Planetary Planner

Plan your planetary astronomoy and astrophotography sessions with precision using our astronomy calculator to see optimal viewing times and altitudes for planets throughout the year. Perfect for astronomers and astrophotographers to determine the best observation times based on your location. The calculator generates altitude data for Mercury, Venus, Mars, Jupiter, and Saturn. Below that, you'll see a top-down view of the solar system (not to scale) to show relative positioning throughout the year. This web app is free and open source.

Enter your location then choose the time you'd like to observe. You'll see how high the planets will be in the sky.

Planetary Planner: Altitude and Position Calculator

Please set your location to start

or

8:00 PM
January
Mars-Earth Distance: AU

Quick Start Guide

The Astronomy Weather Dashboard provides an easy way to check if conditions are favorable for astronomy and astrophotography at your location. Here's how to use it:

Set Your Location

  • Click "Detect My Location" to automatically determine your position, or
  • Enter your city, address, or location name in the search field
  • Your coordinates will be displayed for verification

Select Time Settings

  • Choose the year you want to plan for (current year plus next 3 years available)
  • Use the time slider to select your preferred observation hour
  • The graphs will automatically update to show planetary altitudes for your chosen time

Reading the Graphs

  • Each planet has its own graph showing its altitude throughout the year
  • The vertical axis shows altitude in degrees above horizon
  • The horizontal axis shows months of the year
  • Hover over any point to see exact altitude and date
  • Higher altitudes generally mean better viewing conditions

Privacy Note

The plugin only requests location access when explicitly activated by the user. No location data is stored or transmitted beyond what's needed for immediate weather forecasting.

Technical Details

The calculator generates altitude data for Mercury, Venus, Mars, Jupiter, and Saturn, providing a comprehensive tool for planning astronomical observations and astrophotography sessions.

Grab the code on GitHub: https://github.com/jagbanana/jg-planet-planner

Core Engine

  • Utilizes the Astronomy-Engine JavaScript library for precise planetary position calculations
  • Implements rigorous coordinate transformations from celestial to horizontal coordinates
  • Accounts for proper motion, atmospheric refraction, and planetary orbits

Location Processing

  • Converts geographic coordinates to astronomical observer positions
  • Uses the OpenStreetMap Nominatim API for geocoding and reverse geocoding
  • Handles location data in standard WGS84 coordinate system

Astronomical Calculations

  • Computes topocentric positions (as seen from the observer's location)
  • Calculates altitude angles accounting for: precession of the equinoxes, planetary orbital elements, local sidereal time, observer's latitude and longitude

Data Visualization

  • Implements Chart.js for responsive, interactive graphs
  • Provides real-time data updates when parameters change
  • Optimizes performance by pre-calculating daily positions

Technical Stack

  • WordPress integration using standard plugin architecture
  • Bootstrap 5 for responsive layouts
  • Vanilla JavaScript with jQuery for DOM manipulation
  • Asynchronous data loading and calculation processes