Below is the list of asteroid close approaches to Earth in 2011.

A list of known near-Earth asteroid close approaches less than 1 lunar distance (384,400 km or 0.00256 AU) from Earth in 2011.^{[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 2011, none of which were discovered in advance, but were recorded by sensors designed to detect detonation of nuclear devices.

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

(size of a person for comparison)

Abs 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)

•   After closest approach: 1 (50.0%)
•   < 24 hours before: 0 (0.0%)
•   up to 7 days before: 0 (0.0%)
•   > one week before: 0 (0.0%)
•   > 7 weeks before: 0 (0.0%)
•   > one year before: 1 (50.0%)

• List of asteroid close approaches to Earth
• List of asteroid close approaches to Earth in 2010
• List of asteroid close approaches to Earth in 2012