Circles the sphere it is following (6)
I believe the answer is:
orbits
'circles' is the definition.
(orbiting is a kind of circling)
'the sphere it is following' is the wordplay.
I cannot really understand how this works, but
'the' could be 't' (the is pronounced as a 't' sound in some dialects) and 't' is present in the answer.
'sphere' could be 'orb' (orb is a kind of sphere) and 'orb' is found within the answer.
'is' is found in the answer.
No letters remain.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for orbits that I've seen before include "Bistro (anag)" , "Goes around like paths of planets" , "Paths of e.g. planets" , "Paths of satellites around planets" , "Whole rounds" .)