List_of_asteroid_close_approaches_to_Earth_in_2020

List of asteroid close approaches to Earth in 2020

List of asteroid close approaches to Earth in 2020

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Below is the list of asteroid close approaches to Earth in 2020.

Quick Facts
Quick Facts
Quick Facts

Timeline of known close approaches less than one lunar distance from Earth

Radar animation of asteroid 1998 OR2, which came within 16 lunar distances in April 2020

A list of known near-Earth asteroid close approaches less than 1 lunar distance (0.0025696 AU (384,410 km; 238,860 mi)) from Earth in 2020.[note 2]

For reference, the radius of Earth is about 0.0000426 AU (6,370 km; 3,960 mi) or 0.0166 lunar distances. Geosynchronous satellites have an orbit with semi-major axis length of 0.000282 AU (42,200 km; 26,200 mi) or 0.110 lunar distances. A number of known asteroids came closer than this in 2020, notably 2020 CW, 2020 JJ, 2020 QG, and 2020 VT4 which all approached Earth within 0.05 lunar distances.

Two objects have been observed to be temporary satellites of Earth: 2020 CD3 in February 2020 and 2020 SO in September 2020, albeit the latter has been confirmed to be a rocket booster from the Surveyor 2 mission launched in 1966.[1]

The largest asteroid to pass within 1 LD of Earth in 2020 was 2020 LD with an estimated diameter of around 145 meters and an absolute magnitude of 22.4. The fastest asteroid to pass within 1 LD of Earth in 2020 was 2020 FD2 that passed Earth with a velocity with respect to Earth of 33.4 km/s (75,000 mph).[2][note 3]

  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)

More information Date ofclosest approach, Date discovered ...

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. It shows the effectiveness of asteroid warning systems at detecting close approaches in 2021. 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

Silhouette of man standing and facing forward
Silhouette of man standing and facing forward

(size of a person for comparison)

After closest approach: 4 (50.0%)< 24 hours before: 3 (37.5%)up to 7 days before: 1 (12.5%)> one week before: 0 (0.0%)> 7 weeks before: 0 (0.0%)> one year before: 0 (0.0%)

Absolute Magnitude 29-30

After closest approach: 14 (53.8%)< 24 hours before: 7 (26.9%)up to 7 days before: 5 (19.2%)> one week before: 0 (0.0%)> 7 weeks before: 0 (0.0%)> one year before: 0 (0.0%)

Absolute Magnitude 28-29

After closest approach: 19 (63.3%)< 24 hours before: 2 (6.7%)up to 7 days before: 8 (26.7%)> one week before: 1 (3.3%)> 7 weeks before: 0 (0.0%)> one year before: 0 (0.0%)

Absolute Magnitude 27-28

After closest approach: 12 (70.6%)< 24 hours before: 2 (11.8%)up to 7 days before: 3 (17.6%)> one week before: 0 (0.0%)> 7 weeks before: 0 (0.0%)> one year before: 0 (0.0%)

Absolute Magnitude 26-27

After closest approach: 12 (75.0%)< 24 hours before: 0 (0.0%)up to 7 days before: 4 (25.0%)> one week before: 0 (0.0%)> 7 weeks before: 0 (0.0%)> one year before: 0 (0.0%)

Absolute Magnitude 25-26

After closest approach: 4 (80.0%)< 24 hours before: 0 (0.0%)up to 7 days before: 0 (0.0%)> one week before: 1 (20.0%)> 7 weeks before: 0 (0.0%)> one year before: 0 (0.0%)

Absolute Magnitude less than 25 (largest)

After closest approach: 1 (100.0%)< 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: 0 (0.0%)
  •   After closest approach: 1 (100.0%)
  •   < 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: 0 (0.0%)

Predicted close approaches

Below is the list of predicted close approaches of near-Earth asteroids larger than magnitude 27, that were predicted to occur in 2020.[note 1] This relates to asteroid cataloging systems effectiveness at predicting close approaches in 2020.

For asteroids which were observed but not predicted, see the main list above. In 2020, at the outset of the year, no asteroids were predicted to pass within 1 lunar distance of Earth. Table omitted.

Notes

  1. Absolute magnitude 27 is the estimated magnitude of the Chelyabinsk meteor, which caused widespread damage and injury, but no deaths. Objects smaller than this are excluded.
  2. For a list of current Earth close approaches see Close Approaches and NEO Earth Close Approaches
  3. 2020 FD2 passed Earth with a velocity with respect to Earth of 33.4 km/s and was moving away from the Sun at 38.6 km/s.
  4. 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 (0.0166 LD).
  5. Objects that approached closer to the Moon than Earth are marked with a check.

Additional examples

Radar image of 2020 BX12 and its satellite during close approach in February 2020
Path of 1998 OR2 near close approach to Earth in April 2020

An example list of near-Earth asteroids that passed or will pass more than 1 lunar distance (384,400 km or 0.00256 AU) from Earth in 2020.

More information Object, Size (meters) ...

Notes

  1. For comparison
  2. 2018 VP1 could potentially pass less than 1 lunar distance to Earth, but the chances are fairly low and as such it was not listed in the main table unless followup observations confirm that it will pass less than 1 LD from Earth. A longer observation arc is required to constrain the orbit better. The Earth approach distance has an uncertainty of about 4 million km, ±3 days, and a 1:240 chance of impacting Earth.

See also


References

  1. "New Data Confirm 2020 SO to be the Upper Centaur Rocket Booster from the 1960's". NASA. 2 December 2020.
  2. "JPL Small-Body Database Browser". JPL Solar System Dynamics. NASA Jet Propulsion Laboratory.
  3. "MPC Database". IAU Minor Planet Center. International Astronomical Union. Retrieved 1 January 2021.

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