Existence of strong and large scale magnetic fields on planets and stars is one of the most fundamental problems in planetary and stellar physics. The turbulent motions of the electrically conducting fluids in planets and stars twist and churn the pervasive tiny magnetic field perturbations and give rise to much stronger and large scale magnetic fields. This process is called the Dynamo mechanism. Rakesh uses some of the worlds fastest supercomputers to simulate these physical processes and tries to understand how Dynamo works in stars and planets. The results from these complex magnetohydrodynamic simulations help us to better interpret the observations. Rakesh has extensively worked on modelling the dynamo in the Earth's core and in relatively tiny stars called M-stars (Proxima Centauri is one of them). At EPS, Rakesh is working to understand the geodynamo in greater details as well as to connect theoretical dynamo models for Jupiter with the incoming observations from the Juno space mission.