Asteroids which came closer to Earth than the Moon in 2008 by time of discovery Below is the list of asteroid close approaches to Earth in 2008.

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 0.00257 AU) from Earth in 2008, based on the close approach database of the Center for Near-Earth Object Studies (CNEOS).

The CNEOS database of close approaches lists some close approaches a full orbit or more before the discovery of the object, derived by orbit calculation. The list below only includes close approaches that are evidenced by observations, thus the pre-discovery close approaches would only be included if the object was found by precovery, but there was no such close approach in 2008.

This list and the relevant databases do not consider impacts on Earth as close approaches. The impact of was the first successfully predicted asteroid impact, while the impact of several small asteroids in Earth's atmosphere were observed visually or recorded by sensors designed to detect the detonation of nuclear devices as bolides.

Date ofclosestapproach Datediscovered Object Nominal geocentricdistance (AU)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.Nominal geocentricdistance (LD)Size (m)(approximate)(H)(abs. mag.) Closerapproachto Moon Refs 2008-01-13 2008-01-10 0.98 16–36 26.1 2008-01-16 2008-01-19 0.93 3.1–6.8 29.7 2008-01-31 2008-01-30 0.77 13–28 26.6 Yes 2008-02-05 2008-02-03 0.35 7.7–17 27.7 2008-02-15 2008-02-09 0.97 28–62 24.9 2008-03-09 2008-03-07 0.42 11–24 27.0 2008-03-10 2008-03-11 0.17 3.5–7.8 29.4 2008-03-10 2008-03-08 0.58 8.4–19 27.5 2008-03-23 2008-03-27 0.84 9.2–21 27.3 Yes 2008-03-29 2008-03-28 0.44 15–33 26.3 2008-04-03 2008-04-06 0.54 5.8–13 28.3 2008-04-07 2008-04-05 0.76 5.8–13 28.3 Yes 2008-05-10 2008-05-11 0.45 3.2–7.1 29.6 Yes 2008-07-29 2008-07-30 0.45 10–23 27.1 2008-10-03 2008-10-08 0.64 7.3–16 27.8 2008-10-09 2008-10-09 0.03 0.61–1.4 33.2 2008-10-18 2008-10-29 0.87 3.5–7.8 29.4 2008-10-20 2008-10-21 0.09 1.4–3.1 31.4 2008-10-22 2008-10-22 0.22 1.0–2.3 32.1 2008-11-03 2008-11-03 0.12 2.4–5.4 30.2 Warning times by size

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

Absolute magnitude H ≥ 30 (smallest) (size of a person for comparison)

Absolute magnitude 30 > H ≥ 29

Absolute magnitude 29 > H ≥ 28

Absolute magnitude 28 > H ≥ 27

Absolute magnitude 27 > H ≥ 26

Absolute magnitude 26 > H ≥ 25

None

Absolute magnitude 25 > H (largest)

Notes

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. (~250 meters in diameter) passed 1.44 LD (554,000 km) from Earth on January 29, 2008. (~18 meters in diameter) passed between 0.9997 and 1.0023 LD (384,300 to 385,300 km) from Earth on February 6, 2008. (~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.

See also List of asteroid close approaches to Earth List of asteroid close approaches to Earth in 2000-2007 List of asteroid close approaches to Earth in 2009

References