Asteroids

2021GX9

Last update: 2023-03-21 02:34 UTC

Orbital Properties

Epoch

60000.0

MJD

Orbit type

Apollo

Perihelion (q)

0.746

Aphelion (Q)

3.180

Eccentricity (e)

0.620

Inclination (i)

4.1

deg

Orbit period (P)

1004.4

Earth MOID

0.00066

U parameter

7.0

Next Earth close approach

Date

2032-04-22

Nominal distance (from Earth center)

0.06822

10205232

Maximum Brightness

23.3

mag

Risk

Object is in risk list

Object is not in priority list

Physical Properties

Absolute Magnitude (H)

25.4

mag

Diameter

30*

Taxonomic type

Rotation period (T)

Discovery Information

Discovery Date

2021-04-14

Observatory

Pan-STARRS 1, Haleakala

Orbit Visualiser

Click the button to start Orbit Visualiser

External links

Proper elements

Epoch

Near present day

Near middle of observation arc

Orbit properties

Epoch
Semimajor Axis
Eccentricity (e)
Inclination (i)
Ascending Node (Ω)
Arg. of Perihelion (ω)
Mean Anomaly (M)
Perihelion
Aphelion
Asc. Node-Earth Sep.
Desc. Node-Earth Sep.
MOID
Orbit Period
U parameter

Value

1-sigma variation

Unit

Epoch

Value

60000.0000

1-sigma variation

Unit

MJD

Semimajor Axis

Value

1.962731

1-sigma variation

0.000707

Unit

Eccentricity (e)

Value

0.620007

1-sigma variation

0.000160

Unit

Inclination (i)

Value

4.1412

1-sigma variation

0.0009

Unit

Ascending Node (Ω)

Value

207.5729

1-sigma variation

0.0002

Unit

Arg. of Perihelion (ω)

Value

70.2765

1-sigma variation

0.0006

Unit

Mean Anomaly (M)

Value

226.95908

1-sigma variation

0.12121

Unit

Perihelion

Value

0.745823

1-sigma variation

Unit

Aphelion

Value

3.179639

1-sigma variation

Unit

Asc. Node-Earth Sep.

Value

-0.004633

1-sigma variation

Unit

Desc. Node-Earth Sep.

Value

0.531358

1-sigma variation

Unit

MOID

Value

0.000663

1-sigma variation

Unit

Orbit Period

Value

1004.3604

1-sigma variation

Unit

U parameter

Value

7.0

1-sigma variation

Unit

Covariance Matrix

	a	e	i	Ω	ω	M
a	4.99715E-7	1.12841E-7	6.25067E-7	-1.35558E-7	3.97156E-7	-8.56815E-5
e	1.12841E-7	2.54809E-8	1.41148E-7	-3.06106E-8	8.97018E-8	-1.93479E-5
i	6.25067E-7	1.41148E-7	7.82005E-7	-1.69644E-7	4.97164E-7	-1.07175E-4
Ω	-1.35558E-7	-3.06106E-8	-1.69644E-7	3.68409E-8	-1.07824E-7	2.32429E-5
ω	3.97156E-7	8.97018E-8	4.97164E-7	-1.07824E-7	3.20911E-7	-6.80972E-5
M	-8.56815E-5	-1.93479E-5	-1.07175E-4	2.32429E-5	-6.80972E-5	1.46910E-2

Date of computation: 2022-11-23 04:56 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

25.376

Unit

mag

Source

[1]

Slope Parameter (G)

Value

0.15**

Unit

mag

Source

[1]

Albedo
Diameter

Size and albedo

Value

Unit

Source

Albedo

Value

Unit

Source

[-]

Diameter

Value

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

[-]

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Sources

No.	Name	Additional
[1]	ESA ODIM	ESA orbit determination and impact monitoring system
[2]	Estimation	Estimated from absolute magnitude

Observational Information

Arc Length
Unobserved

Arc Information

Value

Unit

Source

Arc Length

Value

Unit

Source

[1]

Unobserved

Value

702

Unit

Source

[1]

Astrometry Summary

RMS of Residuals
First Observation
Last Observation
Total Optical Observations (Discarded)

Optical

Value

Unit

Source

RMS of Residuals

Value

0.824218

Unit

arcsec

Source

[1]

First Observation

Value

2021-04-03.362502

Unit

Source

[2]

Last Observation

Value

2021-04-17.891717

Unit

Source

[2]

Total Optical Observations (Discarded)

Value

44 (2)

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

[3]

Last Observation

Value

Unit

Source

[3]

Delay (Discarded)

Value

0 (0)

Unit

Source

[1]

Doppler (Discarded)

Value

0 (0)

Unit

Source

[1]

Total Radar Observations (Discarded)

Value

0 (0)

Unit

Source

[1]

Note: The ASCII file is in a format suitable for Orbfit input.

Sources

No.	Name	Additional
[1]	ESA ODIM	ESA orbit determination and impact monitoring system
[2]	MPC	Minor Planet Center: https://www.minorplanetcenter.net
[3]	JPL Radar Observations	Jet Propulsion Laboratory: https://ssd.jpl.nasa.gov/dat/radar_data_ast.txt

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 2021GX9 from 1950 to 2123

Body	Date in UTC	Time uncert. in min	Nominal distance in au	Min. possibile distance in au	Distance uncert. in au
EARTH	1958-04-22 00:53	> 1 d	0.0625029	0.0199479	0.0142383
EARTH	1969-04-05 00:54	> 1 d	0.1818305	0.0522873	0.0432252
EARTH	1977-09-20 16:39	> 1 d	0.1373990	0.0460877	0.0621206
EARTH	1988-08-30 11:36	> 1 w	0.1311385	0.0452259	0.0660246
EARTH	2021-04-18 06:36	< 1 s	0.0156897	0.0156787	0.0000037
EARTH	2032-04-22 19:08	> 1 d	0.0682178	0.0007209	0.0329581
EARTH	2043-04-24 06:44	> 1 d	0.0783553	0.0011474	0.0277153
EARTH	2054-04-27 18:47	672.7	0.1067785	0.0954141	0.0037882
EARTH	2109-09-01 01:27	> 1 w	0.1397317	0.0383073	0.0471905
EARTH	2120-09-07 17:24	> 1 d	0.0921609	0.0393928	0.0291142

Download as:

2021GX9

Date in UTC	MJD	σ	σ_imp	Distance ± Width in RE	Stretching in RE/σ	IP	Exp. energy	PS	TS
2032-04-16.911	63338.911	-1.982	0.000	1.14 ± 0.000	8.45E2	5.03E-5	7.64E-5	-3.63	0


Based on 44 optical observations (of which 2 are rejected as outliers) from 2021/04/03.363 to 2021/04/17.892.
Coordinates are given on the Target Plane.
Unit is one Earth radius, but impact cross section has radius between 1.20 and 1.20 Earth radii.
Coordinates for LOV = EQU scaled= 1 second= F.
Aegis software version= 4.0, Date of computation=20220728 154020.010 UTC.

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Download Impactor Table as: