Asteroids

2021WR help

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

Orbital Properties

Epoch

61000.0

MJD

Orbit type

Apollo

Perihelion (q)

0.973

Aphelion (Q)

4.057

Eccentricity (e)

0.613

Inclination (i)

1.3

deg

Orbit period (P)

1456.9

Earth MOID

0.01019

U parameter

6.9

Next Earth close approach

Date

2025-11-22

Nominal distance (from Earth center)

0.04709

7044639

Maximum Brightness

20.7

mag

Risk

Object is not in risk list

Physical Properties

Absolute Magnitude (H)

25.4

mag

Diameter

22 - 50*

Taxonomic type

Rotation period (T)

Discovery Information

Discovery Date

2021-11-25

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

61000.0000

1-sigma variation

Unit

MJD

Semimajor Axis

Value

2.515114

1-sigma variation

0.000960

Unit

Eccentricity (e)

Value

0.612957

1-sigma variation

0.000148

Unit

Inclination (i)

Value

1.2628

1-sigma variation

0.0001

Unit

Long. of Ascending Node (Ω)

Value

226.6634

1-sigma variation

0.0005

Unit

Arg. of Perihelion (ω)

Value

223.1820

1-sigma variation

0.0003

Unit

Mean Anomaly (M)

Value

354.21325

1-sigma variation

0.11924

Unit

Perihelion distance

Value

0.973456

1-sigma variation

Unit

Aphelion distance

Value

4.056771

1-sigma variation

Unit

Asc. Node-Earth Sep.

Value

1.832837

1-sigma variation

Unit

Desc. Node-Earth Sep.

Value

0.093876

1-sigma variation

Unit

MOID

Value

0.010189

1-sigma variation

Unit

Orbit Period

Value

1456.9171

1-sigma variation

Unit

U parameter

Value

6.9

1-sigma variation

Unit

Covariance Matrix

	a	e	i	Ω	ω	M
a	9.22001E-7	1.42541E-7	8.71324E-8	-4.86262E-7	-3.23181E-7	-1.14498E-4
e	1.42541E-7	2.20368E-8	1.34705E-8	-7.51761E-8	-4.99624E-8	-1.77013E-5
i	8.71324E-8	1.34705E-8	8.27618E-9	-4.55208E-8	-3.10222E-8	-1.08204E-5
Ω	-4.86262E-7	-7.51761E-8	-4.55208E-8	2.62592E-7	1.64202E-7	6.03859E-5
ω	-3.23181E-7	-4.99624E-8	-3.10222E-8	1.64202E-7	1.20284E-7	4.01337E-5
M	-1.14498E-4	-1.77013E-5	-1.08204E-5	6.03859E-5	4.01337E-5	1.42187E-2

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

25.429

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

22 - 50*

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

1435

Unit

Source

[1]

Normalized RMS of residuals

Value

0.606662

Unit

Source

[1]

Astrometry Summary

First Observation
Last Observation
Total Optical Observations (Discarded)

Optical

Value

Unit

Source

First Observation

Value

2021-10-28.303048

Unit

Source

[2]

Last Observation

Value

2021-11-29.909538

Unit

Source

[2]

Total Optical Observations (Discarded)

Value

72 (2)

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 2021WR 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	2009-11-02 18:00	> 1 d	0.1889409	0.1239904	0.0216514
EARTH	2013-11-03 22:03	> 1 d	0.1687517	0.1195303	0.0164081
EARTH	2017-11-02 23:13	929.6	0.1851531	0.1581745	0.0089930
EARTH	2021-12-01 16:39	< 1 s	0.0173191	0.0173124	0.0000022
EARTH	2025-11-22 11:10	> 1 d	0.0470905	0.0275794	0.0065888
EARTH	2029-11-07 12:57	930.1	0.1745019	0.1495779	0.0083087
EARTH	2033-11-17 07:09	1065.1	0.1233077	0.1036115	0.0065695
EARTH	2037-11-14 12:43	617.6	0.1445887	0.1314381	0.0043844
EARTH	2045-11-23 06:52	376.4	0.1213227	0.1151943	0.0020435
EARTH	2049-12-03 08:12	> 1 d	0.0632979	0.0527372	0.0035462
EARTH	2053-12-02 10:09	> 1 d	0.0698999	0.0554404	0.0048566
EARTH	2057-12-28 02:55	> 1 d	0.0613487	0.0565896	0.0015864
EARTH	2062-01-21 03:56	> 1 d	0.1647049	0.1344706	0.0100925
EARTH	2123-01-13 12:37	> 1 d	0.1781350	0.1117621	0.0221736

Download as:

Stationary Points

Ecc. an. ast.	Ecc. an. Earth	Distance in au	Classification
352.33470658	332.43342202	0.01018659	MINIMUM
5.33803959	358.46689858	0.01774181	MINIMUM
1.68183976	351.14882602	0.01825259	SADDLE
359.73097965	167.23829251	1.98954653	SADDLE
179.94051577	167.49173531	3.04117008	SADDLE
179.93313149	347.48970378	5.04086739	MAXIMUM

Download:

MOID Plots

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