Asteroids

2021GW3 help

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

Orbital Properties

Epoch

61000.0

MJD

Orbit type

Apollo

Perihelion (q)

0.785

Aphelion (Q)

1.859

Eccentricity (e)

0.406

Inclination (i)

1.1

deg

Orbit period (P)

554.9

Earth MOID

0.00289

U parameter

7.8

Next Earth close approach

Date

2049-10-30

Nominal distance (from Earth center)

0.08124

12153007

Maximum Brightness

25.8

mag

Risk

Object is not in risk list

Physical Properties

Absolute Magnitude (H)

28.4

mag

Diameter

6 - 13*

Taxonomic type

Rotation period (T)

Discovery Information

Discovery Date

2021-04-07

Observatory

Pan-STARRS 1, Haleakala

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

1.321579

1-sigma variation

0.000729

Unit

Eccentricity (e)

Value

0.406375

1-sigma variation

0.000474

Unit

Inclination (i)

Value

1.1028

1-sigma variation

0.0013

Unit

Long. of Ascending Node (Ω)

Value

20.9783

1-sigma variation

0.0004

Unit

Arg. of Perihelion (ω)

Value

95.8877

1-sigma variation

0.0065

Unit

Mean Anomaly (M)

Value

53.33863

1-sigma variation

0.98039

Unit

Perihelion distance

Value

0.784523

1-sigma variation

Unit

Aphelion distance

Value

1.858636

1-sigma variation

Unit

Asc. Node-Earth Sep.

Value

0.154326

1-sigma variation

Unit

Desc. Node-Earth Sep.

Value

0.055162

1-sigma variation

Unit

MOID

Value

0.002892

1-sigma variation

Unit

Orbit Period

Value

554.9301

1-sigma variation

Unit

U parameter

Value

7.8

1-sigma variation

Unit

Covariance Matrix

	a	e	i	Ω	ω	M
a	5.31383E-7	3.44280E-7	8.85792E-7	3.48789E-8	-6.49686E-7	-7.14667E-4
e	3.44280E-7	2.25044E-7	5.56848E-7	3.49947E-8	-7.06803E-7	-4.63036E-4
i	8.85792E-7	5.56848E-7	1.63090E-6	-7.13413E-8	1.38926E-6	-1.19125E-3
Ω	3.48789E-8	3.49947E-8	-7.13413E-8	1.52796E-7	-1.89680E-6	-4.69589E-5
ω	-6.49686E-7	-7.06803E-7	1.38926E-6	-1.89680E-6	4.19940E-5	8.74881E-4
M	-7.14667E-4	-4.63036E-4	-1.19125E-3	-4.69589E-5	8.74881E-4	9.61169E-1

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

[-]

Taxonomy (all)

Value

Unit

Source

[-]

Absolute Magnitude (H)
Slope Parameter (G)

H / G

Value

Unit

Source

Absolute Magnitude (H)

Value

28.356

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

6 - 13*

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

1626

Unit

Source

[1]

Normalized RMS of residuals

Value

0.614533

Unit

Source

[1]

Astrometry Summary

First Observation
Last Observation
Total Optical Observations (Discarded)

Optical

Value

Unit

Source

First Observation

Value

2021-04-07.414483

Unit

Source

[2]

Last Observation

Value

2021-04-10.23363

Unit

Source

[2]

Total Optical Observations (Discarded)

Value

12 (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 2021GW3 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	1952-04-02 08:50	> 1 d	0.0051116	0.0031930	0.0436266
MARS	1952-06-24 18:28	741.7	0.0088905	0.0032320	0.0467491
EARTH	1955-03-31 08:15	> 1 w	0.0347611	0.0034134	0.2732347
EARTH	1958-03-23 04:22	> 1 mo	0.0909802	0.0030094	0.3294623
EARTH	1961-03-06 16:25	> 1 mo	0.1438831	0.0004081	0.2548149
EARTH	1964-02-17 11:45	> 1 mo	0.1793196	0.0018767	0.1448900
EARTH	1967-02-01 08:39	> 1 mo	0.1988546	0.0143651	0.0615108
EARTH	1973-01-03 07:07	> 1 mo	0.1985374	0.0251020	0.0583110
EARTH	1975-12-19 15:15	> 1 mo	0.1789082	0.0040557	0.1155873
EARTH	1978-12-01 15:07	> 1 mo	0.1438217	0.0008783	0.1781419
EARTH	1981-11-15 15:32	> 1 mo	0.0933096	0.0046968	0.1915220
EARTH	1984-11-07 14:16	> 1 w	0.0410559	0.0056863	0.1204775
EARTH	1987-11-05 09:05	> 1 d	0.0106806	0.0058362	0.0346606
EARTH	1990-11-11 04:29	> 1 d	0.0656864	0.0055674	0.0413248
EARTH	1993-11-24 06:05	> 1 w	0.1238340	0.0363900	0.0291811
EARTH	1996-12-11 20:25	> 1 w	0.1656642	0.1185947	0.0156899
EARTH	1999-12-28 01:52	> 1 w	0.1893666	0.1681529	0.0070712
EARTH	2009-02-10 22:07	> 1 d	0.1852667	0.1821779	0.0010296
EARTH	2012-03-02 03:19	> 1 d	0.1499058	0.1437486	0.0020524
EARTH	2015-03-22 00:06	> 1 d	0.0920310	0.0631037	0.0096435
EARTH	2018-03-30 12:18	> 1 d	0.0287723	0.0029397	0.0162390
EARTH	2021-04-02 06:45	3.4	0.0051151	0.0050961	0.0000063
MARS	2042-10-03 04:28	753.5	0.0220762	0.0057384	0.0781299
EARTH	2049-10-30 22:30	> 1 w	0.0812378	0.0070857	0.1621694
EARTH	2052-11-29 13:07	> 1 mo	0.1338253	0.0044835	0.1129524
EARTH	2059-03-16 01:47	> 1 mo	0.1156666	0.0000992	0.1025298
EARTH	2062-04-09 13:03	> 1 d	0.1003964	0.0027908	0.1006990
MARS	2082-04-03 02:02	90.6	0.0435803	0.0055194	0.1191764
EARTH	2090-11-03 01:31	> 1 w	0.0420610	0.0072716	0.2406610
EARTH	2093-12-04 07:50	> 1 w	0.1441957	0.0044528	0.0528412
EARTH	2100-03-06 14:10	> 1 mo	0.1435465	0.0015861	0.1084253
EARTH	2103-04-07 04:48	> 1 w	0.0369376	0.0024813	0.2799007

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Stationary Points

Ecc. an. ast.	Ecc. an. Earth	Distance in au	Classification
53.19697183	88.94707223	0.00296808	MINIMUM
307.88207017	301.49617240	0.00718591	MINIMUM
0.67190703	15.35820638	0.20039706	SADDLE
180.29051062	194.95570579	0.84331463	SADDLE
0.72141153	195.42313253	1.80016388	SADDLE
180.28927689	14.95076122	2.84271557	MAXIMUM

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MOID Plots

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