Asteroids

2025SB21 help

Last update: 2025-09-30 15:45 UTC

Orbital Properties

Epoch

61000.0

MJD

Orbit type

Apollo

Perihelion (q)

0.994

Aphelion (Q)

2.708

Eccentricity (e)

0.463

Inclination (i)

6.9

deg

Orbit period (P)

920.0

Earth MOID

0.00108

U parameter

8.8

Next Earth close approach

Date

2083-08-13

Nominal distance (from Earth center)

0.11652

17431653

Maximum Brightness

29.3

mag

Risk

Object is in risk list

Physical Properties

Absolute Magnitude (H)

31.2

mag

Diameter

1.5 - 3*

Taxonomic type

Rotation period (T)

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

1.851286

1-sigma variation

0.009134

Unit

Eccentricity (e)

Value

0.462817

1-sigma variation

0.002687

Unit

Inclination (i)

Value

6.9316

1-sigma variation

0.0295

Unit

Long. of Ascending Node (Ω)

Value

185.3025

1-sigma variation

0.0006

Unit

Arg. of Perihelion (ω)

Value

166.1379

1-sigma variation

0.0297

Unit

Mean Anomaly (M)

Value

25.45919

1-sigma variation

0.18332

Unit

Perihelion distance

Value

0.994480

1-sigma variation

Unit

Aphelion distance

Value

2.708093

1-sigma variation

Unit

Asc. Node-Earth Sep.

Value

1.642998

1-sigma variation

Unit

Desc. Node-Earth Sep.

Value

0.001370

1-sigma variation

Unit

MOID

Value

0.001085

1-sigma variation

Unit

Orbit Period

Value

920.0445

1-sigma variation

Unit

U parameter

Value

8.8

1-sigma variation

Unit

Covariance Matrix

	a	e	i	Ω	ω	M
a	8.34247E-5	2.45443E-5	2.69378E-4	5.17808E-6	-2.71280E-4	-1.67437E-3
e	2.45443E-5	7.22113E-6	7.92533E-5	1.52344E-6	-7.98137E-5	-4.92615E-4
i	2.69378E-4	7.92533E-5	8.69827E-4	1.67201E-5	-8.75951E-4	-5.40655E-3
Ω	5.17808E-6	1.52344E-6	1.67201E-5	3.21401E-7	-1.68386E-5	-1.03926E-4
ω	-2.71280E-4	-7.98137E-5	-8.75951E-4	-1.68386E-5	8.83396E-4	5.44431E-3
M	-1.67437E-3	-4.92615E-4	-5.40655E-3	-1.03926E-4	5.44431E-3	3.36056E-2

Date of computation: 2025-09-30 15:45 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

31.241

Unit

mag

Source

[1]

Slope Parameter (G)

Value

0.15**

Unit

mag

Source

[1]

Albedo
Diameter

Size and albedo

Value

Unit

Source

Albedo

Value

0.05 - 0.25

Unit

Source

[2]

Diameter

Value

1.5 - 3*

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

[-]

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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

0.3

Unit

Source

[1]

Unobserved

Value

Unit

Source

[1]

Normalized RMS of residuals

Value

0.190759

Unit

Source

[1]

Astrometry Summary

First Observation
Last Observation
Total Optical Observations (Discarded)

Optical

Value

Unit

Source

First Observation

Value

2025-09-28.511328

Unit

Source

[2]

Last Observation

Value

2025-09-28.851112

Unit

Source

[2]

Total Optical Observations (Discarded)

Value

9 (1)

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 2025SB21 from 1950 to 2125

Body	Date in UTC	Time uncert. in min	Nominal distance in au	Min. possible distance in au	Distance uncert. in au
EARTH	1954-09-15 06:16	> 1 mo	0.0340441	0.0078524	3.2947646
3 Juno	2002-04-17 12:34	> 1 mo	0.0182746	0.0150485	0.1038048
EARTH	2003-09-16 19:05	> 1 mo	0.0320787	0.0084350	0.5625296
EARTH	2025-09-28 10:13	< 1 min	0.0015661	0.0015431	0.0000077
EARTH	2083-08-13 02:29	> 1 mo	0.1165234	0.0684694	1.5036678
EARTH	2088-10-01 07:28	> 1 mo	0.0099196	0.0009395	1.3944108
EARTH	2116-08-11 10:11	> 1 mo	0.1272481	0.0701576	154.2682723

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Stationary Points

Ecc. an. ast.	Ecc. an. Earth	Distance in au	Classification
8.23958044	264.67918900	0.00108496	MINIMUM
179.12890090	69.36423239	1.71402835	SADDLE
358.02748250	67.91369169	1.98876522	SADDLE
179.44605015	249.55064157	3.71445432	MAXIMUM

Download:

MOID Plots

Click on the images to zoom-in and zoom-out

Level lines of the squared distance function

2025SB21

Date in UTC	MJD	σ	Distance ± Width in RE	Stretching in RE	IP	Impact energy	PS
2083-09-28.851	82130.851	-0.963	1.44 ± 0.003	3.45E4	1.44E-5	2.36E-4	-7.99
2091-09-28.781	85052.781	0.369	1.68 ± 0.000	2.24E6	1.49E-7	2.50E-4	-10.00
2113-09-29.209	93088.209	-0.895	1.66 ± 0.004	2.63E5	2.50E-6	2.36E-4	-8.93
2113-09-29.262	93088.262	-0.878	1.67 ± 0.000	1.68E4	4.72E-5	2.36E-4	-7.65
2120-09-28.997	95644.997	1.392	0.61 ± 0.000	2.04E8	2.41E-9	2.61E-4	-11.94


Based on 9 optical observations (of which 1 are rejected as outliers) from 2025/09/28.511 to 2025/09/28.851.
Coordinates are given on the Target Plane.
Unit is one Earth radius, but impact cross section has radius between 1.74 and 1.74 Earth radii.
Coordinates for LOV = EQU scaled= 1 second= F.
Aegis software version= 5.0, Date of computation=20250930 170049.384 UTC.

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Download Impactor Table as: