Table 4
Dynamical time scales and cumulative numbers of 1-km asteroids in the main belt (mb) and the near-Earth region (neo).
| 1-km | 1-km | 1-km | 1-km | 1-km | 1-km | ||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Num. | Family | Res. | τg18 | τneo | τmb | ρ | Nmb | Nneo | obs. | obs. | Notes |
| – | – | – | Myr | Myr | Myr | g cm−3 | 103 | 1 | 1 | % | |
| 4 | Vesta (HED) | v6 | 6.98 | 4.39 | 1713 | 2.5! | 11.4 | 29.2 | |||
| 25 | Phocaea(H) | v6 | 6.98 | 5.91 | 796 | 2.5 | 2.7 | 20.0! | |||
| 170 | Maria (H) | 3:1 | 1.83 | 0.954 | 1533 | 3.0 | 5.5 | 3.4 | |||
| 808 | Merxia (H) | 5:2 | 0.68 | 0.24 | 866 | 2.5 | 2.0 | 0.6 | |||
| 847 | Agnia (H) | 5 2 | 0.68 | 0.19 | 1004 | 2.5 | 3.1 | 0.6 | |||
| 158 | Koronis (H) | 5:2 | 0.68 | 0.824 | 1438 | 3.0 | 9.2 | 5.2 | |||
| 158′ | Koronis2 (H) | 5:2 | 0.68 | (a) | (a) | 3.0 | 0.4 | 0.0 | |||
| 832 | Karin (H) | 5:2 | 0.68 | (a) | (a) | 2.5 | 1.1 | 0.0 | |||
| 20 | Massalia (L) | 3:1 | 1.83 | 0.45 | 1140 | 2.5 | 1.3? | 0.5? | |||
| 20′ | Massalia2 (L) | 3:1 | 1.83 | 0.45 | 1140 | 2.5 | 1.3? | 0.5? | |||
| 1272 | Gefion (L) | 5:2 | 0.68 | 0.69 | 749 | 2.5 | 3.8 | 3.5 | |||
| 3 | Juno (L) | 8:3 | 1.70 | 2.55 | 519 | 2.5 | 4.2 | 20.6 | |||
| 8 | Flora (LL) | V6 | 6.98 | 11.93 | 722 | 2.5 | 7.2 | 119.5 | |||
| 15 | Eunomia (LL) | 3:1 | 1.83 | 4.48 | 3078 | 3.54 | 7.0 | 10.2 | |||
| 44 | Nysa (LL) | 3:1 | 1.83 | 4.04 | 789 | 2.5 | 2.9 | 14.6 | |||
| 144 | Vibilia (CM) | 8:3 | 1.70 | 0.60u | 2412u | 1.7 | 0.7 | 0.2 | All CM are CM/CR | ||
| 145 | Adeona (CM) | 8:3 | 1.70 | 1.76 | 864 | 1.7 | 10.9 | 22.2 | |||
| 163 | Erigone (CM) | 3:1 | 1.83 | 4.64(a) | 932(a) | 1.7 | 2.7 | 0.0 | Only sub-km nearby 3:1 | ||
| 410 | Chloris (CM) | 8:3 | 1.70 | 1.19 | 399 | 1.7 | 0.9 | 2.7 | |||
| 490 | Veritas (CM) | 2:1 | 0.40 | (a) | (a) | 1.7 | 30.6 | 0.0 | |||
| 668 | Dora (CM) | 5:2 | 0.68 | 0.36 | 322 | 1.7 | 6.2 | 6.9 | |||
| 778 | Theobalda (CM) | 2:1 | 0.40 | (a) | (a) | 1.7 | 15.9 | 0.0 | |||
| 1128 | Astrid (CM) | 5:2 | 0.68 | 0.23 | 786 | 1.7 | 8.1 | 2.4 | |||
| 3815 | König (CM) | 3:1 | 1.83 | (a) | (a) | 1.7 | 3.9 | 0.0 | |||
| 10 | Hygiea (CI) | 2:1 | 0.40 | 0.27u | 1899u | 2.1 | 20.0e | 2.8 | All CI are CI/IDP | ||
| 24 | Themis (CI) | 2:1 | 0.40 | 0.62 | 1292 | 1.3 | 20.0e | 9.6 | |||
| 31 | Euphrosyne (CI) | 2:1 | 0.40 | 0.56 | 399 | 1.6 | 28.0e | 39.3 | High-i C-type NEOs | ||
| 128 | Nemesis (CI) | 8:3 | 1.70 | (a) | (a) | 3.5 | 6.3 | 0.0 | |||
| 142 | Polana (CI) | 3:1 | 1.83 | 5.12! | 1261 | 1.7 | 14.2 | 57.7 | Low-i C-type NEOs | ||
| 302 | Clarissa (CI) | 3:1 | 1.83 | (a) | (a) | 1.7 | 0.8 | 0.0 | |||
| 375 | Ursula (CI) | 2:1 | 0.40 | 0.30u | 2187u | 1.7 | 10.4e | 1.4 | |||
| 569 | Misa (CI) | 8:3 | 1.70 | 0.63u | 2002u | 1.7 | 2.8 | 0.9 | |||
| 618 | Elfriede (CI) | 2:1 | 0.40 | (a) | (a) | 1.7 | 10.6 | 0.0 | |||
| 656 | Beagle (CI) | 2:1 | 0.40 | (a) | (a) | 1.3 | 1.3 | 0.0 | |||
| 702 | Alauda (CI) | 2:1 | 0.40 | 0.30 | 1041 | 1.7 | 12.1 | 3.5 | |||
| 845 | Naema (CI) | 5:2 | 0.68 | 0.24 | 469 | 1.7 | 4.1 | 2.1 | |||
| 1726 | Hoffmeister (CI) | 2:1 | 0.40 | 0.16 | 432 | 1.7 | 19.5 | 7.2 | |||
| 3556 | Lixiaohua (CI) | 2:1 | 0.40 | (a) | (a) | 1.7 | 14.1e | 0.0 | |||
| 283 | Emma (IDP) | 9:4 | 0.40 | 0.22 | 1689 | 1.7 | 3.3e | 0.4 | |||
| 363 | Padua (IDP) | 8:3 | 1.70 | 0.13u | 2522u | 1.7 | 2.1 | 0.1 | |||
| 2 | Pallas (B) | 5:2 | 0.68 | 9.54! | 824 | 2.9 | 0.3 | 3.5 | High-i B-type NEOs | ||
| 221 | Eos (CO/CV/CK) | 7:3 | 0.20 | 0.28 | 1816 | 3.1 | 44.0 | 6.5 | |||
| 729 | Watsonia (CO/CV/CK) | 5:2 | 0.68 | 1.24 | 1391 | 3.1 | 0.3 | 0.3 | CAI-like | ||
| 298 | Baptistina (?) | v6 | 6.98 | 8.31 | 2833 | 3.1 | 3.0 | 8.8 | Low-i 1.00-µ NEOs | ||
| 396 | Aeolia (?) | 5:2 | 0.68 | (a) | (a) | 1.7 | 1.9 | 0.0 | |||
| 4203 | Brucato (?) | 8:3 | 1.70 | (a) | (a) | 1.7 | 2.1 | 0.0 | |||
| 22 | Kalliope (M) | 5:2 | 0.68 | 0.31 | 1635 | 4.1 | 0.6 | 0.1 | |||
| 293 | Brasilia (M) | 5:2 | 0.68 | 0.83 | 285 | 3.5 | 4.4 | 12.8 | CH? | ||
| 369 | Aëria (M) | 8:3 | 1.70 | (a) | (a) | 3.5 | 0.8 | 0.0 | |||
| 606 | Brangäne (M) | 3:1 | 1.83 | (a) | (a) | 3.1 | 0.7 | 0.0 | CB? | ||
| 1222 | Tina (M) | 5:2 | 0.68 | 1.31 | 539 | 3.5 | 1.7 | 3.6 | |||
| 44′ | Nysa (E) | 3:1 | 1.83 | 4.04 | 789 | 2.5 | 2.9 | 14.6 | Faint Xn-type NEOs | ||
| 434 | Hungaria (E) | 5:1 | 36.0 | 14.70! | 1752 | 3.1 | 0.6 | 5.0 | High-i E-type NEOs | ||
| 87 | Sylvia (P) | 2:1 | 0.40 | 0.33 | 1207 | 1.3 | 7.0e | 1.9 | |||
| 2732 | Witt (?) | 5:2 | 0.68 | 0.15 | 2070 | 2.5 | 2.8 | 0.2 | |||
| 3200 | Phaethon (CY?) | – | – | – | – | 1.7 | – | 3.0 | |||
| 4652 | Iannini (Aca/Lod) | 11:4 | – | (a) | (a) | 2.5 | 0.3 | 0.0 | |||
| HED | 11.4 | 29.2 | 16 | 1.8% | Marsset et al. (2022) | ||||||
| H | 23.6 | 29.8 | – | – | Brož et al. (2024) | ||||||
| L | 10.6 | 25.1 | – | – | Brož et al. (2024) | ||||||
| LL | 17.1 | 144.3 | – | – | Brož et al. (2024) | ||||||
| CM | 79.9 | 34.4 | – | – | |||||||
| CI | 164.2 | 124.5 | – | – | |||||||
| IDP | 5.4 | 0.5 | – | – | |||||||
| B | 0.3 | 3.5! | 70 | 7.6% | Outliers of CI-like? | ||||||
| CO/CV/CK | 44.3 | 6.8 | 8 | 0.9% | Reclassified K- and L-type | ||||||
| CR | – | – | – | – | CM-type? | ||||||
| CH | – | – | – | – | M-type? | ||||||
| CB | – | – | – | – | M-type? | ||||||
| M | 8.2 | 16.5 | 29 | 3.1% | |||||||
| E | 3.5 | 19.6 | 5 | 0.5% | |||||||
| P | 7.0 | 1.9! | 26 | 2.8% | Outliers of CI-like? | ||||||
| D | – | – | 45 | 4.9% | Jupiter-family comets? | ||||||
| Aca/Lod | 0.3 | 0.0 | – | – | |||||||
| ? | 4.9 | 8.8 | 24 | 2.6% | Reclassified K- and L-type | ||||||
| ? | 2.1 | 0.0 | – | – | |||||||
| CM+CI+IDP+B+CO/CV/CK+CR+CH+CB | 304.1 | 178.5 | 303 | 32.8% | |||||||
| H+L+LL | 51.3! | 199.2 | 287 | 31.1% | |||||||
| all bodies | 1360H | 925H |
Notes. For all families, we report the neighbouring resonances, the NEO life time τg18 from Granvik et al. (2018), the NEO life times τneo from this work, computed for 1-km bodies, the main belt life times τmb, the volumetric density of simulated bodies, the observed cumulative number Nmb(> 1 km) of main belt bodies, the computed cumulative number Nneo of NEOs and meteoroids. Additional notes: H Harris & Chodas (2021), N Nesvorný et al. (2023), (a) after ≈ 100 Myr or more, e extrapolated using a collisional model, u undersampled, ? uncertain value, ! exceptional value.
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.