Hanami Planum
| Feature type | Planum; highland region |
|---|---|
| Location | Ceres |
| Coordinates | 15°00′N 130°00′W / 15.00°N 130.00°W[1] |
| Diameter | 555 km[2]: 741 |
| Peak | 6 km[2]: 741 |
| Discoverer | Dawn |
| Eponym | Hanami |
Hanami Planum, formerly named Erntedank Planum, is a highland region on the dwarf planet and giant asteroid Ceres.
Observation and naming
On 5 March 2015, NASA's Dawn spacecraft entered orbit around Ceres, observing and mapping its surface features in detail for the first time.[3] The plateau was originally given the name Erntedank Planum by the International Astronomical Union (IAU) on 4 December 2015, after the German thanksgiving festival of Erntedankfest.[4] However, the name was dropped on 20 June 2016 and replaced with Hanami Planum. The new name comes from Hanami, the Japanese custom of viewing cherry blossoms.[1]
Geography and geology
Hanami Planum is a highland area centered near 15°N, 130°W, primarily placing it inside the Occator quadrangle. Spanning about 555 kilometres (345 mi) and rising as high as 6 kilometres (3.7 mi), it is the only discrete topographic high on Ceres[5]: 130 [2]: 741 It is the third largest geological feature on Ceres, after Vendimia Planitia and Samhain Catenae;[6] the latter broadly coincides with Hanami Planum.[7]: 11 Several major named craters occupy the highland, including Nepen, Azacca, Lociyo, and the bright Occator.[5]: 130 [6] Other major craters border Hanami Planum, such as Kirnis to the east and Ezinu to the northwest.[5]: 130 [8]: 3195
Hanami Planum is associated with a broad, distinct negative isostatic gravity anomaly,[2]: 741 meaning that local gravity is weaker than normal.[9] The negative gravity anomalies suggest that Hanami Planum lies in a region of low-density material, with a mass deficit of 97.1+1.6
−1.5×1016 kg, ~0.1% the mass of Ceres. The region includes the most extreme negative anomaly observed on Ceres, with a strength of < –95 mGal southeast of Occator at 12°N, 113°W. This anomaly is associated with a 70 by 30 kilometres (43 mi × 19 mi) dome that rises 2–3 kilometres (1.2–1.9 mi) above the surrounding terrain. Another distinct local anomaly crosses Samhain Catenae. It overlaps with a large dome within Kirnis and a 2 kilometres (1.2 mi) high dome to the southwest.[2]: 741–742
See also
- Yamor Mons – A mountain on Ceres whose name was changed from Ysolo Mons in 2016
References
- ^ a b "Hanami Planum". Gazetteer of Planetary Nomenclature. USGS Astrogeology Research Program. (Center Latitude: 15.00, Center Longitude: 230.00°; Planetocentric, +East)
- ^ a b c d e Raymond, C. A.; et al. (August 2020). "Impact-driven mobilization of deep crustal brines on dwarf planet Ceres". Nature Astronomy. 4: 741–747. Bibcode:2020NatAs...4..741R. doi:10.1038/s41550-020-1168-2.
- ^ "Dawn at Ceres". NASA. Archived from the original on 17 May 2025. Retrieved 2 November 2025.
- ^ "Erntedank Planum". Gazetteer of Planetary Nomenclature. USGS Astrogeology Research Program. No longer approved.
- ^ a b c Buczkowski, Debra L.; et al. (2018). "The geology of the Occator quadrangle of dwarf planet Ceres: floor-fractured craters and other geomorphic evidence of cryomagmatism". Icarus. 316: 128–139. Bibcode:2018Icar..316..128B. doi:10.1016/j.icarus.2017.05.025. S2CID 134030861.
- ^ a b "Hanami Planum on Ceres". NASA. 23 March 2018. Retrieved 29 November 2025.
- ^ King, Scott D.; et al. (June 2022). "Ceres' Broad-Scale Surface Geomorphology Largely Due To Asymmetric Internal Convection". AGU Advances. 3 (3). Bibcode:2022AGUA....300571K. doi:10.1029/2021AV000571. hdl:10919/110514. e2021AV000571.
- ^ Buczkowski, Debra L.; et al. (December 2018). "Floor-Fractured Craters on Ceres and Implications for Interior Processes". Journal of Geophysical Research: Planets. 123 (12): 3188–3204. Bibcode:2018JGRE..123.3188B. doi:10.1029/2018JE005632.
- ^ "Studying Earth's Gravity Field from Space" (PDF). NASA. 2001. Retrieved 30 November 2025.