To periodically obtain, update, and compare data in Android, use WorkManager for reliable background tasks, even after app restarts. It’s perfect for fetching data like Aurora Borealis visibility updates. Store previous results in a local database (e.g., Room), and compare new data using simple logic or DiffUtil for efficient UI updates. This setup ensures your app always shows the latest data — whether it's forecasts, locations, or any changing real-time info.