Based on JPL Horizons ephemeris data, Ted Molczan’s magnitude estimates, and the Artemis II mission timeline, here is a day-by-day assessment. A typical “backyard telescope” — say a 6-inch (150 mm) reflector reaching about magnitude 13, or a 12-inch (300 mm) scope reaching about magnitude 15 — could detect the Orion capsule on the following mission days:
This is the best day. During the initial elliptical orbits, Orion’s range stays between roughly 0.0002–0.0005 AU (30,000–75,000 km), putting it at estimated magnitude 10.7–12.7 — well within reach of a 6-inch scope.
The perigee pass around 23:00–23:30 UTC is the highlight: the range plunges to ~0.000045 AU (6,700 km), bringing the capsule to roughly magnitude 7–9, which is bright enough for binoculars. The catch is that it’s moving very fast at perigee — several degrees per minute.
After the TLI burn, Orion is heading outbound. By 06:00 UTC it’s at ~88,000 km (mag ~13), still within a 6-inch scope. By the end of the day it’s at ~175,000 km (mag ~14.5), requiring a 10–12 inch scope.
Range reaches ~236,000 km (mag ~15.3). This is the last realistic day for a 12-inch backyard scope, and it’s right at the limit.
At 300,000–400,000 km, the capsule fades to magnitude 16–17. This is beyond backyard telescopes — you’d need observatory-class instruments or CCD imaging with long exposures through a large scope.
On the return leg, Orion brightens steadily. By 06:00 UTC it’s back to ~172,000 km (mag ~14.4), re-entering 12-inch scope range. By 18:00 UTC it’s at ~83,000 km (mag ~12.8), and by 22:00 UTC it’s down to ~38,000 km (mag ~11.1) — comfortably visible in a 6-inch scope again.
The final hours before reentry bring the capsule very close, but the window is brief before it enters the atmosphere.
Days 1–3 and Days 9–10 — roughly the first three days outbound and the last two days inbound — are the window for backyard telescopes. The middle of the mission around the lunar flyby is out of reach. All estimates carry Molczan’s ±2 magnitude uncertainty, so the capsule could surprise you in either direction.
| Equipment | Approx. Limiting Magnitude |
|---|---|
| Naked eye (dark sky) | 6.0–6.5 |
| 7×50 binoculars | 9–10 |
| 6-inch (150 mm) telescope | ~13 |
| 8-inch (200 mm) telescope | ~14 |
| 12-inch (300 mm) telescope | ~15 |
| 16-inch (400 mm) telescope | ~16 |