Himeros (crater)
 Himeros as viewed by NEAR Shoemaker. | |
| Feature type | Impact crater |
|---|---|
| Location | Eros |
| Coordinates | 21°12′N 77°42′E / 21.20°N 77.7°E[1] |
| Diameter | 11 km[2] |
| Depth | ~1.5 km[3]: 1654 |
| Discoverer | NEAR Shoemaker |
| Eponym | Himeros |
Himeros, also nicknamed The Saddle,[4] is a large impact crater on the asteroid Eros. It is centered at roughly 21.20°N, 77.7°E, on Eros's eastern "hemisphere." The crater is named after Himeros of Greek mythology, one of seven Erotes, attendant to Eros, and the personification of the longing for love. The name Himeros was officially approved by the International Astronomical Union (IAU) in 2003.[1]
Geology and characteristics
[edit]At roughly 11 kilometers in diameter, Himeros is the largest identified feature on Eros. The crater is so large that it nearly exceeds the diameter of Eros in the north-south direction.[a] As a result, Himeros's northern and southern rims are degraded or absent, giving the crater an elongated shape. The southwestern rim of Himeros is interrupted by Shoemaker, a smaller (~7 km) and younger impact crater. The rim of Himeros, like the rims of Eros's second- and third-largest impact craters (Shoemaker and Psyche, respectively), is very rounded and smooth.[3]: 1654–1655 Within Himeros are several features. An extensive ridge, Rahe Dorsum, begins within the floor of Himeros before continuing over the crater rim towards Psyche. Given Rahe Dorsum's straightness, it likely represents a "plane" of strong material that was more resistant to the violent formation of Himeros, forming a ridge.[2]
Himeros's immense size relative to Eros means that the impact event that created it likely had widespread consequences for the asteroid. In 2015, a team of astronomers led by Yasui Minami proposed that seismic waves from the Himeros impact event would have shaken the entire asteroid, with the modelled peak ground acceleration exceeding that of Eros's surface gravity up to 134 kilometers from the crater. As a result, surface material on Eros likely moved globally because of Himeros's formation.[6] Himeros's central location on Eros means that its formation should have obliterated most craters smaller than 500 meters in diameter. Though the interior of Himeros has relatively few craters, that there are many small craters on Eros indicates that Himeros is ancient. The low crater density within Himeros is therefore likely due to the formation of Shoemaker.[7]
Notes
[edit]References
[edit]- ^ a b "Himeros". Gazetteer of Planetary Nomenclature. USGS Astrogeology Research Program. (Center Latitude: 21.20°, Center Longitude: 282.30°; Planetographic, +West)
- ^ a b Greenberg, Richard (14 September 2006). "Eros' Rahe Dorsum: Implications for internal structure". Meteoritics & Planetary Science. 43 (3): 435–449. Bibcode:2008M&PS...43..435G. doi:10.1111/j.1945-5100.2008.tb00664.x.
- ^ a b Robinson, M. S.; Thomas, P. C.; Veverka, J.; Murchie, S. L.; Wilcox, B. B. (9 August 2002). "The geology of 433 Eros". Meteoritics & Planetary Science. 37 (12): 1651–1684. Bibcode:2002M&PS...37.1651R. doi:10.1111/j.1945-5100.2002.tb01157.x.
- ^ "Color View of the Saddle". Johns Hopkins University Applied Physics Laboratory. 31 May 2000. Archived from the original on 14 May 2023. Retrieved 22 May 2024.
- ^ 433 Eros (1898 DQ). JPL Small-Body Database Browser (last obs.). Jet Propulsion Laboratory. 4 June 2017. Archived from the original on 11 July 2020. Retrieved 16 August 2017.
- ^ Yasui, Minami; Matsumoto, Eri; Arakawa, Masahiko (1 November 2015). "Experimental study on impact-induced seismic wave propagation through granular materials". Icarus. 260: 320–331. Bibcode:2015Icar..260..320Y. doi:10.1016/j.icarus.2015.07.032.
- ^ Thomas, P. C.; Robinson, M. S. (21 July 2005). "Seismic resurfacing by a single impact on the asteroid 433 Eros". Nature. 436 (7049): 366–369. Bibcode:2005Natur.436..366T. doi:10.1038/nature03855. PMID 16034412.
External links
[edit]Himeros Crater at the IAU Gazetteer of Planetary Nomenclature