# Good sources to get velocity/position vectors for all planets and moons in the Solar System for building an orbital simulator?

I’m building an $N$-body simulator, and I have everything ready to begin simulating. But my issue is is that I have no idea how to get all the starting positions and velocities for the celestial bodies in the Solar System, such as the planets and their moons. I suppose that if I knew their periods and their positions, I might be able to find out their velocities, but I don’t know how. Is there a source or database that can give me all this data?

Also, the point of this simulator is to simulate the trajectory of the Asteroid Apophis. If you know of any sources to find the data for its position and velocity vector, that would be very helpful. Otherwise, I’ll have to figure out some other way to find the velocity vectors/positions.

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• NASA has a wealth of information here. – HiddenBabel Jun 23 '18 at 22:59
• @HiddenBabel You mean JPL has a wealth of information there. – JEB Jun 23 '18 at 23:13
• – Kyle Kanos Jul 5 '18 at 11:53