Asteroid albedos: graphs of data
by Wm. Robert Johnston
last updated 25 March 2017
The following figures show asteroid albedos as a function of orbital parameters, based on a compilation of 139,900 reported measurements of asteroid/TNO albedos (through 2014). Most of these measurements are from WISE. A breakdown and list of sources is provided at the end of the page.
This shows albedo vs. distance for asteroids with measured albedos: 139,727 asteroids are shown, mostly with WISE-measured albedos. Note the lower albedos for asteroids beyond 3.3 AU, including Jupiter Trojans at 5.2 AU.
This graph shows the trend in asteroid albedo vs. distance as statistics for the sample from the previous graph (binned in distance with 100-1000 per bin). The blue line shows median albedo, the red and green lines span 95% of the binned samples.
This shows asteroid eccentricities vs. semimajor axis with colors indicating albedo ranges. These and remaining plots are limited to the 5,957 asteroids with measured diameters of 13 km or more, and use osculating elements.
Same as previous plot, but a closer view of the main belt.
This shows asteroid inclination vs. semimajor axis with colors indicating albedo ranges.
Same as previous plot, but a closer view of the main belt.
The following table summarizes the sources for albedo values used in the above figures, as of 2014 ("object count, adopted figures") and the total number of objects with albedo measurements available from each source (the latter values overlap amongst sources).
| method/source | object count, adopted figures | percent | total objects observed (figures overlap) |
|---|
| thermal/WISE | 137,616 | 98.37 | 139,465 |
| thermal/Akari | 1,633 | 1.17 | 5,112 |
| thermal/IRAS | 158 | 0.11 | 2,470 |
| thermal/Spitzer, MSX, others | 264 | 0.19 | 826 |
| radar/ground-based | 44 | 0.03 | 117 |
| direct imaging/HST, spacecraft, adaptive optics | 12 | 0.01 | 101 |
| occultation timing/ground-based | 0 | 0.00 | 56 |
| TNOs and Centaurs, all methods | 173 | 0.12 | 173 |
The following table provides updated figures as of March 2017 (this includes data not yet represented in the figures above).
| method/source | object count, adopted figures | percent | total objects observed (figures overlap) |
|---|
| thermal/WISE | 140,368 | 97.24 | 141,860 |
| thermal/Spitzer | 1,965 | 1.36 | 2,921 |
| thermal/Akari | 1,534 | 1.06 | 5,115 |
| thermal/IRAS | 151 | 0.105 | 2,470 |
| radar/ground-based | 140 | 0.097 | 321 |
| thermal/other | 79 | 0.055 | 292 |
| thermal/Herschel | 70 | 0.048 | 86 |
| dynamic (TNOs/Centaurs) | 21 | 0.015 | 35 |
| direct imaging/HST, spacecraft | 11 | 0.008 | 26 |
| occultation timing/ground-based | 7 | 0.005 | 56 |
| direct imaging/ground-based adaptive optics | 2 | 0.001 | 80 |
| TOTAL | 144,341 | 100.00 | N/A |
Fraction of known asteroids and TNOs with measured diameters (as of March 2017):
| | numbered objects | unnumbered objects | total objects | percent numbered |
| with diameter measurement | 127,893 | 16,455 | 144,348 | 88.60 |
| without diameter measurement | 360,556 | 225,420 | 585,976 | 61.53 |
| total | 488,449 | 241,875 | 730,324 | 66.88 |
| percent with diameter measurement | 26.18 | 6.80 | 19.76 | 100.00 |
Sources:
- WISE/NEOWISE:
- Grav, T., et al., 2011, WISE/NEOWISE observations of the Jovian trojans: Preliminary results, Astrophys. J., 742:40.
- Grav, T., et al., 2012, WISE/NEOWISE observations of the Hilda population: Preliminary results, Astrophys. J., 744:197.
- Mainzer, A., et al., 2011, NEOWISE observations of near-Earth objects: Preliminary results, Astrophys. J., 743:156.
- Mainzer, A., et al., 2012, Physical parameters of asteroids estimated from the WISE 3-band data and NEOWISE post-cryogenic survey, Astrophys. J. Lett., 760:L12.
- Mainzer, A., et al., 2014, Initial performance of the NEOWISE reactivation mission, in press.
- Masiero, J. R., et al., 2011, Main belt asteroids wtih WISE/NEOWISE. I. Preliminary albedos and diameters, Astrophys. J., 741:68.
- Masiero, J. R., et al., 2012, Preliminary analysis of WISE/NEOWISE 3-band cryogenic and post-cryogenic observations of main belt asteroids, Astrophys. J. Lett., 759:L8.
- Pravec, P. et al., 2014, Absolute magnitudes of asteroids and a revision of asteroid albedo estimates from WISE thermal observations, in press.
- additional sources, list under construction.
- AKARI:
- SPITZER:
- Harris, A. W., et al., 2011, ExploreNEOs. II. The accuracy of the warm SPITZER near-Earth object survey, Astron. J., 141:75.
- Marchis, F., et al., 2012, Multiple asteroid systems: Dimensions and thermal properties from Spitzer Space Telescope and ground-based observatiosn, Icarus, 221:1130.
- Mueller, M., et al., 2011, ExploreNEOs. III. Physical characterization of 65 potential spacecraft target asteroids, Astron. J., 141:109.
- Ryan, E. L., and C. E. Woodward, 2011, Albedos of small Hilda group asteroids as revealed by SPITZER, Astron. J., 141:186.
- Thomas, C. A., et al., 2011, ExploreNEOs. V. Average albedo by taxonomic complex in the near-Earth asteroid population, Astron. J., 142:85.
- Thomas, C. A., et al., 2014, Physical characterization of Warm Spitzer-observed near-Earth objects, Icarus, 228:217.
- Trilling, D. E., et al., 2010, ExploreNEOs. I. Description and first results from the warm SPITZER near-Earth object survey, Astron. J., 140:770.
- sources listed at W. R. Johnston, 2017, Asteroid diameters and albedos from Spitzer Space Telescope observations.
- PDS data sets:
- Delbo, M., 2006, Delbo Thermal Infrared Asteroid Diameters and Albedos V1.0, EAR-A-KECK1LWS/ETAL-5-DELBO-V1.0, NASA Planetary Data System.
- Morrison, D. and Zellner, B., 2007, TRIAD Radiometric Diameters and Albedos V1.0. EAR-A-COMPIL-5-TRIADRAD-V1.0. NASA Planetary Data System.
- Shevchenko, V.G. and Tedesco, E.F., 2007, Asteroid Albedos from Stellar Occultations V1.0. EAR-A-VARGBDET-5-OCCALB-V1.0. NASA Planetary Data System.
- Tedesco, E.F., P.V. Noah, M. Noah, and S.D. Price, 2004, IRAS Minor Planet Survey. IRAS-A-FPA-3-RDR-IMPS-V6.0. NASA Planetary Data System.
- Tedesco, E.T., M.P. Egan, and S.D. Price, 2004, MSX Infrared Minor Planet Survey. MSX-A-SPIRIT3-5-SBN0003-MIMPS-V1.0. NASA Planetary Data System.
- additional published measurements:
- (list under construction)
- thermal/radiometric: Ali-Lagoa et al., 2013; Bauer et al., 2011; Busch et al., 2008; Delbo, 2004; Fernandez et al., 2003; Fernandez et al., 2009; Harris et al., 2008; Matter et al., 2011; Mommert et al., 2014; Polishook et al., 2012; Trilling et al., 2007; Trilling et al., 2008; Volguardsen et al., 2006; Wolters et al., 2005.
- adaptive optics: Busch et al., 2007; Carry et al., 2010; Conrad et al., 2007; Drummond and Christou, 2008; Drummond et al., 2014; Hanus et al., 2013; Marchis et al., 2006.
- HST: Schmidt et al., 2008; Storrs et al., 1999; Storrs et al., 2004; Thomas et al., 2005.
- spacecraft: Carry et al., 2012; Duxbury et al., 2004; Ernakov et al., 2014; Fujiwara et al., 2006; Jorda et al., 2012; Newburn et al., 2003.
- radar measurements:
- Benner et al., 1999; Benner et al., 2001; Brozovic et al., 2009; Busch et al., 2006; Busch et al., 2007; Busch et al., 2011; de Leon et al., 2013; Hudson and Ostro, 1999; Hudson et al., 2003; Magri et al., 2007; Mueller et al., 2013; Naidu et al., 2013; Nolan et al., 2013; Shepard et al., 2008; Shepard et al., 2011; http://echo.jpl.nasa.gov/~lance/small.neas.html; http://echo.jpl.nasa.gov/~lance/binary.neas.html; http://echo.jpl.nasa.gov/~lance/asteroid_radar_properties/nea.radaralbedo.html.
- sources listed in W. R. Johnston, 2017, Radar-detected asteroids with radar-measured parameters.
- TNO and Centaur diameters:
- sources listed in W. R. Johnston, 2016, TNO and Centaur Diameters, Albedos, and Densities V4.0, EAR-A-COMPIL-5-TNOCENALB-V4.0, NASA Planetary Data System, on line, updated at TNO/Centaur diameters, albedos, and densities.
- Osculating elements:
© 2003-2016, 2017 by Wm. Robert Johnston.
Last modified 25 March 2017.
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