Asteroids

2021GK1 help

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

Orbital Properties

Epoch

61000.0

MJD

Orbit type

Apollo

Perihelion (q)

1.006

Aphelion (Q)

1.176

Eccentricity (e)

0.078

Inclination (i)

1.3

deg

Orbit period (P)

416.2

Earth MOID

0.00533

U parameter

2.5

Next Earth close approach

Date

2029-04-08

Nominal distance (from Earth center)

0.13639

20402998

Maximum Brightness

25.4

mag

Risk

Object is not in risk list

Physical Properties

Absolute Magnitude (H)

26.9

mag

Diameter

11 - 24*

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

1.090938

1-sigma variation

2.042E-7

Unit

Eccentricity (e)

Value

0.078147

1-sigma variation

1.791E-7

Unit

Inclination (i)

Value

1.2756

1-sigma variation

1.280E-6

Unit

Long. of Ascending Node (Ω)

Value

236.6950

1-sigma variation

3.042E-5

Unit

Arg. of Perihelion (ω)

Value

1.1565

1-sigma variation

0.0001

Unit

Mean Anomaly (M)

Value

345.05644

1-sigma variation

0.00043

Unit

Perihelion distance

Value

1.005684

1-sigma variation

Unit

Aphelion distance

Value

1.176191

1-sigma variation

Unit

Asc. Node-Earth Sep.

Value

-0.007357

1-sigma variation

Unit

Desc. Node-Earth Sep.

Value

0.187816

1-sigma variation

Unit

MOID

Value

0.005329

1-sigma variation

Unit

Orbit Period

Value

416.1965

1-sigma variation

Unit

U parameter

Value

2.5

1-sigma variation

Unit

Covariance Matrix

	a	e	i	Ω	ω	M
a	4.17094E-14	3.65736E-14	1.80698E-13	-5.11658E-12	1.15266E-11	-8.71487E-11
e	3.65736E-14	3.20920E-14	1.56625E-13	-4.53593E-12	1.01484E-11	-7.64090E-11
i	1.80698E-13	1.56625E-13	1.63933E-12	-2.40321E-11	5.52663E-11	-3.80371E-10
Ω	-5.11658E-12	-4.53593E-12	-2.40321E-11	9.25569E-10	-1.58724E-9	1.05764E-8
ω	1.15266E-11	1.01484E-11	5.52663E-11	-1.58724E-9	3.38004E-9	-2.40956E-8
M	-8.71487E-11	-7.64090E-11	-3.80371E-10	1.05764E-8	-2.40956E-8	1.82199E-7

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

26.935

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 - 24*

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

177

Unit

Source

[1]

Unobserved

Value

1479

Unit

Source

[1]

Normalized RMS of residuals

Value

0.626116

Unit

Source

[1]

Astrometry Summary

First Observation
Last Observation
Total Optical Observations (Discarded)

Optical

Value

Unit

Source

First Observation

Value

2021-03-15.437772

Unit

Source

[2]

Last Observation

Value

2021-09-08.242833

Unit

Source

[2]

Total Optical Observations (Discarded)

Value

120 (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 2021GK1 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	1952-11-18 09:55	> 1 w	0.1747470	0.1676370	0.0023733
EARTH	1961-01-29 02:32	> 1 w	0.1639213	0.1591850	0.0015797
EARTH	1961-08-13 14:21	278.1	0.1909219	0.1702339	0.0068962
EARTH	1969-05-03 22:22	209.5	0.0521534	0.0480740	0.0013601
EARTH	1969-09-26 11:46	> 1 d	0.1114730	0.1091978	0.0007584
EARTH	1978-02-07 07:31	> 1 d	0.1506744	0.1491960	0.0004929
EARTH	1978-08-13 03:06	75.2	0.1491885	0.1441753	0.0016711
EARTH	1986-11-29 03:47	1277.5	0.1766846	0.1763177	0.0001222
EARTH	1995-06-16 23:58	53.1	0.0103798	0.0103706	0.0000031
EARTH	2004-01-11 16:22	33.2	0.1673375	0.1673256	0.0000040
EARTH	2012-11-12 23:06	18.2	0.1720038	0.1719972	0.0000022
EARTH	2021-05-11 17:21	< 1 min	0.0037927	0.0037927	0.0000000
EARTH	2029-04-08 05:18	< 1 min	0.1363856	0.1363435	0.0000140
EARTH	2029-09-27 04:46	26.6	0.1459623	0.1459484	0.0000046
EARTH	2037-11-14 19:38	22.9	0.1851001	0.1850972	0.0000010
EARTH	2045-12-29 08:17	28.0	0.1730881	0.1730772	0.0000036
EARTH	2054-02-27 03:39	73.3	0.1070155	0.1069833	0.0000107
EARTH	2054-07-08 00:18	3.4	0.0518339	0.0517856	0.0000161
EARTH	2062-02-08 03:23	181.9	0.1340013	0.1338919	0.0000365
EARTH	2062-07-13 21:58	6.6	0.1010176	0.1007765	0.0000803
EARTH	2070-01-01 12:31	96.8	0.1797560	0.1797174	0.0000129
EARTH	2077-11-28 18:29	53.4	0.1967488	0.1967476	0.0000004
EARTH	2085-10-26 02:26	18.3	0.1829874	0.1829782	0.0000031
EARTH	2093-04-11 03:03	1.2	0.1148236	0.1147681	0.0000185
EARTH	2093-09-18 15:06	39.7	0.1398383	0.1398164	0.0000073
EARTH	2101-04-19 11:30	6.7	0.0441273	0.0440349	0.0000308
EARTH	2101-08-23 16:53	124.6	0.1029202	0.1028590	0.0000204
EARTH	2109-11-03 00:58	327.1	0.1775046	0.1774224	0.0000269
EARTH	2117-12-23 23:55	623.8	0.1779604	0.1777642	0.0000654

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Stationary Points

Ecc. an. ast.	Ecc. an. Earth	Distance in au	Classification
351.39178842	125.50549317	0.00432342	MINIMUM
186.40765098	321.98235950	0.18861968	SADDLE
7.13228702	322.72811986	1.99318880	SADDLE
186.33211416	141.92573699	2.18844582	MAXIMUM

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MOID Plots

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