Asteroids

2021UA1 help

Last update: 2024-05-01 23:55 UTC

Orbital Properties

Epoch

60400.0

MJD

Orbit type

Apollo

Perihelion (q)

0.646

Aphelion (Q)

1.525

Eccentricity (e)

0.405

Inclination (i)

6.076E-3

deg

Orbit period (P)

413.2

Earth MOID

0.00006

U parameter

6.3

Next Earth close approach

Date

2028-03-31

Nominal distance (from Earth center)

0.11488

17185440

Maximum Brightness

29.8

mag

Risk

Object is in risk list

Object is not in priority list

Physical Properties

Absolute Magnitude (H)

31.7

mag

Diameter

1.2 - 2.7*

Taxonomic type

Rotation period (T)

Discovery Information

Discovery Date

2021-10-25

Observatory

Catalina Sky Survey

Orbit Visualiser

Click the button to start Orbit Visualiser

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

60400.0000

1-sigma variation

Unit

MJD

Semimajor Axis

Value

1.085623

1-sigma variation

0.000052

Unit

Eccentricity (e)

Value

0.404568

1-sigma variation

0.000066

Unit

Inclination (i)

Value

0.0061

1-sigma variation

2.400E-6

Unit

Long. of Ascending Node (Ω)

Value

124.4749

1-sigma variation

0.4701

Unit

Arg. of Perihelion (ω)

Value

164.7024

1-sigma variation

0.4702

Unit

Mean Anomaly (M)

Value

109.02065

1-sigma variation

0.06297

Unit

Perihelion distance

Value

0.646414

1-sigma variation

Unit

Aphelion distance

Value

1.524832

1-sigma variation

Unit

Asc. Node-Earth Sep.

Value

0.424680

1-sigma variation

Unit

Desc. Node-Earth Sep.

Value

-0.345601

1-sigma variation

Unit

MOID

Value

0.000063

1-sigma variation

Unit

Orbit Period

Value

413.1588

1-sigma variation

Unit

U parameter

Value

6.3

1-sigma variation

Unit

Covariance Matrix

	a	e	i	Ω	ω	M
a	2.68236E-9	3.43008E-9	8.35396E-11	1.05870E-5	-1.05924E-5	-3.26136E-6
e	3.43008E-9	4.38856E-9	1.07771E-10	1.37890E-5	-1.37962E-5	-4.17055E-6
i	8.35396E-11	1.07771E-10	5.75912E-12	1.07282E-6	-1.07307E-6	-1.01613E-7
Ω	1.05870E-5	1.37890E-5	1.07282E-6	2.20985E-1	-2.21026E-1	-1.28833E-2
ω	-1.05924E-5	-1.37962E-5	-1.07307E-6	-2.21026E-1	2.21067E-1	1.28900E-2
M	-3.26136E-6	-4.17055E-6	-1.01613E-7	-1.28833E-2	1.28900E-2	3.96534E-3

Date of computation: 2024-04-23 10:08 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

31.711

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

1.2 - 2.7*

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 ODIM	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

0.9

Unit

Source

[1]

Unobserved

Value

919

Unit

Source

[1]

Normalized RMS of residuals

Value

0.729217

Unit

Source

[1]

Astrometry Summary

First Observation
Last Observation
Total Optical Observations (Discarded)

Optical

Value

Unit

Source

First Observation

Value

2021-10-25.255448

Unit

Source

[2]

Last Observation

Value

2021-10-26.116061

Unit

Source

[2]

Total Optical Observations (Discarded)

Value

23 (1)

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

[3]

Last Observation

Value

Unit

Source

[3]

Delay (Discarded)

Value

0 (0)

Unit

Source

[1]

Doppler (Discarded)

Value

0 (0)

Unit

Source

[1]

Total Radar Observations (Discarded)

Value

0 (0)

Unit

Source

[1]

Note: The ASCII file is in a format suitable for Orbfit input.

Sources

No.	Name	Additional
[1]	ESA ODIM	ESA orbit determination and impact monitoring system
[2]	MPC	Minor Planet Center: https://www.minorplanetcenter.net
[3]	JPL Radar Observations	Jet Propulsion Laboratory: https://ssd.jpl.nasa.gov/dat/radar_data_ast.txt

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 2021UA1 from 1950 to 2124

Body	Date in UTC	Time uncert. in min	Nominal distance in au	Min. possibile distance in au	Distance uncert. in au
EARTH	1956-03-18 03:35	> 1 d	0.1569255	0.1237862	0.0425485
EARTH	1957-03-08 09:01	> 1 d	0.1335789	0.1219437	0.0275521
EARTH	1984-10-28 18:06	399.6	0.1228759	0.0977651	0.0083703
EARTH	1985-10-24 05:07	330.0	0.0319529	0.0007683	0.0116635
EARTH	1986-10-28 16:02	> 1 d	0.1902135	0.1568433	0.0111334
EARTH	1994-03-16 17:42	1120.4	0.1443490	0.1295422	0.0060606
EARTH	1995-03-07 04:35	755.8	0.1497601	0.1332845	0.0064608
EARTH	2020-10-30 08:34	27.3	0.1615954	0.1599064	0.0005630
EARTH	2021-10-25 03:06	< 1 min	0.0000630	0.0000630	0.0000000
EARTH	2028-03-31 12:05	149.4	0.1148776	0.1053990	0.0031595
EARTH	2038-10-18 21:53	26.4	0.1906295	0.1755154	0.0050380
VENUS	2041-12-14 08:25	> 1 d	0.0466617	0.0347675	0.0040679
EARTH	2045-03-24 02:19	185.8	0.0735327	0.0639921	0.0031802
EARTH	2047-10-30 13:12	98.9	0.1141356	0.1105368	0.0011996
EARTH	2064-10-22 20:30	564.0	0.0541406	0.0233080	0.0102776
EARTH	2071-03-29 16:59	283.9	0.0474195	0.0305087	0.0056370
EARTH	2088-03-20 08:50	1378.7	0.1581570	0.0871386	0.0236729
EARTH	2090-10-26 19:21	> 1 d	0.0279683	0.0003223	0.0264845
EARTH	2105-03-20 08:21	> 1 d	0.1979373	0.0001720	0.1021364
EARTH	2107-10-27 20:06	> 1 d	0.0205724	0.0003658	0.1150024
EARTH	2122-03-29 18:10	> 1 mo	0.0076412	0.0002706	0.8615108

Download as:

2021UA1

Date in UTC	MJD	σ	Distance ± Width in RE	Stretching in RE/σ	IP	Exp. energy	PS
2071-03-27.350	77562.350	-3.637	1.02 ± 0.008	2.51E3	3.58E-7	5.19E-11	-9.67
2076-10-24.940	79600.940	-4.571	0.72 ± 0.000	1.16E6	2.27E-11	3.29E-15	-13.92
2079-03-27.416	80484.416	-3.604	1.26 ± 0.008	4.26E5	1.10E-9	1.60E-13	-12.25
2079-10-19.250	80690.250	-3.627	0.80 ± 0.029	4.76E6	2.48E-10	3.59E-14	-12.91
2080-03-26.516	80849.516	-3.992	0.91 ± 0.008	3.97E3	6.71E-8	9.73E-12	-10.47
2080-03-26.568	80849.568	-4.052	0.92 ± 0.008	1.02E4	2.03E-8	2.94E-12	-10.99
2080-03-26.615	80849.615	-3.815	1.09 ± 0.008	9.48E3	5.30E-8	7.69E-12	-10.58
2081-03-26.790	81214.790	-3.667	1.26 ± 0.008	7.09E5	5.71E-10	8.29E-14	-12.55
2084-10-29.324	82527.324	4.578	0.22 ± 0.032	2.71E5	1.08E-10	1.57E-14	-13.30
2087-10-26.112	83619.112	-4.876	0.07 ± 0.001	2.62E5	2.77E-11	4.01E-15	-13.92
2088-03-26.539	83771.539	-3.974	1.17 ± 0.008	8.16E5	4.01E-10	5.82E-14	-12.75
2088-10-22.627	83981.627	4.254	0.14 ± 0.004	2.84E5	4.36E-10	6.34E-14	-12.72
2091-03-27.314	84867.314	-4.047	0.92 ± 0.008	5.24E6	4.05E-11	5.88E-15	-13.77
2094-03-28.389	85964.389	4.256	1.11 ± 0.008	4.30E5	1.54E-10	2.24E-14	-13.21
2095-10-30.123	86545.123	4.548	0.86 ± 0.028	2.10E6	1.22E-11	1.78E-15	-14.32
2096-03-26.637	86693.637	-3.997	0.75 ± 0.008	1.58E7	1.88E-11	2.73E-15	-14.13
2098-10-27.782	87638.782	3.077	0.45 ± 0.015	2.83E7	3.08E-10	4.48E-14	-12.93
2099-03-26.259	87788.259	-4.352	0.82 ± 0.009	5.29E5	1.47E-10	2.14E-14	-13.26
2101-10-22.032	88728.032	4.338	0.87 ± 0.014	1.09E6	6.10E-11	8.86E-15	-13.66
2104-10-22.379	89824.379	3.046	1.14 ± 0.006	1.55E6	5.10E-9	7.41E-13	-11.75
2106-03-24.735	90342.735	3.527	1.21 ± 0.009	3.32E7	6.07E-11	8.84E-15	-13.68
2106-03-28.040	90346.040	-3.926	0.56 ± 0.008	5.49E4	7.84E-9	1.14E-12	-11.57
2106-03-28.087	90346.087	-3.850	0.50 ± 0.008	8.45E4	6.98E-9	1.01E-12	-11.62
2108-03-27.803	91076.803	-3.709	0.53 ± 0.008	2.29E5	4.40E-9	6.38E-13	-11.83
2110-03-28.280	91807.280	-2.243	1.28 ± 0.000	3.95E7	1.88E-9	2.72E-13	-12.21
2111-10-31.788	92389.788	-2.729	1.00 ± 0.033	1.75E6	9.66E-9	1.40E-12	-11.51
2112-03-28.597	92538.597	3.942	1.32 ± 0.007	5.24E5	8.42E-10	1.22E-13	-12.57
2112-03-30.288	92540.288	-0.980	0.95 ± 0.007	4.27E5	1.07E-6	1.55E-10	-9.46
2112-10-24.132	92748.132	4.249	0.86 ± 0.004	7.98E5	1.21E-10	1.76E-14	-13.41
2112-10-25.638	92749.638	-1.047	0.31 ± 0.000	6.93E7	8.80E-9	1.28E-12	-11.55
2112-11-02.289	92757.289	-3.647	0.66 ± 0.059	3.90E6	3.02E-10	4.38E-14	-13.02
2113-10-24.354	93113.354	3.063	0.42 ± 0.003	7.03E6	1.32E-9	1.91E-13	-12.38
2114-03-28.234	93268.234	-3.514	1.00 ± 0.008	1.03E5	1.41E-8	2.05E-12	-11.35
2114-10-23.712	93477.712	-2.608	1.02 ± 0.005	1.07E6	2.34E-8	3.40E-12	-11.14
2114-10-23.743	93477.743	-2.390	0.99 ± 0.006	7.81E5	5.41E-8	7.87E-12	-10.77
2114-10-25.721	93479.721	3.079	0.88 ± 0.002	9.85E6	6.99E-10	1.02E-13	-12.66
2115-03-28.921	93633.921	-1.998	0.42 ± 0.007	2.00E5	6.97E-7	1.01E-10	-9.66
2115-03-29.432	93634.432	-1.638	0.51 ± 0.007	6.42E6	4.23E-8	6.15E-12	-10.88
2115-03-29.492	93634.492	-1.581	0.52 ± 0.007	1.85E7	1.51E-8	2.19E-12	-11.33
2115-03-29.595	93634.595	-1.932	0.96 ± 0.007	1.06E7	1.05E-8	1.53E-12	-11.48
2115-10-23.210	93842.210	-1.679	1.16 ± 0.012	3.39E6	6.66E-8	9.69E-12	-10.69
2115-10-27.160	93846.160	0.129	0.38 ± 0.000	6.30E5	1.62E-6	2.34E-10	-9.30
2116-10-24.986	94209.986	-3.859	0.30 ± 0.001	7.74E6	7.77E-11	1.13E-14	-13.62
2117-03-28.228	94364.228	-3.707	1.03 ± 0.008	1.82E6	3.80E-10	5.51E-14	-12.94
2119-10-20.946	95300.946	-2.305	0.85 ± 0.021	7.56E6	9.73E-9	1.41E-12	-11.54
2119-10-23.954	95303.954	3.047	1.07 ± 0.009	2.28E7	4.28E-10	6.22E-14	-12.90
2119-10-26.855	95306.855	-1.064	0.04 ± 0.000	1.03E7	5.81E-8	8.44E-12	-10.76
2120-03-28.509	95460.509	3.954	0.80 ± 0.007	3.62E5	9.38E-10	1.36E-13	-12.56
2122-03-28.704	96190.704	3.398	0.48 ± 0.008	1.55E4	2.03E-7	2.95E-11	-10.23


Based on 23 optical observations (of which 1 are rejected as outliers) from 2021/10/25.255 to 2021/10/26.116.
Coordinates are given on the Target Plane.
Unit is one Earth radius, but impact cross section has radius between 1.32 and 1.32 Earth radii.
Coordinates for LOV = EQU scaled= 1 second= F.
AstOD software version= 4.0, Date of computation=20240110 090430.550 UTC.

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