Asteroids

2021FJ3 help

Last update: 2026-06-04 23:11 UTC

Orbital Properties

Epoch

61200.0

MJD

Orbit type

Apollo

Perihelion (q)

0.848

Aphelion (Q)

2.802

Eccentricity (e)

0.535

Inclination (i)

5.3

deg

Orbit period (P)

900.3

Earth MOID

0.00686

U parameter

7.5

Next Earth close approach

Date

2048-08-30

Nominal distance (from Earth center)

0.11072

16564130

Maximum Brightness

21.3

mag

Risk

Object is not in risk list

Physical Properties

Absolute Magnitude (H)

23.4

mag

Diameter

60 - 120*

Taxonomic type

Rotation period (T)

Discovery Information

Discovery Date

2021-03-23

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

1.824769

1-sigma variation

0.000971

Unit

Eccentricity (e)

Value

0.535340

1-sigma variation

0.000265

Unit

Inclination (i)

Value

5.2690

1-sigma variation

0.0018

Unit

Long. of Ascending Node (Ω)

Value

31.0636

1-sigma variation

0.0001

Unit

Arg. of Perihelion (ω)

Value

241.0218

1-sigma variation

0.0003

Unit

Mean Anomaly (M)

Value

12.43106

1-sigma variation

0.58745

Unit

Perihelion distance

Value

0.847898

1-sigma variation

Unit

Aphelion distance

Value

2.801640

1-sigma variation

Unit

Asc. Node-Earth Sep.

Value

0.761813

1-sigma variation

Unit

Desc. Node-Earth Sep.

Value

0.029269

1-sigma variation

Unit

MOID

Value

0.006864

1-sigma variation

Unit

Orbit Period

Value

900.3474

1-sigma variation

Unit

U parameter

Value

7.5

1-sigma variation

Unit

Covariance Matrix

	a	e	i	Ω	ω	M
a	9.41910E-7	2.56945E-7	1.74688E-6	7.27505E-8	-1.62070E-7	-5.70129E-4
e	2.56945E-7	7.00932E-8	4.76550E-7	1.98208E-8	-4.39295E-8	-1.55526E-4
i	1.74688E-6	4.76550E-7	3.24081E-6	1.33393E-7	-2.94413E-7	-1.05737E-3
Ω	7.27505E-8	1.98208E-8	1.33393E-7	8.55720E-9	-2.13295E-8	-4.40343E-5
ω	-1.62070E-7	-4.39295E-8	-2.94413E-7	-2.13295E-8	1.06407E-7	9.80883E-5
M	-5.70129E-4	-1.55526E-4	-1.05737E-3	-4.40343E-5	9.80883E-5	3.45094E-1

Date of computation: 2026-06-04 23:11 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

23.405

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

60 - 120*

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

1921

Unit

Source

[1]

Normalized RMS of residuals

Value

0.680243

Unit

Source

[1]

Astrometry Summary

First Observation
Last Observation
Total Optical Observations (Discarded)

Optical

Value

Unit

Source

First Observation

Value

2021-03-23.421401

Unit

Source

[2]

Last Observation

Value

2021-04-15.358946

Unit

Source

[2]

Total Optical Observations (Discarded)

Value

57 (5)

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 2021FJ3 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
MARS	1962-06-03 20:16	> 1 d	0.0446295	0.0217390	0.1105539
EARTH	1974-08-11 09:02	> 1 w	0.1171794	0.0833118	0.0902523
EARTH	1979-05-17 16:39	> 1 mo	0.1240301	0.0106948	0.1069666
MARS	2001-12-02 17:06	> 1 d	0.0449111	0.0195036	0.0728385
EARTH	2011-08-30 13:00	> 1 d	0.1154043	0.0823718	0.0337417
EARTH	2016-06-25 11:20	> 1 w	0.1832445	0.1819352	0.0005682
EARTH	2021-04-20 09:32	< 1 min	0.0583381	0.0582647	0.0000245
EARTH	2048-08-30 09:33	> 1 w	0.1107244	0.0806865	0.0903330
EARTH	2053-06-23 22:20	> 1 mo	0.1824883	0.1710138	0.0084422
EARTH	2058-04-19 19:10	> 1 w	0.0791362	0.0074448	0.1611743
EARTH	2085-08-30 11:23	> 1 w	0.1028747	0.0793888	0.0855585
EARTH	2090-06-16 12:24	> 1 mo	0.1805635	0.1112529	0.0322604
EARTH	2095-04-16 00:14	> 1 w	0.1381028	0.0064576	0.2271036
EARTH	2122-08-25 23:34	> 1 w	0.0788884	0.0788812	0.0023704

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Stationary Points

Ecc. an. ast.	Ecc. an. Earth	Distance in au	Classification
326.62760726	112.67650509	0.00643034	MINIMUM
34.40013821	230.36244597	0.08134190	MINIMUM
2.01284622	174.21541991	0.18625568	SADDLE
180.26142300	350.86882237	1.82294577	SADDLE
0.44624955	351.30786553	1.83027112	SADDLE
180.00507901	170.73028332	3.81732479	MAXIMUM

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MOID Plots

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