Makemake
On the 31st of March 2005, astronomers Michael E. Brown, Chad Trujillo, and David Rabinowitz captured images of a faint point of light using the 1.22-meter Samuel Oschin telescope at Palomar Observatory in California. They did not know it was Makemake until April 3, when Brown reviewed the digital files and spotted an exceptionally bright object moving against the background stars. This discovery came during a search for large bodies beyond Neptune that began in 2001. The team had already found two other massive objects named Eris and Haumea before finding this one. A race to announce discoveries erupted later that year after a Spanish team led by José Luis Ortiz Moreno claimed credit for Haumea on the 27th of July 2005. Fearing their own findings would be stolen, Brown contacted Brian G. Marsden of the Minor Planet Center on the 29th of July 2005. The announcement triggered a global debate about what constitutes a planet. This pressure eventually led the International Astronomical Union to redefine Pluto as a dwarf planet in August 2006. Before receiving its official name, the object carried the provisional designation 2005 FY9. It also bore the nickname Easterbunny because the discovery happened shortly after the Easter holiday. Brown considered naming it after the Anglo-Saxon goddess Eostre or the Anishinaabe trickster rabbit Manabozho but rejected both options. He finally chose Makemake, the Rapa Nui creator god of fertility from Easter Island mythology. The IAU approved the name in July 2008.
Makemake orbits the Sun at an average distance of 45.5 astronomical units, completing one revolution every 307 years. Its path is highly inclined at 29 degrees relative to the ecliptic plane, placing it far above the flat disk where most planets orbit. The dwarf planet reaches aphelion in May 2033, when it will be roughly 52.8 AU from the Sun. It currently sits well above the ecliptic and will remain there for decades before crossing back down in 2103. This extreme tilt creates severe seasonal changes similar to those seen on Pluto. Makemake belongs to the dynamically hot population of classical Kuiper belt objects. These bodies have high inclinations greater than 5 degrees and low eccentricities less than 0.2. They do not share orbital resonances with Neptune like other trans-Neptunian objects. Simulations show its orbit remains stable over billions of years despite gravitational interactions. Scientists classify Makemake as a plutoid because it orbits beyond Neptune and has sufficient mass to be spherical. It is the largest member of the classical Kuiper belt but represents only a small fraction of the total mass in that region. The object likely formed closer to the Sun before being scattered outward by Neptune during the early history of the Solar System.
Spectroscopic data collected by the James Webb Space Telescope reveals frozen methane dominates the surface of Makemake. The dwarf planet appears bright and reflective with an albedo of 82 percent, making it more visible than Pluto. Long-chain hydrocarbons including ethane, acetylene, and propane coat the ice in reddish-brown tholins. These complex molecules form when ultraviolet sunlight breaks down methane and triggers photochemical reactions. Unlike Pluto or Eris, Makemake lacks detectable nitrogen and carbon monoxide ices on its surface. This absence allows methane to remain pure and grow into thick slabs or large pellets. Observations from 2011 showed no significant change in brightness between 2006 and 2017 despite shifting aspect angles. The uniform appearance suggests minimal longitudinal variation across the terrain. Planetary scientists hypothesize that seasonal volatile transport could create bladed terrain or convecting glaciers similar to Sputnik Planitia on Pluto. The lack of water and carbon dioxide ices implies they are completely hidden beneath layers of volatile material. Methane ice exists as smooth grains resembling snow according to phase curve measurements from the New Horizons spacecraft.
Makemake has a bulk density of approximately 1.7 grams per cubic centimeter suggesting a rocky core surrounded by layers of water ice. Scientists suspect internal heat sources sustain a subsurface liquid ocean either today or in the past. Radioactive decay within the core provides enough energy to drive hydrothermal geochemistry at temperatures around 273 Kelvin. Spectroscopy detected deuterium-poor methane with a D/H ratio matching cometary water rather than primordial nebula gas. This low ratio points to active interior processes where hydrogen originates from subsurface reactions. Infrared radiation measured by the Spitzer Space Telescope since 2008 indicates excess mid-infrared emission. A 2025 study proposed this glow comes from a cryovolcanic hotspot reaching roughly 140 Kelvin. Such eruptions could eject ammonia and salts dissolved in liquid water onto the surface. The hotspot might cover an area equivalent to a circle with a radius of 100 kilometers. Alternatively, dust rings orbiting the dwarf planet could explain the infrared signature but would destabilize quickly due to solar pressure. The presence of these features suggests Makemake is geologically active despite its distance from the Sun.
A single known moon orbits Makemake with the provisional designation S/2015 (136472) 1. Astronomers Alex H. Parker, Marc W. Buie, William M. Grundy, and Keith S. Noll discovered it in Hubble Space Telescope images taken on the 27th of April 2015. The satellite appears about 1,300 times fainter than the main body and has an estimated diameter of 175 kilometers. It follows a circular orbit every 18 days at a semi-major axis of approximately 21,000 kilometers. The moon's edge-on orientation from Earth allows for potential eclipses between 2009 and 2013 or again during 2023 and 2027. No confirmed eclipses have been reported yet. Some researchers suggest additional dark moons larger than 100 kilometers might exist close to Makemake to explain excess infrared emission. Such objects could remain hidden if they orbit very near the dwarf planet. Hypotheses also propose ring systems made of tiny carbonaceous dust particles. These rings would likely orbit equatorially and could be missed during stellar occultations due to their edge-on configuration. However, solar radiation pressure would destroy such rings within a decade unless continuously replenished by cryovolcanic eruptions or shepherd moons.
Makemake remains invisible as anything more than a star-like point even through powerful telescopes. Its angular diameter measures only 38 milliarcseconds making detailed surface imaging impossible with current technology. The object reaches peak brightness around apparent magnitude 17 during opposition in March and April. Amateur astronomers can observe it using high-end equipment but cannot resolve features. Precovery images date back to the 29th of January 1955 showing the dwarf planet on photographic plates from Palomar Observatory. Only one successful stellar occultation occurred on the 23rd of April 2011 involving seven positive detections across South America. Scientists desire to send probes to explore its potential subsurface ocean and geological activity. A 2011 study calculated that a flyby mission launched the 24th of August 2036 could reach Makemake in just over 16 years using Jupiter gravity assists. More recent studies suggest powered gravity assists might shorten travel time to between 9.6 and 16.4 years depending on payload mass. Launch windows exist for dates ranging from 2025 to 2049 offering multiple trajectory options via Jupiter or Saturn. New Horizons observed Makemake from distances of 52 AU and 70 AU in October 2007 and January 2017 respectively.
Common questions
Who discovered Makemake and when was it found?
Astronomers Michael E. Brown, Chad Trujillo, and David Rabinowitz captured images of Makemake on the 31st of March 2005 using the Samuel Oschin telescope at Palomar Observatory in California.
What is the official name origin for Makemake?
The International Astronomical Union approved the name Makemake in July 2008 after Brown selected the Rapa Nui creator god of fertility from Easter Island mythology instead of other proposed names like Eostre or Manabozho.
How far does Makemake orbit from the Sun?
Makemake orbits the Sun at an average distance of 45.5 astronomical units and completes one revolution every 307 years with a highly inclined path of 29 degrees relative to the ecliptic plane.
What surface materials cover Makemake according to spectroscopic data?
Spectroscopic data collected by the James Webb Space Telescope reveals frozen methane dominates the surface while long-chain hydrocarbons including ethane, acetylene, and propane coat the ice in reddish-brown tholins.
When was the moon of Makemake discovered and what are its characteristics?
Astronomers Alex H. Parker, Marc W. Buie, William M. Grundy, and Keith S. Noll discovered the single known moon designated S/2015 (136472) 1 on the 27th of April 2015 using Hubble Space Telescope images.