Asteroids

2021NU help

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

Orbital Properties

Epoch

61000.0

MJD

Orbit type

Apollo

Perihelion (q)

0.925

Aphelion (Q)

3.335

Eccentricity (e)

0.566

Inclination (i)

5.9

deg

Orbit period (P)

1135.7

Earth MOID

0.00094

U parameter

5.7

Next Earth close approach

Date

2049-07-21

Nominal distance (from Earth center)

0.15315

22910857

Maximum Brightness

21.9

mag

Risk

Object is not in risk list

Physical Properties

Absolute Magnitude (H)

23.4

mag

Diameter

60 - 130*

Taxonomic type

Rotation period (T)

Discovery Information

Discovery Date

2021-07-04

Observatory

Pan-STARRS 1, 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

61000.0000

1-sigma variation

Unit

MJD

Semimajor Axis

Value

2.130303

1-sigma variation

0.000100

Unit

Eccentricity (e)

Value

0.565705

1-sigma variation

0.000021

Unit

Inclination (i)

Value

5.8676

1-sigma variation

0.0001

Unit

Long. of Ascending Node (Ω)

Value

134.3610

1-sigma variation

0.0003

Unit

Arg. of Perihelion (ω)

Value

220.4693

1-sigma variation

0.0004

Unit

Mean Anomaly (M)

Value

129.14844

1-sigma variation

0.03530

Unit

Perihelion distance

Value

0.925180

1-sigma variation

Unit

Aphelion distance

Value

3.335426

1-sigma variation

Unit

Asc. Node-Earth Sep.

Value

1.556155

1-sigma variation

Unit

Desc. Node-Earth Sep.

Value

-0.002468

1-sigma variation

Unit

MOID

Value

0.000940

1-sigma variation

Unit

Orbit Period

Value

1135.6918

1-sigma variation

Unit

U parameter

Value

5.7

1-sigma variation

Unit

Covariance Matrix

	a	e	i	Ω	ω	M
a	1.00385E-8	2.09220E-9	1.38148E-8	3.21892E-8	-3.97109E-8	-3.53652E-6
e	2.09220E-9	4.36052E-10	2.87934E-9	6.70896E-9	-8.27535E-9	-7.37071E-7
i	1.38148E-8	2.87934E-9	1.90459E-8	4.42711E-8	-5.45489E-8	-4.86689E-6
Ω	3.21892E-8	6.70896E-9	4.42711E-8	1.03468E-7	-1.27463E-7	-1.13401E-5
ω	-3.97109E-8	-8.27535E-9	-5.45489E-8	-1.27463E-7	1.57843E-7	1.39899E-5
M	-3.53652E-6	-7.37071E-7	-4.86689E-6	-1.13401E-5	1.39899E-5	1.24590E-3

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

23.37

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

60 - 130*

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

1481

Unit

Source

[1]

Normalized RMS of residuals

Value

0.401523

Unit

Source

[1]

Astrometry Summary

First Observation
Last Observation
Total Optical Observations (Discarded)

Optical

Value

Unit

Source

First Observation

Value

2021-07-04.555503

Unit

Source

[2]

Last Observation

Value

2021-09-05.609786

Unit

Source

[2]

Total Optical Observations (Discarded)

Value

33 (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 2021NU 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	1968-10-15 18:55	> 1 w	0.0980662	0.0978463	0.0022649
EARTH	1993-07-29 15:14	> 1 d	0.0514162	0.0169047	0.0116139
EARTH	2021-07-24 07:38	< 1 s	0.1161817	0.1161714	0.0000034
EARTH	2049-07-21 21:35	1239.1	0.1531496	0.1170867	0.0120246
EARTH	2052-11-11 06:49	1169.9	0.1987970	0.1675114	0.0108116
EARTH	2080-10-24 04:54	> 1 d	0.0984926	0.0979750	0.0007963
EARTH	2108-10-21 04:08	> 1 d	0.0971752	0.0971747	0.0000146

Download as:

Stationary Points

Ecc. an. ast.	Ecc. an. Earth	Distance in au	Classification
337.97772647	212.57843964	0.00001835	MINIMUM
16.83110747	284.83358436	0.09766333	MINIMUM
4.67251710	262.33171036	0.10415554	SADDLE
358.83376478	71.21359145	1.91956551	SADDLE
179.79773433	72.09867061	2.34409789	SADDLE
179.50999411	251.94473533	4.33901285	MAXIMUM

Download:

MOID Plots

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