Asteroids

2021HA help

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

Orbital Properties

Epoch

61000.0

MJD

Orbit type

Apollo

Perihelion (q)

0.919

Aphelion (Q)

1.472

Eccentricity (e)

0.231

Inclination (i)

3.2

deg

Orbit period (P)

477.3

Earth MOID

0.00799

U parameter

7.4

Next Earth close approach

Date

2034-09-03

Nominal distance (from Earth center)

0.08941

13375044

Maximum Brightness

23.1

mag

Risk

Object is not in risk list

Physical Properties

Absolute Magnitude (H)

25.6

mag

Diameter

21 - 50*

Taxonomic type

Rotation period (T)

Discovery Information

Discovery Date

2021-04-16

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

1.195205

1-sigma variation

0.000359

Unit

Eccentricity (e)

Value

0.231362

1-sigma variation

0.000333

Unit

Inclination (i)

Value

3.1763

1-sigma variation

0.0036

Unit

Long. of Ascending Node (Ω)

Value

224.2998

1-sigma variation

0.0004

Unit

Arg. of Perihelion (ω)

Value

49.4957

1-sigma variation

0.0053

Unit

Mean Anomaly (M)

Value

140.96911

1-sigma variation

0.54373

Unit

Perihelion distance

Value

0.918680

1-sigma variation

Unit

Aphelion distance

Value

1.471729

1-sigma variation

Unit

Asc. Node-Earth Sep.

Value

-0.026751

1-sigma variation

Unit

Desc. Node-Earth Sep.

Value

0.340289

1-sigma variation

Unit

MOID

Value

0.007992

1-sigma variation

Unit

Orbit Period

Value

477.2674

1-sigma variation

Unit

U parameter

Value

7.4

1-sigma variation

Unit

Covariance Matrix

	a	e	i	Ω	ω	M
a	1.28523E-7	1.19389E-7	1.30615E-6	1.02377E-7	1.90636E-6	-1.94929E-4
e	1.19389E-7	1.10906E-7	1.21333E-6	9.53211E-8	1.77110E-6	-1.81075E-4
i	1.30615E-6	1.21333E-6	1.32745E-5	1.03936E-6	1.93777E-5	-1.98101E-3
Ω	1.02377E-7	9.53211E-8	1.03936E-6	1.47939E-7	1.53704E-6	-1.55323E-4
ω	1.90636E-6	1.77110E-6	1.93777E-5	1.53704E-6	2.83363E-5	-2.89137E-3
M	-1.94929E-4	-1.81075E-4	-1.98101E-3	-1.55323E-4	-2.89137E-3	2.95644E-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

25.55

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

21 - 50*

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

1609

Unit

Source

[1]

Normalized RMS of residuals

Value

0.472775

Unit

Source

[1]

Astrometry Summary

First Observation
Last Observation
Total Optical Observations (Discarded)

Optical

Value

Unit

Source

First Observation

Value

2021-04-06.455465

Unit

Source

[2]

Last Observation

Value

2021-04-22.165625

Unit

Source

[2]

Total Optical Observations (Discarded)

Value

21 (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 2021HA 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	1952-06-18 05:38	> 1 w	0.1051112	0.0981867	0.0024628
EARTH	1965-04-29 20:27	569.5	0.0190086	0.0130328	0.0021194
EARTH	1978-06-21 06:27	> 1 d	0.1053880	0.1031302	0.0007979
EARTH	1991-08-22 10:36	> 1 d	0.0614272	0.0523764	0.0075312
EARTH	2004-09-05 07:58	> 1 d	0.1102950	0.0522370	0.0320443
EARTH	2008-04-17 19:25	> 1 d	0.0976160	0.0095352	0.0353003
EARTH	2021-04-30 09:05	< 1 min	0.0198885	0.0198089	0.0000265
EARTH	2034-09-03 12:30	> 1 d	0.0894066	0.0526222	0.0287198
EARTH	2038-04-23 16:21	> 1 d	0.0353056	0.0077106	0.0387600
EARTH	2051-07-10 21:58	> 1 mo	0.1056330	0.0934948	0.0272365
EARTH	2064-09-06 00:59	> 1 w	0.1184107	0.0524359	0.3330679
EARTH	2068-04-21 13:57	> 1 w	0.0546168	0.0077885	0.3515129
EARTH	2081-05-28 02:11	> 1 mo	0.0852418	0.0300562	0.3595714
EARTH	2094-08-17 10:01	> 1 mo	0.0719464	0.0528974	0.7148050
EARTH	2107-09-08 19:05	> 1 mo	0.1260536	0.0521442	1.7461831
EARTH	2111-04-22 01:51	> 1 mo	0.0721115	0.0075139	1.8015136
EARTH	2124-05-05 19:12	> 1 mo	0.0374742	0.0075803	1.4335304

Download as:

Stationary Points

Ecc. an. ast.	Ecc. an. Earth	Distance in au	Classification
313.62324057	113.77301973	0.00757916	MINIMUM
49.01335473	232.28690265	0.05298016	MINIMUM
3.97553313	176.47794110	0.10630794	SADDLE
181.07485272	352.44101522	0.49071026	SADDLE
0.75052928	352.32555633	1.90200590	SADDLE
180.23900788	171.79056121	2.48745983	MAXIMUM

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MOID Plots

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