Asteroids

2021QA2 help

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

Orbital Properties

Epoch

61000.0

MJD

Orbit type

Apollo

Perihelion (q)

0.881

Aphelion (Q)

3.250

Eccentricity (e)

0.574

Inclination (i)

7.1

deg

Orbit period (P)

1084.4

Earth MOID

0.00407

U parameter

7.1

Next Earth close approach

Date

2098-12-13

Nominal distance (from Earth center)

0.13382

20018730

Maximum Brightness

23.6

mag

Risk

Object is not in risk list

Physical Properties

Absolute Magnitude (H)

mag

Diameter

40 - 100*

Taxonomic type

Rotation period (T)

Discovery Information

Discovery Date

2021-08-29

Observatory

Pan-STARRS 2, 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

2.065609

1-sigma variation

0.000747

Unit

Eccentricity (e)

Value

0.573601

1-sigma variation

0.000166

Unit

Inclination (i)

Value

7.1024

1-sigma variation

0.0015

Unit

Long. of Ascending Node (Ω)

Value

180.6878

1-sigma variation

0.0004

Unit

Arg. of Perihelion (ω)

Value

226.4796

1-sigma variation

0.0002

Unit

Mean Anomaly (M)

Value

133.48328

1-sigma variation

0.27761

Unit

Perihelion distance

Value

0.880774

1-sigma variation

Unit

Aphelion distance

Value

3.250444

1-sigma variation

Unit

Asc. Node-Earth Sep.

Value

1.293580

1-sigma variation

Unit

Desc. Node-Earth Sep.

Value

-0.010227

1-sigma variation

Unit

MOID

Value

0.004066

1-sigma variation

Unit

Orbit Period

Value

1084.3526

1-sigma variation

Unit

U parameter

Value

7.1

1-sigma variation

Unit

Covariance Matrix

	a	e	i	Ω	ω	M
a	5.58386E-7	1.24106E-7	1.15807E-6	2.61382E-7	-1.36141E-7	-2.07445E-4
e	1.24106E-7	2.75836E-8	2.57396E-7	5.80835E-8	-3.02234E-8	-4.61063E-5
i	1.15807E-6	2.57396E-7	2.40214E-6	5.41351E-7	-2.80165E-7	-4.30234E-4
Ω	2.61382E-7	5.80835E-8	5.41351E-7	1.24087E-7	-6.86732E-8	-9.71052E-5
ω	-1.36141E-7	-3.02234E-8	-2.80165E-7	-6.86732E-8	4.87073E-8	5.05761E-5
M	-2.07445E-4	-4.61063E-5	-4.30234E-4	-9.71052E-5	5.05761E-5	7.70675E-2

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

23.961

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

40 - 100*

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

1507

Unit

Source

[1]

Normalized RMS of residuals

Value

0.399099

Unit

Source

[1]

Astrometry Summary

First Observation
Last Observation
Total Optical Observations (Discarded)

Optical

Value

Unit

Source

First Observation

Value

2021-08-29.335803

Unit

Source

[2]

Last Observation

Value

2021-09-15.894918

Unit

Source

[2]

Total Optical Observations (Discarded)

Value

103 (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 2021QA2 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	2009-12-26 07:16	> 1 d	0.1266253	0.1219274	0.0099098
EARTH	2012-12-05 02:11	> 1 d	0.1322922	0.1267569	0.0052613
EARTH	2015-11-04 18:55	> 1 d	0.1319879	0.1200770	0.0044119
EARTH	2018-10-08 20:47	> 1 d	0.0840299	0.0628770	0.0071076
EARTH	2021-09-18 23:15	< 1 min	0.0272471	0.0272258	0.0000071
EARTH	2024-09-04 11:57	902.4	0.1995097	0.1679385	0.0105284
EARTH	2098-12-13 04:41	> 1 mo	0.1338169	0.1243934	0.0469901
EARTH	2101-10-18 07:26	> 1 mo	0.1214159	0.0474199	0.0897085
EARTH	2104-09-11 06:52	> 1 w	0.0955279	0.0114151	0.1617342

Download as:

Stationary Points

Ecc. an. ast.	Ecc. an. Earth	Distance in au	Classification
333.83595406	257.73545959	0.00385203	MINIMUM
23.17527739	348.12550522	0.12159582	MINIMUM
4.69220125	314.47708131	0.14111619	SADDLE
359.06290814	123.80459829	1.88776626	SADDLE
179.94185611	124.43989495	2.24718139	SADDLE
179.51735531	304.22265302	4.23805681	MAXIMUM

Download:

MOID Plots

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