Asteroids

2021SM3 help

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

Orbital Properties

Epoch

61000.0

MJD

Orbit type

Apollo

Perihelion (q)

0.783

Aphelion (Q)

2.232

Eccentricity (e)

0.481

Inclination (i)

16.1

deg

Orbit period (P)

676.1

Earth MOID

0.00382

U parameter

8.3

Next Earth close approach

Date

2033-03-11

Nominal distance (from Earth center)

0.19808

29631936

Maximum Brightness

21.5

mag

Risk

Object is not in risk list

Physical Properties

Absolute Magnitude (H)

22.8

mag

Diameter

70 - 160*

Taxonomic type

Rotation period (T)

Discovery Information

Discovery Date

2021-09-30

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

1.507492

1-sigma variation

0.002093

Unit

Eccentricity (e)

Value

0.480800

1-sigma variation

0.000824

Unit

Inclination (i)

Value

16.0773

1-sigma variation

0.0218

Unit

Long. of Ascending Node (Ω)

Value

23.0867

1-sigma variation

0.0026

Unit

Arg. of Perihelion (ω)

Value

71.1907

1-sigma variation

0.0177

Unit

Mean Anomaly (M)

Value

51.63695

1-sigma variation

1.60332

Unit

Perihelion distance

Value

0.782689

1-sigma variation

Unit

Aphelion distance

Value

2.232295

1-sigma variation

Unit

Asc. Node-Earth Sep.

Value

0.006457

1-sigma variation

Unit

Desc. Node-Earth Sep.

Value

0.367464

1-sigma variation

Unit

MOID

Value

0.003819

1-sigma variation

Unit

Orbit Period

Value

676.0533

1-sigma variation

Unit

U parameter

Value

8.3

1-sigma variation

Unit

Covariance Matrix

	a	e	i	Ω	ω	M
a	4.38190E-6	1.72508E-6	4.56720E-5	5.44986E-6	-3.69765E-5	-3.35623E-3
e	1.72508E-6	6.79141E-7	1.79805E-5	2.14544E-6	-1.45564E-5	-1.32129E-3
i	4.56720E-5	1.79805E-5	4.76045E-4	5.67979E-5	-3.85363E-4	-3.49816E-2
Ω	5.44986E-6	2.14544E-6	5.67979E-5	6.78102E-6	-4.60079E-5	-4.17422E-3
ω	-3.69765E-5	-1.45564E-5	-3.85363E-4	-4.60079E-5	3.12168E-4	2.83214E-2
M	-3.35623E-3	-1.32129E-3	-3.49816E-2	-4.17422E-3	2.83214E-2	2.57064E0

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

22.787

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

70 - 160*

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

1437

Unit

Source

[1]

Normalized RMS of residuals

Value

0.609277

Unit

Source

[1]

Astrometry Summary

First Observation
Last Observation
Total Optical Observations (Discarded)

Optical

Value

Unit

Source

First Observation

Value

2021-09-30.425288

Unit

Source

[2]

Last Observation

Value

2021-10-11.485868

Unit

Source

[2]

Total Optical Observations (Discarded)

Value

56 (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 2021SM3 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	1957-03-19 01:58	> 1 w	0.1973976	0.1592472	0.1754747
EARTH	1958-10-13 15:47	> 1 w	0.0563032	0.0000391	0.3642739
EARTH	1970-03-12 05:58	> 1 w	0.1776555	0.1597113	0.1433891
EARTH	2008-10-23 22:27	> 1 w	0.0922857	0.0015060	0.1665266
EARTH	2021-10-15 02:40	< 1 min	0.0332352	0.0330858	0.0000498
EARTH	2033-03-11 01:09	> 1 d	0.1980773	0.1546354	0.0897162
EARTH	2057-03-17 13:18	> 1 w	0.1634446	0.1544341	0.1131026
EARTH	2058-10-07 19:20	> 1 w	0.1664468	0.0004711	0.3752687
EARTH	2093-10-10 08:54	> 1 mo	0.1179012	0.0042084	0.8946057
EARTH	2104-10-26 23:19	> 1 mo	0.1138458	0.0007490	0.4634831

Download as:

Stationary Points

Ecc. an. ast.	Ecc. an. Earth	Distance in au	Classification
314.56834027	282.41129247	0.00403852	MINIMUM
52.23775782	71.42837565	0.15680402	MINIMUM
6.78757207	3.12016378	0.31306380	SADDLE
181.85894472	172.41496690	1.28020600	SADDLE
1.07353160	173.35465847	1.78313871	SADDLE
179.07324727	350.70200818	3.19226487	MAXIMUM

Download:

MOID Plots

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