1- create new document 300*300 px white background
2- shoose the orb color and with the elipse tool (u) and maintaining shift button to have a perfect elipse create and center a elipse
3- apply innerglow black color and color burn in blend mode
4- apply inner shadow color white blend mode color dodge
result
5- create a new layer , ctrl click the elepse layer to create selection fill selection in the new layer with any color right click layer and select blending option in the tab blending options default reduce fill opacity to 0 and apply inner shadow and satin
result
6- create new layer ctrl click elipse layer to create selection ctrl+t reduce the size to 80%
7- select white color as background and select the gradian tool from white to transparent drag from the top of the selection to lil more than half way and release move the ton of selection to the top of the original elipse
and you are done
final result
