Eclipse Calculator 2, from Serviastro - Univ. Barcelona, is an Android app for computing and visualizing solar and lunar eclipses and planetary transits. The tool calculates local contact times, produces visibility maps, and runs animated simulations to show shadow paths and sky views. It also offers advanced observational outputs such as lunar limb profiles and countdowns. Designed for amateur astronomers, students, educators, and researchers who need accurate event timing and demonstrable visualisations for teaching or fieldwork.

What events it actually calculates and displays

The app computes solar and lunar eclipses and the transits of Mercury and Venus, producing both general and local circumstances for each event. It generates global visibility maps and interactive local maps so users can inspect where an event is visible. Animated simulations illustrate the Moon's shadow across Earth and the sky at totality, making the numerical results visible rather than only listed as tables.

How it supports teaching and observational demonstrations

Its animated shadow paths and representations of totality give teachers a visual aid for classroom demonstrations, while advanced outputs such as lunar limb profiles and Baily's beads simulations provide material suitable for higher-level observational labs. Real-time GPS updating adapts contact times for moving observers, which is practical for field trips or demonstrations from vehicles where position changes during observation.

Who can use it and how accessible it is

The app targets amateur astronomers, students, educators, and researchers and runs on Android devices. Users can set location via a built-in database, manual coordinate entry, or device GPS, and the interface supports several languages including English, Spanish, Catalan, and Chinese. Those new to eclipse geometry can use the visual simulations to follow events, while experienced observers can access precise timing data for planning.

How it organizes events for study and extended timelines

Calendar integration and built-in countdown timers let instructors schedule demonstrations and keep classes aligned to upcoming events. The internal database covers 1900–2100 by default and can be extended to span 1550–2300, enabling historical study or long-range project planning. These scheduling and timeline options support multi-session lessons or individual research projects that require cross-century event comparisons.

A scholarly teaching aid best for guided demonstrations and serious observers

Eclipse Calculator 2 is a scientifically grounded option for educators and experienced amateurs who need precise event timing and demonstrable visualisations; the app’s academic origin and data range suit curriculum-level exploration. New learners benefit from instructor-led activities to interpret the advanced outputs. A practical tip: pair a classroom simulation with a timed observation exercise to turn the app’s data into hands-on learning moments.