Asteroids

2021PJ help

Last update: 2025-07-29 02:36 UTC

Orbital Properties

Epoch

60800.0

MJD

Orbit type

Amor

Perihelion (q)

1.021

Aphelion (Q)

2.103

Eccentricity (e)

0.346

Inclination (i)

9.7

deg

Orbit period (P)

713.1

Earth MOID

0.00916

U parameter

7.0

Next Earth close approach

Date

2062-08-04

Nominal distance (from Earth center)

0.01362

2037786

Maximum Brightness

16.2

mag

Risk

Object is not in risk list

Physical Properties

Absolute Magnitude (H)

23.4

mag

Diameter

50 - 120*

Taxonomic type

Rotation period (T)

Discovery Information

Discovery Date

2021-08-03

Observatory

ATLAS-HKO, 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

60800.0000

1-sigma variation

Unit

MJD

Semimajor Axis

Value

1.562076

1-sigma variation

0.000391

Unit

Eccentricity (e)

Value

0.346162

1-sigma variation

0.000163

Unit

Inclination (i)

Value

9.6779

1-sigma variation

0.0033

Unit

Long. of Ascending Node (Ω)

Value

308.7294

1-sigma variation

0.0007

Unit

Arg. of Perihelion (ω)

Value

7.8743

1-sigma variation

0.0001

Unit

Mean Anomaly (M)

Value

328.70854

1-sigma variation

0.26216

Unit

Perihelion distance

Value

1.021345

1-sigma variation

Unit

Aphelion distance

Value

2.102808

1-sigma variation

Unit

Asc. Node-Earth Sep.

Value

0.009279

1-sigma variation

Unit

Desc. Node-Earth Sep.

Value

1.107121

1-sigma variation

Unit

MOID

Value

0.009158

1-sigma variation

Unit

Orbit Period

Value

713.1023

1-sigma variation

Unit

U parameter

Value

7.0

1-sigma variation

Unit

Covariance Matrix

	a	e	i	Ω	ω	M
a	1.53265E-7	6.37168E-8	1.30161E-6	-2.64210E-7	-3.60651E-8	-1.02635E-4
e	6.37168E-8	2.64890E-8	5.41119E-7	-1.09840E-7	-1.49932E-8	-4.26683E-5
i	1.30161E-6	5.41119E-7	1.10542E-5	-2.24378E-6	-3.06540E-7	-8.71631E-4
Ω	-2.64210E-7	-1.09840E-7	-2.24378E-6	4.55484E-7	6.21124E-8	1.76930E-4
ω	-3.60651E-8	-1.49932E-8	-3.06540E-7	6.21124E-8	9.27353E-9	2.41509E-5
M	-1.02635E-4	-4.26683E-5	-8.71631E-4	1.76930E-4	2.41509E-5	6.87298E-2

Date of computation: 2025-07-29 02:36 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

23.426

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

50 - 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

1475

Unit

Source

[1]

Normalized RMS of residuals

Value

0.606479

Unit

Source

[1]

Astrometry Summary

First Observation
Last Observation
Total Optical Observations (Discarded)

Optical

Value

Unit

Source

First Observation

Value

2021-08-03.284859

Unit

Source

[2]

Last Observation

Value

2021-08-16.459082

Unit

Source

[2]

Total Optical Observations (Discarded)

Value

149 (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

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 2021PJ 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	1957-07-21 03:56	> 1 mo	0.0550200	0.0014193	0.9990355
EARTH	1986-08-04 06:40	> 1 w	0.0134980	0.0079009	0.0522829
EARTH	2021-08-06 01:49	< 1 s	0.0209023	0.0208777	0.0000082
EARTH	2062-08-04 08:40	> 1 w	0.0136218	0.0077072	0.0603223
EARTH	2064-07-02 17:05	> 1 d	0.1901398	0.1395987	0.0168634
EARTH	2113-08-30 01:35	> 1 mo	0.1211766	0.0379169	2.2456923
EARTH	2115-07-21 05:00	> 1 mo	0.0636671	0.0033265	2.1651152

Download as:

Stationary Points

Ecc. an. ast.	Ecc. an. Earth	Distance in au	Classification
354.85020893	207.40159540	0.00915845	MINIMUM
179.86435884	33.91624477	1.11688508	SADDLE
358.91191322	33.20997352	2.00758972	SADDLE
179.15664596	213.42628807	3.11614107	MAXIMUM

Download:

MOID Plots

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