Asteroids

2021GJ3 help

Last update: 2026-07-30 14:25 UTC

Orbital Properties

Epoch

61200.0

MJD

Orbit type

Apollo

Perihelion (q)

0.813

Aphelion (Q)

2.656

Eccentricity (e)

0.531

Inclination (i)

1.5

deg

Orbit period (P)

834.5

Earth MOID

0.00938

U parameter

8.0

Next Earth close approach

Date

2030-09-11

Nominal distance (from Earth center)

0.15078

22556434

Maximum Brightness

22.4

mag

Risk

Object is not in risk list

Physical Properties

Absolute Magnitude (H)

23.7

mag

Diameter

50 - 110*

Taxonomic type

Rotation period (T)

Discovery Information

Discovery Date

2021-04-04

Observatory

University of Arizona 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

61200.0000

1-sigma variation

Unit

MJD

Semimajor Axis

Value

1.734703

1-sigma variation

0.001916

Unit

Eccentricity (e)

Value

0.531072

1-sigma variation

0.000578

Unit

Inclination (i)

Value

1.5372

1-sigma variation

0.0013

Unit

Long. of Ascending Node (Ω)

Value

10.3179

1-sigma variation

0.0079

Unit

Arg. of Perihelion (ω)

Value

263.4280

1-sigma variation

0.0064

Unit

Mean Anomaly (M)

Value

69.39822

1-sigma variation

0.92774

Unit

Perihelion distance

Value

0.813451

1-sigma variation

Unit

Aphelion distance

Value

2.655956

1-sigma variation

Unit

Asc. Node-Earth Sep.

Value

0.323638

1-sigma variation

Unit

Desc. Node-Earth Sep.

Value

0.176427

1-sigma variation

Unit

MOID

Value

0.009379

1-sigma variation

Unit

Orbit Period

Value

834.5191

1-sigma variation

Unit

U parameter

Value

8.0

1-sigma variation

Unit

Covariance Matrix

	a	e	i	Ω	ω	M
a	3.67139E-6	1.10678E-6	2.42490E-6	1.51187E-5	-1.21692E-5	-1.77763E-3
e	1.10678E-6	3.33653E-7	7.31012E-7	4.55769E-6	-3.66853E-6	-5.35887E-4
i	2.42490E-6	7.31012E-7	1.60228E-6	9.98924E-6	-8.04100E-6	-1.17410E-3
Ω	1.51187E-5	4.55769E-6	9.98924E-6	6.22801E-5	-5.01336E-5	-7.32023E-3
ω	-1.21692E-5	-3.66853E-6	-8.04100E-6	-5.01336E-5	4.03588E-5	5.89214E-3
M	-1.77763E-3	-5.35887E-4	-1.17410E-3	-7.32023E-3	5.89214E-3	8.60699E-1

Date of computation: 2026-07-30 14:25 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

23.659

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

50 - 110*

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

Unit

Source

[1]

Unobserved

Value

1936

Unit

Source

[1]

Normalized RMS of residuals

Value

0.583071

Unit

Source

[1]

Astrometry Summary

First Observation
Last Observation
Total Optical Observations (Discarded)

Optical

Value

Unit

Source

First Observation

Value

2021-03-23.38004

Unit

Source

[2]

Last Observation

Value

2021-04-17.914671

Unit

Source

[2]

Total Optical Observations (Discarded)

Value

110 (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

Filters

Initial Date: *

Final Date: *

Normalised Only accepted

Max residual (arcsec):

* - these fields are required

Plot

Computation parameters

As seen from:

Initial Date: *

Final Date: *

Output option:

One line per time step

Time step:*

* - these fields are required

Note: Ephemerides requests are limited to a maximum of 1000 points and a final date not exceeding 2040/12/31 00:00.

Close Approaches for 2021GJ3 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
EARTH	1957-09-04 20:13	1311.1	0.0723381	0.0369143	0.0121516
EARTH	1964-04-10 18:35	> 1 d	0.1276713	0.0081541	0.0479294
EARTH	1973-08-24 00:44	> 1 w	0.0623699	0.0160470	0.1173061
EARTH	1989-07-09 17:37	> 1 mo	0.1979039	0.1035832	0.0315845
MARS	1991-06-04 18:26	> 1 d	0.0465099	0.0237696	0.0971755
EARTH	2005-05-20 19:23	> 1 w	0.1577576	0.0027617	0.0561881
MARS	2005-09-18 05:40	> 1 d	0.0398725	0.0281134	0.0638597
EARTH	2021-04-21 02:25	< 1 min	0.0098736	0.0098528	0.0000069
EARTH	2030-09-11 02:59	> 1 d	0.1507804	0.0141158	0.0786642
EARTH	2037-04-22 08:47	> 1 w	0.0202616	0.0093617	0.1178093
EARTH	2053-06-15 16:17	> 1 mo	0.1992229	0.0058352	0.1179761
EARTH	2069-08-21 03:44	> 1 mo	0.0830290	0.0135337	1.2921736
EARTH	2076-04-13 12:49	> 1 mo	0.1015342	0.0096365	1.1312979
EARTH	2085-09-13 10:15	> 1 d	0.1866413	0.1019070	0.0285696
EARTH	2092-05-10 22:25	> 1 mo	0.1269918	0.0074556	0.5815561
EARTH	2108-07-14 03:46	> 1 mo	0.1951041	0.0107926	0.5462454
MARS	2111-01-19 19:57	> 1 mo	0.0353845	0.0297181	1.1710843
EARTH	2124-09-05 01:38	> 1 mo	0.0434699	0.0133661	3.4294027

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Stationary Points

Ecc. an. ast.	Ecc. an. Earth	Distance in au	Classification
322.37057169	105.17798783	0.00937924	MINIMUM
38.19273461	234.17937886	0.01456940	MINIMUM
0.37169758	169.80066335	0.20456451	SADDLE
180.10747119	349.46446497	1.67272608	SADDLE
0.33221365	349.73481877	1.79707164	SADDLE
180.10462911	169.46504377	3.67225203	MAXIMUM

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MOID Plots

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