the earth, and came up with an age of 10­8 years, an order of magnitude off of the actual value. While the correct age of the earth is much greater because Kelvin did not know about convection in the mantle, the arguing for an age of the earth based on a finite starting energy was an important first step.

(Dynamics) Non-Earth Cores in the Solar System
Cores of the terrestrial planets are similar in composition to that of the Earth. Mercury, Venus, and Mars all have and iron-dominant core, which may be liquid or solid [textbook]. Venus and Mars are thought to have another major element in the core. Venus’ core is believed to be iron-nickel, while Mars has two models for the core: an iron-iron sulfur component that would make the core molten, or an iron-nickel core, which would mean a solid, much smaller core. Cores of the terrestrial planets heat their planetary body the same way as the earth: with secular cooling from the principle gravitational energy. There is a noticeable trend within the rocky planets: the relative size of the core is inversely proportional to its orbital radius. This is believed to be because yada yada.

As for the gas giants, current understanding points to small “rock” cores, surrounded by a layer of ice, and in Jupiter and Saturn models suggest a large region of metallic hydrogen and helium. Phase diagrams for metallic hydrogen and helium predict this metallic phase, but it has yet to be substantially created in lab. In 2017, a group from Harvard University claims to have formed metallic hydrogen, but reviewers are skeptical or that result. Jupiter and Saturn appear to release a lot more energy than they would get from the sun, which could be a result of the hydrogen and helium layer. While Uranus does not appear to have a significant heat source, Neptune does, which can be attributed to a “hot” formation.

As for magnetic fields, there is no clear correlation over the rocky and gas planets. Venus and Mars, as well as the moon, do not have magnetic fields. This could be due to a lack of a convecting liquid layer interacting with a solid inner core.

(Observed Types) Remnant Planetary Cores
Missions to bodies in the asteroid belt will provide more insight to planetary core formation. The asteroid belt is believed to be a planet that was broken apart early on in solar system formation. It was long assumed that collisions in the solar system resulted in merges, but that is not necessarily the case. Remnants of collisions have their outer layers stripped, leaving behind a body that would eventually become a planetary core. By directly studying objects in the asteroid belt, planetary cores can be better understood. One such mission is the Psyche mission. Titled “Journey to a Metal World,” the Psyche mission is studying a body that could possibly be a remnant planetary core.

(Observed Types) Extrasolar
As the exoplanet field grows as new techniques allow for the discovery of both more and more diverse exoplanets, the cores of exoplanets are being modeled.

Figures
1.  Collision figure from Lindy Elkins-Tanton

2. Figure of solar systems - made myself