Asteroids

2021LC3 help

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

Orbital Properties

Epoch

61000.0

MJD

Orbit type

Apollo

Perihelion (q)

0.769

Aphelion (Q)

1.562

Eccentricity (e)

0.340

Inclination (i)

3.0

deg

Orbit period (P)

459.6

Earth MOID

0.00055

U parameter

6.6

Next Earth close approach

Date

2026-07-16

Nominal distance (from Earth center)

0.18151

27153660

Maximum Brightness

28.8

mag

Risk

Object is in risk list

Physical Properties

Absolute Magnitude (H)

26.5

mag

Diameter

13 - 29*

Taxonomic type

Rotation period (T)

Discovery Information

Discovery Date

2021-06-08

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

1.165565

1-sigma variation

0.000091

Unit

Eccentricity (e)

Value

0.339903

1-sigma variation

0.000089

Unit

Inclination (i)

Value

3.0213

1-sigma variation

0.0007

Unit

Long. of Ascending Node (Ω)

Value

79.1599

1-sigma variation

0.0001

Unit

Arg. of Perihelion (ω)

Value

266.9967

1-sigma variation

0.0020

Unit

Mean Anomaly (M)

Value

143.64701

1-sigma variation

0.13930

Unit

Perihelion distance

Value

0.769386

1-sigma variation

Unit

Aphelion distance

Value

1.561744

1-sigma variation

Unit

Asc. Node-Earth Sep.

Value

0.064428

1-sigma variation

Unit

Desc. Node-Earth Sep.

Value

-0.003616

1-sigma variation

Unit

MOID

Value

0.000554

1-sigma variation

Unit

Orbit Period

Value

459.6245

1-sigma variation

Unit

U parameter

Value

6.6

1-sigma variation

Unit

Covariance Matrix

	a	e	i	Ω	ω	M
a	8.31642E-9	8.01284E-9	6.29766E-8	1.30857E-8	-1.13741E-7	-1.27031E-5
e	8.01284E-9	7.84972E-9	6.22949E-8	1.24039E-8	-9.12552E-8	-1.22403E-5
i	6.29766E-8	6.22949E-8	5.03967E-7	9.47427E-8	-6.30361E-7	-9.62061E-5
Ω	1.30857E-8	1.24039E-8	9.47427E-8	2.14291E-8	-2.08391E-7	-1.99866E-5
ω	-1.13741E-7	-9.12552E-8	-6.30361E-7	-2.08391E-7	4.15379E-6	1.73607E-4
M	-1.27031E-5	-1.22403E-5	-9.62061E-5	-1.99866E-5	1.73607E-4	1.94036E-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

26.522

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

13 - 29*

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

[-]

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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

0.8

Unit

Source

[1]

Unobserved

Value

1566

Unit

Source

[1]

Normalized RMS of residuals

Value

0.562509

Unit

Source

[1]

Astrometry Summary

First Observation
Last Observation
Total Optical Observations (Discarded)

Optical

Value

Unit

Source

First Observation

Value

2021-06-08.457836

Unit

Source

[2]

Last Observation

Value

2021-06-09.211678

Unit

Source

[2]

Total Optical Observations (Discarded)

Value

22 (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 2021LC3 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	1960-06-02 13:56	> 1 mo	0.1029237	0.0020046	0.8862140
EARTH	1965-06-08 23:33	1022.3	0.0041592	0.0013818	0.0103063
EARTH	1975-12-07 12:48	750.8	0.1680717	0.1312366	0.0122856
EARTH	1979-06-02 05:54	630.8	0.1232418	0.0941869	0.0096856
EARTH	1989-11-29 13:01	57.3	0.0230062	0.0208249	0.0007409
EARTH	2003-12-04 05:30	573.1	0.0952618	0.0703784	0.0083153
EARTH	2007-06-02 16:48	572.5	0.1296637	0.1050811	0.0081943
EARTH	2021-06-09 08:54	< 1 s	0.0047681	0.0047646	0.0000011
EARTH	2026-07-16 09:25	> 1 d	0.1815110	0.1749144	0.0021997
EARTH	2041-11-19 16:47	> 1 d	0.1151924	0.0935831	0.0072051
EARTH	2046-12-04 23:45	530.6	0.0634897	0.0429054	0.0068964
EARTH	2060-06-07 17:54	378.4	0.0356835	0.0230041	0.0042265
EARTH	2065-06-27 05:49	46.9	0.1351138	0.1345494	0.0001881
EARTH	2080-10-25 11:30	> 1 d	0.1822765	0.1589902	0.0077641
EARTH	2085-11-30 13:18	> 1 d	0.0195188	0.0088794	0.0152322
EARTH	2090-12-06 19:07	> 1 d	0.0888372	0.0103982	0.0273641
EARTH	2104-06-01 22:54	> 1 d	0.1647082	0.0009694	0.1102786
EARTH	2109-06-09 16:22	> 1 w	0.0246716	0.0002118	0.1305255
EARTH	2114-06-14 03:22	> 1 w	0.0378570	0.0001450	0.2775614
EARTH	2119-06-27 10:10	> 1 mo	0.1311278	0.0061104	0.2938830

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Stationary Points

Ecc. an. ast.	Ecc. an. Earth	Distance in au	Classification
292.35654331	156.21258125	0.00024493	MINIMUM
63.31874891	327.04226125	0.00944066	MINIMUM
357.22164250	241.02240695	0.24243916	SADDLE
178.60041786	62.40035604	0.57292032	SADDLE
357.10999792	60.84445018	1.76114312	SADDLE
178.50621976	242.32642980	2.56805508	MAXIMUM

Download:

MOID Plots

Click on the images to zoom-in and zoom-out

Level lines of the squared distance function

2021LC3

Date in UTC	MJD	σ	Distance ± Width in RE	Stretching in RE	IP	Impact energy	PS
2065-06-09.777	75445.777	4.363	0.98 ± 0.002	6.93E4	1.21E-9	1.58E-1	-9.64
2070-06-09.983	77271.983	4.353	1.34 ± 0.002	1.00E5	5.35E-10	1.57E-1	-10.05
2104-06-10.645	89690.645	4.049	1.21 ± 0.005	5.41E5	3.41E-10	1.58E-1	-10.48


Based on 22 optical observations (of which 1 are rejected as outliers) from 2021/06/08.458 to 2021/06/09.212.
Coordinates are given on the Target Plane.
Unit is one Earth radius, but impact cross section has radius between 1.48 and 1.48 Earth radii.
Coordinates for LOV = EQU scaled= 1 second= F.
AstOD software version= 4.0, Date of computation=20250805 130500.123 UTC.

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Download Impactor Table as: