List of asteroid close approaches to Earth in 2023

Below is the list of asteroids that have come close to Earth in 2023.

Timeline of known close approaches less than one lunar distance from Earth
A list of known near-Earth asteroid close approaches less than 1 lunar distance (0.0025696 AU) from Earth in 2023. As most asteroids passing within a lunar distance are less than 40 meters in diameter, they generally are not detected until they are within several million km of Earth. Objects coming from the direction of the Sun may not be publicly announced until a few days after closest approach. For example, was first imaged six hours after closest approach, then confirmed by other observations, but not officially announced until 3.5 days after closest approach. that approached from the direction of the Sun was not first observed until 3.6 days after closest approach. The largest asteroid on this list that is risk–listed is at about 17 meters in diameter with a 3.5-day observation arc and a 1:$91,000$ chance of Earth impact on 2118 September 24.

For reference, the radius of Earth is about 0.0000426 AU or 0.0166 lunar distances. Geosynchronous satellites have an orbit with semi-major axis length of 0.000282 AU or 0.110 lunar distances.

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.

Absolute magnitude 30 and greater (size of a person for comparison)

Absolute magnitude 29-30

Absolute magnitude 28-29

Absolute magnitude 27-28

Absolute magnitude 26-27

Absolute magnitude 25-26

Absolute magnitude less than 25 (largest)

Beyond 1 LD
Below is an example list of near-Earth asteroids that nominally will pass more than 1 lunar distance (384,400 km or 0.00256 AU) from Earth in 2023. During 2022, over 1,000 asteroids passed within 10 LD of Earth.