FAQ
If something here is wrong or missing, email hello@starrypic.com.
StarryPic answers this directly for your exact location. It combines four weather models (ECMWF, NOAA GFS, DWD ICON, ECCC GEM), checks cloud cover during the astronomical-dark window, and returns a single verdict: Skip, Backyard, or Drive. Open the home page — you have your answer in one glance.
Astronomical darkness begins when the Sun is 18° below the horizon (astronomical dusk) and ends at astronomical dawn or moonrise — whichever comes first. Only during that window are faint deep-sky objects visible. StarryPic shows the exact minutes for tonight at your location.
A 1–9 scale measuring how dark a sky is. Bortle 1 is pristine wilderness (Milky Way casts shadows); Bortle 9 is inner-city (only the brightest stars visible). The light-pollution map and dark-site reviews in StarryPic both report Bortle values so you know what to expect.
None is universally best. ECMWF wins for Europe, GFS for the US, ICON for Germany, GEM for Canada. The honest answer is to run all four and watch agreement. StarryPic reports ensemble agreement as a percentage — if the four models disagree, the forecast is uncertain, regardless of which single model says what.
It pulls the NOAA SWPC planetary Kp index forecast (refreshed every 15 minutes), computes your geomagnetic latitude (which is what actually matters for aurora visibility — not geographic latitude), and applies a logistic-curve probability model. The result is a percent chance of visible aurora tonight at your location.
ISS (magnitude -4, the brightest), Tiangong (magnitude -2), and Hubble Space Telescope (magnitude 2). It uses CelesTrak two-line elements, propagates orbits via SGP4 (the satellite.js library), and only reports passes when the satellite is sunlit AND the sky is dark — i.e., actually visible from the ground.
Yes. The 7-day outlook ranks every night this week as Skip / Backyard / Drive. The 14-night trip planner (Pro tier) extends that out two full weeks — useful for booking a dark-site Airbnb without weather risk.
Sampling = arcseconds per pixel = (pixel pitch in μm × 206.265) ÷ focal length in mm. The seeing-limit floor is around 1.5"/px in average conditions, so the FOV calculator flags below-floor (oversampled, no extra detail), well-matched (1.5–3"/px), or below-Nyquist (undersampled, aliasing). It frames bright targets at your scale so you can see what fits in the field.
Skip = forecast says it is not worth setting up tonight. Backyard = good enough for casual visual observing or solar-system imaging from home — do not drive an hour to a dark site. Drive = the night is genuinely good, ensemble agrees, plenty of dark window — go to your dark site.
Because the four weather models disagree. When ECMWF says 20% cloud, GFS says 80%, ICON says 40%, GEM says 60%, the truth could be anywhere. StarryPic reports that disagreement honestly rather than hiding it. Low confidence means: maybe wait until tomorrow morning when the next model run lands.
Astrospheric is North America only and uses one hidden ensemble. Clear Outside is global but single-model. StarryPic works worldwide, runs four models, reports disagreement, and lives on the home screen via push and widgets. It is also 60% cheaper than Astrospheric annual.
Honestly: rough. Forecast skill drops off sharply past day 3–4. StarryPic shows ensemble agreement per night so you can see for yourself — day 1–2 forecasts are usually reliable; days 5–7 should be treated as planning hints, not commitments. Re-check the night-of.
Yes. /calendar.ics is a subscribable iCal feed combining upcoming meteor showers, conjunctions, eclipses, and the next week of visible ISS passes for your location. Subscribe it in Google Calendar, Apple Calendar, or Outlook.
The marketing site shows your local forecast based on browser geolocation, no sign-in required. To save locations, get push alerts, write dark-site reviews, or use the FOV calculator presets across devices, sign in with Google or Apple.