Is it Possible for Planetary Bodies To Exist In Close Proximity Without Adverse Effects? There are several sci-fi movies where planetary bodies are shown in the sky in order to indicate that the characters are on an alien planet. A good example is in Predators (2010):



Is it actually possible for such planetary bodies to exist so close to each other as to be visible in such detail to the naked eye? Wouldn't gravitational forces cause disruptions on them that inhibit the development of life (whether plant or animal)? In our Solar system there's a good example in Io which has severe volcanic activity resulting from tidal heating due to its proximity to Jupiter.
Quick calculation of Roche limit for two identical earthlike (fluid) bodies.
Roche distance is about equal to 2.44 X radius X(density1/density2)^1/3.
For identical bodies the density conveniently cancels, so we get
Rd = 2.44 X radius.
Earth radius is 6378 km.
So Rd = 2.44 X 6378 = 15500 km (center to center).
The distance surface to surface (15500- 6378) is 9184km.

At that distance, by trigonometry, another earth would subtend about 44° of sky, pretty big!, and just at the bleeding edge of stability.

The nearest planet in the provided picture looks like it might be at about that distance. Evacuation might be in order as the other three planets or moons will degrade the close binary's orbital stability.