Asteroids

1998WB2 help

Last update: 2025-03-31 10:04 UTC

Orbital Properties

Epoch

60800.0

MJD

Orbit type

Apollo

Perihelion (q)

0.816

Aphelion (Q)

3.130

Eccentricity (e)

0.587

Inclination (i)

2.4

deg

Orbit period (P)

1012.0

Earth MOID

0.01468

U parameter

0.0

Next Earth close approach

Date

2035-03-16

Nominal distance (from Earth center)

0.09978

14926728

Maximum Brightness

21.7

mag

Risk

Object is not in risk list

Object is not in priority list

Physical Properties

Absolute Magnitude (H)

21.8

mag

Diameter

150

Taxonomic type

Rotation period (T)

0.3130

Discovery Information

Discovery Date

1998-11-18

Observatory

Lincoln Laboratory ETS, New Mexico

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

1.972649

1-sigma variation

1.270E-9

Unit

Eccentricity (e)

Value

0.586512

1-sigma variation

5.446E-9

Unit

Inclination (i)

Value

2.3725

1-sigma variation

2.606E-6

Unit

Long. of Ascending Node (Ω)

Value

52.1319

1-sigma variation

2.217E-5

Unit

Arg. of Perihelion (ω)

Value

78.8334

1-sigma variation

2.176E-5

Unit

Mean Anomaly (M)

Value

170.14208

1-sigma variation

3.460E-7

Unit

Perihelion distance

Value

0.815666

1-sigma variation

Unit

Aphelion distance

Value

3.129633

1-sigma variation

Unit

Asc. Node-Earth Sep.

Value

0.173477

1-sigma variation

Unit

Desc. Node-Earth Sep.

Value

0.448410

1-sigma variation

Unit

MOID

Value

0.014676

1-sigma variation

Unit

Orbit Period

Value

1011.9832

1-sigma variation

Unit

U parameter

Value

0.0

1-sigma variation

Unit

Covariance Matrix

	a	e	i	Ω	ω	M
a	1.61223E-18	3.42392E-18	1.53156E-15	-1.44490E-14	1.47450E-14	-3.21458E-16
e	3.42392E-18	2.96640E-17	4.14363E-15	6.76474E-16	7.52609E-15	-1.67213E-15
i	1.53156E-15	4.14363E-15	6.78869E-12	2.47441E-11	-2.40488E-11	-4.44578E-13
Ω	-1.44490E-14	6.76474E-16	2.47441E-11	4.91602E-10	-4.81288E-10	6.89127E-13
ω	1.47450E-14	7.52609E-15	-2.40488E-11	-4.81288E-10	4.73695E-10	-1.11182E-12
M	-3.21458E-16	-1.67213E-15	-4.44578E-13	6.89127E-13	-1.11182E-12	1.19700E-13

Date of computation: 2025-03-31 10:04 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

0.3130

Unit

Source

[3]

Quality

Value

Unit

Source

[3]

Amplitude

Value

0.6

Unit

mag

Source

[3]

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

[1]

Taxonomy (all)

Value

Unit

Source

[2]

Absolute Magnitude (H)
Slope Parameter (G)

H / G

Value

Unit

Source

Absolute Magnitude (H)

Value

21.767

22.1

Unit

mag

Source

[4]

[1]

Slope Parameter (G)

Value

0.15**

Unit

mag

Source

[4]

Albedo
Diameter

Size and albedo

Value

Unit

Source

Albedo

Value

0.151

Unit

Source

[5]

Diameter

Value

150

Unit

Source

[5]

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]	EARN	1.) Pravec, P. et al. (2000) Icarus 147, 477-486. (Fast rotating asteroids 1999 TY2, 1999 SF10, and 1998 WB2)
[2]	EARN	1.) Pravec, P. et al. (2000) Icarus 147, 477-486. (Fast rotating asteroids 1999 TY2, 1999 SF10, and 1998 WB2) 2.) Whiteley, R.J. (2001) PhD. Thesis, University of Hawaii. (A Compositional and Dynamical Survey of the Near-Earth Asteroids)
[3]	EARN	1.) Pravec, P. et al. (2000) Icarus 147, 477-486. (Fast rotating asteroids 1999 TY2, 1999 SF10, and 1998 WB2) 2.) Whiteley, R.J. et al. (2002) Proceedings of ACM2002, ESA-SP500, pp. 473-480. (Monolithic fast-rotating asteroids) (H-values and rotation properties of 36 NEAs)
[4]	ESA Aegis	ESA orbit determination and impact monitoring system
[5]	EARN	1.) Mainzer, A. et al. (2014) Astrophys. J. 784, 110. (The Population of Tiny Near-Earth Objects Observed by NEOWISE) 2.) Binzel, R.P. et al. (2002) in "Asteroids III" (Eds. W.F.Bottke et al.), Univ.Ariz.Press, Tucson, USA, pp. 255-271. (Physical Properties of NEOs)

Observational Information

Arc Length
Unobserved
Normalized RMS of residuals

Arc Information

Value

Unit

Source

Arc Length

Value

9147

Unit

Source

[1]

Unobserved

Value

524

Unit

Source

[1]

Normalized RMS of residuals

Value

0.595343

Unit

Source

[1]

Astrometry Summary

First Observation
Last Observation
Total Optical Observations (Discarded)

Optical

Value

Unit

Source

First Observation

Value

1998-11-18.26448

Unit

Source

[2]

Last Observation

Value

2023-12-04.453998

Unit

Source

[2]

Total Optical Observations (Discarded)

Value

352 (5)

Unit

Source

[1]

Radar Summary

First Observation
Last Observation
Delay (Discarded)
Doppler (Discarded)
Total Optical Observations (Discarded)

Radar

Value

Unit

Source

First Observation

Value

2023-12-02

Unit

Source

[3]

Last Observation

Value

2023-12-03

Unit

Source

[3]

Delay (Discarded)

Value

3 (0)

Unit

Source

[1]

Doppler (Discarded)

Value

0 (0)

Unit

Source

[-]

Total Radar Observations (Discarded)

Value

3 (0)

Unit

Source

[1]

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
[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 1998WB2 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	1959-12-25 17:09	< 1 min	0.1134444	0.1134418	0.0000009
MARS	1968-03-02 11:05	< 1 min	0.0116286	0.0116269	0.0000006
EARTH	1985-03-14 13:28	< 1 min	0.1075381	0.1075369	0.0000004
EARTH	1998-12-05 05:38	< 1 s	0.0168441	0.0168440	0.0000000
EARTH	2010-04-06 23:06	< 1 s	0.0739774	0.0739773	0.0000001
EARTH	2023-12-03 12:27	< 1 s	0.0281525	0.0281525	0.0000000
EARTH	2035-03-16 10:56	< 1 min	0.0997790	0.0997789	0.0000000
EARTH	2059-12-31 15:36	< 1 min	0.1316019	0.1316016	0.0000001
EARTH	2071-04-03 18:32	< 1 min	0.0350829	0.0350826	0.0000001
EARTH	2084-11-29 14:48	< 1 min	0.0827790	0.0827784	0.0000002
EARTH	2096-03-21 10:52	< 1 min	0.0820406	0.0820402	0.0000001
EARTH	2120-12-14 02:23	< 1 min	0.0542765	0.0542758	0.0000002

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Stationary Points

Ecc. an. ast.	Ecc. an. Earth	Distance in au	Classification
328.41345972	331.19157550	0.01467559	MINIMUM
32.90100834	87.90948349	0.02727474	MINIMUM
0.91377576	29.94409452	0.17393171	SADDLE
0.80984113	209.72793667	1.82948772	SADDLE
180.21494429	208.97480742	2.11662482	SADDLE
180.19105873	28.95838708	4.11464947	MAXIMUM

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MOID Plots

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