List of asteroid close approaches to Earth in 2008

	Time of discovery of asteroids which came closer to Earth than the moon in 2008
	After closest approach: 11 (52.4%); < 24 hours before: 2 (9.5%); up to 7 days before: 8 (38.1%); > one week before: 0 (0.0%); > 7 weeks before: 0 (0.0%); > one year before: 0 (0.0%);

Last updated February 10, 2024

Below is the list of asteroid close approaches to Earth in 2008. 2008 was the first year that an asteroid was successfully detected before it impacted earth ( 2008 TC3 was the first successfully predicted asteroid impact).

Timeline of close approaches less than one lunar distance from Earth in 2008

A list of known near-Earth asteroid close approaches less than 1 lunar distance (384,400 km or 0.00256 AU) from Earth in 2008.^{[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)

Apart from 2008 TC3 , this list does not include any of the other objects that collided with earth in 2008 as they were not discovered in advance, but were recorded by sensors designed to detect detonation of nuclear devices.^{[note 2]}

Date of closest approach	Date discovered	Object	Nominal geocentric distance (AU)^{[note 3]}	Nominal geocentric distance (LD)	Size (m) (approximate)	(H) (abs. mag)	Closer approach to Moon	Refs^[1]^[2]
2008-01-13	2008-01-10	2008 AF₃	0.00252 AU (377,000 km; 234,000 mi)	0.98	16–36	26.1		data · 2008 AF₃
2008-01-16	2008-01-19	2008 BW₂	0.00238 AU (356,000 km; 221,000 mi)	0.93	3.1–6.8	29.7		data · 2008 BW₂
2008-01-31	2008-01-30	2008 BC₁₅	0.00198 AU (296,000 km; 184,000 mi)	0.77	13–28	26.6	Yes	data · 2008 BC₁₅
2008-02-05	2008-02-03	2008 CT₁	0.00089 AU (133,000 km; 83,000 mi)	0.35	7.7–17	27.7		data · 2008 CT₁
2008-02-15	2008-02-09	2008 CK70	0.00248 AU (371,000 km; 231,000 mi)	0.97	28–62	24.9		data · 2008 CK₇₀
2008-03-09	2008-03-07	2008 EZ₇	0.00108 AU (162,000 km; 100,000 mi)	0.42	11–24	27.0		data · 2008 EZ₇
2008-03-10	2008-03-11	2008 EF₃₂	0.00044 AU (66,000 km; 41,000 mi)	0.17	3.5–7.8	29.4		data · 2008 EF₃₂
2008-03-10	2008-03-08	2008 EM₆₈	0.00148 AU (221,000 km; 138,000 mi)	0.57	8.4–19	27.5		data · 2008 EM₆₈
2008-03-23	2008-03-27	2008 FK	0.00218 AU (326,000 km; 203,000 mi)	0.85	9.2–21	27.3	Yes	data · 2008 FK
2008-03-29	2008-03-28	2008 FP	0.00114 AU (171,000 km; 106,000 mi)	0.44	15–33	26.3		data · 2008 FP
2008-04-03	2008-04-06	2008 GM₂	0.00139 AU (208,000 km; 129,000 mi)	0.54	5.8–13	28.3		data · 2008 GM₂
2008-04-07	2008-04-05	2008 GF₁	0.00196 AU (293,000 km; 182,000 mi)	0.76	5.8–13	28.3	Yes	data · 2008 GF₁
2008-05-10	2008-05-11	2008 JL₂₄	0.00115 AU (172,000 km; 107,000 mi)	0.45	3.2–7.1	29.6	Yes	data · 2008 JL₂₄
2008-07-29	2008-07-30	2008 OT₇	0.00116 AU (174,000 km; 108,000 mi)	0.45	10–23	27.1		data · 2008 OT₇
2008-10-03	2008-10-08	2008 TN₉	0.00165 AU (247,000 km; 153,000 mi)	0.64	7.3–16	27.8		data · 2008 TN₉
2008-10-07	2008-10-06	2008 TC3	impact	impact	4.1	30.4^[3]		data · 2008 TC₃
2008-10-09	2008-10-09	2008 TS₂₆	0.0000844 AU (12,630 km; 7,850 mi)	0.03	0.61–1.4	33.2		data · 2008 TS₂₆
2008-10-18	2008-10-29	2008 UA₂₀₂	0.00223 AU (334,000 km; 207,000 mi)	0.87	3.5–7.8	29.4		data · 2008 UA₂₀₂
2008-10-20	2008-10-21	2008 US	0.00022 AU (33,000 km; 20,000 mi)	0.09	1.4–3.1	31.4		data · 2008 US
2008-10-22	2008-10-22	2008 UM₁	0.00057 AU (85,000 km; 53,000 mi)	0.22	1.0–2.3	32.1		data · 2008 UM₁
2008-11-03	2008-11-03	2008 VM	0.00031 AU (46,000 km; 29,000 mi)	0.12	2.4–5.4	30.2		data · 2008 VM

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 30 and greater

Silhouette of man standing and facing forward

(size of a person for comparison)

Abs Magnitude 29-30

Absolute Magnitude 28-29

Absolute Magnitude 27-28

Absolute Magnitude 26-27

Absolute Magnitude less than 25 (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
↑ Asteroids which collide with earth before being detected never receive a designation and do not appear in either the NASA or IAU lists of asteroids as there is no astrometry for them.
↑ 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.

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 2008.

2007 TU24 (~250 meters in diameter) passed 1.44 LD (554,000 km) from Earth on January 29, 2008.
2008 CE₂₂ (~18 meters in diameter) passed between 0.9997 and 1.0023 LD (384,300 to 385,300 km) from Earth on February 6, 2008.
(450894) 2008 BT18 (~650 meters in diameter) passed 5.9 LD (2.3 million km) from Earth on July 14, 2008.
2008 XK (~12 meters in diameter) may have passed as close as 0.23 LD (89,300 km) from Earth on December 5, 2008, but the nominal orbit suggests it passed nearer to 1.46 LD (560,500 km) from Earth instead.

Related Research Articles

<span class="mw-page-title-main">2018 AH</span> Near-Earth asteroid Christmas 2021

2018 AH is a sub-kilometer asteroid, classified as near-Earth object of the Apollo group, approximately 100 m (300 ft) in diameter. It was first observed on 4 January 2018, by the Asteroid Terrestrial-impact Last Alert System (ATLAS) on Mauna Loa and quickly followed-up by many other surveys, with precovery observations found from Pan-STARRS and PTF from the day previous.

2018 GE₃ is a sub-kilometer asteroid on a highly eccentric orbit, classified as a near-Earth object of the Apollo group, approximately 48–110 meters (160–360 feet) in diameter. It was first observed on 14 April 2018, by astronomers with the Catalina Sky Survey one day prior to its sub-lunar close encounter with Earth at 0.5 lunar distance. It is one of the largest known asteroids (possibly the largest) in observational history to ever pass that close to Earth (also see list).

2019 MO, temporarily designated A10eoM1, was a small, harmless 3-meter near-Earth asteroid discovered by ATLAS–MLO that impacted Earth's atmosphere on 22 June 2019 at 21:25 UT. The impact of the bolide generated a 5-kiloton-equivalent explosion off the south coast of Puerto Rico which was detected by infrasound detectors. The strewn field would be spread over the Caribbean Sea.

<span class="mw-page-title-main">2020 QG</span> Earth-crossing asteroid

2020 QG, also known by its internal designation ZTF0DxQ, is an Earth-crossing asteroid, a few meters in diameter. It belongs to the Apollo group, and passed above the surface of Earth approximately 2,950 kilometres (1,830 mi) away on 16 August 2020 at 04:09 UT. It was first imaged by the Zwicky Transient Facility (ZTF) at the Palomar Observatory about 6 hours after this closest approach, and was later identified by Kunal Deshmukh, a student at the Indian Institute of Technology Bombay, along with colleagues Kritti Sharma, Chen-Yen Hsu and Bryce T. Bolin analyzing images from the ZTF.

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.
↑ "JPL Small-Body Database Browser: (2008 TC3)" (last observation: 2008-10-07).

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

[2] Asteroids which collide with earth before being detected never receive a designation and do not appear in either the NASA or IAU lists of asteroids as there is no astrometry for them.

[3] 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.

[nasa-jpl-ssd-database-4] "JPL Small-Body Database Browser". JPL Solar System Dynamics. NASA Jet Propulsion Laboratory.

[iau-mpc-db-5] "MPC Database". IAU Minor Planet Center. International Astronomical Union. Retrieved 1 January 2021.

[2008TC3-6] "JPL Small-Body Database Browser: (2008 TC3)" (last observation: 2008-10-07).

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