ISS Transit Finder & Tracker

ISS Transit Finder & Tracker is an astronomy app for iPhone and iPad that predicts when the International Space Station, the Hubble Space Telescope or the Tiangong station crosses in front of the Sun or the Moon, as seen from the location you choose.

A transit almost always lasts under 2 seconds, so timing and position are everything. The app finds these rare alignments and shows where to stand to see or photograph one. It also tracks the ISS live on a world map and lists upcoming rocket launches and space news.

WHAT IT DOES
• Transit finder: the ISS, Hubble and Tiangong crossing the Sun and/or the Moon, with solar and lunar filters.
• Details for each transit: local date and time, distance to the center line, width of the visibility path, altitude and azimuth, duration and an interactive map.
• Live Station: the ISS on a world map (position refreshed about every 5 seconds), its orbit, the day and night line and the crew in space right now.
• ISS guide: key facts, main modules, a 1998 to 2030 timeline and how to see the station with the naked eye.
• Launches: worldwide upcoming and past rocket launches with a live countdown and rocket, mission, orbit and launch pad details.
• Reminders: a notification 1 hour before a transit you pick and 30 minutes before a launch.
• Explore: space news headlines (mostly in English), a daily astronomy photo, an agencies directory, links for sky watchers and a glossary.

WHO IT IS FOR AND WHERE IT WORKS
Astrophotographers chasing solar and lunar transits, amateur astronomers and anyone curious about the ISS and rocket launches. It works anywhere on Earth: set your spot by GPS, by tapping the map or by typing coordinates. The interface is in English and Spanish; it follows your device language and you can switch it in Settings.

HOW IT WORKS
1. Set your location, a date range of up to 30 days and how far you are willing to travel.
2. Pick the Sun and/or the Moon, and the ISS, Hubble and/or Tiangong.
3. Tap Find Transits to get every transit within your travel radius. Wide searches can take up to 30 seconds.

Never look at the Sun without a certified solar filter, and never point a camera or telescope at it without one.

FAQ
What is an ISS transit?
It is the moment the International Space Station (or Hubble, or the Tiangong station) passes in front of the Sun or the Moon as seen from one specific place on Earth.