Asteroids

2021OC1 help

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

Orbital Properties

Epoch

61000.0

MJD

Orbit type

Aten

Perihelion (q)

0.414

Aphelion (Q)

1.087

Eccentricity (e)

0.448

Inclination (i)

9.8

deg

Orbit period (P)

237.5

Earth MOID

0.00130

U parameter

7.1

Next Earth close approach

Date

2034-07-26

Nominal distance (from Earth center)

0.02369

3544451

Maximum Brightness

23.7

mag

Risk

Object is not in risk list

Physical Properties

Absolute Magnitude (H)

26.8

mag

Diameter

11 - 26*

Taxonomic type

Rotation period (T)

Discovery Information

Discovery Date

2021-07-29

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

0.750490

1-sigma variation

0.000061

Unit

Eccentricity (e)

Value

0.448134

1-sigma variation

0.000179

Unit

Inclination (i)

Value

9.8390

1-sigma variation

0.0064

Unit

Long. of Ascending Node (Ω)

Value

304.2737

1-sigma variation

0.0007

Unit

Arg. of Perihelion (ω)

Value

204.2872

1-sigma variation

0.0018

Unit

Mean Anomaly (M)

Value

356.39231

1-sigma variation

0.26597

Unit

Perihelion distance

Value

0.414170

1-sigma variation

Unit

Aphelion distance

Value

1.086810

1-sigma variation

Unit

Asc. Node-Earth Sep.

Value

-0.002729

1-sigma variation

Unit

Desc. Node-Earth Sep.

Value

-0.559053

1-sigma variation

Unit

MOID

Value

0.001300

1-sigma variation

Unit

Orbit Period

Value

237.4737

1-sigma variation

Unit

U parameter

Value

7.1

1-sigma variation

Unit

Covariance Matrix

	a	e	i	Ω	ω	M
a	3.71103E-9	-1.08644E-8	-3.86169E-7	-3.87297E-8	9.45806E-8	-1.62013E-5
e	-1.08644E-8	3.19498E-8	1.13851E-6	1.11496E-7	-2.65570E-7	4.73968E-5
i	-3.86169E-7	1.13851E-6	4.06379E-5	3.92613E-6	-9.21320E-6	1.68400E-3
Ω	-3.87297E-8	1.11496E-7	3.92613E-6	4.30078E-7	-1.13679E-6	1.69531E-4
ω	9.45806E-8	-2.65570E-7	-9.21320E-6	-1.13679E-6	3.30672E-6	-4.15608E-4
M	-1.62013E-5	4.73968E-5	1.68400E-3	1.69531E-4	-4.15608E-4	7.07380E-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

26.83

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

11 - 26*

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

1515

Unit

Source

[1]

Normalized RMS of residuals

Value

0.458094

Unit

Source

[1]

Astrometry Summary

First Observation
Last Observation
Total Optical Observations (Discarded)

Optical

Value

Unit

Source

First Observation

Value

2021-07-29.278225

Unit

Source

[2]

Last Observation

Value

2021-07-31.08159

Unit

Source

[2]

Total Optical Observations (Discarded)

Value

22 (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 2021OC1 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	1954-08-02 03:51	> 1 w	0.0491280	0.0065422	0.0723468
EARTH	1956-09-14 14:42	1149.7	0.1726010	0.1253652	0.0426959
EARTH	1963-07-26 22:20	> 1 d	0.0214158	0.0011977	0.0725184
EARTH	1965-09-10 17:29	> 1 d	0.1270534	0.1215534	0.0166738
EARTH	1972-07-26 07:06	1143.1	0.1703919	0.0554221	0.0384173
EARTH	1974-08-18 20:42	> 1 d	0.1028499	0.0815521	0.0086767
EARTH	1983-07-29 11:27	1316.4	0.0181711	0.0008582	0.0097813
EARTH	1985-09-14 06:59	485.7	0.1489975	0.1335951	0.0063526
EARTH	1992-07-25 08:33	240.2	0.0570563	0.0167671	0.0134535
EARTH	1994-09-07 21:46	> 1 d	0.1217275	0.1196114	0.0017773
EARTH	2001-07-26 10:58	297.4	0.1624644	0.1323293	0.0100471
EARTH	2003-08-22 09:54	> 1 d	0.1075959	0.1021071	0.0020013
EARTH	2012-08-04 09:19	1024.3	0.0632753	0.0538588	0.0031483
EARTH	2014-09-15 11:02	12.3	0.1871264	0.1782761	0.0030272
EARTH	2021-07-27 11:36	< 1 min	0.0029169	0.0029124	0.0000015
EARTH	2023-09-03 04:58	235.0	0.1212002	0.1206933	0.0001736
EARTH	2034-07-26 19:55	376.4	0.0236932	0.0010120	0.0075818
EARTH	2036-08-27 09:24	1266.2	0.1176488	0.1149108	0.0009713
EARTH	2047-07-26 17:14	294.8	0.1296639	0.0902732	0.0131333
EARTH	2049-08-08 20:59	> 1 d	0.0826394	0.0583936	0.0082611
EARTH	2051-09-15 16:15	1300.7	0.1396980	0.1294845	0.0063973
EARTH	2062-07-28 12:11	> 1 d	0.0080739	0.0013569	0.0280704
EARTH	2064-09-07 22:04	> 1 w	0.1238430	0.1236616	0.0030654
EARTH	2073-07-26 14:52	> 1 w	0.1510199	0.0043825	0.6518730
EARTH	2075-08-11 18:59	> 1 mo	0.0891462	0.0343488	0.3495006
EARTH	2077-09-16 15:56	> 1 w	0.1624720	0.1311534	0.5024792
EARTH	2086-07-26 20:18	> 1 mo	0.0271284	0.0014527	1.2311141
EARTH	2088-08-31 11:01	> 1 mo	0.1200519	0.1169247	0.1044028
EARTH	2099-07-30 06:52	> 1 mo	0.0252403	0.0013888	1.2751664
EARTH	2101-09-12 00:08	> 1 mo	0.1268392	0.1239478	0.2403902
EARTH	2110-07-27 12:06	> 1 w	0.1201170	0.0027823	0.8120448
EARTH	2112-08-17 14:09	> 1 mo	0.1024212	0.0629584	0.2234575
EARTH	2114-09-18 07:16	> 1 d	0.1834649	0.1271410	0.3246612
EARTH	2123-07-29 14:25	> 1 w	0.0043969	0.0028158	0.2718260
EARTH	2125-09-14 01:03	> 1 w	0.1279871	0.0379810	0.2166416

Download as:

Stationary Points

Ecc. an. ast.	Ecc. an. Earth	Distance in au	Classification
141.79327977	202.54451098	0.00036708	MINIMUM
6.37453459	54.41775420	0.57763101	SADDLE
4.61304511	231.62004575	1.42398422	SADDLE
180.62604587	47.01514248	2.07430481	MAXIMUM

Download:

MOID Plots

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