Asteroids

2025YS4 help

Last update: 2025-12-25 13:00 UTC

Orbital Properties

Epoch

61000.0

MJD

Orbit type

Apollo

Perihelion (q)

0.557

Aphelion (Q)

1.575

Eccentricity (e)

0.477

Inclination (i)

26.9

deg

Orbit period (P)

402.2

Earth MOID

0.02441

U parameter

8.2

Next Earth close approach

Date

2036-12-27

Nominal distance (from Earth center)

0.03828

5727316

Maximum Brightness

mag

Risk

Object is not in risk list

Physical Properties

Absolute Magnitude (H)

25.5

mag

Diameter

21 - 50*

Taxonomic type

Rotation period (T)

Discovery Information

Discovery Date

2025-12-22

Observatory

Mt. Lemmon Survey

ORBIT VISUALISATION TOOLS

External links

Proper elements

Epoch

Near present day

Near middle of observation arc

Orbit properties

Epoch
Semimajor Axis
Eccentricity (e)
Inclination (i)
Long. of Ascending Node (Ω)
Arg. of Perihelion (ω)
Mean Anomaly (M)
Perihelion distance
Aphelion distance
Asc. Node-Earth Sep.
Desc. Node-Earth Sep.
MOID
Orbit Period
U parameter

Value

1-sigma variation

Unit

Epoch

Value

61000.0000

1-sigma variation

Unit

MJD

Semimajor Axis

Value

1.066265

1-sigma variation

0.000853

Unit

Eccentricity (e)

Value

0.477338

1-sigma variation

0.000590

Unit

Inclination (i)

Value

26.8732

1-sigma variation

0.0427

Unit

Long. of Ascending Node (Ω)

Value

272.4669

1-sigma variation

0.0014

Unit

Arg. of Perihelion (ω)

Value

294.0529

1-sigma variation

0.0333

Unit

Mean Anomaly (M)

Value

273.19309

1-sigma variation

0.14503

Unit

Perihelion distance

Value

0.557296

1-sigma variation

Unit

Aphelion distance

Value

1.575235

1-sigma variation

Unit

Asc. Node-Earth Sep.

Value

-0.328696

1-sigma variation

Unit

Desc. Node-Earth Sep.

Value

0.038376

1-sigma variation

Unit

MOID

Value

0.024406

1-sigma variation

Unit

Orbit Period

Value

402.1577

1-sigma variation

Unit

U parameter

Value

8.2

1-sigma variation

Unit

Covariance Matrix

	a	e	i	Ω	ω	M
a	7.26781E-7	5.02770E-7	3.64348E-5	1.19377E-6	-2.83444E-5	1.23640E-4
e	5.02770E-7	3.47864E-7	2.52050E-5	8.25834E-7	-1.96033E-5	8.55341E-5
i	3.64348E-5	2.52050E-5	1.82659E-3	5.98471E-5	-1.42093E-3	6.19830E-3
Ω	1.19377E-6	8.25834E-7	5.98471E-5	1.96087E-6	-4.65560E-5	2.03085E-4
ω	-2.83444E-5	-1.96033E-5	-1.42093E-3	-4.65560E-5	1.10579E-3	-4.82174E-3
M	1.23640E-4	8.55341E-5	6.19830E-3	2.03085E-4	-4.82174E-3	2.10338E-2

Date of computation: 2025-12-25 13:00 UTC

Note: The ASCII file is in a format suitable for Orbfit input.

Download ASCII file:

Physical properties

Rotation Period
Quality
Amplitude
Rotation Direction
Spinvector L
Spinvector B

Rotational properties

Value

Unit

Source

Rotation Period

Value

Unit

Source

[-]

Quality

Value

Unit

Source

[-]

Amplitude

Value

Unit

mag

Source

[-]

Rotation Direction

Value

Unit

Source

[-]

Spinvector L

Value

Unit

Source

[-]

Spinvector B

Value

Unit

Source

[-]

Taxonomy
Taxonomy (all)

Taxonomy

Value

Unit

Source

Taxonomy

Value

Unit

Source

[-]

Taxonomy (all)

Value

Unit

Source

[-]

Absolute Magnitude (H)
Slope Parameter (G)

H / G

Value

Unit

Source

Absolute Magnitude (H)

Value

25.52

Unit

mag

Source

[1]

Slope Parameter (G)

Value

0.15**

Unit

Source

[1]

Albedo
Diameter

Size and albedo

Value

Unit

Source

Albedo

Value

0.05 - 0.25

Unit

Source

[2]

Diameter

Value

21 - 50*

Unit

Source

[2]

Color Index Information

Color Index Information

Value

Unit

Source

Color Index Information

Value

Unit

mag

Source

[-]

Sightings

Sightings

Value

Unit

Source

Sightings

Value

Unit

Source

[-]

Download this part as:

Sources

No.	Name	Additional
[1]	ESA Aegis	ESA orbit determination and impact monitoring system
[2]	Estimation	Estimated from absolute magnitude

Observational Information

Arc Length
Unobserved
Normalized RMS of residuals

Arc Information

Value

Unit

Source

Arc Length

Value

Unit

Source

[1]

Unobserved

Value

Unit

Source

[1]

Normalized RMS of residuals

Value

0.330772

Unit

Source

[1]

Astrometry Summary

First Observation
Last Observation
Total Optical Observations (Discarded)

Optical

Value

Unit

Source

First Observation

Value

2025-12-22.401827

Unit

Source

[2]

Last Observation

Value

2025-12-25.008772

Unit

Source

[2]

Total Optical Observations (Discarded)

Value

27 (0)

Unit

Source

[1]

Radar Summary

First Observation
Last Observation
Delay (Discarded)
Doppler (Discarded)
Total Optical Observations (Discarded)

Radar

Value

Unit

Source

First Observation

Value

Unit

Source

[-]

Last Observation

Value

Unit

Source

[-]

Delay (Discarded)

Value

0 (0)

Unit

Source

[-]

Doppler (Discarded)

Value

0 (0)

Unit

Source

[-]

Total Radar Observations (Discarded)

Value

0 (0)

Unit

Source

[-]

Note: The ASCII file is in a format suitable for Orbfit input.

Sources

No.	Name	Additional
[1]	ESA Aegis	ESA orbit determination and impact monitoring system
[2]	MPC	Minor Planet Center: https://www.minorplanetcenter.net

Computation parameters

As seen from:

Initial Date: *

Final Date: *

Output option:

One line per time step

Time step:*

* - these fields are required

Close Approaches for 2025YS4 from 1950 to 2126

Body	Date in UTC	Time uncert. in min	Nominal distance in au	Min. possible distance in au	Distance uncert. in au
VENUS	1981-01-31 18:25	> 1 w	0.0369211	0.0367417	0.0155538
EARTH	1992-12-19 12:28	> 1 d	0.1909616	0.0212317	0.1330046
VENUS	2002-01-03 07:48	> 1 w	0.0489669	0.0375804	0.0930066
EARTH	2003-12-22 21:02	> 1 d	0.1237704	0.0231903	0.1127401
EARTH	2014-12-25 02:17	> 1 d	0.0567067	0.0239167	0.0696521
EARTH	2025-12-26 08:26	< 1 min	0.0251074	0.0249982	0.0000364
EARTH	2036-12-27 03:27	> 1 d	0.0382847	0.0247754	0.0604555
EARTH	2047-12-29 18:57	> 1 d	0.1090125	0.0256292	0.1322562
EARTH	2090-12-22 18:17	> 1 d	0.1297419	0.0245972	0.0737748
VENUS	2091-03-18 15:43	> 1 d	0.0490335	0.0386722	0.0549042
EARTH	2101-12-26 19:00	984.2	0.0414111	0.0257654	0.0178710
EARTH	2112-12-28 07:37	> 1 d	0.0373273	0.0263838	0.0268103
EARTH	2123-12-31 06:51	> 1 d	0.1249130	0.0270730	0.0895756

Download as:

Stationary Points

Ecc. an. ast.	Ecc. an. Earth	Distance in au	Classification
277.57224771	353.42768466	0.02440616	MINIMUM
62.50118979	194.23337286	0.25758837	MINIMUM
352.10070793	91.27312785	0.55678944	SADDLE
170.15597697	282.06517803	0.79280497	SADDLE
358.14699296	282.46949558	1.52046100	SADDLE
184.98538832	111.56422855	2.52778193	MAXIMUM

Download:

MOID Plots

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