{ "id": "ep6p2nyw4a", "slug": "246-asporina", "title": "246 Asporina", "updated": "2026-10-21", "topic_path": [ { "id": "places", "label": "Places and geography", "api_url": "https://www.edgepedia.org/api/v1/topics/places" }, { "id": "places.extraterrestrial", "label": "Extraterrestrial places", "api_url": "https://www.edgepedia.org/api/v1/topics/places.extraterrestrial" }, { "id": "places.extraterrestrial.small-bodies", "label": "Small bodies of the Solar System", "api_url": "https://www.edgepedia.org/api/v1/topics/places.extraterrestrial.small-bodies" }, { "id": "places.extraterrestrial.small-bodies.asteroids-main-belt", "label": "Main-belt asteroids and numbered minor planets", "api_url": "https://www.edgepedia.org/api/v1/topics/places.extraterrestrial.small-bodies.asteroids-main-belt" }, { "id": "places.extraterrestrial.small-bodies.asteroids-main-belt.middle-belt-asteroids", "label": "Middle-belt asteroids", "api_url": "https://www.edgepedia.org/api/v1/topics/places.extraterrestrial.small-bodies.asteroids-main-belt.middle-belt-asteroids" }, { "id": "places.extraterrestrial.small-bodies.asteroids-main-belt.middle-belt-asteroids.asteroids-named-for-mythological-figures", "label": "Asteroids named for mythological figures", "api_url": "https://www.edgepedia.org/api/v1/topics/places.extraterrestrial.small-bodies.asteroids-main-belt.middle-belt-asteroids.asteroids-named-for-mythological-figures" } ], "geo": [ { "id": "geo.nongeo.nodate.places.extraterrestrial.small-bodies.asteroids-main-belt.middle-belt-asteroids.asteroids-named-for-mythological-figures", "label": "Non-geographic · Not dated: Asteroids named for mythological figures", "api_url": "https://www.edgepedia.org/api/v1/geo/geo.nongeo.nodate.places.extraterrestrial.small-bodies.asteroids-main-belt.middle-belt-asteroids.asteroids-named-for-mythological-figures", "path": [ { "id": "geo.nongeo", "label": "Non-geographic", "api_url": "https://www.edgepedia.org/api/v1/geo/geo.nongeo" }, { "id": "geo.nongeo.nodate", "label": "Non-geographic · Not dated", "api_url": "https://www.edgepedia.org/api/v1/geo/geo.nongeo.nodate" }, { "id": "geo.nongeo.nodate.places", "label": "Places and geography", "api_url": "https://www.edgepedia.org/api/v1/geo/geo.nongeo.nodate.places" }, { "id": "geo.nongeo.nodate.places.extraterrestrial", "label": "Extraterrestrial places", "api_url": "https://www.edgepedia.org/api/v1/geo/geo.nongeo.nodate.places.extraterrestrial" }, { "id": "geo.nongeo.nodate.places.extraterrestrial.small-bodies", "label": "Small bodies of the Solar System", "api_url": "https://www.edgepedia.org/api/v1/geo/geo.nongeo.nodate.places.extraterrestrial.small-bodies" }, { "id": "geo.nongeo.nodate.places.extraterrestrial.small-bodies.asteroids-main-belt", "label": "Main-belt asteroids and numbered minor planets", "api_url": "https://www.edgepedia.org/api/v1/geo/geo.nongeo.nodate.places.extraterrestrial.small-bodies.asteroids-main-belt" }, { "id": "geo.nongeo.nodate.places.extraterrestrial.small-bodies.asteroids-main-belt.middle-belt-asteroids", "label": "Middle-belt asteroids", "api_url": "https://www.edgepedia.org/api/v1/geo/geo.nongeo.nodate.places.extraterrestrial.small-bodies.asteroids-main-belt.middle-belt-asteroids" }, { "id": "geo.nongeo.nodate.places.extraterrestrial.small-bodies.asteroids-main-belt.middle-belt-asteroids.asteroids-named-for-mythological-figures", "label": "Asteroids named for mythological figures", "api_url": "https://www.edgepedia.org/api/v1/geo/geo.nongeo.nodate.places.extraterrestrial.small-bodies.asteroids-main-belt.middle-belt-asteroids.asteroids-named-for-mythological-figures" } ] } ], "excerpt": "246 Asporina (A885EA) is a roughly 51 km main-belt asteroid discovered 1885 by Borrelly at Marseille, an olivine-dominated A-type asteroid with a 16.2 h rotation and the best spectral analog for angrite meteorites.", "snippet": "246 Asporina (A885EA) is a roughly 51 km main-belt asteroid discovered 1885 by Borrelly at Marseille, an olivine-dominated A-type asteroid with a 16.2 h rotation and the best spectral analog for angrite meteorites.", "node": "places.extraterrestrial.small-bodies.asteroids-main-belt.middle-belt-asteroids.asteroids-named-for-mythological-figures", "markdown": "# 246 Asporina\n\n**246 Asporina** (provisional designation A885EA) is a main-belt asteroid about 51 km across, discovered on 1885-03-08 by A. Borrelly at [Marseille](https://www.edgepedia.org/marseille)[1](https://www.lpi.usra.edu/resources/asteroids/asteroid/?asteroid_id=A885EA). It is one of the comparatively rare A-type asteroids, a class defined by spectra dominated by the mineral olivine, and it has served as a reference object for studies of differentiated planetesimals[2](https://ntrs.nasa.gov/citations/20050175725).\n\n| Key fact | Detail |\n|---|---|\n| Designation and discovery | Number 246, provisional A885EA; discovered 1885-03-08 by Borrelly, A. at Marseille[1](https://www.lpi.usra.edu/resources/asteroids/asteroid/?asteroid_id=A885EA) |\n| Class | Main-belt asteroid (MBA); A-type, olivine-dominated spectrum[1](https://www.lpi.usra.edu/resources/asteroids/asteroid/?asteroid_id=A885EA) • [3](https://academic.oup.com/mnras/article/477/2/2786/4937819) |\n| Size | Diameter 50.891 km; about 60 km in a 2007 occultation prediction[1](https://www.lpi.usra.edu/resources/asteroids/asteroid/?asteroid_id=A885EA) • [4](https://www.occultations.org.nz/planet/2007/updates/071127_246_9245_u.htm) |\n| Rotation | 16.222 h (catalog value); 16.234 h from 2009 photometry with 433 data points[1](https://www.lpi.usra.edu/resources/asteroids/asteroid/?asteroid_id=A885EA) • [5](https://mpbulletin.org/issues/MPB_38-4.pdf) |\n| Orbit | Semi-major axis 2.695 au, eccentricity 0.1088, inclination 15.6216 degrees[1](https://www.lpi.usra.edu/resources/asteroids/asteroid/?asteroid_id=A885EA) |\n| Reflectivity | Geometric albedo 0.193[1](https://www.lpi.usra.edu/resources/asteroids/asteroid/?asteroid_id=A885EA) |\n| Meteorite link | Best spectral analog for the angrite meteorites among 712 asteroids compared[6](https://www.sciencedirect.com/science/article/pii/S0019103524004895) |\n\n## Orbit and physical properties\n\nAsporina orbits in the main asteroid belt at a semi-major axis of 2.695 au with eccentricity 0.1088 and an inclination of 15.6216 degrees to the ecliptic[1](https://www.lpi.usra.edu/resources/asteroids/asteroid/?asteroid_id=A885EA). Its cataloged diameter is 50.891 km and its geometric albedo is 0.193, a moderately bright surface for an asteroid[1](https://www.lpi.usra.edu/resources/asteroids/asteroid/?asteroid_id=A885EA). A stellar occultation prediction for 2007 used a diameter of about 60 km[4](https://www.occultations.org.nz/planet/2007/updates/071127_246_9245_u.htm).\n\nThe rotation period is long for a main-belt object. A 2009 lightcurve campaign over 2009-04-23 to 2009-04-29, using 433 data points at phase angles of 14.7 to 16.6 degrees, gave a period of 16.234 h with an uncertainty of 0.001 h[5](https://mpbulletin.org/issues/MPB_38-4.pdf); the cataloged value is 16.222 h[1](https://www.lpi.usra.edu/resources/asteroids/asteroid/?asteroid_id=A885EA).\n\n## The A-type class and olivine\n\nA-type asteroids are a rare taxonomic class; a 2005 review counted no more than 17 known objects at that time, and later surveys such as SMASS and SMASS II added 12 new members to the original five[2](https://ntrs.nasa.gov/citations/20050175725). The class is defined by moderately high albedos (0.13 to 0.39), extremely reddish slopes shortward of 0.7 micrometers, and a strong absorption feature centered near 1.05 micrometers[2](https://ntrs.nasa.gov/citations/20050175725). In the Bus and Binzel definition, A-types show a very steep to extremely steep ultraviolet slope shortward of 0.75 micrometers and a moderately deep absorption feature longward of 0.75 micrometers[3](https://academic.oup.com/mnras/article/477/2/2786/4937819).\n\nThe absorption band is the signature of olivine. High-resolution infrared spectra in the 0.8 to 2.6 micrometer region published for 246 Asporina, [289 Nenetta](https://www.edgepedia.org/289-nenetta), and [446 Aeternitas](https://www.edgepedia.org/446-aeternitas) all show the distinctive deep multiple absorption band of olivine near 1.1 micrometers, with an overall continuum slope suggesting a metal component; this interpretation makes A-type asteroids potential parent bodies of pallasites, the stony-iron meteorites composed of olivine crystals in metallic nickel-iron[7](https://www.lpi.usra.edu/lpi/contribution_docs/LPI-000537.pdf). Asporina is a standard member of the class in later work: one survey of olivine-rich near-Earth asteroids lists it among six A-type objects alongside (289) Nenetta, (446) Aeternitas, (863) Benkoela, (1951) Lick, and (2501) Lohja[3](https://academic.oup.com/mnras/article/477/2/2786/4937819), and spectroscopic studies of olivine-dominated asteroids regularly include it[8](https://www.boulder.swri.edu/~bottke/Reprints/Sanchez_2014_Icarus_228_288_Olivine_Asteroids.pdf).\n\n## Meteorite connections\n\nIn 2024, researchers who matched the ultraviolet-visible-near-infrared spectra of ten angrite meteorites against those of 712 asteroids determined that (246) Asporina is the closest spectral match to the angrites, and suggested it may be a piece of a Moon- to Mars-sized parent body that formerly occupied the inner [Solar System](https://www.edgepedia.org/solar-system) before being built into the terrestrial planets as they formed.[6](https://www.sciencedirect.com/science/article/pii/S0019103524004895) Angrites are a rare group of igneous meteorites, so a main-belt spectral match is a clue to where such differentiated material survives today.\n\n## Observational record\n\nAsporina is bright enough for targeted campaigns. It was observed by radar on 2014-05-28, when a Doppler-only continuous-wave echo power spectrum was obtained at 20 Hz frequency resolution; the polarization ratio on that date was 0.32[1](https://www.lpi.usra.edu/resources/asteroids/asteroid/?asteroid_id=A885EA). Stellar occultations also probe its size and shape: on 2007 Nov 27 UT the asteroid occulted a magnitude 10.1 star in Orion along a path across New Zealand's North Island passing near Auckland and Whangarei[4](https://www.occultations.org.nz/planet/2007/updates/071127_246_9245_u.htm), and further occultation events have been predicted since[9](https://astro.kretlow.de/cora/events/sodis/2025-12-31/UCAC4%20466-035942/%28246%29%20Asporina/). Its spectral behavior has also been examined against Gaia reflectance spectra, with marked differences noted between Gaia and ground-based spectra of Asporina, a caution for taxonomy built on different observing conditions[10](https://www.aanda.org/articles/aa/pdf/2023/06/aa43791-22.pdf).\n\n## References\n\n1. [LPI Asteroids: 246 Asporina (A885EA)](https://www.lpi.usra.edu/resources/asteroids/asteroid/?asteroid_id=A885EA)\n2. [Reddy, V., Hardersen, P. S., Gaffey, M. J., Abell, P. A. (2005). Mineralogy and Temperature-induced Spectral Investigations of A-type Asteroids 246 Asporina and 446 Aeternitas. Lunar and Planetary Science XXXVI.](https://ntrs.nasa.gov/citations/20050175725)\n3. [de León et al. (2018). Olivine-rich asteroids in the near-Earth space. Monthly Notices of the Royal Astronomical Society 477, 2786.](https://academic.oup.com/mnras/article/477/2/2786/4937819)\n4. [RASNZ Occultation Section: Asporina Occultation Update, 2007 Nov 27](https://www.occultations.org.nz/planet/2007/updates/071127_246_9245_u.htm)\n5. [Minor Planet Bulletin 38 (2011): 246 Asporina lightcurve, 2009 observations](https://mpbulletin.org/issues/MPB_38-4.pdf)\n6. [Remnants of a lost Planetesimal: Searching for the Angrite parent body. Icarus (2024).](https://www.sciencedirect.com/science/article/pii/S0019103524004895)\n7. [Bell, J. F., Gaffey, M. J., Hawke, B. R. Spectroscopic Identification of Probable Pallasite Parent Bodies. LPI Contributions.](https://www.lpi.usra.edu/lpi/contribution_docs/LPI-000537.pdf)\n8. [Sanchez et al. (2014). Olivine-dominated asteroids in the main belt. Icarus 228, 288-300.](https://www.boulder.swri.edu/~bottke/Reprints/Sanchez_2014_Icarus_228_288_Olivine_Asteroids.pdf)\n9. [CORA: 2025-12-31 occultation by (246) Asporina](https://astro.kretlow.de/cora/events/sodis/2025-12-31/UCAC4%20466-035942/%28246%29%20Asporina/)\n10. [Mahlke et al. (2023). Asteroid taxonomy from cluster analysis of spectrometry and albedo. A&A 674, A35.](https://www.aanda.org/articles/aa/pdf/2023/06/aa43791-22.pdf)\n\n---\n*Topic: Encyclopedia › Places and geography › Extraterrestrial places › Small bodies of the Solar System › Main-belt asteroids and numbered minor planets › Middle-belt asteroids › Asteroids named for mythological figures*\n\n*Initially written Oct 21, 2026*\n\n*Copyright 2026 EdgeChat AI, a subsidiary of Biostate AI.*\n\nLicense: Edgepedia Community License 1.0, https://www.edgepedia.org/edgepedia/license\n", "same_as": [ "https://www.boulder.swri.edu/~bottke/Reprints/Sanchez_2014_Icarus_228_288_Olivine_Asteroids.pdf" ], "url": "https://www.edgepedia.org/246-asporina", "markdown_url": "https://www.edgepedia.org/246-asporina.md", "license": { "name": "Edgepedia Community License 1.0", "url": "https://www.edgepedia.org/edgepedia/license", "summary": "Free with credit, commercial use included. AI training is open to everyone. For other uses, organizations over USD 100M in revenue or 100M monthly users license separately.", "spdx": "LicenseRef-Edgepedia-Community-1.0" }, "credit": "\"246 Asporina\", Edgepedia (EdgeChat), https://www.edgepedia.org/246-asporina. Edgepedia Community License 1.0.", "credit_md": "\"[246 Asporina](https://www.edgepedia.org/246-asporina)\", Edgepedia (EdgeChat), [https://www.edgepedia.org/246-asporina](https://www.edgepedia.org/246-asporina). [Edgepedia Community License 1.0](https://www.edgepedia.org/edgepedia/license).", "credit_html": "\"246 Asporina\", Edgepedia (EdgeChat), https://www.edgepedia.org/246-asporina. Edgepedia Community License 1.0.", "speakable": "246 Asporina is a roughly 51 km main-belt asteroid discovered 1885 by Borrelly at Marseille, an olivine-dominated A-type asteroid with a 16.2 h rotation and the best spectral analog for angrite meteorites." }