Asteroids

226554 2003WR21 help

Last update: 2025-09-10 00:30 UTC

Orbital Properties

Epoch

61000.0

MJD

Orbit type

Apollo

Perihelion (q)

0.826

Aphelion (Q)

1.411

Eccentricity (e)

0.261

Inclination (i)

9.3

deg

Orbit period (P)

432.0

Earth MOID

0.03095

U parameter

0.0

Next Earth close approach

Date

2030-06-20

Nominal distance (from Earth center)

0.06515

9746490

Maximum Brightness

mag

Risk

Object is not in risk list

Physical Properties

Absolute Magnitude (H)

19.6

mag

Diameter

230

Taxonomic type

Rotation period (T)

Discovery Information

Discovery Date

2003-11-20

Observatory

Catalina Sky 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

1.118317

1-sigma variation

1.290E-9

Unit

Eccentricity (e)

Value

0.261442

1-sigma variation

1.352E-8

Unit

Inclination (i)

Value

9.2655

1-sigma variation

2.953E-6

Unit

Long. of Ascending Node (Ω)

Value

85.7625

1-sigma variation

1.279E-5

Unit

Arg. of Perihelion (ω)

Value

108.1085

1-sigma variation

1.460E-5

Unit

Mean Anomaly (M)

Value

96.44633

1-sigma variation

0.00001

Unit

Perihelion distance

Value

0.825942

1-sigma variation

Unit

Aphelion distance

Value

1.410691

1-sigma variation

Unit

Asc. Node-Earth Sep.

Value

0.149977

1-sigma variation

Unit

Desc. Node-Earth Sep.

Value

-0.054005

1-sigma variation

Unit

MOID

Value

0.030947

1-sigma variation

Unit

Orbit Period

Value

431.9620

1-sigma variation

Unit

U parameter

Value

0.0

1-sigma variation

Unit

Covariance Matrix

	a	e	i	Ω	ω	M
a	1.66451E-18	-1.00519E-17	3.92133E-16	-2.29238E-15	1.93082E-15	-3.71348E-15
e	-1.00519E-17	1.82864E-16	-1.76796E-15	-2.53192E-14	4.43044E-14	3.02391E-15
i	3.92133E-16	-1.76796E-15	8.72293E-12	-2.49824E-12	3.40766E-12	-1.44824E-12
Ω	-2.29238E-15	-2.53192E-14	-2.49824E-12	1.63536E-10	-1.72631E-10	9.53695E-12
ω	1.93082E-15	4.43044E-14	3.40766E-12	-1.72631E-10	2.13200E-10	-3.57005E-11
M	-3.71348E-15	3.02391E-15	-1.44824E-12	9.53695E-12	-3.57005E-11	3.18692E-11

Date of computation: 2025-09-10 00:30 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

[1]

Taxonomy (all)

Value

Unit

Source

[2]

Absolute Magnitude (H)
Slope Parameter (G)

H / G

Value

Unit

Source

Absolute Magnitude (H)

Value

19.55

Unit

mag

Source

[3]

Slope Parameter (G)

Value

0.15**

Unit

mag

Source

[3]

Albedo
Diameter

Size and albedo

Value

Unit

Source

Albedo

Value

0.125

0.434

Unit

Source

[5]

[4]

Diameter

Value

230

Unit

Source

[4]

Color Index Information

Color Index Information

Value

Unit

Source

Color Index Information

Value

0.3509

Unit

g-r

Source

[1]

Sightings

Sightings

Value

Unit

Source

Sightings

Value

Radar R

Unit

Source

[6]

Download this part as:

Sources

No.	Name	Additional
[1]	EARN	1.) A. V. Sergeyev, B. Carry et al A&A, 658 (2022) A109
[2]	EARN	Earth Asteroids Research Node: https://earn.dlr.de
[3]	ESA Aegis	ESA orbit determination and impact monitoring system
[4]	EARN	1.) Joseph R. Masiero et al 2020 Planet. Sci. J. 1 5
[5]	EARN	1.) Mainzer, A. et al. (2014) Astrophys. J. 784, 110. (The Population of Tiny Near-Earth Objects Observed by NEOWISE) 2.) Mainzer, A.; Bauer, J.; Grav, T.; Masiero, J.; et al. (2014) Astrophys. J. 784, A110.
[6]	EARN	1.) href="http://echo.jpl.nasa.gov/asteroids/index.html">JPL's NEO Radar Detection Program Webpage

Observational Information

Arc Length
Unobserved
Normalized RMS of residuals

Arc Information

Value

Unit

Source

Arc Length

Value

12071

Unit

Source

[1]

Unobserved

Value

712

Unit

Source

[1]

Normalized RMS of residuals

Value

0.533397

Unit

Source

[1]

Astrometry Summary

First Observation
Last Observation
Total Optical Observations (Discarded)

Optical

Value

Unit

Source

First Observation

Value

1990-10-24.425

Unit

Source

[2]

Last Observation

Value

2023-11-11.202281

Unit

Source

[2]

Total Optical Observations (Discarded)

Value

507 (3)

Unit

Source

[1]

Radar Summary

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

Radar

Value

Unit

Source

First Observation

Value

2017-06-04

Unit

Source

[3]

Last Observation

Value

2017-06-04

Unit

Source

[3]

Delay (Discarded)

Value

1 (0)

Unit

Source

[1]

Doppler (Discarded)

Value

1 (0)

Unit

Source

[1]

Total Radar Observations (Discarded)

Value

2 (0)

Unit

Source

[1]

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
[3]	JPL Radar Observations	Jet Propulsion Laboratory: https://ssd.jpl.nasa.gov/dat/radar_data_ast.txt

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 226554 2003WR21 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	1952-01-09 10:54	< 1 min	0.0732960	0.0732956	0.0000001
EARTH	1959-06-22 11:57	< 1 min	0.0488507	0.0488495	0.0000004
EARTH	1965-01-09 06:19	< 1 s	0.0918946	0.0918940	0.0000002
EARTH	1972-06-25 18:40	< 1 s	0.0287693	0.0287692	0.0000000
EARTH	1978-01-06 06:31	< 1 min	0.1452313	0.1452308	0.0000002
EARTH	1985-07-02 21:00	< 1 min	0.1010076	0.1010070	0.0000002
EARTH	2004-05-03 17:56	< 1 min	0.1969886	0.1969884	0.0000001
EARTH	2010-01-06 13:51	< 1 s	0.1258551	0.1258548	0.0000001
EARTH	2017-06-07 19:15	< 1 s	0.1216011	0.1216011	0.0000000
EARTH	2023-01-09 13:58	< 1 s	0.0725379	0.0725378	0.0000000
EARTH	2030-06-20 05:06	< 1 min	0.0651513	0.0651509	0.0000001
EARTH	2036-01-10 05:36	< 1 s	0.0773226	0.0773224	0.0000001
EARTH	2043-06-20 13:48	< 1 min	0.0646814	0.0646807	0.0000002
EARTH	2049-01-09 02:19	< 1 s	0.0721917	0.0721916	0.0000000
EARTH	2056-06-09 18:13	< 1 min	0.1147944	0.1147934	0.0000003
EARTH	2062-01-07 07:56	< 1 min	0.1024710	0.1024700	0.0000003
EARTH	2069-05-07 04:38	< 1 min	0.1929569	0.1929563	0.0000002
EARTH	2089-07-03 02:24	< 1 min	0.0940996	0.0940981	0.0000005
EARTH	2095-01-05 11:07	< 1 min	0.1535845	0.1535834	0.0000003
EARTH	2102-06-27 23:59	< 1 min	0.0319218	0.0319216	0.0000001
EARTH	2108-01-11 04:43	< 1 min	0.1049000	0.1048986	0.0000004
EARTH	2115-06-25 15:27	< 1 min	0.0405252	0.0405235	0.0000006
EARTH	2121-01-10 15:33	< 1 min	0.0785525	0.0785503	0.0000007

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Stationary Points

Ecc. an. ast.	Ecc. an. Earth	Distance in au	Classification
66.03290826	172.06748565	0.02988121	MINIMUM
290.06927125	6.40847134	0.07235329	MINIMUM
356.74470333	86.41148145	0.22377781	SADDLE
178.62351776	271.46260255	0.45013927	SADDLE
3.13657544	274.85666286	1.81963647	SADDLE
183.22747114	95.02158348	2.40473527	MAXIMUM

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MOID Plots

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