Asteroids at 138971 (2001 CB21)
Right now
The most recent data we hold from NEOWS arrived 11 hours ago, and this point is in it.
What the source measured
NEOWS reported: Asteroid 138971 (2001 CB21) will pass within 0.0541 AU (8,096,702 km) of Earth on 2026-09-29. Estimated diameter: 0.521–1.164 km. Velocity: 10.2 km/s. Classified as Potentially Hazardous.
How we know
One source: NEOWS. Not yet confirmed by a second, independent source.
Our own score for this event is 21 out of 100.
This is our versioned heuristic index, not source severity or a calibrated probability. Urban PEI does not count unique people.
Computed under scoring rules v5. Rows carrying other versions were judged by different rules and are not directly comparable.
Event Data
| Type | Asteroids |
| Severity | Low |
| Calamity Score (ours) | 21 / 100 |
| Legacy data-support index | 0.49/1 |
| Coordinates | 0.0000, 0.0000 |
| Timestamp | 2026-09-29T07:18:00.000Z |
| Source | https://ssd.jpl.nasa.gov/tools/sbdb_lookup.html#/?sstr=2138971 |
Physical priority index · v5. Heuristic priority, not calibrated probability, predictive accuracy or damage. The legacy data-support index combines assigned source support and field availability. Urban PEI is distance-weighted and does not count unique people; zero does not establish that nobody is present. Model cards.
Source and revision timeline
Source: neows. Occurrence: 2026-09-29T07:18:00.000Z.
First archived: 2026-09-22T00:08:51.077Z. Material modification: not recorded.
Retained revisions are prospective; earlier versions may be unavailable. No revision entry does not prove that a record never changed.
Score Breakdown
Technical Details
| AbsoluteMagnitude | 18.54 |
| DiameterMinKm | 0.52 |
| DiameterMaxKm | 1.16 |
| IsPotentiallyHazardous | true |
| CloseApproachDate | 2026-09-29 |
| MinDistAu | 0.05 |
| MinDistKm | 8096701.94 |
| VelocityKms | 10.23 |
Safety Information
Always follow official guidance from your local emergency management agency. This platform provides scientific monitoring data and is not a substitute for official warnings. If you are in immediate danger, contact your local emergency number.
Series begins 8 March 2026. Comparisons refer to that period only. Collection gap: 14-26 August 2026.
This data is aggregated algorithmically from scientific sources. Not a replacement for official emergency warnings.