Makemake
A dwarf planet slightly smaller than Pluto and the second-brightest object in the Kuiper belt, with frozen methane on its surface and a moon found in 2016.
At a glance
- Status
- IAU dwarf planet[1]One of the five the International Astronomical Union recognizes; its discovery, with Eris's, prompted the IAU to reconsider the definition of a planet
- Size
- About 1,430 km across[1]Slightly smaller than Pluto; the second-brightest object in the Kuiper belt as seen from Earth, after Pluto
- Orbit
- 45.8 au from the Sun on average, once every 305 years[1]About 6.8 billion km; sunlight takes 6 hours and 20 minutes to reach it
- Orbit shape
- 38.3 to 52.8 au from the Sun, tilted 29° to the plane of the planets[3]Semi-major axis 45.6 au
- Day
- About 22.5 hours[1]Similar to a day on Earth or Mars
- Moons
- One provisional moon, S/2015 (136472) 1, nicknamed MK 2[1]More than 1,300 times fainter than Makemake, with an estimated radius of about 80 km
- Surface
- Reddish-brown, with frozen methane and ethane[1]Pellets of frozen methane up to 1 cm across may rest on the surface
Timeline
- March 31, 2005Discovered[3]Mike Brown, Chad Trujillo and David Rabinowitz at the Palomar Observatory, California; provisional designation 2005 FY9
- April 2015Moon photographed[4]Hubble Space Telescope, Wide Field Camera 3
- April 26, 2016Moon announced[4]In a Minor Planet Electronic Circular; the moon is provisionally designated S/2015 (136472) 1
Makemake is a dwarf planet in the Kuiper belt, slightly smaller than Pluto and the second-brightest object in the belt as seen from Earth, after Pluto itself.[1] It is one of the five dwarf planets the International Astronomical Union recognizes, and it holds a place in the history of the solar system's classification: its discovery, along with that of Eris, prompted the IAU to reconsider the definition of a planet and to create the new group of dwarf planets.[2][1]
How it was found
Makemake was first observed in March 2005 by Mike Brown, Chad Trujillo and David Rabinowitz at the Palomar Observatory in California; JPL's record gives the discovery date as 31 March 2005.[1][3] Its provisional designation was 2005 FY9, and the team's code name for it was Easterbunny.[1] It is named after the creator of humanity and god of fertility in the mythology of Rapa Nui, or Easter Island, in the South Pacific.[1][3]
Orbit
Makemake orbits the Sun at an average distance of 45.8 astronomical units, about 6.8 billion km, and takes about 305 years to complete one orbit; sunlight takes 6 hours and 20 minutes to reach it.[1] JPL's catalogue gives a path from 38.3 to 52.8 astronomical units, tilted 29 degrees to the plane of the planets.[3] It completes one rotation every 22 and a half hours, so its day is similar in length to Earth's and Mars's.[1]
Surface and interior
Makemake appears reddish-brown, similar to Pluto, and astronomers have detected frozen methane and ethane on its surface; pellets of frozen methane as big as 1 cm across may rest there.[1] Its surface is extremely cold, and it has no known rings.[1] It may develop a very thin atmosphere, most likely of nitrogen, when it is closest to the Sun.[1] Scientists know very little about its internal structure and do not know whether it has a magnetic field.[1]
The moon
In April 2015 the Hubble Space Telescope photographed a small, dark moon next to Makemake, announced on 26 April 2016 in a Minor Planet Electronic Circular.[4] Provisionally designated S/2015 (136472) 1 and nicknamed MK 2, it is more than 1,300 times fainter than Makemake and was seen about 13,000 miles, roughly 21,000 km, from it.[4] NASA's Makemake page estimates its radius at about 80 km.[1] Pluto, Eris and Haumea already had known moons, so the discovery fitted a pattern among the belt's largest bodies.[4]
What is not yet known
No spacecraft has visited Makemake. Its interior, the orbit and exact size of its moon, and whether its thin atmosphere comes and goes along its orbit are among the open questions.[1]
Sources
- [1]NASA, Makemake — science.nasa.gov, retrieved November 5, 2026
- [2]NASA, Pluto & Dwarf Planets — science.nasa.gov, retrieved November 5, 2026
- [3]NASA/JPL Small-Body Database, 136472 Makemake (2005 FY9) — ssd.jpl.nasa.gov, retrieved November 5, 2026
- [4]NASA, Hubble Discovers Moon Orbiting the Dwarf Planet Makemake — science.nasa.gov, retrieved November 5, 2026
Related
- What is a dwarf planet?The definition that made Pluto a dwarf planet in 2006, the five the IAU recognises, why the list grows so slowly, and the candidates waiting to join it.
- The Kuiper belt and beyondThe ring of icy worlds past Neptune, the scattered disk and the Oort cloud beyond it, how many objects are known, and how new ones are found.
- PlutoThe largest known body in the Kuiper belt and the first dwarf planet, counted as the ninth planet from 1930 to 2006 and visited by New Horizons in July 2015.
- ErisThe dwarf planet about the size of Pluto whose discovery in 2005 led to Pluto's reclassification; it orbits about 68 au from the Sun once every 557 years.
- HaumeaA dwarf planet shaped like a football by its four-hour spin, with two moons and a ring found in 2017, orbiting about 43 au from the Sun once every 285 years.
- QuaoarA dwarf-planet candidate about 1,110 km across on a nearly circular orbit beyond Pluto, with a moon, Weywot, and two rings where none were expected.