There is currently no scientific evidence to support the claim that Pluto and Mercury were once connected and subsequently separated due to the Sun's heat. The formation and evolution of celestial bodies, including planets, involve complex processes, and the idea that Pluto and Mercury were once connected is not supported by mainstream scientific understanding.
Pluto and Mercury belong to different regions of the solar system and have distinct characteristics. Mercury is an innermost planet, located closer to the Sun, while Pluto is classified as a dwarf planet and resides in the Kuiper Belt, a region beyond Neptune. Their differences in composition, size, orbital characteristics, and geological features indicate that they formed and evolved independently in different regions of the early solar system.
Scientific understanding of the formation of planets suggests that they arise from the protoplanetary disk—a rotating disk of gas and dust surrounding a young star. Various factors, such as the composition of the disk, distance from the star, and gravitational interactions, contribute to the formation of planets. The formation of Mercury and Pluto likely involved distinct processes specific to their respective regions.
It's important to rely on scientific consensus and empirical evidence supported by observations and rigorous research when considering the formation and evolution of celestial bodies. As of now, the idea that Pluto and Mercury were once connected and subsequently separated due to the Sun's heat is not substantiated by scientific evidence.