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The Asteroid Was Quietly Steering Itself
A missed predicted position and weak tail showed near-Earth object 1998 SH2 is an active comet pushed by escaping gas.
Summary
A missed predicted position and weak tail showed near-Earth object 1998 SH2 is an active comet pushed by escaping gas.
NASA reclassified 1998 SH2 after its post-flyby position no longer matched an orbit governed by gravity alone. Astrometry showed nongravitational acceleration from escaping gas, while follow-up observations revealed a faint coma and tail. Now designated P/1998 SH2, it is not a newly announced impact threat. The case matters because apparently inert objects can move differently when weak outgassing is present, and planetary-defense orbit models must account for that force.
Why it matters
A missed predicted position and weak tail showed near-Earth object 1998 SH2 is an active comet pushed by escaping gas.
Limits and context
- Now designated P/1998 SH2, it is not a newly announced impact threat.
Key claims
A missed predicted position and weak tail showed near-Earth object 1998 SH2 is an active comet pushed by escaping gas.
Qualification: Now designated P/1998 SH2, it is not a newly announced impact threat.
Evidence: source-2026-07-17-002
Sources
- NASA: Near-Earth asteroid is actually a cometNASA · official announcement
Corrections
No corrections have been recorded for this story.