Eclipse Countdown

The Eclipse App is a high-fidelity astronomical tool engineered for observers who demand absolute accuracy as well as beginners who need a guide through the exceptional experience of their first total solar eclipse


Powered by the latest 3D computational models developed by the Besselian Elements Team, this App provides accurate sub-second eclipse contact timings using lunar limb profile corrections.

Whether you are a professional researcher, an astrophotographer, or a dedicated eclipse chaser, this app provides the rigorous data necessary for a successful expedition, from interactive map useful for planning, to simulating the countdown and exercise with the equipment, and for real time tracking in case you are moving in search of the right spot.


Core Features:
• Precision Timing Engine: Real-time calculations of Contact Times based on your exact GPS coordinates
• Interactive Mapping: High-resolution path-of-totality overlays including umbral limits an the center-line. The IQP method accounts for the topography on both the lunar limb and at the observer site, as well as relying on an improved value for the eclipse solar radius (959.95" ± 0.05", based on research by the Besselian Elements Team). The eclipse center-line and the northern and southern limits of the umbral shadow path also account for these three factors. Hence, these lines are not smooth lines, as in most publicly-available eclipse maps, but are noticeably jagged. Two lines are presented at each path limit corresponding to two values of the eclipse solar radius (959.90" and 960.00") in order to display a region of uncertainty rather than a single limit line.
• Live Audio Synchronization: A sophisticated voice-cue system that announces critical contact phases and astronomical phenomena (e.g., shadow bands, corona visibility, and solar filtration changes), allowing you to keep your eyes on the sky or your equipment.
• List of phenomena to observe during the eclipse at every step, so that you can be reminded to watch at the right time


Designed for the Rigorous Observer:
The Eclipse App eliminates the margin of error inherent in simplified models.
Prepare for the next Great Eclipse with the most scientifically robust tool available on the App Store.