Astrophyzix Observatory PHA & NEO Asteroid News

Daily Asteroid Bulletin · NASA NeoWs catalogue · UTC

Near-Earth Object (NEO) and PHA Close-Approach Report: September 23, 2026

Catalogued Earth close-approaches across a 7-day window from the NASA NeoWs feed (JPL small-body solutions; cached at source). This bulletin is a catalogue report, not a live CNEOS CAD/Scout stream. Live Multi-watch CAD/Scout/Sentry tracker.

On September 23, 2026 (UTC), screening of the NASA NeoWs catalogue resolves 39 near-Earth object close approaches across the report window. The single closest encounter is 2018 SP2, passing at approximately 5.01 lunar distances (1,927,097 km) with a relative velocity near 14.3 km/s. No listed object is on an impacting trajectory.

CLOSEST CATALOGUED APPROACH IN OBSERVATION WINDOW

2018 SP2

5.01 LD

1,927,097 km · 0.012882 au · v_rel 14.26 km/s

EARTH SURFACE19.5 LD (FILTER EDGE)

Encounter (UTC)

2026-Sep-30 20:54

Est. diameter

0.044 km (NeoWs)

Diameter range

0.029 - 0.065 km

Earth radii

302 R(E)

Close Approaches On Report Date

Object	Epoch (UTC)	Dist (LD)	Dist (km)	v_rel	Diameter	Status
2012 VB37	2026-Sep-23 04:08	26.80	10,304,606	6.3	0.032	ROUTINE
2016 SE	2026-Sep-23 05:10	73.14	28,128,969	8.9	0.027	ROUTINE
2015 KT120	2026-Sep-23 10:12	123.10	47,340,691	13.1	0.038	ROUTINE
2013 ES11	2026-Sep-23 14:51	134.55	51,742,444	20.4	0.072	ROUTINE
2004 FH	2026-Sep-23 17:58	155.18	59,678,378	13.0	0.021	ROUTINE
2008 CO116	2026-Sep-23 19:23	189.67	72,943,128	21.9	0.239	ROUTINE

Lead Object Orbital Dossier

2018 SP2

Heliocentric osculating elements from NeoWs, epoch JD 2461000.5. Dynamical class: ATE (Near-Earth asteroid orbits similar to that of 2062 Aten).

Semi-major axis a

0.9246 au

Eccentricity e

0.2055

Inclination i

26.825 deg

Orbital period

0.889 yr

Asc. node OM

187.202 deg

Arg. perihelion w

303.398 deg

JPL Small-Body Database record: https://ssd.jpl.nasa.gov/tools/sbdb_lookup.html#/?sstr=3830890

7-Day Forward Outlook - Scroll Left/Right

Object	Epoch (UTC)	Dist (LD)	Dist (km)	v_rel	Diameter	Status
2015 SY16	2026-Sep-24 04:31	192.03	73,848,077	30.5	0.192	PHA
2006 TL	2026-Sep-24 08:32	106.00	40,765,882	9.8	0.066	ROUTINE
2019 VW2	2026-Sep-24 12:39	115.78	44,525,498	14.4	0.115	ROUTINE
2011 TB4	2026-Sep-24 21:17	114.75	44,130,095	21.9	0.033	ROUTINE
2016 LY8	2026-Sep-25 12:12	34.17	13,142,327	7.3	0.098	ROUTINE
2018 HN	2026-Sep-25 14:23	43.20	16,612,224	11.8	0.040	ROUTINE
2018 KS	2026-Sep-25 16:03	88.88	34,180,550	6.9	0.010	ROUTINE
376848 (2001 RY47	2026-Sep-26 00:32	51.29	19,724,629	12.1	0.476	ROUTINE
2019 QY1	2026-Sep-26 02:49	192.77	74,134,163	20.0	0.279	PHA
2005 SP9	2026-Sep-26 09:37	147.43	56,699,115	16.5	0.189	ROUTINE
2001 SY169	2026-Sep-26 10:58	182.86	70,322,608	25.9	0.095	ROUTINE
2013 ET	2026-Sep-26 11:01	182.88	70,330,128	25.9	0.095	ROUTINE
2018 SD1	2026-Sep-26 14:58	93.16	35,828,310	22.8	0.048	ROUTINE
2015 HA10	2026-Sep-26 21:33	101.02	38,850,386	15.5	0.300	ROUTINE
2008 ST	2026-Sep-26 23:54	38.69	14,878,930	6.2	0.015	ROUTINE
2019 DJ1	2026-Sep-27 01:53	109.49	42,105,243	12.4	0.017	ROUTINE
2019 SH7	2026-Sep-27 05:50	84.37	32,446,693	9.6	0.087	ROUTINE
2014 TU	2026-Sep-27 10:19	105.70	40,650,768	15.6	0.038	ROUTINE
2017 GK4	2026-Sep-28 00:38	47.91	18,423,686	12.2	0.174	PHA
2016 FL12	2026-Sep-28 06:57	165.39	63,605,340	7.3	0.022	ROUTINE

Automated analysis · same clock as the feed

The window contains 39 catalogued Earth close-approaches (6 on the report date, 33 in the forward outlook). The nearest listed geometry is 2018 SP2 at 5.01 LD (non-PHA), relative velocity 14.3 km/s. 6 objects in the window are flagged potentially hazardous (size and MOID criteria, not this week's miss distance). No listed object is on an impacting trajectory in this catalogue.

Approaches in window

39

On report date

6

PHA in window

6

Inside 1 LD

0

Inside 5 LD

0

Median miss

102.36 LD

Fastest v_rel

30.5 km/s

Closest object

2018 SP2

DATA PROVENANCE AND TRANSPARENT SOURCE PIPELINE 

Module: Astrophyzix-NEO-Daily/2.2.0
Generated (UTC): 2026-09-23T00:00:04.706Z
Cache state: MISS
Analysis digest: 39 approaches (6 today / 33 outlook); closest 2018 SP2 @ 5.01 LD; PHA 6; sub-lunar 0; notable 0; median miss 102.36 LD; anomalies 0
Analysis generated (UTC): 2026-09-23T00:00:04.706Z
Source 1: NASA NeoWs feed
  endpoint: https://api.nasa.gov/neo/rest/v1/feed?start_date=2026-09-23&end_date=2026-09-30&api_key=***
  docs: https://api.nasa.gov/
  retrieved: 2026-09-23T00:00:04.994Z
Source 2: NASA NeoWs lookup
  endpoint: https://api.nasa.gov/neo/rest/v1/neo/3830890?api_key=***
  docs: https://api.nasa.gov/
  retrieved: 2026-09-23T00:00:06.627Z
Constants:
  - AU = 149597870.7 km (IAU 2012 Resolution B2)
  - Lunar distance = 384400 km (JPL/IAU nominal mean)
  - Earth mean radius = 6371 km (IUGG)
  - TT - UTC = 69.184 s (37 leap seconds + 32.184 s), valid 2026
  - Diameter self-test: D[km] = 1329 / sqrt(pv) * 10^(-H/5), pv 0.25-0.05 (Bowell)
Source note: For live CNEOS Scout and JPL Close Approach Data use the Dual-watch PHA and NEO Tracking System: https://www.astrophyzix.org/p/cneo-observatory.html
Pipeline trace: INIT@838ms -> CACHE_LOOKUP@838ms -> FETCH_FEED@1126ms -> FETCH_ENRICH@2378ms -> PARSE@2760ms -> COMPUTE@2761ms -> VALIDATE@2761ms -> ANALYSE@2761ms -> RENDER@2762ms

Primary references: NASA NeoWs / api.nasa.gov (api.nasa.gov), NASA CNEOS (cneos.jpl.nasa.gov). Object hazard status should be verified against the CNEOS Sentry table.

Astrophyzix Observatory. (2026). Astrophyzix Risk Index - A Heuristic Scoring System for Near-Earth Object Close Approach Visualisation (Version 2.0). Zenodo. https://doi.org/10.5281/zenodo.22240223

Astrophyzix Observatory. (2026). Astrophyzix Digital Observatory Daily Close Approach Report: Methods, Provenance and Limitations Documentation (Version 1). Astrophyzix Digital Observatory. https://doi.org/10.5281/zenodo.22868834

Newly Discovered NEO Asteroid 2026SC Close Approach Report, Analysis and Complete Official Data Profile - Astrophyzix Digital Observatory

Astrophyzix Scientific Close-Approach & Orbital Report NEO 2026SC Official Data

Asteroid 2026 SC — Small Aten NEO Close-Approach & Orbital Profile · JPL CAD confirmed

✅ Data source: JPL Close-Approach Data (CAD) · confirmed solution, 6-day arc

Top-down schematic. Orbit size and shape are drawn from the published elements (a, e, q, Q); the orientation of the orbit and the marked encounter point are approximate. Note how small and Earth-like this orbit is compared with 2026 SY2's — 2026 SC is an Aten, spending most of its time inside Earth's orbit. 

Copyright © 2026 Astrophyzix - All images, original calculations and analysis are the digital property of Astrophyzix. No distribution without proper attribution 

Aten NEO6-Day Data Arc30 ObservationsARI 42 / 100NO IMPACT RISK — Not on Sentry

Key Takeaways of Asteroid 2026 SC

• Close approach: predicted for 25 Sep 2026 at 13:47 TDB (timing uncertainty ± 4 minutes), confirmed in the JPL CAD record. The miss distance is 1.705 LD (≈ 655,383 km, 0.00438 au).
• Speed: 7.75 km/s relative to Earth (≈ 27,900 km/h) — much slower than 2026 SY2's 25.1 km/s; v∞ 7.68 km/s.
• Orbit class: Aten NEO — a = 0.832 au, e = 0.322, i = 4.66°, orbital period ≈ 277 days (0.76 years). Unlike an Apollo, an Aten spends most of its orbit inside Earth's.
• Earth MOID: 0.0034 au (≈ 509,000 km). This pass, at 0.00438 au, is about 30% farther than the geometric MOID — not the tightest approach this orbit allows.
• Size estimate: absolute magnitude H = 26.159, giving a diameter of about 21 m (range 15.6–34.9 m, albedo-dependent). The size is H-derived, not measured.
• Orbit quality: the solution rests on a 6-day data arc with 30 observations — a longer baseline than a 1-day discovery arc, but still short enough that the elements are provisional.
• Risk context: not a Potentially Hazardous Asteroid (H is above the H ≤ 22 PHA threshold), not on the Sentry watchlist, and no Scout entry.
• Keep it in proportion: a lunar-distance-class flyby from a ~20 m object is a routine, expected detection for current sky surveys. This one is tracked, confirmed and shows no impact geometry.

Approach Scale

Scientific Consensus Snapshot of 2026 SC

Parameter	Status
Orbit class	Aten NEO (a < 1 au, Q > 0.983 au — Earth-crossing, orbit mostly interior to Earth's)
Semi-major axis (a)	0.832 au
Eccentricity (e)	0.322
Perihelion distance (q)	0.564 au
Aphelion distance (Q)	1.10 au
Inclination (i)	4.66°
Orbital period	≈ 277 days (0.76 years)
Earth MOID	0.0034 au (≈ 509,000 km)
Tisserand parameter (TJ)	≈ 7.0 † — well above 3, firmly asteroidal
Absolute magnitude (H)	26.159 (very small object)
Estimated diameter	≈ 21 m (15.6–34.9 m), H-derived
Observations / data arc	30 observations over 6 days
Sentry / Scout	Not on Sentry watchlist · no Scout entry
Hazard level	Non-hazardous size; not PHA-class

† Derived by Astrophyzix from a, e and i. All other values are taken from the JPL CAD/SBDB record.

2026 SC Close-Approach Overview

Date/Time (TDB)	Body	Nominal distance	Min–Max distance (au)	Vrel (km/s)
2026-09-25 13:47 ± 00:04	Earth	0.00438 au 1.705 LD	0.00437 – 0.00440	7.75

1. Asteroid 2026 SC

Small Aten NEO on a compact, Earth-orbit-hugging path, with a lunar-distance flyby predicted for 25 September 2026 and a tight Earth MOID — a routine, well-characterised approach with no impact geometry in current solutions.

Asteroid 2026 SC Orbital Geometry

Parameter	Value
Orbit class	Aten (ATE) — Earth-crossing NEO
Semi-major axis (a)	0.832 au
Eccentricity (e)	0.322
Perihelion distance (q)	0.564 au
Aphelion distance (Q)	1.10 au
Inclination (i)	4.66°
Longitude of node (Ω)	180°
Argument of perihelion (ω)	325°
Mean anomaly (M)	103°
Mean motion (n)	≈ 1.30 deg/day †
Orbital period	≈ 277 days (0.76 years)
Earth MOID	0.0034 au (≈ 509,000 km)
Data arc	6 days
Observations used	30

Physical Characteristics of NEO 2026 SC

Parameter	Value
Absolute magnitude (H)	26.159
Estimated diameter	≈ 15.6–34.9 m (nominal 20.8 m, assuming albedo 0.25–0.05)
Size source	H-derived (no radar or thermal measurement)
Rotation period	Not published
Spectral type	Unknown (no published taxonomy)
PHA classification	No — below PHA-class threshold (derived)

2026 SC is a small Aten NEO whose orbit lies almost entirely inside Earth's, ranging from 0.564 au at perihelion (between Mercury's and Venus's distances) out to 1.10 au at aphelion, just beyond Earth's own orbit. That small overshoot at aphelion is what makes it Earth-crossing and gives it a tight MOID of 0.0034 au. At an estimated 15–35 m across, it is in the same general size class as the 2013 Chelyabinsk fireball (about 18–20 m), though it is passing at a safe distance with no impact geometry in current solutions.

Interpretation of the Predicted Approach

The 6-day data arc and 30 observations give a noticeably firmer orbit than a bare 1-day discovery arc, but the elements are still short-arc and will tighten further as more astrometry comes in before and after the 25 September pass.

Because the approach distance (0.00438 au) sits somewhat above the orbit's Earth MOID (0.0034 au), this particular encounter is not the closest geometry the orbit permits — a useful reminder that MOID describes the orbits' closest possible separation, not any single flyby.

Astrophyzix Assessment:

Astrophyzix confirms that it's predicted 25 September 2026 approach is safe, non-hazardous and a good target for follow-up astrometry. Astrophyzix Orbital calculations are consistent with NASA and no impact risk is suggested. Its Aten orbit and short period make it a candidate for early recovery in future apparitions.

Astrophyzix Risk Index (ARI)

42 / 100 for 2026 SC — close to the ARI recorded for 2026 SY2 (43) despite a much slower, more distant pass, reflecting its somewhat larger estimated size.

ARI is an Astrophyzix composite index used to rank close approaches at a glance. It is not an official NASA, ESA or IAU hazard rating; the authoritative impact-risk sources are Sentry and Scout.