Open the planet using the editor.
Open up Objects.ini for the planet.
Go down to the part for particles:
; ******************** Particle ********************
[Particle]
Image=Effects\Particle.png
Y Offset=100
Controller=Smoke
(c) Y Speed=-30
(c) Y Speed +-Random=15
(c) Rotation +-Random=20
(c) Cycle Time=250
(c) Cycle Time +Random=100
[Close Particle]
Image=Effects\Close Particle.png
Y Offset=50
Controller=Smoke
(c) Y Speed=-60
(c) Y Speed +-Random=30
(c) Rotation +-Random=35
(c) Cycle Time=250
(c) Cycle Time +Random=100
[Red Particle]
Image=Effects\Red Particle.png
Y Offset=100
Controller=Smoke
(c) Y Speed=-50
(c) Y Speed +-Random=15
(c) Rotation +-Random=20
(c) Cycle Time=250
(c) Cycle Time +Random=100
Now, open a room in the editor.
Click "Screen Settings"
You will see something like this:
[Emitter 0]
Angle +-Random=180
Count=80
Layer=5
Layer +Random=4
Margin Bottom=-25
Object=Particle
Scale +-Random=25
[Emitter 1]
Angle +-Random=180
Count=50
Layer=8
Layer +Random=2
Margin Bottom=-25
Object=Close Particle
Scale=200
Scale +-Random=50
[Emitter 2]
Angle +-Random=180
Count=4
Layer=1
Layer +Random=2
Margin Bottom=-100
Margin Top=500
Object=Yellow Glow
Scale=500
Scale +-Random=50
[Emitter 3]
Count=4
Layer=1
Layer +Random=2
Object=Red Glow
Scale=500
[General]
Ambiance 0=..\..\..\Data\Ambiance\Gass Giant Heavy.ogg
Ambiance 0 Volume=50
Ambiance 2=Music\The Intergalactic Express.ogg
Ambiance 2 Volume=0
Ambiance 2 Volume +Timer=60
Background=Backgrounds\Sky.png
I have not really messed with this stuff myself.
But I think that is how you do it.