Asteroids

2021GZ9 help

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

Orbital Properties

Epoch

61000.0

MJD

Orbit type

Amor

Perihelion (q)

1.026

Aphelion (Q)

1.589

Eccentricity (e)

0.215

Inclination (i)

3.5

deg

Orbit period (P)

546.1

Earth MOID

0.03330

U parameter

8.2

Next Earth close approach

Date

2027-03-29

Nominal distance (from Earth center)

0.08886

13292771

Maximum Brightness

23.3

mag

Risk

Object is not in risk list

Physical Properties

Absolute Magnitude (H)

26.2

mag

Diameter

16 - 30*

Taxonomic type

Rotation period (T)

Discovery Information

Discovery Date

2021-04-13

Observatory

Kitt Peak-Bok

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

1.307582

1-sigma variation

0.001282

Unit

Eccentricity (e)

Value

0.215491

1-sigma variation

0.000637

Unit

Inclination (i)

Value

3.4630

1-sigma variation

0.0197

Unit

Long. of Ascending Node (Ω)

Value

60.9544

1-sigma variation

0.1193

Unit

Arg. of Perihelion (ω)

Value

141.7744

1-sigma variation

0.1880

Unit

Mean Anomaly (M)

Value

27.97073

1-sigma variation

1.39723

Unit

Perihelion distance

Value

1.025810

1-sigma variation

Unit

Aphelion distance

Value

1.589355

1-sigma variation

Unit

Asc. Node-Earth Sep.

Value

0.513610

1-sigma variation

Unit

Desc. Node-Earth Sep.

Value

0.052336

1-sigma variation

Unit

MOID

Value

0.033304

1-sigma variation

Unit

Orbit Period

Value

546.1375

1-sigma variation

Unit

U parameter

Value

8.2

1-sigma variation

Unit

Covariance Matrix

	a	e	i	Ω	ω	M
a	1.64389E-6	8.16378E-7	2.53047E-5	-1.52984E-4	2.41059E-4	-1.79145E-3
e	8.16378E-7	4.05424E-7	1.25666E-5	-7.59735E-5	1.19713E-4	-8.89656E-4
i	2.53047E-5	1.25666E-5	3.89536E-4	-2.35504E-3	3.71086E-3	-2.75761E-2
Ω	-1.52984E-4	-7.59735E-5	-2.35504E-3	1.42381E-2	-2.24351E-2	1.66716E-1
ω	2.41059E-4	1.19713E-4	3.71086E-3	-2.24351E-2	3.53511E-2	-2.62697E-1
M	-1.79145E-3	-8.89656E-4	-2.75761E-2	1.66716E-1	-2.62697E-1	1.95225E0

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

26.161

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

16 - 30*

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

1646

Unit

Source

[1]

Normalized RMS of residuals

Value

0.50208

Unit

Source

[1]

Astrometry Summary

First Observation
Last Observation
Total Optical Observations (Discarded)

Optical

Value

Unit

Source

First Observation

Value

2021-04-13.434709

Unit

Source

[2]

Last Observation

Value

2021-04-24.42257

Unit

Source

[2]

Total Optical Observations (Discarded)

Value

26 (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 2021GZ9 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
MARS	1966-06-11 07:21	> 1 d	0.0124220	0.0108226	0.0266625
MARS	2003-08-03 05:15	> 1 d	0.0437360	0.0340074	0.0314518
EARTH	2012-03-13 21:15	> 1 d	0.1854060	0.0520613	0.0513569
EARTH	2015-03-25 21:55	> 1 d	0.0987122	0.0391826	0.0359716
EARTH	2018-04-13 19:39	> 1 w	0.0514310	0.0162416	0.0118269
EARTH	2021-04-22 06:41	1.0	0.0409632	0.0406912	0.0000906
EARTH	2024-04-16 17:14	> 1 w	0.0472646	0.0149253	0.0110094
MARS	2026-02-28 22:56	> 1 d	0.0376073	0.0375926	0.0004124
EARTH	2027-03-29 10:22	> 1 w	0.0888567	0.0354712	0.0395599
EARTH	2030-03-16 19:59	> 1 d	0.1713714	0.0478074	0.0610212
MARS	2041-09-01 15:56	> 1 d	0.0147364	0.0089380	0.0476562
MARS	2077-05-27 06:06	> 1 d	0.0119328	0.0088312	0.0326042
EARTH	2094-05-27 10:51	> 1 w	0.1868502	0.0109163	0.1569097
EARTH	2097-05-18 11:58	> 1 w	0.0929652	0.0203236	0.1444345
EARTH	2100-05-09 00:57	> 1 w	0.0397206	0.0306634	0.0507777
EARTH	2103-05-06 19:57	> 1 w	0.0350225	0.0327675	0.0233453
EARTH	2106-05-12 13:55	> 1 mo	0.0480640	0.0278073	0.1721782
EARTH	2109-05-23 01:18	> 1 w	0.1205688	0.0150837	0.3096557

Download as:

Stationary Points

Ecc. an. ast.	Ecc. an. Earth	Distance in au	Classification
14.77976007	118.05647268	0.03454051	MINIMUM
181.82235793	282.57086805	0.59468021	SADDLE
3.77097213	284.34485361	2.02179830	SADDLE
182.77986077	103.34234296	2.59227203	MAXIMUM

Download:

MOID Plots

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