Celestia Forums

This site shows a range of comet tails
http://www.solarviews.com/eng/comet.htm

I am wondering if there is any way to alter the comet tails
rendered by Celestia.

Billboards might work for some stills but not for travelling
images.

Any suggestions from this amazing group are welcome.

-- Scott

Use a 3ds model instead of the comet class...

Comet Tail Size and Orientation

How do I change the size and oriention of each of the tails relative to the Sun or other star around which the comet orbits?

I would like to model Nucleus, Coma (Head), Type I Tail ( Ionic or Plasma Tail), Type II Tail (Dust Tail), Anomalous Tail, Sodium Tail & Hydrogen Tail.

What I see now in Celestia is just the Plasma Tail, which points away from the Sun. Normally activity increases in the approach to perihelion, as do sizes of its dust and plasma tails. Currently in Celestia it appears that the plasma tail is constant.

"The Dust Tail is the most spectacular part: it extends over several millions km and is made up of particles of dust whose size varies between 0.1 and 10 m m. It is very different from the ion tail. Although remaining in the plane of the orbit, the dust trails behind the motion of the comet giving this tail a curved appearance. The dominant colour of the dust tail is yellowish." Mostly reflected light from the sun.

References:
http://www.astronomysight.com/as/info/comet_dia.html
http://earthsci.org/space/comets/comet.html
"Comet Science" by Crovisier and Encrenaz



-- Scott
Mac OS X 10.3.5 :: Nvdia GForce4 MX 32 MB :: Dual 867MHz G4 :: Celestia 1.3.1

Scott,

The size of the tail that Celestia draws is proportional to the Radius of the comet object, but there's no way to control its orientation.

As Ras' wrote above, someone probably will have to create 3D models of the comets using a 3D design program in order for Celestia to display accurate representations of them.

Think of Celestia's current "comet" objects as markers rather than as an attempt to draw them entirely accurately.

I agree that it'd be nice to be able to specify the various parameters that you mention, but someone would have to write new code for Celestia to be able to draw those features.