G.K. Sasidharan has held positions in educational institutions as lecturer, postgraduate professor, principal, pro-vice-chancellor and vice-chancellor. He has published many papers on cosmology and astrophysics, and is a regular writer on scientific topics in journals and periodicals. He is the architect of the astronomical observatory on the Calicut University campus and was instrumental in the introduction of compulsory social service (CSS) as part of the curriculum in university and colleges.
Sasidharan visited colleges in various states in the country as chairman of the National Assessment and Accreditation Council (NAAC) peer team. He is the founder president of the All Kerala Astrosciences Society (AKAS). He has also authored widely accepted bestsellers. His books have been translated into many languages by eminent academicians and he is also the recipient of many awards.