"Open data can change your view of the night sky." Martin Venzina Martin Vezina
Solar System Simulator
jsOrrery is a fascinating way to learn about orbital mechanics, as well as our Solar system in general. It's open to anyone as it uses data and code that is freely available on the internet.

An orrery is a solar system model that can be viewed from multiple viewpoints and manipulated to present the positional relationships among celestial bodies. Martin created an incredible simulation utilizing open data.

Martin was always interested in everything related to space and the history of exploration. After a visit to the Kennedy Space Center in 2012, he wanted to understand orbital mechanics and especially how the Apollo missions got to the Moon. 

He decided to program a mini simulation system that evolved into a complete orrery of the solar system and was determined to input accurate positions into the system.

jsOrrery shows you in 3D the position of planets, spacecraft, comets, visible stars, etc. You can use it to visualize interesting phenomenons such as apparent retrograde motions of the planets, librations of the Moon or solar eclipses, but also historical events such as the Apollo missions to the moon. It is written in Javascript, so anyone can view it in a browser, and the code is open-source.

Simulator screenshot simulating Apollo 8 near the moon

You can find and use Martin's project here: jsOrrery and read more about how he tackled the project at his blog. He outlines step by step how he identified the positions of the planets and calculated the gravitational forces and velocity.

Martin said, "I am completely amazed at how, just by plugging in numbers found on NASA's websites into equations, I was able to witness the behavior of our solar system and simulate space exploration. It's completely fascinating to experiment first hand such accessible science... that's what impressed me the most: it is accessible to anyone."

About Martin

Martin has been developing websites professionally for more than 15 years and is one of three partners in Montreal-based La Grange, specializing in promotional websites. He is passionate about history as well as science, and likes combine these interests whenever he can.

Resources Used

To build jsOrrery, Martin leveraged NASA's websites which provided the precise data that made the simulation accurate, such as planets orbital elements, star coordinates, near-Earth objects, historical NASA missions orbital elements, plus invaluable explanations about the many phenomenons that occur in space.