Sky score
78/100
Live space-weather monitoring
Never miss the northern lights again.
Moose watches Kp, Bz, solar wind, cloud cover, and moonlight for your exact location — and only wakes you up when the sky actually has something to show you.
Kp index
4.7
Bz (IMF)
-6.2 nT
Solar wind
548 km/s
The Android app
One number that answers one question: will you see the aurora tonight?
Moose is a free Android app for your phone, available on Google Play. Set your location once and it checks the sky for you in the background, with no account needed.
Under the hood
Real instruments, not a coin flip.
Every reading comes from the same public feeds professional space-weather forecasters use — Moose just decides, second by second, whether it's worth putting your boots on.
Kp · Bz · wind
Three-instrument tracking
Live Kp index, interplanetary magnetic field (Bz), and solar wind speed, each with its own trend chart — so you can see a southward Bz turn before Kp has even caught up.
Dark · clear · active
Alerts gated on all three
A notification only fires when your sky is actually dark, mostly cloud-free, and geomagnetically active — not just whenever Kp crosses a number.
G1 – G5
3-day storm outlook
NOAA's official geomagnetic storm scale, daily, so you can plan a drive north two nights before a major event — not scramble the moment it starts.
Zones 0 – 7b
Light-pollution aware
Pulled from the World Atlas of Artificial Night Sky Brightness, so the app knows a clear city sky still won't show you much.
New → full
Moon-phase discount
A near-full moon washes out fainter displays — the visibility score quietly accounts for it, up to a 30% trim around full moon.
Southern alert
Rare-event heads-up
A separate, fixed-threshold alert for G4+ storms strong enough to reach unusually far south — Germany, the UK, and similar latitudes.
How it works
One score, three real numbers.
The visibility score starts at NOAA's OVATION probability for your exact spot, then gets discounted for cloud cover and moonlight — the two things that turn "aurora happening" into "aurora you can't see."
score
=
OVATION %
×
cloud factor
×
moon factor
Available in
English
Deutsch
Français
Español
Română
+ more coming
Free, and always will be.
The aurora and weather data behind Moose is public, so the app is too — no subscription, no paywalled forecast. Get it free on Google Play.
