1P/Halley scaled one in 200 thousand

prusaprinters

<p>Originally published here: <a href="https://www.thingiverse.com/thing:3866873">1P/Halley scaled one in 200 thousand by tato_713 - Thingiverse</a></p><p>This model was rendered using MATLAB R2016a on the ICQ model of the PSI made by Philip Stooke. With this model I've try a modification of the surf2stl function I use for all the models, along with the interpolation method I have described <a href="https://www.thingiverse.com/thing:3865910">here</a>. Like many, if not all, comets its rotation is chaotic and may change over the time, so the northern and southern hemispheres cannot be determined, and the labels "north" and "south" in the model's file names and the model inclination are arbitrary.</p><p>The file's names explained:<i>name_1_x_10_y.stl</i> is 1 : x* 10^y. So _1_6_10_7 is 1:600000000 or one in 60 million.&nbsp;</p><h4>1P/Halley</h4><p>Halley's comet is the only naked-eye visible short periodic comet, most of the comets seen have periods of thousand of years, and most of the periodic comets are too small and faint to be seen. This comet was the first one to be identificated as periodic, by Edmond Halley, and can be tracked back to 240 BC in ancient records. Short period comets are though to be former <a href="https://www.thingiverse.com/thing:3442743">Kuiper belt and Scattered disk objects</a> that fall down into a highly elliptical, Jupiter resonant, orbit. They could be, but it is unusual, deorbited long period comets, which origin is in the hypothetical Oort cloud. Halley's comet has one of the biggest known nucleus of any comet. The nucleus of a comet (the solid part) is composed of water ice, dust particles and organic compounds. <a href="https://www.thingiverse.com/thing:3703414">Arrokoth</a> may be a prototype of a cometary body before the perturbation from another object makes it fall into a lower orbit. When any comet come close to the inner Solar System, the volatile material sublimates and creates an atmosphere, that elongates in the oposite direction of the Sun, because of the solar wind, creating the coma of the comet. The dust impulsed by the thrown material creates the tail. Comets come so close to the Sun that they could be destroyed, evaporating completely, or breaking apart into smaller pieces, that could coalesce again to a weak rubble pile or create a new comet family. A comet could eventually impact with a planets or other objects, like the comet Shoemaker - Levy 9 which collided with <a href="https://www.thingiverse.com/thing:3928031">Jupiter</a> after being disrupted in many pieces in a close encounter with it. Comets have unstable orbits and they cross the orbits of all the planets, so close encounters can be common. Short period comets have also relatively low inclined orbits, so the the probability of this interaction are greater. They could be responsible for various extinction events, not only because the possibility of an impact with the <a href="https://www.thingiverse.com/thing:3612782">Earth</a>, but because the possibility of shattering a minor planet like an asteroid that create a new asteroid family, scattering the smallest bodies like bullets through the Solar System. If a comet survives this tragic endings, it could deplete of volatile materials and became an extinct comet, that resemble an asteroid. Damocloids, asteroids with elliptic, comet-like orbits, and many <a href="/tato_713/collections/near-earth-asteroids">Near Earth Asteroids</a>, like <a href="https://www.thingiverse.com/thing:4232421">Phaethon</a>, can be extinct comets.</p><ul><li><strong>Type:</strong> Comet.&nbsp;</li><li><strong>Orbit:</strong> Sun.&nbsp;</li><li><strong>Orbital period:</strong> 75.32 yr.&nbsp;</li><li><strong>Composition:</strong> Icy body.&nbsp;</li><li><strong>Density:</strong> 0.6 g/cm3.&nbsp;</li><li><strong>Dimensions:</strong> 15 km × 8 km&nbsp;</li><li><strong>Model scale:</strong> 1:8x104 (20cm) 1:2x105 (8cm)</li></ul><h4>References</h4><ul><li><a href="https://sbn.psi.edu/pds/resource/stkshape.html">"Stooke. P., Stooke Small Body Shape Models V2.0. EAR-A-5-DDR-STOOKE-SHAPE-MODELS-V2.0. NASA Planetary Data System, 2016."</a></li><li><a href="https://www.mathworks.com/matlabcentral/fileexchange/4512-surf2stl">Original surf to STL function for MATLAB&nbsp;</a></li></ul><h3>Other astronomical objects</h3><p><a href="https://www.prusaprinters.org/social/120859-tato_713/collections/49826">Inner Solar System</a></p><p><a href="https://www.prusaprinters.org/social/120859-tato_713/collections/49832">Artificial</a></p><p><a href="https://www.prusaprinters.org/social/120859-tato_713/collections/49820">Near Earth Asteroids</a></p><p><a href="https://www.prusaprinters.org/social/120859-tato_713/collections/49291">Main Belt Asteroids</a></p><p><a href="https://www.prusaprinters.org/social/120859-tato_713/collections/49829">Jovian System</a></p><p><a href="https://www.prusaprinters.org/social/120859-tato_713/collections/49828">Saturn System</a></p><p><a href="https://www.prusaprinters.org/social/120859-tato_713/collections/49830">Uranian System</a></p><p><a href="https://www.prusaprinters.org/social/120859-tato_713/collections/49345">Neptunian System</a></p><p><a href="https://www.prusaprinters.org/social/120859-tato_713/collections/49827">Centaurs</a></p><p><a href="https://www.prusaprinters.org/social/120859-tato_713/collections/49833">Comets</a></p><p><a href="https://www.prusaprinters.org/social/120859-tato_713/collections/49341">Trans Neptunian Objects</a></p><p><a href="https://www.prusaprinters.org/social/120859-tato_713/collections/49824">Extrasolar Objects</a></p><p><a href="https://www.prusaprinters.org/social/120859-tato_713/collections/49837">Sky Maps</a></p><p><a href="https://www.prusaprinters.org/social/120859-tato_713/collections/49831">Ancient</a></p><p><a href="https://www.prusaprinters.org/social/120859-tato_713/collections/49822">Speculative</a></p><p><a href="https://www.prusaprinters.org/social/120859-tato_713/collections/49821">Science Fiction</a></p>