Asteroids

2021GR18 help

Last update: 2025-02-19 13:28 UTC

Orbital Properties

Epoch

60800.0

MJD

Orbit type

Apollo

Perihelion (q)

0.980

Aphelion (Q)

2.233

Eccentricity (e)

0.390

Inclination (i)

12.2

deg

Orbit period (P)

743.9

Earth MOID

0.10572

U parameter

7.6

Next Earth close approach

Date

2078-08-14

Nominal distance (from Earth center)

0.11414

17075020

Maximum Brightness

20.1

mag

Risk

Object is not in risk list

Object is not in priority list

Physical Properties

Absolute Magnitude (H)

22.9

mag

Diameter

70 - 160*

Taxonomic type

Rotation period (T)

Discovery Information

Discovery Date

2021-04-15

Observatory

Mt. Lemmon Survey

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

60800.0000

1-sigma variation

Unit

MJD

Semimajor Axis

Value

1.606706

1-sigma variation

0.000906

Unit

Eccentricity (e)

Value

0.389950

1-sigma variation

0.000334

Unit

Inclination (i)

Value

12.2143

1-sigma variation

0.0090

Unit

Long. of Ascending Node (Ω)

Value

160.5821

1-sigma variation

0.0099

Unit

Arg. of Perihelion (ω)

Value

110.4205

1-sigma variation

0.0087

Unit

Mean Anomaly (M)

Value

326.81185

1-sigma variation

0.56002

Unit

Perihelion distance

Value

0.980171

1-sigma variation

Unit

Aphelion distance

Value

2.233240

1-sigma variation

Unit

Asc. Node-Earth Sep.

Value

0.585861

1-sigma variation

Unit

Desc. Node-Earth Sep.

Value

0.190803

1-sigma variation

Unit

MOID

Value

0.105718

1-sigma variation

Unit

Orbit Period

Value

743.8801

1-sigma variation

Unit

U parameter

Value

7.6

1-sigma variation

Unit

Covariance Matrix

	a	e	i	Ω	ω	M
a	8.21133E-7	3.02437E-7	8.11035E-6	8.95952E-6	-7.83035E-6	-5.07471E-4
e	3.02437E-7	1.11394E-7	2.98701E-6	3.29908E-6	-2.88281E-6	-1.86910E-4
i	8.11035E-6	2.98701E-6	8.01332E-5	8.86238E-5	-7.75070E-5	-5.01230E-3
Ω	8.95952E-6	3.29908E-6	8.86238E-5	9.84159E-5	-8.63032E-5	-5.53704E-3
ω	-7.83035E-6	-2.88281E-6	-7.75070E-5	-8.63032E-5	7.58518E-5	4.83915E-3
M	-5.07471E-4	-1.86910E-4	-5.01230E-3	-5.53704E-3	4.83915E-3	3.13624E-1

Date of computation: 2025-02-19 13:28 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

22.889

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

70 - 160*

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

1462

Unit

Source

[1]

Normalized RMS of residuals

Value

0.568409

Unit

Source

[1]

Astrometry Summary

First Observation
Last Observation
Total Optical Observations (Discarded)

Optical

Value

Unit

Source

First Observation

Value

2021-04-05.40917

Unit

Source

[2]

Last Observation

Value

2021-05-10.335882

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 2021GR18 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	1968-07-31 12:30	> 1 w	0.1599560	0.0901838	0.1875415
EARTH	1970-08-17 14:28	> 1 w	0.1549555	0.1041342	0.1847816
EARTH	2023-08-10 13:40	987.5	0.1084452	0.1063232	0.0018663
EARTH	2078-08-14 21:47	> 1 w	0.1141395	0.1030318	0.1221262

Download as:

Stationary Points

Ecc. an. ast.	Ecc. an. Earth	Distance in au	Classification
32.32609599	217.37250567	0.10632448	MINIMUM
329.42934393	123.03153303	0.20931673	MINIMUM
345.96117292	147.52395481	0.21458097	SADDLE
178.68445587	348.75677596	1.28458379	SADDLE
359.47895443	348.56112432	1.95420010	SADDLE
180.82942205	170.19486660	3.23554464	MAXIMUM

Download:

MOID Plots

Click on the images to zoom-in and zoom-out