🌌 Your Personalized Space Control Center
Know exactly which satellites, planets, comets or deep-sky objects are passing above you — and learn something fascinating about the Universe every single day.
🔭 Personalized Astronomical Monitoring
AstroAlert automatically calculates the most remarkable sky events visible from your location, using your latitude, longitude and time zone.
Only objects rising above 70° altitude are selected, ensuring you see only the most impressive and worthwhile sky shows.
🛰️ 1,000+ Satellites Tracked
From the brightest satellites to massive constellations like Starlink, AstroAlert analyzes fresh orbital data every day.
See which spacecraft are actually passing above you, their trajectories, their purpose — and even the story behind each one.
🌍 Planets and Deep-Sky Objects Included
AstroAlert covers the major planets of the Solar System, as well as the Moon, the Sun, and a wide range of deep-sky objects — nebulae, bright stars, clusters and even certain supernovae.
Every position is calculated with scientific precision using official NASA ephemerides.
✨ AstroAlert+: For the Curious & the Cosmic
With AstroAlert+, explore over 1,000 celestial objects in detail: full technical sheets, official images, scientific data, history, explanations and captivating anecdotes.
Unlock automatic alerts for remarkable sky events, get access to new features before anyone else, and turn your phone into a true personal space control center.
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Developer
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Celestial objects
Users
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What Users Say
A truly useful astronomy app. I’ve seen objects I never would have spotted without AstroAlert. The detailed sheets are fascinating.
Emily, AstroAlert+ user
The automatic alerts are amazing — I get notified at the perfect moment and see satellites with the naked eye. The Premium experience is absolutely worth it.
Lucas, astrophotography enthusiast
❓ Why AstroAlert?
Because the sky above you changes every day — and no other app truly tells you what to observe, when to observe it, and why it’s fascinating.
AstroAlert combines scientific accuracy, educational content and a beautifully simple experience to turn your phone into a personal space control center.
You know exactly what crosses your sky, you understand the story behind each object, and you get automatic alerts when a sky event is worth your attention.
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