AstroAlert: Satellite Tracker

AstroAlert tells you what is passing over your head tonight: satellites like the ISS, planets, the Moon and deep-sky objects, calculated for your exact location.

Open the app, look up at the right moment. AstroAlert turns your phone into a personal space control center for stargazing and satellite tracking.

WHAT YOU CAN DO
• See today's satellite passes above you, with time, azimuth and altitude
• Track the ISS, Starlink and bright satellites, planets, the Moon and the Sun
• Keep only the spectacular events, high above the horizon (altitude over 70°)
• Explore galaxies, nebulae and star clusters with official images
• Space weather: solar flares, geomagnetic storms and aurora chances, with alerts
• Watch the Solar System animate in real time
• Learn astronomy with a clear glossary and daily space facts
• Discover the NASA Astronomy Picture of the Day

HOW IT WORKS
Positions are computed from NASA JPL planetary ephemerides and official TLE orbital data for satellites, then projected onto your sky from your GPS location. No telescope needed: most passes are visible with the naked eye.

WHO IT IS FOR
Curious beginners, families, students, amateur astronomers and astrophotographers who want to know where and when to look up.

ASTROALERT+ (PREMIUM)
• Automatic, personalized alerts before each pass
• 1,000+ detailed celestial object sheets
• Every deep-sky object unlocked
• Early access to new features

AstroAlert: the sky above you, explained with precision, simplicity and wonder.

Privacy Policy: https://astroalert.app/privacy-policy

Recent changes:
A big update to enjoy the night sky even more ✨
🔭 Tonight: observing score (clouds, Moon, passes, best time to go out)
🛰️ ISS passes visible to the naked eye, reminder 10 min before
🌌 Aurora alerts
☀️ Today's space weather (NASA, NOAA)
📓 Observing log with photos and badges
🪐 Solar system in the navigation bar, ISS live stream fixed, notifications in your profile, faster and more stable app