Below is the list of asteroid close approaches to Earth in 2016.
A list of known near-Earth asteroid close approaches less than 1 lunar distance () from Earth in 2016, based on the close approach database of the Center for Near-Earth Object Studies (CNEOS).
For reference, the radius of Earth is approximately or 0.0166 Lunar distances.<br />The orbit of geosynchronous satellites, however, is or 0.110 Lunar distances. This year, 6 (possibly 7) asteroids traveled nearer than this, most notably , which approached a mere 1.25 Earth radii (8000 km) from the surface.
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 2016.
This list and relevant databases do not consider impacts as close approaches, thus this list does not include any of the 32 objects that collided with Earth's atmosphere in 2016, none of which were discovered in advance, but were observed visually or recorded by sensors designed to detect detonation of nuclear devices.
In addition to the confirmed asteroids on the above list, which feature in the CNEOS close approach database, there have been well-observed unconfirmed or confirmed but poorly observed objects with a 50% or greater chance of passing within 1 LD of the Earth, which are listed separately below.
This sub-section visualizes the warning times of the close approaches listed in the table of confirmed close approaches, 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.
Absolute magnitude H âÂÂ¥ 30 (smallest) (size of a person for comparison)
Absolute magnitude 30 > H âÂÂ¥ 29
Absolute magnitude 29 > H âÂÂ¥ 28
Absolute magnitude 28 > H âÂÂ¥ 27
Absolute magnitude 27 > H âÂÂ¥ 26
Absolute magnitude 26 > H âÂÂ¥ 25
Absolute magnitude 25 > H (largest)
None
The number of asteroids listed here are significantly less than those of asteroids that approach Earth for several reasons. Asteroids that approach Earth not only move faster, but are brighter and are easier to detect with modern surveys because:
These factors severely limit the amount of Moon-approaching asteroids, to a level many times lower than the asteroids detected passing as close to Earth.
An example list of near-Earth asteroids that passed more than 1 lunar distance (384,400 km or 0.00256 AU) from Earth in 2016.
XF38FAC (Satellite 2015-007B) with an observation arc of only 17 minutes was estimated to have a chance of impacting Earth at 16:51 on 20 March 2016, but turned out to be the SpaceX Falcon 9 second stage that sent Deep Space Climate Observatory out to L1.