List of asteroid close approaches to Earth in 2009

	Time of discovery of asteroids which came closer to Earth than the moon in 2009
	After closest approach: 7 (36.8%); < 24 hours before: 1 (5.3%); up to 7 days before: 11 (57.9%); > one week before: 0 (0.0%); > 7 weeks before: 0 (0.0%); > one year before: 0 (0.0%);

Below is the list of asteroid close approaches to Earth in 2009.

Timeline of close approaches less than one lunar distance from Earth in 2009

A list of known near-Earth asteroid close approaches less than 1 lunar distance (384,400 km or 0.00256 AU) from Earth in 2009.[note 1]

Rows highlighted red indicate objects which were not discovered until after closest approach

Rows highlighted yellow indicate objects discovered less than 24 hours before closest approach

Rows highlighted green indicate objects discovered more than one week before closest approach

Rows highlighted turquoise indicate objects discovered more than 7 weeks before closest approach

Rows highlighted blue indicate objects discovered more than one year before closest approach (i.e.
objects successfully cataloged on a previous orbit, rather than being detected during final approach)

This list does not include any of the objects that collided with earth in 2009, none of which were discovered in advance, but were recorded by sensors designed to detect detonation of nuclear devices.

Date of closest approach	Date discovered	Object	Nominal geocentric distance (AU)[note 2]	Nominal geocentric distance (LD)	Size (m) (approximate)	(H) (abs. mag)	Closer approach to Moon	Refs[1][2]
2009-02-02	2009-02-04	2009 CC₂	0.00123 AU (184,000 km; 114,000 mi)	0.48	7.3–16	27.8		data · 2009 CC₂
2009-02-27	2009-03-03	2009 EJ₁	0.00041 AU (61,000 km; 38,000 mi)	0.16	5.6–12	28.4		data · 2009 EJ₁
2009-03-02	2009-02-27	2009 DD₄₅	0.00048 AU (72,000 km; 45,000 mi)	0.19	18–41	25.8		data · 2009 DD₄₅
2009-03-06	2009-03-02	2009 EW	0.00227 AU (340,000 km; 211,000 mi)	0.88	14–31	26.4		data · 2009 EW
2009-03-18	2009-03-17	2009 FH	0.00057 AU (85,000 km; 53,000 mi)	0.22	13–28	26.6		data · 2009 FH
2009-03-19	2009-03-17	2009 FK	0.00250 AU (374,000 km; 232,000 mi)	0.97	5.8–13	28.3	Yes	data · 2009 FK
2009-05-05	2009-05-04	2009 JF₁	0.00196 AU (293,000 km; 182,000 mi)	0.76	10–23	27.1	Yes	data · 2009 JF₁
2009-05-13	2009-05-12	2009 JL₂	0.00177 AU (265,000 km; 165,000 mi)	0.69	17–38	26.0		data · 2009 JL₂
2009-06-01	2009-05-31	2009 KR₂₁	0.00190 AU (284,000 km; 177,000 mi)	0.74	12–27	26.7	Yes	data · 2009 KR₂₁
2009-10-01	2009-10-02	2009 TB	0.00046 AU (69,000 km; 43,000 mi)	0.18	3.8–8.6	29.2		data · 2009 TB
2009-10-05	2009-10-09	2009 TD₁₇	0.00173 AU (259,000 km; 161,000 mi)	0.67	7.7–17	27.7		data · 2009 TD₁₇
2009-10-08	2009-10-10	2009 TU	0.00204 AU (305,000 km; 190,000 mi)	0.79	9.2–21	27.3		data · 2009 TU
2009-10-17	2009-10-15	2009 TM₈	0.00232 AU (347,000 km; 216,000 mi)	0.90	5.6–12	28.4		data · 2009 TM₈
2009-11-06	2009-11-06	2009 VA	0.00014 AU (21,000 km; 13,000 mi)	0.05	5.1–11	28.6		data · 2009 VA
2009-11-12	2009-11-10	2009 VZ₃₉	0.00174 AU (260,000 km; 162,000 mi)	0.68	6.5–14	28.1	Yes?[note 3]	data · 2009 VZ₃₉
2009-11-15	2009-11-18	2009 WP₆	0.00176 AU (263,000 km; 164,000 mi)	0.69	12–26	26.8		data · 2009 WP₆
2009-11-16	2009-11-18	2009 WQ₆	0.00235 AU (352,000 km; 218,000 mi)	0.91	3.8–8.6	29.2		data · 2009 WQ₆
2009-11-20	2009-11-19	2009 WJ₆	0.00119 AU (178,000 km; 111,000 mi)	0.46	8.8–20	27.4		data · 2009 WJ₆
2009-11-24	2009-11-23	2009 WV₅₁	0.00101 AU (151,000 km; 94,000 mi)	0.39	10–23	27.1		data · 2009 WV₅₁

Warning Times by Size

This sub-section visualises the warning times of the close approaches listed in the above table, depending on the size of the asteroid. The sizes of the charts show the relative sizes of the asteroids to scale. For comparison, the approximate size of a person is also shown. This is based the absolute magnitude of each asteroid, an approximate measure of size based on brightness.

Abs Magnitude 29-30

Silhouette of man standing and facing forward

(size of a person for comparison)

Absolute Magnitude 28-29

Absolute Magnitude 27-28

Absolute Magnitude 26-27

Absolute Magnitude 25-26 (largest)

After closest approach: 0 (0.0%)
< 24 hours before: 0 (0.0%)
up to 7 days before: 1 (100.0%)
> one week before: 0 (0.0%)
> 7 weeks before: 0 (0.0%)
> one year before: 0 (0.0%)

Notes

For a list of current Earth close approaches see NEO Earth Close Approaches
Distance from the center of Earth to the center of the object. See the NASA/JPL Solar System Dynamics Glossary: Geocentric. Earth has a radius of approximately 6,400 km.
The orbit of 2009 VZ₃₉ is known quite poorly- it could have passed as closely as 0.029 and as far as 3.1 LD from Earth, as well as anything from 3.4 LD to colliding head-on with the Moon. As such, the values are based on the nominal calculations. Considering a fireball would likely be noticed if it had collided with the Moon, as it would have created a crater over 150 meters in diameter, it can probably be concluded that the actual orbit was not too far from the nominal one- with a closest approach somewhere between 0.5 and 0.8 lunar distances.

Additional examples

An example list of near-Earth asteroids that passed more than 1 lunar distance (384,400 km or 0.00256 AU) from Earth in 2009.

(136849) 1998 CS1 (~990 meters in diameter) passed 11.33 Lunar distances (4.4 million km) from Earth on 17 January 2009.
(208023) 1999 AQ₁₀ (~285 meters in diameter) passed 4.39 Lunar distances (1.7 million km) from Earth on 18 February 2009.
2009 FW₄ (~41 meters in diameter) passed 2.82 Lunar distances (1.1 million km) from Earth on 17 March 2009.
2009 DO₁₁₁ (~95 meters in diameter) passed 1.22 Lunar distances (468,000 km) from Earth on 20 March 2009.
(410777) 2009 FD (472 meters in diameter) passed 1.62 Lunar distances (624,000 km) from Earth on 27 March 2009.
(136617) 1994 CC (~990 meters in diameter) passed 6.55 Lunar distances (2.5 million km) from Earth on 10 June 2009.
2009 MU (~41 meters in diameter) passed 2.31 Lunar distances (889,000 km) from Earth on 24 June 2009.
2009 RY₃ (~41 meters in diameter) passed 1.94 Lunar distances (745,000 km) from Earth on 11 September 2009.
2009 SH₁ (~5 meters in diameter) may have passed as close as 1.01 Lunar distances (390,000 km) from Earth on 14 September 2009, but the nominal orbit suggests an approach nearer to 2.40 LD (922,000 km).
(68216) 2001 CV₂₆ (1277 meters in diameter) passed 9.79 Lunar distances (3.8 million km) from Earth on 8 October 2009.
(159402) 1999 AP₁₀ (~2067 meters in diameter) passed 29.68 Lunar distances (11.4 million km) from Earth on 20 October 2009.
2009 WV₂₅ (~54 meters in diameter) passed 2.91 Lunar distances (112,000 km) from Earth on 1 December 2009.

References

"JPL Small-Body Database Browser". JPL Solar System Dynamics. NASA Jet Propulsion Laboratory.
"MPC Database". IAU Minor Planet Center. International Astronomical Union. Retrieved 1 January 2021.

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[1] For a list of current Earth close approaches see NEO Earth Close Approaches

[2] Distance from the center of Earth to the center of the object. See the NASA/JPL Solar System Dynamics Glossary: Geocentric. Earth has a radius of approximately 6,400 km.

[5] The orbit of 2009 VZ₃₉ is known quite poorly- it could have passed as closely as 0.029 and as far as 3.1 LD from Earth, as well as anything from 3.4 LD to colliding head-on with the Moon. As such, the values are based on the nominal calculations. Considering a fireball would likely be noticed if it had collided with the Moon, as it would have created a crater over 150 meters in diameter, it can probably be concluded that the actual orbit was not too far from the nominal one- with a closest approach somewhere between 0.5 and 0.8 lunar distances.

[nasa-jpl-ssd-database-3] "JPL Small-Body Database Browser". JPL Solar System Dynamics. NASA Jet Propulsion Laboratory.

[iau-mpc-db-4] "MPC Database". IAU Minor Planet Center. International Astronomical Union. Retrieved 1 January 2021.