Which two planets in the Solar System are the most similar in terms of properties like size, mass, composition, interior structure, and magnetic field?

The earth and the Venus are the similar planets in terms of properties.

Explanation:

The earth and the Venus are the similar planets in terms of properties so that the Venus is called as the twin sister of earth. both plants have quite similar properties in terms of mass , composition, and internal structure.

Size & mass :-

                       The mean radius of the earth is around 6400 km. and Venus is around 6371 Km.  thus the size of Venus and earth have similarities. the mass of the earth is around  5,972,350,000 quadrillion kg and that of Venus is around 4,867,550,000 quadrillion kg. thus in terms of mass also both have the similarities.

Internal structure :-  

                        Now in terms of these internal structure both Venus and the earth have similarities  because like an earth the internal structure of Venus also divides  in to the crest, mantle, core etc. The composition of internal structure of the earth and the Venus also same. so that these two plants are similar in internal structure also. the internal structure of both the planets have the same composition.both planets internal structure made up of  iron, nickel and other similar components.

Magnetic Field :-

                       Now the Magnetic Field of the earth is very important feature. its origin is from the core of the earth. Venus magnetic field is also similar to earth's magnetic field, but in the Venus its origin is from the two layers of the atmosphere.

                      Thus the two planets The Earth & The Venus have the similarities in the solar system.