# Intro - The Kuiper Belt and Beyond Beyond the orbit of Neptune lies the Kuiper Belt. This is a region not dissimilar from our asteroid belt, though a greater proportion of its mass consists of ice rather than rock. Consisting of the remnant light material from the sun's formation, this area of the solar system, far from the light of the sun and even Neptune itself, is dark, cold, and harbours a very special type of object - the Trans-Neptunian Object (TNO). Of which many are also **Dwarf Planets** (DPs). These planet-like objects aren't bound to any larger bodies (unlike Triton %%link this!%%) though they don't have the mass to *clear their orbits of any planetoids*. They are, for the most part, spherical, being massive enough for their surfaces to be 'smoothened' by their gravities - though there are outliers. The reason I refer to Kuiper Belt objects as TNOs are because DPs exist too in the asteroid belt. Though most people associate DPs with Pluto anyways... ![[Pasted image 20241214003329.png]] *"A Wannabe Clyde Tombaugh"* # Ceres - The Pit Stop Would Ceres, or any asteroid belt object, come to your mind first if you think about dwarf planets? First discovered by the astronomer Giuseppe Piazzi in 1801, the dwarf planet Ceres is the largest and most massive object in the asteroid belt. In fact, it alone consists of almost *25%* of the asteroid belt's mass. It's named after the Roman name for the goddess [Demeter](https://fitzmuseum.cam.ac.uk/learn-with-us/the-story-of-demeter-and-persephone#:~:text=Demeter%20was%20the%20Ancient%20Greek,like%20her%20mum%2C%20loved%20nature.), which represented the autumn harvest and nature. With a radius of and is the only one of the asteroid belt objects to show signs of [[Hydrostatics (Mechanics)#Stellar Hydrodynamics|hydrostatic equilibrium (LINK TO UNFINISHED FILE)]], meaning that it's rounded. Ceres makes 1 rotation every 9 hours [^1], and has a radius of roughly 470km. In addition, it's relatively dense for a dwarf planet - at around 2.0-2.3 $\mathrm{g \ cm^{-3}}$ [^2], or grams per centimetre cubed, with some sources even going as high as 2.7 $\mathrm{g \ cm^{-3}}$ [^3]. This points to a mixed rocky-ice internal composition, though the density's likely too high for there to be a significant underwater ocean beneath Ceres' surface. ![[ceres.png.png]] *Ceres! [Credit:NASA/JPL-Caltech/UCLA/MPS/DLR/IDA](https://www.jpl.nasa.gov/news/dawn-captures-sharper-images-of-ceres/)* Being one of the largest and closest 'icy rocks' (meaning that it's got a differentiated interior of rock and ice) to us, Ceres has naturally been subject to tremendous interest from those hoping to understand moons further and further beyond our grasp - and it's therefore been the subject of many missions itself. One such mission was the **Dawn** mission, which was able to enter into an orbit around Ceres. When making in-depth observations of the Cererian surface, it stumbled upon an Olympus Mons-esque mountain made purely of hydrocarbons and among the pockmarked surface of Ceres stands one mountain that points towards a more complicated interior - **Ahuna Mons**! ![[ahuna_mons.png.png]] *Ahuna Mons! Credit: [NASA/JPL-Caltech/UCLA/MPS/DLR/IDA](https://www.dlr.de/dlr/presse/en/desktopdefault.aspx/tabid-10172/213_read-35076/year-all/#/gallery/35497)* Standing at roughly 4,000 metres tall, Ahuna Mons is a *Cryovolcano* - a volcano that spews water, ice and mud rather than the lava that we're used to. It's quite a spectacle - these cryovolcanoes function more like geysers than the volcanoes on Earth. The 'Mountain' of Ahuna Mons is the result of thousands of years of eruptions slowly but surely piling atop other eruptions. Like any volcano on Earth, the 'cryovolcano' will eventually peter out, becoming inactive. Once this happens, the cone of the 'mountain' will slowly erode as Ceres plows through the intersolar medium, until Ahuna Mons eventually becomes one with the surface it now towers over. These cryovolcanoes offer a glimpse into the composition of Ceres' mantle; as what Ahuna Mons is primarily made of is brine, water ice and mud, it is often assumed that Ceres' mantle is either a briny (very salty!) ocean or an ocean of mud with high concentrations of mineral salts. This is important - if we use the same logic to look at cryovolcanoes on other planets or moons, we can gain insights into the compositions of their mantles too - and if they're likely to have water-ice compositions or not. Sometimes, we can even detect the presence of organic molecules on these mountains, which is a great sign for us in discovering life. %%geographical studies - remember the phys.org article?%% %%now craters and surface and other special things!%% # Eris - The Largest Dwarf Planet # Haumea - The Oblong Planet # Glossary (Footer Form) - **Ice Line**: The arbitrary 'line' in the solar system that determines where water becomes ice on planetary bodies # Sources ## Ceres *For the more casual reader! Dwarf Planetary Details cited down below.* 1. https://science.nasa.gov/dwarf-planets/ceres/ 2. https://www.britannica.com/place/Ceres-dwarf-planet 3. https://www.esa.int/About_Us/ESAC/Ahuna_Mons_on_Ceres # What's Next? # Footer [^1]: https://www.sciencedirect.com/science/article/abs/pii/S0019103522000549 [^2]: https://ui.adsabs.harvard.edu/abs/2008AGUFM.P51C1424Z/abstract#:~:text=The%20dwarf%20planet%20Ceres%20is,minerals%20%5B1-3%5D. [^3]: https://www.sciencedirect.com/science/article/pii/0019103587900480