List of Solar System objects by size
This article includes a list of the most massive known objects of the Solar System and partial lists of smaller objects by observed mean radius. These lists can be sorted according to an object's radius and mass and, for the most massive objects, volume, density, and surface gravity, if these values are available.
These lists contain the Sun, the planets, dwarf planets, many of the larger small [Solar System body|small Solar System bodies], all named natural satellites, and a number of smaller objects of historical or scientific interest, such as comets and near-Earth objects.
Many trans-Neptunian objects have been discovered; in many cases their positions in this list are approximate, as there is frequently a large uncertainty in their estimated diameters due to their distance from Earth. There are uncertainties in the figures for mass and radius, and irregularities in the shape and density, with accuracy often depending on how close the object is to Earth or whether it has been visited by a probe.
Solar System objects more massive than 1021 kilograms are known or expected to be approximately spherical. Astronomical bodies relax into rounded shapes, achieving hydrostatic equilibrium, when their own gravity is sufficient to overcome the structural strength of their material. It was believed that the cutoff for round objects is somewhere between 100 km and 200 km in radius if they have a large amount of ice in their makeup; however, later studies revealed that icy satellites as large as Iapetus are not in hydrostatic equilibrium at this time, and a 2019 assessment suggests that many TNOs in the size range of 400–1,000 kilometers may not even be fully solid bodies, much less gravitationally rounded. Objects that are ellipsoids due to their own gravity are here generally referred to as being "round", whether or not they are actually in equilibrium today, while objects that are clearly not ellipsoidal are referred to as being "irregular."
Spheroidal bodies typically have some polar flattening due to the centrifugal force from their rotation, and can sometimes even have quite different equatorial diameters. Unlike bodies such as Haumea, the irregular bodies have a significantly non-ellipsoidal profile, often with sharp edges.
There can be difficulty in determining the diameter for typical objects beyond Saturn. For TNOs there is some confidence in the diameters, but for non-binary TNOs there is no real confidence in the masses/densities. Many TNOs are often just assumed to have Pluto's density of 2.0 g/cm3, but it is just as likely that they have a comet-like density of only 0.5 g/cm3.
For example, if a TNO is incorrectly assumed to have a mass of 3.59 kg based on a radius of 350 km with a density of 2 g/cm3 but is later discovered to have a radius of only 175 km with a density of 0.5 g/cm3, its true mass would be only 1.12 kg.
The sizes and masses of many of the moons of Jupiter and Saturn are fairly well known due to numerous observations and interactions of the Galileo and Cassini orbiters; however, many of the moons with a radius less than ≈100 km, such as Jupiter's Himalia, have far more uncertain masses. Further out from Saturn, the sizes and masses of objects are less clear. There has not yet been an orbiter around Uranus or Neptune for long-term study of their moons. For the small outer irregular moons of Uranus, such as Sycorax, which were not discovered by the Voyager 2 flyby, even different NASA web pages, such as the National [Space Science Data Center] and JPL Solar System Dynamics, give somewhat contradictory size and albedo estimates depending on which research paper is being cited.
Graphical overview
Objects with radii over 400 km
The following objects have a nominal mean radius of 400 km or greater. It was once expected that any icy body larger than approximately 200 km in radius was likely to be in hydrostatic equilibrium. However, is the smallest body for which detailed measurements are consistent with hydrostatic equilibrium, whereas Iapetus is the largest icy body that has been found to not be in hydrostatic equilibrium. The known icy moons in this range are all ellipsoidal, but trans-Neptunian objects up to 450–500 km radius may be quite porous.For simplicity and comparative purposes, the values are manually calculated assuming that the bodies are all spheres. The size of solid bodies does not include an object's atmosphere. For example, Titan looks bigger than Ganymede, but its solid body is smaller. For the giant planets, the "radius" is defined as the distance from the center at which the atmosphere reaches 1 bar of atmospheric pressure.
Because Sedna has no known moons, directly determining its mass is impossible without sending a probe.
Smaller objects by mean radius
From 200 to 399 km
All imaged icy moons with radii greater than 200 km except Proteus are clearly round, although those under 400 km that have had their shapes carefully measured are not in hydrostatic equilibrium. The known densities of TNOs in this size range are remarkably low, implying that the objects retain significant internal porosity from their formation and were never gravitationally compressed into fully solid bodies. Many intrinsically bright TNOs like and do not have directly measured sizes, so their sizes are estimated based on an assumed albedo. In the list below, TNOs with unmeasured sizes are only listed if they have been mentioned in press releases and the scientific literature.From 100 to 199 km
This list contains a selection of objects estimated to be between 100 and 199 km in radius, being 200 km nicknamed the "potato radius" by astronomers. The largest of these may have a hydrostatic-equilibrium shape, but most are irregular. Mass switches from 1021 kg to 1018 kg. Main-belt asteroids have orbital elements constrained by according to JPL Solar System Dynamics. Many TNOs are omitted from this list as their sizes are poorly known.From 50 to 99 km
This list contains a selection of objects 50 and 99 km in radius. The listed objects currently include most objects in the asteroid belt and moons of the giant planets in this size range, but many newly discovered objects in the outer Solar System are missing, such as those included in the following reference. Asteroid spectral types are mostly Tholen, but some might be SMASS.| Body | Image | Radius ' | Mass | Type | Refs ' |
| Elektra 130 | belt asteroid type G; multiple | ||||
| Bienor 54598 | centaur | ||||
| Chiron 2060 or 95P | centaur; has rings | ||||
| Hebe 6 | belt asteroid type S | ||||
| Larissa Neptune VII | moon of Neptune | ||||
| Ursula 375 | belt asteroid type C | ||||
| Eugenia 45 | file:45 Eugenia VLT, deconvolved.pdf|frameless|center|upright=0.2 | belt asteroid type F; trinary | |||
| Hermione 121 | outer belt asteroid type C; binary | ||||
| Daphne 41 | file:41 Daphne VLT, deconvolved.pdf|frameless|center|upright=0.2 | belt asteroid type C; minor [planet moon|binary] | |||
| Aurora 94 | belt asteroid type C | ||||
| Bertha 154 | file:000154-asteroid shape model Bertha.png|frameless|center|upright=0.2 | belt asteroid type C | |||
24835 | cubewano, Haumea family | ||||
| Moon of 532037 Chiminigagua | moon of 532037 Chiminigagua | ||||
| Janus Saturn X | moon of Saturn | ||||
| Teharonhiawako 88611 | cubewano; binary | ||||
| Aegle 96 | belt asteroid type T | ||||
| Galatea Neptune VI | moon of Neptune | ||||
| S/2015 1 | moon of Makemake | ||||
| Phorcys Ceto I | secondary of 65489 Ceto | ||||
| Palma 372 | belt asteroid type B | ||||
| Metis 9 | belt asteroid type S | ||||
| Alauda 702 | belt asteroid type C; binary | ||||
| Hilda 153 | outer belt asteroid; Hildas | ||||
| Himalia Jupiter VI | moon of Jupiter | ||||
| Freia 76 | outer belt asteroid type P/type X | ||||
| Amalthea Jupiter V | moon of Jupiter | ||||
| Agamemnon 911 | Jupiter trojan type D | ||||
| Elpis 59 | belt asteroid type CP/type B | ||||
| Eleonora 354 | file:354 Eleonora VLT, deconvolved.pdf|frameless|center|upright=0.2 | belt asteroid type A | |||
| Weywot Quaoar I | moon of Quaoar | ||||
| Nemesis 128 | file:128 Nemesis VLT, deconvolved.pdf|frameless|center|upright=0.2 | belt asteroid type C | |||
| Puck Uranus XV | moon of Uranus | ||||
307251 | cubewano | ||||
| Sycorax Uranus XVII | moon of Uranus | ||||
| Io 85 | belt asteroid type FC/type B | ||||
| Minerva 93 | belt asteroid type C; trinary | ||||
| Alexandra 54 | belt asteroid type C | ||||
| Laetitia 39 | belt asteroid type S | ||||
| Nemausa 51 | belt asteroid type G | ||||
| Kalliope 22 | file:22 Kalliope VLT, deconvolved.pdf|frameless|center|upright=0.2 | belt asteroid type M; binary | |||
| Despina Neptune V | moon of Neptune | ||||
| Namaka Haumea II | moon of Haumea | ||||
| Manwë 385446 | Resonant [Kuiper belt object|resonant KBO] ; binary | ||||
| Pales 49 | belt asteroid type C | ||||
| Parthenope 11 | file:11 Parthenope VLT, deconvolved.pdf|frameless|center|upright=0.2 | belt asteroid type S | |||
| Arethusa 95 | belt asteroid type C | ||||
| Pulcova 762 | belt asteroid type F; binary | ||||
| Flora 8 | file:8 Flora VLT, deconvolved.pdf|frameless|center|upright=0.2 | belt asteroid type S | |||
| Ino 173 | file:173 Ino VLT, deconvolved.pdf|frameless|center|upright=0.2 | belt asteroid type Xc | |||
| Adeona 145 | file:145 Adeona VLT, deconvolved.pdf|frameless|center|upright=0.2 | belt asteroid type Xc | |||
| Irene 14 | belt asteroid type S | ||||
| Gǃòʼé ǃHú Gǃkúnǁʼhòmdímà I | secondary of 229762 Gǃkúnǁʼhòmdímà | ||||
| Aglaja 47 | belt asteroid type C | ||||
| Melpomene 18 | file:18 Melpomene VLT, deconvolved.pdf|frameless|center|upright=0.2 | belt asteroid type S | |||
| Lamberta 187 | file:Lamberta VLT.png|frameless|center|upright=0.2 | belt asteroid type Ch | |||
| Patroclus 617 | Jupiter trojan type P; binary | ||||
| Julia 89 | belt asteroid type S | ||||
| Typhon 42355 | resonant SDO ; binary | ||||
| ǂKá̦gára 469705 | cold classical KBO; binary | ||||
| Massalia 20 | belt asteroid type S | ||||
| Portia Uranus XII | moon of Uranus | ||||
| Emma 283 | belt asteroid type X; binary | ||||
| Paha Lempo I | moon of 47171 Lempo | ||||
| Lucina 146 | ±? | belt asteroid type C | |||
| Sawiskera Teharonhiawako I | secondary of 88611 Teharonhiawako | ||||
| Achilles 588 | Jupiter trojan type DU | ||||
| Panopaea 70 | belt asteroid type C | ||||
| Thule 279 | outer belt asteroid type D | ||||
| Borasisi 66652 | cubewano; binary | ||||
| Albion 15760 | TNO, first KBO discovered | ||||
| Hestia 46 | belt asteroid type P/type Xc | ||||
| Leto 68 | belt asteroid type S | ||||
| ǃHãunu ǂKá̦gára I | secondary of 469705 ǂKá̦gára | ||||
| Undina 92 | belt asteroid type X | ||||
| Bellona 28 | belt asteroid type S | ||||
| Diana 78 | belt asteroid type C | ||||
| Anchises 1173 | Jupiter trojan type P | ||||
| Bernardinelli-Bernstein C/2014 UN271 | comet | ||||
| Galatea 74 | belt asteroid type C | ||||
| Deiphobus 1867 | Jupiter trojan type D | ||||
| Äneas 1172 | Jupiter trojan type D | ||||
| Kleopatra 216 | belt asteroid type M; trinary | ||||
| Athamantis 230 | belt asteroid type S | ||||
| Diomedes 1437 | Jupiter trojan type D | ||||
| Terpsichore 81 | belt asteroid type C | ||||
| Epimetheus Saturn XI | moon of Saturn | ||||
| Victoria 12 | belt asteroid type S | ||||
| Circe 34 | belt asteroid type C | ||||
| Leda 38 | belt asteroid type C | ||||
| Odysseus 1143 | Jupiter trojan type D | ||||
| Alcathous 2241 | Jupiter trojan type D | ||||
| Melete 56 | belt asteroid type P | ||||
| Mnemosyne 57 | belt asteroid type S | ||||
| Nestor 659 | Jupiter trojan type XC | ||||
| Harmonia 40 | belt asteroid type S | ||||
| Euterpe 27 | belt asteroid type S | ||||
| Antilochus 1583 | Jupiter trojan type D | ||||
| Thorondor Manwë I | secondary of 385446 Manwë | ||||
| Thalia 23 | belt asteroid type S | ||||
| Erato 62 | belt asteroid type BU/type Ch | ||||
| Astraea 5 | belt asteroid type S | ||||
| Pabu Borasisi I | secondary of 66652 Borasisi | ||||
| Eos 221 | belt asteroid type S/type K | ||||
| Aegina 91 | belt asteroid type C | ||||
| Leukothea 35 | belt asteroid type C | ||||
| Menoetius Patroclus I | secondary of 617 Patroclus | ||||
| Isis 42 | belt asteroid type S | ||||
| Klotho 97 | belt asteroid type M | ||||
| Troilus 1208 | Jupiter trojan type FCU |
From 20 to 49 km
This list includes few examples since there are about 589 asteroids in the asteroid belt with a measured radius between 20 and 49 km. Many thousands of objects of this size range have yet to be discovered in the trans-Neptunian region. The number of digits is not an endorsement of significant figures. The table switches from kg to kg. Most mass values of asteroids are assumed.| Body | Image | Radius ' | Mass | Type – notes | Refs ' |
| Asterope 233 | belt asteroid type T/type K | ||||
| Pholus 5145 | centaur | ||||
| Thebe Jupiter XIV | moon of Jupiter | ||||
| Lutetia 21 | belt asteroid type M | ||||
| Kalypso 53 | belt asteroid type XC | ||||
| Notburga 626 | belt asteroid type XC | ||||
| Proserpina 26 | belt asteroid type S | ||||
| Juliet Uranus XI | moon of Uranus | ||||
| Urania 30 | belt asteroid type S | ||||
| Ausonia 63 | belt asteroid type S | ||||
| Beatrix 83 | belt asteroid type X | ||||
| Concordia 58 | belt asteroid type C | ||||
| Echidna Typhon I | moon of 42355 Typhon | ||||
| Automedon 2920 | Jupiter trojan type D | ||||
| Antiope 90 | belt asteroid type C; binary | ||||
| Prometheus Saturn XVI | moon of Saturn | ||||
| Danaë 61 | belt asteroid type S | ||||
| Thetis 17 | belt asteroid type S | ||||
| Pandora 55 | belt asteroid type M | ||||
| Huenna 379 | belt asteroid type B/type C; binary | ||||
| Virginia 50 | belt asteroid type X/type Ch | ||||
| Feronia 72 | belt asteroid type TDG | ||||
| S/2000 1 Antiope I | secondary of 90 Antiope | ||||
| Poulydamas 4348 | Jupiter trojan type C | ||||
| Logos 58534 | cubewano; binary | ||||
| Pandora Saturn XVII | moon of Saturn | ||||
| Thalassa Neptune IV | moon of Neptune | ||||
| Niobe 71 | belt asteroid type S | ||||
| Pomona 32 | belt asteroid type S | ||||
| Belinda Uranus XIV | moon of Uranus | ||||
| Elara Jupiter VII | moon of Jupiter | ||||
| Cressida Uranus IX | moon of Uranus | ||||
| Amycus 55576 | centaur | ||||
| Hylonome 10370 | centaur | ||||
| Socus 3708 | Jupiter trojan type C | ||||
| Nysa 44 | belt asteroid type E | ||||
| Rosalind Uranus XIII | moon of Uranus | ||||
| Maja 66 | belt asteroid type C | ||||
| Ariadne 43 | belt asteroid type S | ||||
| Iphigenia 112 | belt asteroid type C | ||||
| Xiangliu Gonggong I | moon of 225088 Gonggong | ||||
| Dike 99 | belt asteroid type C | ||||
| Echeclus 60558 or 174P | centaur | ||||
| Desdemona Uranus X | moon of Uranus | ||||
| Eurybates 3548 | Jupiter trojan type CP | ||||
| Eurynome 79 | belt asteroid type S | ||||
| Eurydike 75 | belt asteroid type M | ||||
| Halimede Neptune IX | moon of Neptune | ||||
| Phocaea 25 | belt asteroid type S | ||||
| Naiad Neptune III | moon of Neptune | ||||
| Schwassmann– Wachmann 1 29P | comet | ||||
| Neso Neptune XIII | moon of Neptune | ||||
| Angelina 64 | belt asteroid type E | ||||
| Pasiphae Jupiter VIII | moon of Jupiter | ||||
| Alkmene 82 | belt asteroid type S | ||||
| Nessus 7066 | centaur | ||||
| Polana 142 | belt asteroid type F | ||||
| Bianca Uranus VIII | moon of Uranus | ||||
| Mathilde 253 | belt asteroid type C | ||||
| Hidalgo 944 | centaur | ||||
| Orus 21900 | Jupiter trojan type C/type D | ||||
| Amalthea 113 | belt asteroid type S; binary | ||||
| Prospero Uranus XVIII | moon of Uranus | ||||
| Setebos Uranus XIX | moon of Uranus | ||||
| Carme Jupiter XI | moon of Jupiter | ||||
| Klytia 73 | belt asteroid type S | ||||
| Sao Neptune XI | moon of Neptune | ||||
| Echo 60 | belt asteroid type S | ||||
| Metis Jupiter XVI | moon of Jupiter | ||||
| Ophelia Uranus VII | moon of Uranus | ||||
| Lysithea Jupiter X | moon of Jupiter | ||||
| Caliban Uranus XVI | moon of Uranus | ||||
| Laomedeia Neptune XII | moon of Neptune | ||||
| Cordelia Uranus VI | moon of Uranus | ||||
| Psamathe Neptune X | moon of Neptune |
From 1 to 19 km
This list contains some examples of Solar System objects between 1 and 19 km in radius. This is a common size for asteroids, comets and irregular moons.| Body | Image | Radius ' | Mass | Type – notes | Refs ' |
| Urda 167 | belt asteroid type S | ||||
| Hydra Pluto III | moon of Pluto | ||||
| Siarnaq Saturn XXIX | moon of Saturn | ||||
| Koronis 158 | belt asteroid type S | ||||
| Nix Pluto II | moon of Pluto | ||||
| Ganymed 1036 | Amor asteroid type S | ||||
| Okyrhoe 52872 | centaur | ||||
| Blarney 2320 | belt asteroid | ||||
| Helene Saturn XII | moon of Saturn; Dione trojan | ||||
| Sinope Jupiter IX | moon of Jupiter | ||||
| Hippocamp Neptune XIV | moon of Neptune | ||||
| Leucus 11351 | Jupiter trojan type D | ||||
| Stephano Uranus XX | moon of Uranus | ||||
| Arrokoth 486958 | cubewano; binary |contact binary] | ||||
| Ida 243 | belt asteroid type S; binary | ||||
| Atlas Saturn XV | moon of Saturn | ||||
| Ananke Jupiter XII | moon of Jupiter | ||||
| Albiorix Saturn XXVI | moon of Saturn | ||||
| Pan Saturn XVIII | moon of Saturn | ||||
| Linus Kalliope I | asteroid moon of 22 Kalliope | ||||
| Dioretsa 20461 | centaur; damocloid | ||||
| Perdita Uranus XXV | moon of Uranus | ||||
| Telesto Saturn XIII | moon of Saturn; Tethys trojan | ||||
| Mab Uranus XXVI | moon of Uranus | ||||
| Phobos Mars I | moon of Mars | ||||
| Paaliaq Saturn XX | moon of Saturn | ||||
| Francisco Uranus XXII | moon of Uranus | ||||
| Leda Jupiter XIII | moon of Jupiter | ||||
| Calypso Saturn XIV | moons of Saturn; Tethys trojan | ||||
| Polymele 15094 | Jupiter trojan type P | ||||
| Margaret Uranus XXIII | moon of Uranus | ||||
| Ferdinand Uranus XXIV | moon of Uranus | ||||
| Cupid Uranus XXVII | moon of Uranus | ||||
| Ymir Saturn XIX | moon of Saturn | ||||
| Trinculo Uranus XXI | moon of Uranus | ||||
| Eros 433 | Amor asteroid type S | ||||
| Adrastea Jupiter XV | moon of Jupiter | ||||
| Kiviuq Saturn XXIV | moon of Saturn | ||||
| Tarvos Saturn XXI | moon of Saturn | ||||
| Kerberos Pluto IV | moon of Pluto | ||||
| Gaspra 951 | belt asteroid type S | ||||
| Deimos Mars II | moon of Mars | ||||
| Skamandrios Hektor I | asteroid moon of 624 Hektor | ||||
| Ijiraq Saturn XXII | moon of Saturn | ||||
| Tsuchinshan–ATLAS C/2023 A3 | <5.9 ± 0.2 | comet | |||
| Halley's Comet 1P | comet | ||||
| Styx Pluto V | moon of Pluto | ||||
| Romulus Sylvia I | asteroid moon of 87 Sylvia | ||||
| Masursky 2685 | belt asteroid type S | ||||
| Erriapus Saturn XXVIII | moon of Saturn | ||||
| Callirrhoe Jupiter XVII | moon of Jupiter | ||||
| Alexhelios Kleopatra I | asteroid moon of 216 Kleopatra | ||||
| Esclangona 1509 | inner belt asteroid type S; binary | ||||
| Themisto Jupiter XVIII | moon of Jupiter | ||||
| Daphnis Saturn XXXV | moon of Saturn | ||||
| Petit-Prince Eugenia I | asteroid moon of 45 Eugenia | ||||
| Praxidike Jupiter XXVII | moon of Jupiter | ||||
| Bestla Saturn XXXIX | moon of Saturn | ||||
| Remus Sylvia II | asteroid moon of 87 Sylvia | ||||
| Kalyke Jupiter XXIII | moon of Jupiter | ||||
| Cleoselene Kleopatra II | asteroid moon of 216 Kleopatra | ||||
| Moon of 31 Euphrosyne | asteroid moon of 31 Euphrosyne | ||||
| Tempel 1 9P | Jupiter-family comet; Deep Impact flyby and impacted | ||||
| Ireland 5029 | belt asteroid | ||||
| Phaethon 3200 | Apollo asteroid type F | ||||
53319 | Apollo asteroid type X | ||||
| Borrelly 19P | Jupiter-family comet | ||||
| Šteins 2867 | belt asteroid type E | ||||
| Atira 163693 | Atira asteroid type S; binary | ||||
| Annefrank 5535 | belt asteroid type S | ||||
| Balam 3749 | belt asteroid type S; trinary | ||||
| Pallene Saturn XXXIII | moon of Saturn | ||||
| Florence 3122 | Amor asteroid type S; trinary | ||||
| Wild 2 81P | Jupiter family comet | ||||
| Litva 2577 | Mars-crosser type EU; trinary | ||||
| Churyumov–Gerasimenko 67P | Jupiter-family comet | ||||
| Donaldjohanson 52246 | belt asteroid type C | ||||
| Camelot 9500 | belt asteroid | ||||
| Cuno 4183 | Apollo asteroid type S/type Q | ||||
6178 | Amor asteroid type M | ||||
| Pichi üñëm Alauda I | asteroid moon of 702 Alauda | ||||
| Toutatis 4179 | Apollo asteroid type S | ||||
| Methone Saturn XXXII | moon of Saturn | ||||
| Carpo Jupiter XLVI | Moon of Jupiter | ||||
| Gault 6478 | Phocaea asteroid type S | ||||
285263 | Amor asteroid type S; binary | ||||
| Polydeuces Saturn XXXIV | moon of Saturn; Dione trojan | ||||
153591 | Amor asteroid type C; trinary | ||||
| S/2003 1 Moon of 1509 Esclangona | asteroid moon of 1509 Esclangona | ||||
| APL 132524 | belt asteroid type S | ||||
| Camillo 3752 | Apollo asteroid type S | ||||
| Cruithne 3753 | Aten asteroid type Q; quasi-satellite of Earth | ||||
8567 | 1.01 | Amor asteroid |
Below 1 km
This list contains examples of objects below 1 km in radius. That means that irregular bodies can have a longer chord in some directions, hence the mean radius averages out.In the asteroid belt alone there are estimated to be between 1.1 and 1.9 million objects with a radius above 0.5 km, many of which are in the range 0.5–1.0 km. Countless more have a radius below 0.5 km.
Very few objects in this size range have been explored or even imaged. The exceptions are objects that have been visited by a probe, or have passed close enough to Earth to be imaged. Radius is by mean geometric radius. Number of digits not an endorsement of significant figures. Mass scale shifts from × 1015 to 109 kg, which is equivalent to one billion kg or 1012 grams.
Currently most of the objects of mass between 109 kg to 1012 kg listed here are near-Earth asteroids. The Aten asteroid has less mass than the Great Pyramid of Giza, 5.9 × 109 kg.
For more about very small objects in the Solar System, see meteoroid, micrometeoroid, cosmic dust, and interplanetary dust cloud. '