Asteroids

2021NL4 help

Last update: 2026-03-17 23:26 UTC

Orbital Properties

Epoch

61200.0

MJD

Orbit type

Apollo

Perihelion (q)

0.810

Aphelion (Q)

1.846

Eccentricity (e)

0.390

Inclination (i)

4.0

deg

Orbit period (P)

559.0

Earth MOID

0.02700

U parameter

7.9

Next Earth close approach

Date

2027-12-30

Nominal distance (from Earth center)

0.11604

17358785

Maximum Brightness

21.7

mag

Risk

Object is not in risk list

Physical Properties

Absolute Magnitude (H)

23.5

mag

Diameter

50 - 120*

Taxonomic type

Rotation period (T)

Discovery Information

Discovery Date

2021-07-10

Observatory

Observatorio Campo dos Amarais

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

1.328050

1-sigma variation

0.000851

Unit

Eccentricity (e)

Value

0.389751

1-sigma variation

0.000551

Unit

Inclination (i)

Value

4.0434

1-sigma variation

0.0045

Unit

Long. of Ascending Node (Ω)

Value

330.9835

1-sigma variation

0.0041

Unit

Arg. of Perihelion (ω)

Value

51.0555

1-sigma variation

0.0060

Unit

Mean Anomaly (M)

Value

26.15480

1-sigma variation

1.06415

Unit

Perihelion distance

Value

0.810441

1-sigma variation

Unit

Aphelion distance

Value

1.845660

1-sigma variation

Unit

Asc. Node-Earth Sep.

Value

-0.106782

1-sigma variation

Unit

Desc. Node-Earth Sep.

Value

0.503134

1-sigma variation

Unit

MOID

Value

0.026999

1-sigma variation

Unit

Orbit Period

Value

559.0108

1-sigma variation

Unit

U parameter

Value

7.9

1-sigma variation

Unit

Covariance Matrix

	a	e	i	Ω	ω	M
a	7.23426E-7	4.68938E-7	3.80640E-6	3.47136E-6	-5.11667E-6	-9.05108E-4
e	4.68938E-7	3.03974E-7	2.46736E-6	2.25057E-6	-3.31692E-6	-5.86707E-4
i	3.80640E-6	2.46736E-6	2.00288E-5	1.82495E-5	-2.69102E-5	-4.76234E-3
Ω	3.47136E-6	2.25057E-6	1.82495E-5	1.69373E-5	-2.47490E-5	-4.34319E-3
ω	-5.11667E-6	-3.31692E-6	-2.69102E-5	-2.47490E-5	3.63383E-5	6.40169E-3
M	-9.05108E-4	-5.86707E-4	-4.76234E-3	-4.34319E-3	6.40169E-3	1.13242E0

Date of computation: 2026-03-17 23:26 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

23.525

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 - 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

1705

Unit

Source

[1]

Normalized RMS of residuals

Value

0.51436

Unit

Source

[1]

Astrometry Summary

First Observation
Last Observation
Total Optical Observations (Discarded)

Optical

Value

Unit

Source

First Observation

Value

2021-07-10.19145

Unit

Source

[2]

Last Observation

Value

2021-07-30.98059

Unit

Source

[2]

Total Optical Observations (Discarded)

Value

41 (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

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 2021NL4 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	1953-01-02 08:11	> 1 mo	0.1877099	0.0601938	1.2155953
EARTH	1969-07-22 06:41	> 1 mo	0.1405598	0.0301494	1.3424713
EARTH	1972-09-17 05:54	> 1 mo	0.1740652	0.0979804	0.4181954
EARTH	1975-12-15 07:46	> 1 mo	0.0918054	0.0600808	0.8450928
EARTH	1995-08-01 02:36	> 1 w	0.0292899	0.0274454	0.0521594
EARTH	1998-10-14 02:43	> 1 mo	0.1936637	0.1936555	0.0001975
EARTH	2001-12-25 20:33	> 1 w	0.0707869	0.0602646	0.0622930
EARTH	2021-08-03 15:24	< 1 min	0.0327714	0.0326349	0.0000455
EARTH	2024-10-23 05:04	> 1 w	0.1908124	0.1857147	0.0018034
EARTH	2027-12-30 07:48	> 1 d	0.1160363	0.0599773	0.0319157
EARTH	2044-07-20 21:09	> 1 d	0.1712329	0.0295976	0.1151369
EARTH	2047-09-14 14:06	> 1 mo	0.1684044	0.0840886	0.0479496
EARTH	2050-12-15 13:18	> 1 w	0.0923873	0.0600661	0.0921391
EARTH	2070-08-14 22:36	> 1 mo	0.0920050	0.0310611	0.1370030
EARTH	2073-11-13 22:35	> 1 mo	0.1685666	0.0840580	0.0611146
EARTH	2093-07-28 08:13	> 1 d	0.0659312	0.0264200	0.0337369
EARTH	2096-10-04 13:12	> 1 d	0.1906048	0.1854545	0.0017333
EARTH	2099-12-24 04:47	> 1 d	0.0597296	0.0597198	0.0004229
EARTH	2119-08-09 09:18	> 1 mo	0.0540599	0.0262196	0.2049752
EARTH	2122-11-05 04:54	> 1 mo	0.1823830	0.1119990	0.0581172
EARTH	2126-01-04 14:05	> 1 w	0.1820788	0.0595942	0.1964768

Download as:

Stationary Points

Ecc. an. ast.	Ecc. an. Earth	Distance in au	Classification
307.85959651	208.37429286	0.02721092	MINIMUM
49.02378257	350.03664331	0.06041999	MINIMUM
358.91244467	280.22753841	0.19342231	SADDLE
179.14429100	99.56736357	0.84524767	SADDLE
357.31423394	97.82925467	1.81325729	SADDLE
178.63338129	279.23106812	2.84247455	MAXIMUM

Download:

MOID Plots

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