Comet movement

[Kyle (OP)]

Hi, hoping Steve can answer this, I don't see that it's been answered anywhere.

What's the formula for how far a comet travels in a given time period?
When it's < 1 AU from the sun, it's a nice constant speed.
But farther out, comets tend to move slower and slower the farther away they get, and it's not clear exactly how the distance is determined.

Thanks!!

[Father Tim]

Knowing Steve, it's probably the actual formulae for meteors/comets (Start here: http://mathscinotes.com/2011/07/speed-of-a-meteor/) modified ever-so-slightly for Aurora's 360-day year.

[Steve Walmsley]

Here is the code for C#

Code: [Select]

                    double AUTime = 0;
                    double OrbitTime = Math.Pow(Math.Pow(Comet.OrbitalDistance / 2, 3) / Comet.ParentStar.StarType.Mass, 0.5); // result in years

                    if (Comet.CurrentDistance > 1)
                    {
                        double CloserOrbitTime = Math.Pow(Math.Pow((Comet.CurrentDistance - 1) / 2, 3) / Comet.ParentStar.StarType.Mass, 0.5); // result in years

                        // time to move 1 AU at this distance in seconds
                        AUTime = ((OrbitTime - CloserOrbitTime) / 2) * (double) GlobalValues.SECONDSPERYEAR;
                    }
                    else
                        AUTime = 0.18 * (double) GlobalValues.SECONDSPERYEAR; // comet moves about 5.5 AU per year

                    double AUMoved = Timescale / AUTime;

[Kyle (OP)]

AWESOME!

[Kyle (OP)]

Would it make more sense for Comet.OrbitalDistance to be Comet.CurrentDistance in line 2?