2015 MM64 versus 2019 van Albada (1935 SX1)

This case may deserve further investigation because (2019) van Albada (1935 SX1) is a known binary asteroid with a satellite, as reported  here by Johnston’s Archive and a  photometric study by Vladimir Benishek, Petr Pravec, Russell Durkee, Marek Husarik.

Confirming a genetic relationship with 2015 MM64 would make the system particularly intriguing.

The nominal solutions show a clear convergence epoch broadly supported by the covariance clones. However, at the selected minimum-median-velocity epoch, all clone combinations remain outside van Albada’s Hill sphere and above the local escape-velocity curve. 

Thus, the case is intriguing but remains inconclusive.

 

Simulation details

Covariance clone convergence summary

Run setup:

- Pair mode, 100 covariance clones per target plus nominal.

- 101 samples per target, 10,201 sample cross-combinations.

- Analysis epoch: JD 2461200.5.

- Objective: minimize median velocity.

- Nominal sample source: covariance.

- Integrator: REBOUND IAS15 in AU-yr-Msun, initial dt 0.3652564 day (0.001 yr), default IAS15 epsilon.

- Massive bodies: Sun; Mercury, Venus, Earth-Moon, Mars, Jupiter, Saturn, Uranus, Neptune, and Pluto barycenters; Ceres, Pallas, and Vesta.

- Test particles: all nominal/covariance-clone samples for the 2 targets; clones are massless and do not perturb the massive bodies or each other.

Window window_1:

- Window center: 43768.781000 yr before analysis epoch.

- Selected best time: 43768.013514 yr before analysis epoch.

- Selected-time JD: -13525346.551110.

- Median relative velocity at selected time: 9.172443 m/s.

- Median distance at selected time: 168,300.443 km.

Distance distribution at selected time:

- Minimum combination at selected time: 10,143.336 km.

- p05 / p16: 17,042.759 / 53,341.853 km.

- Median / p84 / p95: 168,300.443 / 555,126.540 / 810,551.880 km.

- Max: 1,091,114.734 km.

- Nominal at selected time: 85,208.192 km.

- Fractions below thresholds: 0.00% < 10,000 km; 33.61% < 100,000 km; 99.01% < 1,000,000 km.

Relative-velocity distribution at selected time:

- Minimum combination at selected time: 0.693410 m/s.

- p05 / p16: 0.991334 / 2.770931 m/s.

- Median / p84 / p95: 9.172443 / 29.927771 / 43.668428 m/s.

- Max: 58.722771 m/s.

- Nominal at selected time: 4.752497 m/s.

- Fractions below thresholds: 5.10% < 1 m/s; 52.48% < 10 m/s.

Let's look at the distance and relative velocity distributions at the time when the median relative velocity was minimum:

Let's put together all pair combinations on the same density plot:

2017 VQ75 and 259711 (2003 YL54)

This is a potentially interesting couple.

100 clones + nominals, searching for the time when median relative velocity was lowest

Looking at the time when the median relative velocity was lowest, we can look at its distribution (together with asteroid distance at the same time:

Run setup:

- Pair mode, 100 covariance clones per target plus nominal.

- 101 samples per target, 10,201 sample cross-combinations.

- Analysis epoch: JD 2461000.5.

- Objective: minimize median velocity.

- Nominal sample source: covariance.

- Integrator: REBOUND IAS15 in AU-yr-Msun, initial dt 0.3652564 day (0.001 yr), default IAS15 epsilon.

- Massive bodies: Sun; Mercury, Venus, Earth-Moon, Mars, Jupiter, Saturn, Uranus, Neptune, and Pluto barycenters; Ceres, Pallas, and Vesta.

- Test particles: all nominal/covariance-clone samples for the 2 targets; clones are massless and do not perturb the massive bodies or each other.

Window window_1:

- Window center: 9687.860000 yr before analysis epoch.

- Selected best time: 9892.314224 yr before analysis epoch.

- Selected-time JD: -1152230.581058.

- Median relative velocity at selected time: 2.257536 m/s.

- Median distance at selected time: 44,283.075 km.

Distance distribution at selected time:

- Minimum combination at selected time: 2,700.492 km.

- p05 / p16: 4,837.868 / 12,423.673 km.

- Median / p84 / p95: 44,283.075 / 101,901.503 / 138,618.078 km.

- Max: 270,219.283 km.

- Nominal at selected time: 17,529.654 km.

- Fractions below thresholds: 12.49% < 10,000 km; 83.24% < 100,000 km; 100.00% < 1,000,000 km.

Relative-velocity distribution at selected time:

- Minimum combination at selected time: 0.057856 m/s.

- p05 / p16: 0.211032 / 0.627504 m/s.

- Median / p84 / p95: 2.257536 / 5.200980 / 7.098886 m/s.

- Max: 13.758033 m/s.

- Nominal at selected time: 0.814142 m/s.

- Fractions below thresholds: 25.23% < 1 m/s; 99.18% < 10 m/s.

169451 (2002 BF22) and 853271 (2009 BE162)

Back propagation orbital analysis based on nominal parameters.

Back propagation orbital analysis based on covariance clones.

Covariance clone convergence summary
- 2002 BF22 = 169451 (2002 BF22)
- 2009 BE162 = 853271 (2009 BE162)

Run setup:
- Pair mode, 100 covariance clones per target plus nominal.
- 101 samples per target, 10,201 clone-pair combinations.
- Analysis epoch: JD 2461200.5.
- Window center: 7731.815 yr before analysis epoch.
- Objective: minimize median relative velocity.
- Integrator: REBOUND IAS15, initial dt 1 day, default IAS15 epsilon.
- Massive bodies: Sun; Mercury, Venus, Earth-Moon, Mars, Jupiter, Saturn, Uranus, Neptune, and Pluto barycenters; Ceres, Pallas, and Vesta.
- Test particles: all nominal/covariance-clone samples for the two targets; clones are massless and do not perturb the massive bodies or each other.

Best convergence:
- Best time: 7711.893125 yr before analysis epoch.
- Best-time JD: -355617.820022.
- Median relative velocity: 1.477425 m/s.
- Median distance: 28,530.353 km.

Distance distribution at best time:
- Min / p05 / p16: 2,347.644 / 3,492.095 / 8,338.375 km.
- Median / p84 / p95: 28,530.353 / 63,184.025 / 93,165.494 km.
- Max: 168,315.951 km.
- Fractions below thresholds: 19.32% < 10,000 km; 96.01% < 100,000 km; 100% < 1,000,000 km.

Relative-velocity distribution at best time:
- Min / p05 / p16: 0.151787 / 0.203557 / 0.441629 m/s.
- Median / p84 / p95: 1.477425 / 3.271294 / 4.791772 m/s.
- Max: 8.679414 m/s.
- Fractions below thresholds: 35.73% < 1 m/s; 100% < 10 m/s.


Follwing a question from Adrien Coffinet , I tried to search for an answer by plotting all pairwise orbital parameters:

I do  not see any "abrupt" change around -40K but I notice a couple of facts:

Around the -40K marker:

  - e is near a local minimum.

  - q is near a local maximum.

  - Q is near a local minimum.

  That is internally consistent because:

  q = a(1 - e)

  Q = a(1 + e)

  and a is almost constant. So when e reaches a minimum:

  q increases

  Q decreases

 This looks more like a secular-cycle turning point than an abrupt scattering event. A close planetary encounter would more likely produce a sharper discontinuity or step-like change in a, e, or i.

  So the story may be:

  near -40K: the nominal pair is at/near a secular eccentricity turning point

  after -40K: orbital phasing evolves toward lower pair distance and velocity

  near -7.7K: strong nominal convergence

In conclusion: if the phisical truth is a "fission(?) event around -7.7K, the previous plot is not to be taken into consideration, otherwise the plot must be taken into consideration but no clear reason for what happened at -40K besides "secular cycle".

More expert people may find a better explanation (by the way, all this analysis should be peer-reviewed, do not take it as a proof but just as something that might derserve a better study).

a compact pairwise cluster: 2014 DC113, 2019 CV15, 2003 CL11

 These three objects have very similar orbits:

•   2014 DC113
•   2019 CV15
•   267721 (2003 CL11)

Nominal backward integrations (Rebound IAS15 with big planets + Ceres/Pallas/Vesta) suggest close pairwise convergence epochs, as shown in the pairwise plots:

pair 2014 DC113 and 2019 CV15

pair 2003 CL11 and 2014 DC113

pair 2003 CL11 and 2019 CV15

To check whether these are only nominal-orbit coincidences, I also propagated 30 covariance clones plus nominal and inspected the corresponding pairwise clone boxplots:

cross_pair_dc113_cv15_31x31

cross_pair_cl11_dc113_31x31

cross_pair_cl11_cv15_31x31

For these 31 x 31 clone-pair tests, the boxplot summaries are approximately:

  Each boxplot is evaluated at the refined time, inside the corresponding

  pairwise time window, that minimizes the median distance over the 31 x 31

  clone-pair combinations.

  2014 DC113 - 2019 CV15:

    median distance 150000 km; median relative velocity 10.4 m/s

    4.1% of clone pairs below 10000 km and 1 m/s

    36.6% below 100000 km and 10 m/s

  2003 CL11 - 2014 DC113:

    median distance 89000 km; median relative velocity 6.1 m/s

    2.6% of clone pairs below 10000 km and 1 m/s

    55.5% below 100000 km and 10 m/s

  2003 CL11 - 2019 CV15:

    median distance 217000 km; median relative velocity 15.2 m/s

    1.7% of clone pairs below 10000 km and 1 m/s

    26.7% below 100000 km and 10 m/s

The clone results appear to preserve a non-negligible pairwise signal.

In particular, the 2003 CL11 - 2014 DC113 pair gives the most compact median clone convergence in this preliminary test, while 2014 DC113 - 2019 CV15 also remains interesting. 

The 2003 CL11 - 2019 CV15 pair is weaker, but not obviously irrelevant.

However, an attempt to make all three clone clouds converge simultaneously in the three time windows suggested by the pairwise plots was not successful. In that test, the three-body cluster diameter remained extremely large, as summarized in:

cross_dc113_cv15_cl11_31x31x31

In the 31 x 31 x 31 triple-clone test, the median three-body diameters in the three pairwise windows were about 33, 23, and 70 million km, respectively. No clone triple was below 1 million km in diameter, and no clone triple had maximum internal relative velocity below 10 m/s.

One possible interpretation, offered only as a working hypothesis, is not a simultaneous three-body breakup but a sequential fragmentation history. For example, an older progenitor may have split into 2003 CL11 and an intermediate progenitor, followed later by a split of that intermediate progenitor into 2014 DC113 and 2019 CV15. The pairwise clone behaviour seems at least compatible with such a scenario.

I emphasize that this is only a preliminary flag. The analysis needs independent validation before any physical conclusion can be drawn. I am sharing this mainly because the pairwise clone results suggest that the similarity may deserve closer scrutiny rather than being dismissed immediately as a purely nominal coincidence.

Best regards,

Alessandro Odasso

2026 LD1 and 2018 NC15

 U-Code for asteroid 2026 LD1 is 8 so the uncertainty is exremely high

Backward integration taking into account all big planets plus Ceres, Pallas, Vesta:

it seems that these asteroid are near the end of their synodic cycle on about 16 february 2026.

=== Update --- to avoid sampling errors, just quering JPL Horizons asking for daily resolution:

Fetching data from JPL Horizons...

==================================================
1. ANALYSIS FOR MINIMUM RELATIVE VELOCITY
==================================================
Date of occurrence:       A.D. 2026-Sep-30 00:00:00.0000
MINIMUM Relative Velocity: 0.01525 km/s
Distance at that time:    0.0023457 AU (350,912.15 km)

==================================================
2. ANALYSIS FOR MINIMUM RELATIVE DISTANCE
==================================================
Date of occurrence:       A.D. 2026-Oct-20 00:00:00.0000
MINIMUM Distance:         0.0023008 AU (344,187.88 km)
Velocity at that time:    0.01702 km/s
==================================================

2012 QF86 and 470805 (2008 VY2)

 Potentially  interesting couple.

Backward simulation performed with Rebound software, all planets + Ceres/Pallas/Vesta

asteroid 2026 JT2 versus comet 83D (1985 epoch)

 refer to this MPML message and related thread.

---------------------------------------------------------------------------
DYNAMICAL ANALYSIS: 5:2 JUPITER RESONANCE
Jupiter Period: 11.862 y | 5:2 Resonant Period: 4.745 y | Center: 2.825 AU
---------------------------------------------------------------------------
Querying NASA JPL SBDB for region 2.8 < a < 2.85 AU...

Successfully retrieved 25387 objects matching the criteria.

--- PROXIMITY ANALYSIS RELATIVE TO Comet 83D (1985) --- TOP 10 RESULTS
0.857 deg | ***        (2026 JT2) ***      | i:23.37 | Node:229.6 | e:0.537
1.239 deg |        (2020 UW24)             | i:23.85 | Node:231.7 | e:0.247
1.270 deg | 478974 (2012 XL103)            | i:23.55 | Node:233.2 | e:0.172
1.298 deg |        (2019 OR58)             | i:21.60 | Node:228.8 | e:0.177
2.065 deg |        (2013 VK45)             | i:24.35 | Node:227.9 | e:0.159
2.574 deg |        (2021 QT100)            | i:20.15 | Node:232.4 | e:0.266
2.790 deg | 587626 (2006 KY60)             | i:19.99 | Node:228.6 | e:0.126
2.922 deg |        (2014 HX537)            | i:20.10 | Node:234.7 | e:0.115
3.039 deg |        (2017 TT19)             | i:20.35 | Node:236.2 | e:0.104
3.114 deg | 625997 (2006 US201)            | i:19.67 | Node:228.4 | e:0.180

this is a zoomed view of the plot:

What if we search for the same objects in the (inc - w) plane?

Here is the resulting plot:

The new plot reveals that the objects that share 83D's (i, Node) plane have totally random perihelion orientations (the scattered blue dots in the attached plot).

2026 JT2 is the only object in the entire 5:2 resonance region (out of ~25,000) to share not just the orbital plane, but the exact ω ~ 0° alignment with 83D (epoch 1985).

(h,k) plane

also zoomed

Here I just searched for the top 10 nearest asteroids to 83D in that plane (again shown as blue dots: they are not the same ones as in the previous plot).

--- TOP 10 CLOSEST OBJECTS IN THE (h, k) PLANE ---

Dist (h,k) | Object Name                    | e      | Varpi(°)

---------------------------------------------------------------------

0.0320     |        (2012 FK62)             | 0.486  | 230.38°

0.0341     |        (2011 OA36)             | 0.488  | 229.17°

0.0484     | ***        (2026 JT2) ***      | 0.537  | 235.99°

0.0526     |        (2022 EQ4)              | 0.538  | 225.98°

0.0652     | 306787 (2001 HS8)              | 0.456  | 228.50°

0.0659     |        (2024 JQ8)              | 0.487  | 224.50°

0.0768     |        (2024 BP23)             | 0.490  | 239.39°

0.0797     |        (2008 KB12)             | 0.569  | 237.59°

0.0933     |        (2024 GY2)              | 0.473  | 240.77°

0.0951     |        (2016 EZ155)            | 0.522  | 241.71°

Asteroid 2026 JT2 is third in the list of the nearest to 83D, the two "intruders" actually being false positives because they do not share their orbital plane.

(p,q) plane

also zoomed:

Here again I just searched for the top 10 nearest asteroids to 83D in that plane (again shown as blue dots).

--- TOP 10 CLOSEST OBJECTS IN THE (p, q) PLANE ---

Dist (p,q) | Object Name                    | i(°)     | Node(°) 

---------------------------------------------------------------------

0.0141     | ***        (2026 JT2) ***      | 23.37°   | 229.62°

0.0200     |        (2020 UW24)             | 23.85°   | 231.71°

0.0213     | 478974 (2012 XL103)            | 23.55°   | 233.15°

0.0216     |        (2019 OR58)             | 21.60°   | 228.85°

0.0341     |        (2013 VK45)             | 24.35°   | 227.87°

0.0420     |        (2021 QT100)            | 20.15°   | 232.42°

0.0457     | 587626 (2006 KY60)             | 19.99°   | 228.60°

0.0483     |        (2014 HX537)            | 20.10°   | 234.72°

Asteroid 2026 JT2 is at the top of the list.