your best bet is to fake that, actually. depending on your scene, set up two lights to illuminate it from different angles, and make the suns in Photoshop. Bryce doesn't have more than one Sun, unfortunately, so your only solution would be to fake it. Either like I've just told you or by adding another light high up at the end of nowhere and making it visible... either way. In terms of moons all you need is to make a sphere with the texture, set it high up, and add fuzzy factor, distance, altitude blur, in the object material propreties (down pointing triangle in the top right-middle). Cheers. Drac