Makemake
Low-resolution image of Makemake and its unnamed moon S/2015 (136472) 1 by the Hubble Space Telescope, April 2015 | |
| Discovery | |
|---|---|
| Discovered by | |
| Discovery date | March 31, 2005 |
| Designations | |
| (136472) Makemake | |
| Pronunciation | UK: /ˌmækiˈmæki/, US: /ˌmɑːkiˈmɑːki/ or /ˌmɑːkeɪˈmɑːkeɪ/ ⓘ |
Named after | Makemake |
| 2005 FY9 | |
| Adjectives | Makemakean |
| Symbol | (mostly astrological) |
| Orbital characteristics | |
| Epoch May 31, 2020 (JD 2458900.5) | |
| Earliest precovery date | January 29, 1955 |
| Aphelion | 52.756 AU (7.8922 Tm) |
| Perihelion | 38.104 AU (5.7003 Tm) |
| 45.430 AU (6.7962 Tm) | |
| Eccentricity | 0.16126 |
| 306.21 yr (111,845 d) | |
Average orbital speed | 4.419 km/s |
| 165.514° | |
| Inclination | 28.9835° |
| 79.620° | |
| 17 November 2186 | |
| 294.834° | |
| Known satellites | 1 (S/2015 (136472) 1) |
| Physical characteristics | |
| Dimensions | (1434+48 −18) × projected (1420+18 −24 km) |
| |
| Flattening | 0.0098 |
| 6.42×106 km2 | |
| Volume | 1.53×109 km3 |
| Mass | ≈ 3.1×1021 kg |
Mean density |
|
Equatorial surface gravity | < 0.57 m/s2 |
Equatorial escape velocity | < 0.91 km/s |
| 22.8266±0.0001 h | |
| Temperature |
|
| B−V=0.83, V−R=0.5 | |
| 17.0 (opposition) | |
| |
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Makemake (minor-planet designation: 136472 Makemake) is a dwarf planet and the largest of what is known as the classical population of Kuiper belt objects, with a diameter approximately that of Saturn's moon Iapetus, or 60% that of Pluto. It has one known satellite. Its extremely low average temperature, about 40 K (−230 °C), means its surface is covered with methane, ethane, and possibly nitrogen ices. Makemake shows signs of geothermal activity and thus may be capable of supporting active geology and harboring an active subsurface ocean.
Makemake was discovered on March 31, 2005, by a team led by Michael E. Brown, and announced on July 29, 2005. It was initially known as 2005 FY9 and later given the minor-planet number 136472. In July 2008, it was named after Makemake, a creator god in the Rapa Nui mythology of Easter Island, under the expectation by the International Astronomical Union (IAU) that it would prove to be a dwarf planet.