Asteroids

2021CJ2 help

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

Orbital Properties

Epoch

61000.0

MJD

Orbit type

Apollo

Perihelion (q)

0.369

Aphelion (Q)

2.394

Eccentricity (e)

0.733

Inclination (i)

3.9

deg

Orbit period (P)

593.1

Earth MOID

0.02358

U parameter

2.4

Next Earth close approach

Date

2068-02-06

Nominal distance (from Earth center)

0.19064

28519125

Maximum Brightness

21.4

mag

Risk

Object is not in risk list

Physical Properties

Absolute Magnitude (H)

21.5

mag

Diameter

130 - 290*

Taxonomic type

Rotation period (T)

Discovery Information

Discovery Date

2021-02-05

Observatory

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

61000.0000

1-sigma variation

Unit

MJD

Semimajor Axis

Value

1.381513

1-sigma variation

2.253E-7

Unit

Eccentricity (e)

Value

0.732714

1-sigma variation

0.000001

Unit

Inclination (i)

Value

3.9408

1-sigma variation

3.029E-5

Unit

Long. of Ascending Node (Ω)

Value

107.6766

1-sigma variation

0.0003

Unit

Arg. of Perihelion (ω)

Value

261.8116

1-sigma variation

0.0002

Unit

Mean Anomaly (M)

Value

29.82453

1-sigma variation

0.00026

Unit

Perihelion distance

Value

0.369259

1-sigma variation

Unit

Aphelion distance

Value

2.393767

1-sigma variation

Unit

Asc. Node-Earth Sep.

Value

-0.269692

1-sigma variation

Unit

Desc. Node-Earth Sep.

Value

-0.438420

1-sigma variation

Unit

MOID

Value

0.023577

1-sigma variation

Unit

Orbit Period

Value

593.1042

1-sigma variation

Unit

U parameter

Value

2.4

1-sigma variation

Unit

Covariance Matrix

	a	e	i	Ω	ω	M
a	5.07717E-14	-1.95142E-13	5.86256E-12	6.34868E-11	-4.21219E-11	-5.79388E-11
e	-1.95142E-13	7.80581E-13	-2.34723E-11	-2.55523E-10	1.70221E-10	2.23800E-10
i	5.86256E-12	-2.34723E-11	9.17467E-10	9.45113E-9	-6.87768E-9	-6.71320E-9
Ω	6.34868E-11	-2.55523E-10	9.45113E-9	1.04859E-7	-7.68530E-8	-7.28175E-8
ω	-4.21219E-11	1.70221E-10	-6.87768E-9	-7.68530E-8	5.82108E-8	4.83064E-8
M	-5.79388E-11	2.23800E-10	-6.71320E-9	-7.28175E-8	4.83064E-8	6.62357E-8

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

21.544

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

130 - 290*

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

485

Unit

Source

[1]

Unobserved

Value

1227

Unit

Source

[1]

Normalized RMS of residuals

Value

0.699848

Unit

Source

[1]

Astrometry Summary

First Observation
Last Observation
Total Optical Observations (Discarded)

Optical

Value

Unit

Source

First Observation

Value

2021-01-14.63788

Unit

Source

[2]

Last Observation

Value

2022-05-14.443667

Unit

Source

[2]

Total Optical Observations (Discarded)

Value

37 (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 2021CJ2 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	1970-05-24 00:34	< 1 min	0.1606921	0.1606548	0.0000124
EARTH	1983-05-25 00:17	1.5	0.1474498	0.1473690	0.0000269
EARTH	1996-05-23 11:12	1.6	0.1662394	0.1661502	0.0000297
EARTH	2009-05-22 06:34	< 1 min	0.1987265	0.1986695	0.0000190
VENUS	2014-04-21 21:03	< 1 min	0.0426653	0.0426274	0.0000126
VENUS	2017-09-17 22:18	< 1 min	0.0312637	0.0312526	0.0000037
MERCURY	2035-06-30 17:29	4.3	0.0240190	0.0239521	0.0000223
MERCURY	2041-12-23 12:11	7.5	0.0316938	0.0316381	0.0000186
VENUS	2054-11-27 20:10	2.5	0.0370733	0.0369982	0.0000251
VENUS	2058-04-25 17:36	2.5	0.0389764	0.0388807	0.0000319
EARTH	2068-02-06 04:24	< 1 min	0.1906386	0.1905910	0.0000158
EARTH	2081-02-03 19:25	< 1 min	0.1515710	0.1515500	0.0000070
EARTH	2094-02-02 23:07	1.7	0.1242993	0.1242192	0.0000267
VENUS	2098-12-04 00:36	2.3	0.0246244	0.0245714	0.0000177
EARTH	2107-02-06 14:47	3.3	0.1762064	0.1760492	0.0000524

Download as:

Stationary Points

Ecc. an. ast.	Ecc. an. Earth	Distance in au	Classification
66.83936870	25.28660173	0.02360240	MINIMUM
291.50482171	146.76863310	0.04309816	MINIMUM
357.73434382	263.98391424	0.63318932	SADDLE
357.70167647	83.89143499	1.36720178	SADDLE
179.66464765	86.71290386	1.39878075	SADDLE
179.62612108	266.69700728	3.39286884	MAXIMUM

Download:

MOID Plots

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