Yes, a planet's gravity can affect liquids on a different planet, although the extent of the influence depends on various factors.
Gravity is a force that attracts objects toward each other. The strength of gravity depends on the mass and distance between two objects. In the context of planets, the more massive a planet, the stronger its gravitational force.
If we consider two planets, Planet A and Planet B, the gravitational force of Planet A can have an effect on liquids on Planet B. For example, if Planet A is significantly more massive than Planet B, its gravity can create tidal forces on Planet B. Tidal forces occur due to the difference in gravitational pull between the side of a planet facing the other planet and the side facing away from it. This difference in gravitational pull can cause the liquid on Planet B to experience a gravitational distortion, leading to tides.
The most familiar example of tidal effects caused by the gravitational influence of another celestial body is the Moon's impact on Earth's tides. The Moon's gravity creates tidal bulges on Earth's oceans, causing the water to rise and fall in a regular pattern.
However, it's important to note that the magnitude of these effects depends on the relative masses, distances, and other factors. The gravitational influence between two planets would typically be much weaker compared to the influence of a planet's own gravity on its liquids. So while there may be some minor effects, they would likely be overshadowed by the planet's own gravitational forces.
Additionally, for the gravitational influence of one planet's gravity to significantly affect the liquids on another planet, the two planets would need to be in relatively close proximity to each other. Otherwise, the gravitational effects would diminish with distance.