The second area of research involves the interiors, surfaces, atmospheres, ionospheres, and magnetospheres of the planets and their moons, as well as of comets and asteroids.

The researchers at the MPS are studying the complete range of dynamic and often spectacular processes occurring on the Sun – from the interior to the outer heliosphere.

Instruments developed by MPS aboard the space- craft SOHO and Ulysses have provided fundamentally new insights: Measurements of the ultraviolet spectrometer SUMER on board SOHO played a decisive role in recognizing the significance of the magnetic field for dynamic processes and Ulysses measured the three-dimensional structure of the solar wind for the first time.

Scientists are working intensively on the project STEREO, in which two identical spacecraft trace disturbances from the Sun to the Earth from different observational points, permitting predictions of potentially dangerous events.

The physical processes involved in the origin and development of magnetic fields on the Sun take place on very small scales and therefore require measurements with very high spatial resolution.

The balloon-borne telescope Sunrise, built under Institute leadership and flown in June 2009, was able to make out structures on the Sun's surface as small as 100 kilometers.

Highly specialized cameras have investigated the Saturn moon Titan, analyse the surface of Mars, and probe the clouds and winds of Venus.

Theoretical studies and intensive computer simulations help to understand the processes both inside and surrounding the planets and to interpret the measured data.

Models developed at MPS can describe, for example, interactions with the solar wind, the atmospheric dynamics, or the generation of the terrestrial magnetic field by means of currents deep in the iron core of our planet.

A major highlight was the camera developed at the institute for the ESA spacecraft Giotto which delivered the first photographs ever of a comet's nucleus in 1986.

A particular challenge was the development of numerous scientific instruments for the ESA Mission Rosetta, such as cameras, chemical analyzers, and essential components for the landing module Philae.

The institute has also provided the cameras for the NASA Dawn Mission, launched in 2007, to study two of the largest asteroids, Ceres and Vesta.

Sunspot helioseismology is a challenging science as it requires modelling of the propagation of waves through magnetic structures; this can only be achieved by numerical simulations.

The institute has led, or been involved with, several international scientific projects such as:[8] Solar Orbiter, SDO, Sunrise, STEREO, SOHO, Ulysses, BepiColombo, Exomars, Chandrayaan, Phoenix, Herschel, Dawn, Venus Express, SMART-1, SOFIA, Rosetta, Mars Express, Mars DFG, Cassini, Cluster, Helios, Galileo and Giotto.

After the war an Allied commission decided to move the institute to Lindau am Harz, where buildings of the Technical University of Hannover already existed.