The planet Pluto’s perihelion, or closest point to the sun is 4.4 billion miles (7 billion km) from the Sun.
Its aphelion, or farthest point is 7.4 billion miles (11.8 billion km).
This usually makes Pluto the farthest planet from the Sun, but not always.
Pluto’s orbit crosses the path of Neptune’s orbit, and for 20 years out of its almost 250-year orbit, Pluto is closer to the Sun than Neptune.
From 1979 to 1999, Neptune is the most distant planet in the solar system.
Several dynamical effects keep Pluto’s orbit stable, safe from planetary collision or scattering.
In addition, studies have shown that over millions of years, the general nature of the alignment between Pluto and Neptune’s orbits does not change.