Why your satellite app pings too much

A satellite can be "overhead" and still be completely invisible to you. It can be too low, too dim, eclipsed by Earth's own shadow, washed out by a bright Moon, drowned by a sky that isn't dark enough yet, or sitting under a cloud deck that hides the whole show. A notification that fires whenever something is geometrically above the horizon — the easiest thing to compute, and what a lot of trackers do — will fire constantly, and be wrong (in the sense of "you went outside and saw nothing") most of the time. That's the notification-fatigue problem, and it has a fix that isn't "notify less often" — it's "notify only when every real condition is actually met."

Here's what "every real condition" means in practice, in the actual thresholds one orbital-mechanics engine uses to decide.

The geometric gate

A satellite pass is found down to 10 degrees above the horizon — which is real, but a smudge behind rooftops and trees, not a sighting. Only passes that climb to at least 30 degrees of peak elevation clear the bar worth a notification. Below that, it's rejected outright: too-low.

The eclipse gate

Even a high pass is invisible if the satellite itself isn't catching sunlight at the moment you'd be looking. If it's in Earth's shadow the whole way through, that's satellite-eclipsed — nothing to see, full stop.

The darkness gate

Your sky has to be dark enough, separately from the satellite being lit. Bright objects need the Sun at least 6 degrees below your horizon — past civil dusk. Fainter objects (dimmer than magnitude 3.5) need a darker sky still: 12 degrees down, nautical twilight. Not dark enough yet, or not dark enough for how faint this particular object is: sky-too-bright.

The brightness gate

Past a certain faintness — magnitude 4.5 — nothing is visible to an unaided eye under a real sky, full stop, regardless of every other condition. That's too-faint.

The Moon gate

A bright Moon — more than half illuminated, above your horizon — washes out anything fainter than magnitude 3.5, the same threshold as the darkness gate above. Bright objects like the ISS punch through a full Moon fine; faint ones don't stand a chance. Fails this and it's moon-interference.

The one gate that isn't astronomy at all

Every gate above is pure geometry and physics — fully determined the moment you know the orbit, the Sun, and the Moon. None of it knows whether there's a cloud in the way. That's handled separately, against an actual forecast: a pass only survives if the forecast cloud cover for that hour comes in under 40 percent. Clear that, and it's the one gate that can change its mind by the time you're actually looking up.

Silence is the feature

Stack all six of those, honestly, and most nights, for most locations, nothing clears every gate. That's not a bug to be tuned away — it's the entire point. A ping that fires only when a human outside would genuinely see something worth seeing is worth trusting the next time it fires. A tracker that pings for everything technically overhead trains you to ignore it.

This is why SpacePings' free tier ships the full quality gate — the gate isn't a premium feature held back for Pro, because a satellite app that pings you into an empty, cloudy sky isn't a worse version of the product. It's not the product.

For the fuller checklist this maps to, see what to look for in a satellite flyover app.