Asteroids

2021GC1 help

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

Orbital Properties

Epoch

61000.0

MJD

Orbit type

Apollo

Perihelion (q)

0.948

Aphelion (Q)

1.497

Eccentricity (e)

0.225

Inclination (i)

3.6

deg

Orbit period (P)

493.5

Earth MOID

0.00955

U parameter

7.2

Next Earth close approach

Date

2043-12-30

Nominal distance (from Earth center)

0.07013

10491243

Maximum Brightness

25.1

mag

Risk

Object is not in risk list

Physical Properties

Absolute Magnitude (H)

28.2

mag

Diameter

6 - 14*

Taxonomic type

Rotation period (T)

Discovery Information

Discovery Date

2021-04-03

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

1.222107

1-sigma variation

0.000277

Unit

Eccentricity (e)

Value

0.224589

1-sigma variation

0.000203

Unit

Inclination (i)

Value

3.6201

1-sigma variation

0.0031

Unit

Long. of Ascending Node (Ω)

Value

196.1353

1-sigma variation

0.0004

Unit

Arg. of Perihelion (ω)

Value

306.2141

1-sigma variation

0.0011

Unit

Mean Anomaly (M)

Value

188.16758

1-sigma variation

0.44614

Unit

Perihelion distance

Value

0.947634

1-sigma variation

Unit

Aphelion distance

Value

1.496579

1-sigma variation

Unit

Asc. Node-Earth Sep.

Value

0.022563

1-sigma variation

Unit

Desc. Node-Earth Sep.

Value

0.338805

1-sigma variation

Unit

MOID

Value

0.009547

1-sigma variation

Unit

Orbit Period

Value

493.4716

1-sigma variation

Unit

U parameter

Value

7.2

1-sigma variation

Unit

Covariance Matrix

	a	e	i	Ω	ω	M
a	7.68970E-8	5.64262E-8	8.70246E-7	1.03261E-7	3.01358E-7	-1.23717E-4
e	5.64262E-8	4.14061E-8	6.38569E-7	7.57575E-8	2.20758E-7	-9.07822E-5
i	8.70246E-7	6.38569E-7	9.84882E-6	1.16868E-6	3.41308E-6	-1.40012E-3
Ω	1.03261E-7	7.57575E-8	1.16868E-6	1.38899E-7	4.09173E-7	-1.66136E-4
ω	3.01358E-7	2.20758E-7	3.41308E-6	4.09173E-7	1.30223E-6	-4.84908E-4
M	-1.23717E-4	-9.07822E-5	-1.40012E-3	-1.66136E-4	-4.84908E-4	1.99045E-1

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

28.191

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

6 - 14*

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

1624

Unit

Source

[1]

Normalized RMS of residuals

Value

0.814226

Unit

Source

[1]

Astrometry Summary

First Observation
Last Observation
Total Optical Observations (Discarded)

Optical

Value

Unit

Source

First Observation

Value

2021-04-03.35787

Unit

Source

[2]

Last Observation

Value

2021-04-10.455228

Unit

Source

[2]

Total Optical Observations (Discarded)

Value

30 (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 2021GC1 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	1969-12-21 01:17	> 1 d	0.1130532	0.0620455	0.0728528
EARTH	1974-03-22 10:17	> 1 w	0.0248024	0.0095369	0.0458361
EARTH	1978-04-13 04:37	> 1 d	0.1424159	0.0047837	0.0695732
EARTH	2012-12-19 02:08	> 1 d	0.1283388	0.0802815	0.0177006
EARTH	2017-01-21 20:38	> 1 d	0.0644124	0.0631757	0.0009826
EARTH	2021-03-30 03:35	< 1 min	0.0117987	0.0117660	0.0000109
EARTH	2043-12-30 09:54	> 1 d	0.0701296	0.0623452	0.0210762
EARTH	2048-04-08 23:27	> 1 d	0.0842328	0.0060339	0.0560530
EARTH	2071-01-24 20:57	> 1 mo	0.0643138	0.0638785	0.0038983
EARTH	2075-04-16 11:25	> 1 d	0.1723138	0.0002246	0.0919611
EARTH	2098-02-25 05:13	> 1 mo	0.0569316	0.0273682	0.0670060
EARTH	2125-01-27 13:35	> 1 mo	0.0645728	0.0644020	0.0113144

Download as:

Stationary Points

Ecc. an. ast.	Ecc. an. Earth	Distance in au	Classification
37.03364579	84.83705138	0.01002693	MINIMUM
331.24991823	4.32452044	0.06203189	MINIMUM
350.85287872	28.19979638	0.06531074	SADDLE
180.80872210	221.21145763	0.48819452	SADDLE
2.70059795	222.86440235	1.95919429	SADDLE
181.99092402	42.15028188	2.48335652	MAXIMUM

Download:

MOID Plots

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