Prof. S. A. Haider is a distinguished planetary scientist of international repute. He has made pioneering contributions in the field of planetary atmospheres and ionospheres and their coupling with magnetospheres especially in the areas of Martian ionosphere, airglow, chemistry and aurora in the cometary coma. He specializes in development of complex models for atmospheric processes that include complex chemistry, magnetic fields and plasmas and their interaction. This has made him a unique contributor to the understanding of Martian and cometary atmospheres.