Asteroids

2021TT4 help

Last update: 2025-04-09 07:59 UTC

Orbital Properties

Epoch

60800.0

MJD

Orbit type

Apollo

Perihelion (q)

0.934

Aphelion (Q)

1.140

Eccentricity (e)

0.099

Inclination (i)

3.3

deg

Orbit period (P)

385.7

Earth MOID

0.01150

U parameter

5.7

Next Earth close approach

Date

2040-10-15

Nominal distance (from Earth center)

0.01724

2578997

Maximum Brightness

21.6

mag

Risk

Object is not in risk list

Object is not in priority list

Physical Properties

Absolute Magnitude (H)

mag

Diameter

7 - 15*

Taxonomic type

Rotation period (T)

Discovery Information

Discovery Date

2021-10-04

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

60800.0000

1-sigma variation

Unit

MJD

Semimajor Axis

Value

1.036939

1-sigma variation

0.000020

Unit

Eccentricity (e)

Value

0.099383

1-sigma variation

0.000027

Unit

Inclination (i)

Value

3.3326

1-sigma variation

0.0012

Unit

Long. of Ascending Node (Ω)

Value

192.4283

1-sigma variation

0.0012

Unit

Arg. of Perihelion (ω)

Value

265.9556

1-sigma variation

0.0052

Unit

Mean Anomaly (M)

Value

66.58464

1-sigma variation

0.02993

Unit

Perihelion distance

Value

0.933885

1-sigma variation

Unit

Aphelion distance

Value

1.139994

1-sigma variation

Unit

Asc. Node-Earth Sep.

Value

0.034184

1-sigma variation

Unit

Desc. Node-Earth Sep.

Value

0.019900

1-sigma variation

Unit

MOID

Value

0.011499

1-sigma variation

Unit

Orbit Period

Value

385.6811

1-sigma variation

Unit

U parameter

Value

5.7

1-sigma variation

Unit

Covariance Matrix

	a	e	i	Ω	ω	M
a	4.12663E-10	5.51360E-10	2.50296E-8	2.47288E-8	-1.04796E-7	-6.07919E-7
e	5.51360E-10	7.39802E-10	3.35151E-8	3.31248E-8	-1.39227E-7	-8.12680E-7
i	2.50296E-8	3.35151E-8	1.52004E-6	1.50197E-6	-6.33754E-6	-3.68831E-5
Ω	2.47288E-8	3.31248E-8	1.50197E-6	1.48424E-6	-6.25840E-6	-3.64415E-5
ω	-1.04796E-7	-1.39227E-7	-6.33754E-6	-6.25840E-6	2.68138E-5	1.54269E-4
M	-6.07919E-7	-8.12680E-7	-3.68831E-5	-3.64415E-5	1.54269E-4	8.95625E-4

Date of computation: 2025-04-09 07:59 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

28.022

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

7 - 15*

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 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

1365

Unit

Source

[1]

Normalized RMS of residuals

Value

1.00695

Unit

Source

[1]

Astrometry Summary

First Observation
Last Observation
Total Optical Observations (Discarded)

Optical

Value

Unit

Source

First Observation

Value

2021-10-02.54483

Unit

Source

[2]

Last Observation

Value

2021-10-10.449325

Unit

Source

[2]

Total Optical Observations (Discarded)

Value

26 (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

[-]

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 2021TT4 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	1954-10-09 22:30	> 1 d	0.0802436	0.0075358	0.0381738
EARTH	1955-06-15 12:05	> 1 mo	0.1400072	0.1298437	0.0038145
EARTH	1956-03-15 18:32	> 1 d	0.1369336	0.0346438	0.0368115
EARTH	1971-10-10 03:19	1041.7	0.0852668	0.0342131	0.0171030
EARTH	1972-06-18 02:35	> 1 w	0.1400317	0.1362025	0.0013582
EARTH	1973-03-16 11:41	627.1	0.1240679	0.0739367	0.0169749
EARTH	1988-10-04 22:50	214.8	0.1761516	0.1690962	0.0023522
EARTH	1989-07-19 16:20	> 1 d	0.1367575	0.1346031	0.0007185
EARTH	1990-03-13 21:57	131.1	0.0430904	0.0342801	0.0032214
EARTH	2005-09-28 22:09	> 1 d	0.0798095	0.0734169	0.0021465
EARTH	2005-12-13 12:23	> 1 d	0.0706736	0.0687008	0.0006660
EARTH	2006-04-09 21:42	> 1 d	0.0830826	0.0780897	0.0016951
EARTH	2021-10-14 20:31	< 1 min	0.0130482	0.0130353	0.0000043
EARTH	2022-06-03 22:25	109.9	0.1292050	0.1290797	0.0000418
EARTH	2023-03-22 23:35	1.0	0.1500440	0.1495223	0.0001739
EARTH	2040-10-15 10:21	342.1	0.0172395	0.0112689	0.0026880
EARTH	2041-05-18 11:27	> 1 d	0.1243953	0.1195908	0.0016108
EARTH	2057-10-10 21:25	484.1	0.0544943	0.0347829	0.0066416
EARTH	2058-06-15 12:05	> 1 d	0.1383529	0.1363907	0.0006640
EARTH	2059-03-19 02:01	442.3	0.1254600	0.1192917	0.0020649
EARTH	2075-10-15 04:56	> 1 d	0.0144527	0.0108986	0.0251683
EARTH	2076-05-16 16:57	> 1 mo	0.1275017	0.0983814	0.0225867
EARTH	2091-10-06 02:38	> 1 mo	0.1341633	0.0083101	0.9967094
EARTH	2092-07-02 08:20	> 1 mo	0.1452278	0.0079093	0.0459796
EARTH	2093-03-13 03:44	> 1 mo	0.0845673	0.0200648	0.9810170
EARTH	2107-10-04 13:58	> 1 mo	0.1968216	0.0086266	1.8621248
EARTH	2108-07-21 18:46	> 1 mo	0.1399105	0.0505261	0.3902873
EARTH	2109-03-11 19:21	> 1 mo	0.0371661	0.0213705	1.6707469
EARTH	2123-08-19 16:54	> 1 mo	0.1212019	0.0616049	5.3579861
EARTH	2124-03-09 16:52	> 1 mo	0.0363057	0.0214646	10.5126659

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Stationary Points

Ecc. an. ast.	Ecc. an. Earth	Distance in au	Classification
288.99724204	280.95738612	0.01176012	MINIMUM
72.53223276	73.65331295	0.01949920	MINIMUM
1.41438322	358.09543305	0.07394075	SADDLE
180.53620395	176.93582844	0.13810956	SADDLE
359.30626158	175.80644154	1.94970363	SADDLE
179.31009120	355.80935209	2.12167091	MAXIMUM

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MOID Plots

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