Asteroids

2021TP21 help

Last update: 2025-07-29 02:36 UTC

Orbital Properties

Epoch

60800.0

MJD

Orbit type

Apollo

Perihelion (q)

0.812

Aphelion (Q)

4.225

Eccentricity (e)

0.678

Inclination (i)

25.4

deg

Orbit period (P)

1460.0

Earth MOID

0.03389

U parameter

6.1

Next Earth close approach

Date

2101-03-19

Nominal distance (from Earth center)

0.12608

18861784

Maximum Brightness

mag

Risk

Object is not in risk list

Physical Properties

Absolute Magnitude (H)

20.1

mag

Diameter

260 - 600*

Taxonomic type

Rotation period (T)

Discovery Information

Discovery Date

2021-10-11

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

2.518604

1-sigma variation

0.000344

Unit

Eccentricity (e)

Value

0.677556

1-sigma variation

0.000040

Unit

Inclination (i)

Value

25.4170

1-sigma variation

0.0008

Unit

Long. of Ascending Node (Ω)

Value

8.0533

1-sigma variation

0.0009

Unit

Arg. of Perihelion (ω)

Value

116.3126

1-sigma variation

0.0026

Unit

Mean Anomaly (M)

Value

304.42274

1-sigma variation

0.06205

Unit

Perihelion distance

Value

0.812109

1-sigma variation

Unit

Aphelion distance

Value

4.225100

1-sigma variation

Unit

Asc. Node-Earth Sep.

Value

0.946257

1-sigma variation

Unit

Desc. Node-Earth Sep.

Value

0.049180

1-sigma variation

Unit

MOID

Value

0.033887

1-sigma variation

Unit

Orbit Period

Value

1459.9511

1-sigma variation

Unit

U parameter

Value

6.1

1-sigma variation

Unit

Covariance Matrix

	a	e	i	Ω	ω	M
a	1.18089E-7	1.36312E-8	2.85123E-7	3.16702E-7	-8.80687E-7	-2.13228E-5
e	1.36312E-8	1.57372E-9	3.29115E-8	3.65586E-8	-1.01597E-7	-2.46134E-6
i	2.85123E-7	3.29115E-8	6.89449E-7	7.66272E-7	-2.12749E-6	-5.14837E-5
Ω	3.16702E-7	3.65586E-8	7.66272E-7	8.52245E-7	-2.36364E-6	-5.71858E-5
ω	-8.80687E-7	-1.01597E-7	-2.12749E-6	-2.36364E-6	6.58697E-6	1.59021E-4
M	-2.13228E-5	-2.46134E-6	-5.14837E-5	-5.71858E-5	1.59021E-4	3.85018E-3

Date of computation: 2025-07-29 02:36 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

20.084

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

260 - 600*

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

1378

Unit

Source

[1]

Normalized RMS of residuals

Value

0.585977

Unit

Source

[1]

Astrometry Summary

First Observation
Last Observation
Total Optical Observations (Discarded)

Optical

Value

Unit

Source

First Observation

Value

2021-09-08.527698

Unit

Source

[2]

Last Observation

Value

2021-11-04.47259

Unit

Source

[2]

Total Optical Observations (Discarded)

Value

58 (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 2021TP21 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	2101-03-19 12:57	> 1 w	0.1260832	0.0258119	0.0917207

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Stationary Points

Ecc. an. ast.	Ecc. an. Earth	Distance in au	Classification
28.67477138	82.01731225	0.03388727	MINIMUM
324.71329354	307.98783355	0.34827016	MINIMUM
349.32371606	358.34454206	0.42453108	SADDLE
357.95536758	199.12461596	1.79067573	SADDLE
178.59356608	203.96173706	3.31205610	SADDLE
181.05885424	25.10901710	5.14860680	MAXIMUM

Download:

MOID Plots

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