Summary for : (65803) Didymos
| Dyn | T.T | T.B | T T.L B | T.D | Density (g/cm^3) | Δρ/ρ | Diameter (km) | ΔD/D | Mass (kg) | ΔM/M | Ref | Avg.M |
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| NEA | - | - | - | - | - | 1.95 ± 0.62 (C) | 32 % | 0.8 ± 0.1 | 10.0 % | 5.24e+11 ± 5.24e+10 | 10 % | S | EVM |
| NEA | - | - | - | - | - | 1.95 ± 0.62 (C) | 32 % | 0.8 ± 0.1 | 10.0 % | 5.24e+11 ± 5.24e+10 | 10 % | S | w.avg |
| NEA | - | 1.90 ± 0.53 (C) | 28 % | 0.8 ± 0.1 | 10.0 % | 5.24e+11 ± 5.20e+10 | 10 % | C | ? |
Average asteroid densities (g/cm^3):
C = 1.3 ± 0.6, B = 2.4 ± 0.5, S = 2.7 ± 0.5, M = 3.5 ± 1.0, P = 2.8 ± 1.6,
X = 1.9 ± 0.8, Xc = 4.9 ± 0.9, Xk = 4.2 ± 0.7 (Ref)
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Additional resources:
3D Model |
JPL New Horizons |
Minor Planet Center |
Wikipedia (these auto-generated links might not work)
Note:
The density estimates have been ranked from (A) to (E), corresponding to the relative error: (B) less than 20%,
(C) between 20 and 50%, (D) between 50 and 100%, and (E) more than 100%. (A) stands for (presumably) reliable estimates (accuracy better than 20%), based on more than 5 mass estimates and 5 diameter
estimates, or a spacecraft encounter. Apparently unrealistic densities (ρ > 8) are tagged with (X).
EVM: average by using the Expected Value Method (Ref). w.avg: weighted average (with w = 1/err^2).
T.T: Tholen Tax Class. T.B: Bus & Binzel Tax Class. T T.L: S3OS2 Lazarro (Tholen) Tax Class. T.L B: S3OS2 Lazarro (Bus & Binzel) Tax Class. T.D: DeMeo Tax Class.
Ref: S = SiMDA, C = Carry (2012)
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(Indirect) density estimates
| Density (g/cm^3) | Δρ/ρ | Method | Year | Ref | N |
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| 1.7 ± 0.40 | 23.5 % | PheMu | 2006 | BD7 | |
| 2.1 ± 0.60 | 28.6 % | PheMu | 2006 | BD7 | |
| 1.7 ± 0.50 | 29.4 % | PheMu | 2009 | BD11 | |
| 2.1 ± 0.65 | 31.0 % | PheMu | 2009 | BD11 | |
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PheMu : Mutual eclipsing phenomena in binary systems.
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References
| BD7 | (2006): | Pravec, P., Scheirich, P., Kusnirak, P., Sarounova, L., et al., 2006. Photometric survey of binary near-Earth asteroids. Icarus 181, 63-93. |
| BD11 | (2009): | Scheirich, P., Pravec, P., 2009. Modeling of lightcurves of binary asteroids. Icarus 200, 531-547. |
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Diameter estimates
Notes (N):
1: This estimate is discarded for the average diameter (and derived density) calculation in Carry (2012).
2: This estimate is discarded for the average diameter (and derived density) calculation in SiMDA (catalog).
Radar : Radar imaging.
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EVM diam. average D = (0.8 ± 0.08) km (ΔD/D = 10%, SNR = 10.00)
Derived bulk density ρ = (1.95 ± 0.62) g/cm3 (Δρ/ρ = 32%, SNR = 3.2)
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References
| D66 | (2010): | Benner, L.A.M., Margot, J., Nolan, M.C., Giorgini, J.D., Brozovic, M., Scheeres, D.J., Magri, C., Ostro, S.J., 2010. Radar Imaging and a Physical Model of Binary Asteroid 65803 Didymos, in: AAS/Division for Planetary Sciences Meeting Abstracts |
Mass estimates
Notes (N):
1: This estimate is discarded for the average mass (and derived density) calculation in Carry (2012).
2: This estimate is discarded for the average mass (and derived density) calculation in SiMDA (catalog).
3: This estimate is an average of individual solutions listed before under the same reference (e.g. M125).
BinRad : Binary imaged with radar.
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EVM mass average M = (5.240 ± 0.524) × 1011 kg (ΔM/M = 10%, SNR = 10.0)
Derived bulk density ρ = (1.95 ± 0.62) g/cm3 (Δρ/ρ = 32%, SNR = 3.2)
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References
| M91 | (2010): | Benner, L.A.M., Margot, J., Nolan, M.C., Giorgini, J.D., Brozovic, M., Scheeres, D.J., Magri, C., Ostro, S.J., 2010. Radar Imaging and a Physical Model of Binary Asteroid 65803 Didymos, in: AAS/Division for Planetary Sciences Meeting Abstracts |
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