Velocities on J2000 taken from JPL: Masses and radi taken from a combination of JPL and Wikipedia.

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Console commands

You can use these commands by going into the console (F12 on Chrome, may vary by browser)


This function will simulate up to the next point in which to bodies reach their closest part of a flyby. The bodys can be grabbed from the nbody object where they key for a body is its name.

initialStepSize is the amount of time in seconds that the steps are when simulating, and then it will binary search its way precision times to get closer to the moment of closest approach. Both initialStepSize and precision are optional, the default step size is 360 (6 minutes), and default precision is 5.

One application for this would be simulating up to the next potential Venus transit:


Using a body that's not part of the currently selected preset will not work, although it will still work if one or both of the bodies are hidden.


Similar to getNextApproach() but instead of looking for an approach, it targets a specific date, and for precision, it resets back to J2000 before simulating.

date is the date in milliseconds from 1970, initialStepSize and precision work the same as in getNextApproach()

One application for this would be going to the date of an interesting event, like the 2004 Venus transit:

goToDate(new Date("June 8, 2004").getTime())