Makemake, officially designated 136472 Makemake, is a dwarf planet situated within the Kuiper belt, a vast disc of icy celestial bodies located beyond Neptune's orbit. It ranks as the fourth-largest trans-Neptunian object and holds the distinction of being the largest member of the classical Kuiper belt, possessing a diameter approximately 60% that of Pluto. Its discovery occurred on March 31, 2005, attributed to American astronomers Michael E. ("Mike") Brown, Chad Trujillo, and David Rabinowitz at Palomar Observatory. The identification of Makemake, among the largest objects found by this research group, played a significant role in Pluto's reclassification as a dwarf planet in 2006.
Makemake (minor-planet designation: 136472 Makemake) is a dwarf planet in the Kuiper belt, a disk of icy bodies beyond the orbit of Neptune. It is the fourth largest trans-Neptunian object and the largest member of the classical Kuiper belt, having a diameter 60% that of Pluto. It was discovered on March 31, 2005 by American astronomers Michael E. ("Mike") Brown, Chad Trujillo, and David Rabinowitz at Palomar Observatory. As one of the largest objects found by this team, the discovery of Makemake contributed to the reclassification of Pluto as a dwarf planet in 2006.
Makemake exhibits surface characteristics analogous to Pluto, being highly reflective, predominantly covered by frozen methane, and displaying reddish-brown coloration due to tholins. It possesses a single identified, yet unnamed, satellite. The orbital dynamics of this satellite indicate a substantial axial tilt for Makemake's rotation, suggesting the presence of extreme seasonal variations. Furthermore, Makemake presents indications of geochemical activity and cryovolcanism, prompting scientific speculation regarding the potential existence of a subsurface liquid water ocean. While gaseous methane has been detected on Makemake, its origin—whether from a sustained atmosphere or transient outgassing—remains undetermined.
High-resolution imagery of Makemake's surface is currently unavailable, as no space probe has conducted a close-range flyby or orbital mission. Due to its considerable distance from Earth, Makemake appears merely as a stellar point of light, even when observed through powerful telescopes. Scientists have articulated an interest in dispatching a space probe to investigate Makemake, primarily motivated by its observed geological activity and the hypothesized presence of a subsurface ocean.
History
Discovery
Makemake's discovery occurred in 2005, attributed to a collaborative effort by American astronomers Michael E. ("Mike") Brown, Chad Trujillo, and David Rabinowitz, who were engaged in a systematic search for substantial celestial bodies beyond Neptune's orbit. This team's ongoing quest for trans-Neptunian objects, initiated in 2001, entailed regular imaging of the nocturnal sky utilizing a charge-coupled device camera affixed to the 1.22-meter (48 in) Samuel Oschin telescope, located at Palomar Observatory in California, United States. While the initial images capturing Makemake were acquired by this telescope on March 31, 2005, it was not until April 3, 2005, that Mike Brown identified the object during his image review, noting its exceptional brightness.
Months prior to Makemake's identification, Brown and his research group had already discovered the notably large trans-Neptunian objects Haumea and Eris, both of which were estimated to be at least the size of Pluto, then considered the ninth planet. While organizing subsequent observations for these two bodies, the team initially intended to postpone Makemake's announcement until after Eris's scheduled public disclosure in October 2005. This strategy was disrupted, however, when a group led by José Luis Ortiz Moreno at Sierra Nevada Observatory in Spain independently announced their discovery of Haumea on July 27, 2005. Brown subsequently recognized that his team's observational logs, which detailed the positions of Haumea, Eris, and Makemake, had inadvertently become publicly accessible and were accessed via a computer at Ortiz's institution. Concerned that the discoveries of Eris and Makemake might also be preempted, Brown promptly contacted Brian G. Marsden of the Minor Planet Center (MPC) on July 29, 2005, to formally announce their findings. The MPC subsequently published the discovery announcements for Eris and Makemake on its website at noon California time, with the Central Bureau for Astronomical Telegrams following suit later that evening. The public disclosure of these Pluto-sized objects ignited extensive discourse regarding the definition of a planet, ultimately compelling the International Astronomical Union (IAU) to establish a revised definition of a planet, which resulted in Pluto's reclassification as a dwarf planet in August 2006.
Nomenclature and Symbolism
The dwarf planet is named Makemake, after the Rapa Nui people's creator deity and god of fertility from Easter Island mythology. It was assigned the minor planet catalog number 136472 by the MPC on September 7, 2005, once its orbit was precisely determined. Prior to its official naming, Makemake was identified by its provisional designation 2005 FY9, assigned by the MPC upon the announcement of its discovery. Brown's team also referred to it by the nickname "Easterbunny," referencing its discovery shortly after Easter, and the codename "K05331A," which was automatically generated by Brown's discovery software.
Brown's personal accounts and interviews reveal the difficulty in naming Makemake, as its initial characteristics did not readily align with mythological themes. To maintain the object's association with Easter, Brown considered names like the Anglo-Saxon goddess Ēostre or the Anishinaabe trickster rabbit Manabozho, but ultimately deemed both unsuitable. Ultimately, Brown and his team selected Makemake, a name that honored both the Easter connection and the IAU's guideline for naming classical Kuiper belt objects after creator deities. The IAU formally approved and announced the name Makemake in July 2008.
A unique symbol for Makemake, ⟨⟩, was incorporated into Unicode as U+1F77C in January 2022. The IAU discourages the use of planetary symbols in scientific publications; consequently, Makemake's symbol is primarily adopted by astrologers. Nevertheless, NASA utilized the symbol once in a 2015 infographic. Denis Moskowitz and John T. Whelan designed Makemake's symbol, which depicts a traditional petroglyph of Makemake's face, stylized to evoke the letter 'M'. Other astrologers have independently created and employed their own symbols for Makemake, including ⟨⟩.
Orbital Characteristics and Classification
Makemake orbits the Sun beyond Neptune, maintaining an average distance of 45.5 astronomical units (AU), equivalent to 6.81 billion kilometers or 4.23 billion miles. A single orbit is completed every 307 years. Possessing an orbital eccentricity of 0.16, Makemake traces a moderately elliptical path, approaching the Sun as closely as 38.2 AU (perihelion) and receding to a maximum distance of 52.8 AU (aphelion). Its orbital inclination is notably high, at 29° relative to the ecliptic plane.
Makemake is presently situated near its aphelion, the most distant point in its orbit. As of November 2025, it is located 52.7 AU from the Sun, with aphelion projected for May 2033. The dwarf planet is currently positioned significantly above the ecliptic and will maintain this elevation at aphelion, where its ecliptic latitude will reach 25.9°. It is predicted to cross the ecliptic in 2103 and reach perihelion 26° below the ecliptic in 2186. N-body simulations indicate that Makemake's orbit exhibits long-term stability over billions of years, suggesting minimal significant alteration throughout the Solar System's remaining lifespan.
Makemake shares orbital characteristics with numerous other small, icy trans-Neptunian objects, collectively forming the Kuiper belt. Specifically, Makemake is classified within the "dynamically hot" population of classical Kuiper belt objects, characterized by high orbital inclinations (i > 5°), comparatively low eccentricities (e < 0.2), and a lack of orbital resonance with Neptune. Despite being the largest classical Kuiper belt object, Makemake accounts for only a minor portion of the belt's total mass. These hot classical Kuiper belt objects are theorized to have been gravitationally scattered by Neptune during the early Solar System, leading astronomers to also categorize Makemake as a "scattered" object.
The scientific community generally agrees that Makemake is a dwarf planet, meaning its mass is sufficient for its self-gravity to achieve a spherical shape, yet insufficient to clear its orbital path of other objects, as evidenced by its position within the Kuiper belt. It was the inaugural object named by the IAU under new protocols for anticipated dwarf planets, and the fourth object officially designated as a dwarf planet (following Ceres, Pluto, and Eris) since the category's establishment in 2006. More precisely, Makemake is classified as a plutoid, a subcategory encompassing dwarf planets that orbit beyond Neptune.
Dimensions, Morphology, and Mass
Makemake, a celestial body with an approximate average diameter of 1,430 km (890 mi), exhibits a nearly spherical form. This dimension represents approximately 60% (3⁄5) of Pluto's diameter and 11% (§78§⁄9) of Earth's diameter. Consequently, Makemake ranks as the fourth-largest known dwarf planet and trans-Neptunian object within the Solar System, following Pluto, Eris, and Haumea. Stellar occultation observations conducted in 2011 revealed that Makemake is slightly oblate, or flattened at its poles, with a polar diameter upper limit of approximately 1,420 km (880 mi) and an equatorial diameter of about 1,434 km (891 mi). These measurements align with Makemake possessing a flattened spherical configuration, termed a Maclaurin spheroid. Such a shape arises when an object achieves hydrostatic equilibrium—meaning its gravitational force is sufficient to compress it into a sphere—and is subsequently deformed by its rotational motion.
Makemake's mass is estimated to range between approximately 2.5×1021 and 2.9ק1213§21 kg, a value derived from the orbital period and distance of its satellite. This mass positions Makemake as the fourth-most massive known dwarf planet and trans-Neptunian object within the Solar System, following Eris, Pluto, and Haumea. In comparison to other celestial bodies, Makemake constitutes approximately 3.7% of Earth's moon's mass (or 0.045% of Earth's mass) and about 20% of Pluto's mass. Based on its mass and average diameter, Makemake possesses an average surface gravity of approximately 0.35 m/s§1617§ (equivalent to about 3.6% of Earth's gravity) and a surface escape velocity of about 0.71 km/s.
Rotation
The precise rotation period of Makemake remains uncertain, with current measurements (as of 2025) indicating either 11.4 or 22.8 hours (0.48 or 0.95 days). These determinations are derived from monitoring temporal variations in Makemake's brightness, which are subsequently plotted as a light curve. Makemake displays minimal brightness fluctuation (0.03 magnitudes), likely attributable to subtle albedo variations across its surface. This characteristic complicates the accurate measurement of its light curve and, consequently, its rotation period by telescopes. For instance, investigations preceding 2019 proposed various potential rotation periods, including 7.77, 11.24, 11.5, and 22.48 hours. As of 2025, ambiguity persists regarding whether Makemake's brightness peaks once or twice per rotation, thus leaving the definitive rotation period as either 11.4 hours or its doubled value of 22.8 hours.
Although Makemake's axial tilt has not been directly measured, it is plausibly assumed that its rotation axis aligns with the pole of its moon's orbital plane. Under this assumption, Makemake would exhibit a significant axial tilt, estimated to be between 46° and 78° relative to its solar orbit, or 63°–87° with respect to the ecliptic. At the time of its moon's discovery, Makemake's equator would have been oriented towards the Sun and Earth, approximating an equinox. This substantial axial tilt, combined with Makemake's eccentric orbit, could induce pronounced seasonal variations in its surface temperature and topography, analogous to those observed on Pluto. Predictions indicated that Makemake's moon would eclipse Makemake during either 2009–2013 or 2023–2027, suggesting that Makemake might have experienced an equinox within these periods if its rotation is indeed aligned with its moon's orbit.
Geology
Surface
Due to its considerable distance from the Sun, Makemake's surface maintains an exceptionally low temperature, ranging from 30 to 40 K (−243 to −233 °C; −406 to −388 °F). This frigid environment allows certain volatile substances, such as methane, to persist as solid ice. Astronomical spectroscopy has revealed that Makemake's surface is predominantly composed of frozen methane, supplemented by lesser quantities of long-chain hydrocarbons, including ethane, ethylene, acetylene, and various higher-mass alkanes like propane.
When observed in visible light, Makemake's surface exhibits high brightness and reflectivity, possessing a geometric albedo of 82%, which surpasses that of Pluto. This characteristic implies a recent deposition of methane. Makemake's methane ice demonstrates significant absorption in the near-infrared spectrum, suggesting its presence either as unusually large, centimeter-sized pellets or, more plausibly, as dense layers of sintered particles. Concurrently, phase curve measurements conducted by the New Horizons spacecraft indicate that the regolith on Makemake's surface comprises smooth, snow-like grains.
The long-chain hydrocarbons on Makemake's surface originate from the irradiation of methane by ultraviolet sunlight and cosmic rays, a process that decomposes methane and initiates photochemical reactions. These photochemical reactions can cascade, progressively converting methane into ethane, then ethylene, then acetylene, and further, ultimately forming a dark, reddish mixture of complex hydrocarbons known as tholins. These tholins impart a reddish-brownish hue to Makemake, a coloration akin to that observed on Pluto. Makemake exhibits a less pronounced red coloration than Pluto but appears somewhat redder than Eris; this chromatic variation might stem from differing concentrations of tholins across these dwarf planets. Despite the expected darkening effect of tholins, Makemake's surface maintains its brightness due to a covering layer of fresh methane ice.
Makemake exhibits a high abundance of methane ice, a characteristic shared with Pluto and Eris; however, unlike these two, Makemake seemingly lacks both carbon monoxide and nitrogen ices. Observations by the James Webb Space Telescope (JWST) failed to detect these two ices on Makemake's surface, suggesting a nitrogen content below 3% and carbon monoxide levels below 1 part per million. The absence of nitrogen and carbon monoxide as mixing agents allows methane ice on Makemake to remain pure and accumulate into substantial thicknesses or grain sizes. Makemake's deficiency in nitrogen is anticipated, given nitrogen's high volatility, which facilitates its vapor escape from Makemake's weaker gravitational field compared to the stronger gravities of Pluto and Eris. The rationale for Makemake's apparent lack of carbon monoxide is less definitively understood; potential explanations include removal through atmospheric escape, hydrothermally-driven geochemical reactions within Makemake, or its formation with inherently low carbon monoxide concentrations. Furthermore, water and carbon dioxide ices also appear to be absent from Makemake's surface, despite their prevalence as refractory (non-volatile) materials in Kuiper belt objects; this absence might be attributed to these ices being entirely obscured by volatile substances such as methane and its irradiation byproducts.
Makemake's surface exhibits a uniform appearance, characterized by minimal longitudinal variations in albedo, color, and composition, a stark contrast to Pluto's highly mottled terrain. The presence of latitudinal surface variations on Makemake remains undetermined, as their detection necessitates prolonged, continuous observations of the dwarf planet's changing aspect angle throughout its multi-year solar orbit, analogous to seasonal changes. Between 2006 and 2017, Makemake's absolute magnitude and light curve displayed no alterations, despite an approximate 11° shift in its aspect angle during this period. Should latitudinal surface variations exist on Makemake, they would likely manifest as longitudinally oriented bands. Planetary scientists William M. Grundy, Alex H. Parker, and their collaborators have posited that Makemake's abundant volatile methane could result in geographical and geological features analogous to those on Pluto. If Makemake experiences seasonal volatile transport processes akin to Pluto's, it might generate a longitudinally uniform band of dark material, similar to Pluto's Belton Regio. Conversely, if Makemake possesses a non-global atmosphere that has frozen onto its surface, its equatorial regions could be bright and frost-covered, while its polar areas might appear darker. Seasonal sublimation and deposition of methane could potentially lead to the formation of bladed terrain or even substantial, convecting glaciers reminiscent of Pluto's Sputnik Planitia. Makemake is not anticipated to feature mountains exceeding 10 km (6.2 mi) in height.
Internal Structure and Potential Geological Activity
Makemake possesses a bulk density of approximately 1.76 g/cm3 (with an uncertainty of ±0.17 g/cm§910§), a value comparable to other trans-Neptunian dwarf planets such as Pluto, Gonggong, and Quaoar. This density suggests an internal composition predominantly of water ice and rock, similar to these other dwarf planets. Makemake's substantial size implies a likely differentiated interior, comprising a rocky core enveloped by layers of ice. Planetary scientists hypothesize that Makemake's interior retains sufficient radionuclides and primordial heat to have sustained, or potentially still sustain, a subsurface liquid water ocean. Elevated internal heat within Makemake could potentially lead to geological phenomena, including cryovolcanism.
Spectroscopy conducted by the JWST has identified heavy isotopologues of methane, specifically those containing deuterium (D or 2H) and carbon-13 (13C), on Makemake's surface. From these observations, astronomers have determined a deuterium-to-hydrogen (D/H) ratio of (2.9±0.6)×10−4 and a §1415§C/§1617§C ratio of 0.010±0.003. While Makemake's §2425§C/§2627§C ratio aligns with values found in other Solar System bodies, its D/H ratio exhibits a notable divergence: it is considerably lower than the D/H ratios of methane in comets, yet comparable to the D/H ratios of water in comets. Planetary scientists propose that Makemake's reduced D/H ratio indicates a warm interior characterized by active hydrothermal geochemistry. This interpretation suggests that Makemake's deuterium-depleted methane might have acquired its hydrogen through geochemical reactions occurring in subsurface water, which necessitate elevated temperatures, approximately 150 °C (302 °F), requiring sustained heat from Makemake's core. Within this framework, Makemake's subsurface water could exist as either liquid water or convecting solid ice, with internally generated methane potentially migrating to the surface through outgassing or cryovolcanic eruptions. Nevertheless, an alternative hypothesis posits that Makemake's deuterium-poor methane could be primordial, having originated directly from the protosolar nebula via accretion, thereby implying that internal geochemical activity may not be a prerequisite for its presence.
Makemake exhibits an anomalously high emission of mid-infrared radiation relative to far-infrared, a phenomenon that has prompted diverse interpretations from astronomers since its initial detection by the Spitzer Space Telescope in 2008. Early hypotheses suggested that Makemake's surplus mid-infrared emission originated from a mosaic of dark, warm regions interspersed with bright, cold terrain (a theory later extended to include its moon upon discovery); however, this model failed to precisely account for Makemake's infrared emission across varying wavelengths or its minimal brightness fluctuations. In 2025, Csaba Kiss and colleagues advanced an alternative explanation, proposing that Makemake's excess mid-infrared emission might stem from either a cryovolcanic hotspot, with temperatures approximating 150 K (−123 °C; −190 °F), or an orbital ring composed of minute carbonaceous dust particles. The cryovolcanic hotspot hypothesis is currently preferred, primarily because a dust ring of the type described would rapidly destabilize under solar radiation pressure; nevertheless, such a ring could theoretically be sustained if cryovolcanic eruptions were capable of ejecting carbonaceous dust into Makemake's orbit. This hypothesized cryovolcanic hotspot could potentially release a thermal energy output comparable to that of the south pole geysers on Saturn's moon Enceladus, and might erupt cryolava comprising ammonia and various salts dissolved in liquid water. The precise location of this cryovolcanic hotspot on Makemake's surface remains undetermined, although its estimated coverage area is approximately 350 km§56§ (140 mi§1112§), which is equivalent to a circle with a radius of about 10 km or 6.2 mi.
Atmospheric Presence or Outgassing Phenomena
Spectroscopic analysis conducted by the JWST in 2025 confirmed the existence of gaseous methane on Makemake, which exhibits near-infrared fluorescence resulting from sunlight absorption. Makemake thus becomes the second trans-Neptunian object, following Pluto, for which the presence of gas has been definitively established. Nevertheless, ambiguity persists regarding whether Makemake's methane gas constitutes a gravitationally bound atmosphere or represents temporary outgassing (or even escape) from its surface, potentially driven by methane ice sublimation or cryovolcanic plumes. Theoretically, Makemake possesses sufficient mass and low enough temperatures to retain an atmosphere composed of methane or nitrogen; however, JWST observations indicate an apparent absence of nitrogen gas, suggesting that the majority of it has already been lost through atmospheric escape.
Should the detected methane gas on Makemake be entirely confined within a gravitationally bound atmosphere, the surface atmospheric pressure would approximate 10 picobars (1 micropascal). This pressure is 100 billion times lower than Earth's atmospheric pressure and 1 million times lower than Pluto's. However, observations from Makemake's 2011 stellar occultation did not reveal such an extremely tenuous atmosphere, thereby reinforcing the conclusion that Makemake lacks a significant global atmosphere exceeding 4–12 nanobars (0.4–1.2 millipascals). The hypothetical thin atmosphere would maintain a temperature of approximately 40 K (−233.2 °C; −387.7 °F), which is marginally above the sublimation point of methane at the corresponding surface pressure. This suggests that Makemake's potential atmosphere could be sustained by the sublimation of methane ice present on its surface. Given Makemake's eccentric orbit, its putative atmosphere might fluctuate with varying distances from the Sun; for instance, during the warmer perihelion, Makemake could experience increased methane sublimation but also potential atmospheric escape.
Conversely, if the methane gas identified by JWST originates solely from outgassing, it implies that Makemake is expelling approximately 266 kg (586 lb) of methane per second from 4–30% of its total surface area. The velocity of this outgassed methane, and thus its ability to escape Makemake's gravitational pull, remains undetermined. Should methane gas be escaping, it would likely generate a comet-like coma enveloping Makemake. The projected mass loss rate is comparable to the water plumes observed on Enceladus (300 kg/s or 660 lb/s), and the restricted area of methane emission might be associated with Makemake's hypothesized cryovolcanic hotspot. Cryovolcanic methane outgassing is theorized to be a common phenomenon among trans-Neptunian dwarf planets, including Makemake.
Satellites and Potential Ring Systems
S/2015 (136472) 1
Makemake possesses a single known natural satellite, provisionally designated S/2015 (136472) 1 and informally referred to as "MK 2". This moon was identified by astronomers Alex H. Parker, Marc W. Buie, William M. Grundy, and Keith S. Noll in images captured by the Hubble Space Telescope on April 27, 2015, with its discovery publicly announced on April 26, 2016. S/2015 (136472) 1 appears approximately 1,300 times (7.8 magnitudes) fainter than Makemake in visible light. Its suspected very dark surface and estimated diameter of 175 km (109 mi) are posited to account for a portion of Makemake's observed excess mid-infrared radiation. The satellite maintains a probable circular orbit around Makemake, characterized by an 18-day orbital period and a semi-major axis of 22,250 ± 780 km (13,830 ± 480 mi).
At the time of its discovery, the orbit of S/2015 (136472) 1 was oriented nearly edge-on when viewed from Earth-based observatories, causing the moon to appear to transit across or be occulted by Makemake. While this edge-on alignment complicated the imaging of S/2015 (136472) 1 by telescopes, it concurrently presented opportunities for the moon to eclipse and occult Makemake. Predictions suggest that the moon may have eclipsed Makemake between 2009 and 2013, or could potentially be doing so from 2023 to 2027. As of 2025, no eclipses involving S/2015 (136472) 1 have been officially reported.
Possibility of Additional Satellites
Imaging conducted by the Hubble Space Telescope indicates that Makemake does not possess additional moons brighter than apparent magnitude 26.9 (approximately 10 magnitudes fainter than Makemake) at distances exceeding 30,000 km (19,000 mi). However, larger satellites could remain undetected if their orbits are exceptionally close to Makemake. Astronomers have considered the hypothesis of Makemake hosting an additional dark moon, larger than S/2015 (136472) 1, as a potential explanation for the dwarf planet's excess mid-infrared emission and its seemingly slow rotation. Nevertheless, this proposition was largely dismissed due to the requirement of an implausibly large satellite size.
Possibility of Ring Systems
Makemake is not currently known to possess any rings. Rings orbiting distant celestial bodies are typically too diminutive and faint for direct telescopic imaging, necessitating their detection through observations of stellar occultations. Despite this, no rings were identified during Makemake's stellar occultation event in 2011. Should rings exist around Makemake, their probable equatorial, edge-on orientation, similar to that of S/2015 (136472) 1, might have rendered them undetectable during the 2011 occultation. The hypothesis of a ring around Makemake has been investigated as a potential explanation for its anomalous mid-infrared emission. However, this explanation was largely dismissed due to the requirement that such a ring would consist of exceptionally minute (~100 nm) dust particles, rendering it susceptible to rapid disintegration by solar radiation pressure within approximately ten years. Nonetheless, the sustained existence of such a ring around Makemake could be feasible if the dwarf planet possesses shepherd moons, experiences continuous dust replenishment from particle and small moon collisions, or exhibits cryovolcanic activity that ejects dust into orbit.
Origin
Consistent with other Kuiper belt dwarf planets, Makemake is theorized to have originated approximately 4.5 billion years ago, during the early stages of the Solar System's development. The prevailing hypothesis suggests that Kuiper belt dwarf planets initially formed as small planetesimals, gradually expanding to their current dimensions through the accretion of ambient material and other planetesimals over several million years. Makemake's formative environment must have maintained sufficiently low temperatures to facilitate the condensation of volatile compounds, such as methane, into solid states, which subsequently contributed to the dwarf planet's accretion. Nevertheless, Makemake might have experienced a depletion of its primordial methane during its accretion phase, potentially due to its initial lower mass and elevated temperature, resulting from frequent impact events and increased solar irradiance. Furthermore, a hypothesis posits that a significant collision with another celestial body in Makemake's past could have led to the formation of its moon, S/2015 (136472) 1.
A 2020 hypothesis, derived from updated Solar System formation models (building upon the 2005 Nice model, which first proposed a comparable scenario), suggests that several tens of millions of years following the Solar System's genesis, gravitational interactions among the gas giants prompted Neptune's abrupt outward migration. This migration propelled Neptune into a substantial circumstellar disk situated between 15 and 30 AU from the Sun, leading to the gravitational dispersal of numerous objects within it. The model posits that almost all Kuiper belt objects, including Makemake, initially formed within this circumstellar disk at heliocentric distances closer than their current locations. The subsequent scattering of this disk is believed to have generated the contemporary resonant and "hot" classical populations of the Kuiper belt (where Makemake is presently found), in addition to the scattered disk.
Observation and Exploration
Observation
Regarding its visual absolute magnitude, Makemake ranks as the third intrinsically brightest known trans-Neptunian object, surpassed only by Eris and Pluto. Its considerable intrinsic luminosity is attributable to its substantial size and highly reflective surface. Conversely, in terms of visual apparent magnitude, Makemake is the second brightest trans-Neptunian object observable from Earth, following Pluto, a distinction due to its closer proximity to the Sun compared to Eris. Makemake attains its maximum apparent brightness, approximately magnitude 17, during its opposition period from March to April, rendering it discernible with advanced amateur telescopes. Given its immense distance from Earth, Makemake presents a minuscule angular diameter of approximately 38 milliarcseconds, preventing telescopes from resolving it beyond a stellar point of light. Since its discovery, Makemake has been situated within the northern constellation Coma Berenices, and it is projected to transition into the constellation Boötes in late 2028.
Despite its considerable brightness among trans-Neptunian objects, Makemake's discovery occurred relatively late, postdating numerous fainter counterparts. This delay is attributable to Makemake's highly inclined orbit, which positions it significantly outside the ecliptic plane, a region largely unexplored by earlier sky surveys. Although several surveys inadvertently detected Makemake years prior to its official discovery, these observations, termed "precoveries," remained unrecognized until subsequent analysis. The earliest identified precovery of Makemake originates from a photographic plate captured at Palomar Observatory on January 29, 1955, preceding its discovery by over five decades, which constitutes approximately 16% of Makemake's orbital period.
As Makemake traverses the celestial sphere, it can occasionally pass in front of a background star, momentarily obscuring its light from Earth's perspective, an event known as a stellar occultation. Such occultations by Makemake offer valuable insights into its physical characteristics, including its shape and the potential presence of an atmosphere. However, their accurate prediction is challenging due to the dwarf planet's vast distance from Earth, which introduces substantial uncertainties in its precise positional data. Furthermore, stellar occultations involving Makemake are rare because the dwarf planet is situated in a sky region characterized by a sparse distribution of stars. As of 2025, astronomers have successfully predicted and detected only one stellar occultation by Makemake. This singular observed event occurred on April 23, 2011, yielding seven positive detections from sixteen participating telescopes strategically dispersed across South America.
Exploration
To date, no space probe has conducted a close-range Makemake is considered an appealing target for exploration, primarily due to the potential existence of a subsurface ocean exhibiting ongoing geological activity. Investigating a trans-Neptunian object like Makemake would significantly enhance understanding of the Solar System's formation and evolutionary processes.
A 2011 investigation conducted by Ryan McGranaghan and his collaborators estimated that a flyby mission to Makemake, utilizing a Jupiter gravity assist, could be completed in just over 16 years, assuming a launch date of August 24, 2036. Upon the spacecraft's arrival, Makemake would be approximately 52.3 AU from the Sun. More recently, a 2024 study by the University of Tennessee proposed that incorporating a powered Jupiter gravity assist could reduce the travel time for a Makemake flyby mission to between 9.6 and 16.4 years, contingent upon the spacecraft's payload mass. This powered gravity assist method would be most advantageous for launch dates of August 22, 2036, and September 27, 2048.
In a 2019 study, Amanda Zangari and her team identified multiple potential flyby trajectories to Makemake, considering various gravity assist maneuvers and excess launch energies. For launch windows spanning 2025–2027 or 2036–2039, a single Jupiter gravity assist could facilitate a spacecraft's arrival at Makemake in 12.8–23.6 or 11.6–19.2 years, respectively. Alternatively, a single Saturn gravity assist might offer a more rapid transit for lower-energy launches; specifically, for launch dates between 2032–2033 or 2036–2040, a spacecraft could reach Makemake in 19.2–22.5 or 12.8–19.1 years, respectively. Furthermore, for launch dates from 2037 to 2049, a mission employing gravity assists from both Jupiter and Saturn could achieve arrival at Makemake within 16.8–17.3 years.
The New Horizons spacecraft conducted distant observations of Makemake in October 2007 and January 2017, from respective distances of 52 AU and 70 AU. The spacecraft's outbound trajectory through the Kuiper belt enabled observations of Makemake at high phase angles, which are otherwise unattainable from Earth. These unique observations facilitated the determination of Makemake's surface light scattering properties and its phase curve behavior.
Notes
Notes
References
A podcast episode titled "Geothermal activity on the icy dwarf planets Eris and Makemake," hosted by The Planetary Society's Planetary Radio, aired on March 6, 2024.
- Geothermal activity on the icy dwarf planets Eris and Makemake – Planetary Radio podcast hosted by The Planetary Society (March 6, 2024)
- A video recording of the 2012 Kavli Prize Laureate Lecture, "Tales From the Outer Solar System," delivered by Michael E. Brown.
- Sky charts and coordinate data for Makemake are available from The Sky Live.
- An image of Makemake from a precovery observation, captured by the 1.06-meter Kleť Observatory telescope on April 20, 2003.
- An image of Makemake acquired by the Keck 1 Telescope on February 18, 2010, attributed to Mike Brown.
- Data pertaining to Makemake is accessible through the AstDyS-2, Asteroids—Dynamic Site.