Most terrestrial planets have portions of their surface that appear to be significantly older than other portions of their surface. The craters on Venus are randomly distributed in size and number across the surface. The volcanoes on Venus are not found in isolated groups, but are scattered around the planet. Mars has a sufficient mass and a low enough temperature that water molecules could exist in its atmosphere. All of the water vapor was released in the impact that formed Deimos.
Ultraviolet radiation breaks the water molecules into less massive particles that can escape.
The water molecule combines readily with chlorine to form hydrochloric acid. Cassini's division 15. Pluto should have a magnetic field about one-third as strong as Earth's. Pluto is still geologically active. Pluto probably has a small ring system that hasn't been detected yet.