Astrophyzix Scientific Close-Approach & Orbital Report NEO 2026SC Official Data
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.
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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.
Astrophyzix Digital Observatory Analysis, Interpretation and FAQ about 2026SC
1. How close will 2026 SC come to Earth?
On 2026-09-25, the asteroid is expected to pass at a nominal distance of 0.00438 au, about 655,000 km or 1.7 lunar distances — closer than the Moon, but still well outside any atmospheric or orbital-infrastructure concern.
2. What does the Earth MOID of 0.0034 au mean?
The Earth MOID means the orbits of Earth and 2026 SC come within about 509,000 km of each other at their closest points. This particular pass, at 0.00438 au, is somewhat farther than that — MOID is a geometric limit, not a prediction that every encounter reaches it.
3. Why does a 6-day data arc matter?
A 6-day arc with 30 observations gives a meaningfully better orbit than a same-day discovery, but is still short by orbit-determination standards. The close-approach timing here (±4 minutes) is already tight; the longer-term orbit will keep improving as more astrometry arrives.
4. Is 2026 SC a Potentially Hazardous Asteroid?
No. A PHA needs H ≤ 22 (roughly 140 m or larger) and an Earth MOID of 0.05 au or less. 2026 SC meets the MOID condition, but at H = 26.159 it is only about 15–35 m across, far below the PHA size threshold.
5. What happens next for 2026 SC?
Continued observations through and after the 25 September approach will extend the data arc and refine the orbit. Astrophyzix will update this profile if the JPL solution changes in a scientifically meaningful way.
Track live: Astrophyzix Live Orbital Refinement and 3D Viewer
Risk Assessment
No impact threat.
- 2026 SC is not on the Sentry watchlist and has no Scout entry.
- The predicted 25 September 2026 flyby is a clean miss at 1.705 LD.
Not a PHA.
- With H = 26.159, 2026 SC is well below the size threshold for Potentially Hazardous Asteroids.
- The Astrophyzix classifier records it as below the PHA-class threshold (derived).
Short-arc uncertainty.
- The 6-day data arc and 30 observations are a firmer baseline than a discovery-night arc, but the orbital elements remain provisional.
- This is normal for small NEOs found in the weeks before a close approach and does not imply a hidden impact risk.
Energy regime.
- At an estimated 15–35 m diameter, 2026 SC is in the same general size class as the 2013 Chelyabinsk impactor (≈ 18–20 m) and well below the Tunguska scale (≈ 50–60 m).
- Objects of this size enter Earth's atmosphere roughly once a decade on average; even in a hypothetical impact scenario this would be a local-scale airburst at most, not a regional hazard.
Operational context.
- The flyby passes far beyond geostationary distance and poses no threat to satellites or infrastructure.
Astrophyzix Digital Observatory Scientific Summary
Asteroid 2026 SC is a small Aten-class Near-Earth Object on a moderately eccentric (e ≈ 0.32), low-inclination (i ≈ 4.7°) orbit with a semi-major axis of a ≈ 0.83 au. Its orbit ranges from q ≈ 0.56 au to Q ≈ 1.10 au, with a period of about 277 days (0.76 years) and a Tisserand parameter near 7.0, firmly consistent with an asteroidal, non-cometary orbit.
It is predicted to pass Earth on 25 September 2026 at 0.00438 au (≈ 655,000 km, 1.71 LD) at 7.75 km/s, somewhat outside its Earth MOID of 0.0034 au. It is not on the Sentry watchlist and has no Scout entry.
With an absolute magnitude of H = 26.159, it is a very small NEO, likely around 16–35 m across, with a nominal size near 21 m — in the same size class as the 2013 Chelyabinsk fireball. Its physical scale places it far below the threshold for Potentially Hazardous Asteroids.
The current orbit rests on 30 observations over a 6-day arc, a firmer baseline than a discovery-night solution but still short enough that the elements are provisional and will improve as additional astrometry is obtained. From a planetary-defence standpoint, 2026 SC is safe, non-hazardous and scientifically routine. Its main value lies in orbit refinement, survey-performance benchmarking and public education about how close-approach geometry and MOID are interpreted in modern NEO monitoring. Astrophyzix Analysis Methodology 10.5281/zenodo.22868834