Astrophyzix PHA NEO Close Approach Report and Profile: 837253 (2013 FW13)
Image Credit: NASA JPL Small Body Database
What is a Potentially Hazardous Asteroid?
A Potentially Hazardous Asteroid (PHA) is a near-Earth object with an absolute magnitude of 22.0 or brighter (typically larger than ~140 metres) and a minimum orbit intersection distance (MOID) of 0.05 AU or less. This classification does not indicate an impact threat, but identifies objects that require precise orbital monitoring.
Close Approach Event — 27 March 2026
Asteroid 837253 (2013 FW13) undergoes a monitored Earth flyby on 27 March 2026 at approximately 02:27 UTC. This event represents a routine, non-hazardous close approach within the broader Near-Earth Object tracking catalogue, with a miss distance that remains comfortably beyond the Earth–Moon system.
| Parameter |
Value |
| Close Approach Date |
27 March 2026 |
| Time (UTC) |
02:27 |
| Nominal Distance |
0.17170 au |
| Distance (km) |
~25,685,800 km |
| Distance (Lunar Distances) |
~66.8 LD |
| Relative Velocity |
~19.8 km/s (~71,100 km/h) |
Dynamical Interpretation
At a nominal separation of 0.17170 astronomical units, this flyby occurs at approximately 66.8 times the average Earth–Moon distance, placing it far outside the regime typically considered a “close” encounter in planetary defence terms.
Despite its classification as a Potentially Hazardous Asteroid, this designation is based on long-term orbital geometry (MOID and size) rather than immediate encounter conditions. The March 2026 passage represents a distant orbital crossing alignment rather than a near-Earth interaction.
Context Within NEO Monitoring Framework
For comparison, objects typically flagged for heightened observational campaigns during close approaches pass within <10 lunar distances, and in some cases within 1–2 LD. In contrast, 2013 FW13 remains well beyond even the outer boundary of the Earth–Moon system during this event.
The significance of this flyby is therefore observational rather than hazardous. Events at this scale are routinely used to refine orbital solutions, validate dynamical models, and maintain continuity in long-arc tracking datasets.
