Well I haven't came acress this situation yet, but I believe a Duel Natured being can use stealth in the Astral....after all it is terrain, would it use a specialization? more difficult target numbers? what do you fellers think?

We've always played that anyone can use Stealth in the Astral. The numbers are still resisted as normally, Ie: highest stealth roll vs Highest Perception roll in most cases, however we House Ruled that in certain things like trying to hide from Astral Patrols you add your highest roll to the TN of the Patroller.

There may not be anything saying you can use Stealth in the Astral, but there's also nothing saying you can use it in the Physical either. More importantly, nothing saying you can only use it in the Physical.

Sphynx

If I were to house rule it, I would say that yes you can, but there would be penalties to the stealth roll. Why? Because astral space is a fairly grey and uniform background in which living creatures show up as bright and glowing. It would be like trying to hide at dusk with a bunch of glowsticks attached to your body; possible, but harder than if you didn' have the glowsticks.

That said, if someone were trying to use stealth in a crown, I would probably give a bonus instead of a penalty. This is because my immediate intuition is that it is harder to make out details and determine someone's identity in astral space than in physical space, where millions of years of evolution have made us able to recongize faces almost instantly.

Not to mention the fact that the teeming biomass is very hard to pick out parts of. At least apply the perception modifiers for that

Agree to above. Stealth is possible but only when it would logically be. If youre flying through the astral 500 meters above the ground over farmland it would be hard to be stealthy, while darting through a crowded street corner and in and out of buildings would make it very hard for a persuer to follow. Stealth can be used when applicable, just like in the physical.