As it turns out, the Earth Solar System in Mass Effect 2 shows the correct arrangement of all the planets for the year 2185--the year the game takes place.
All except for one planet (editor's note: not a planet): Pluto.
It’s nice to see some accuracy in science fiction games from time to time. Any space-shooter that doesn’t have the “pew pew” sound of lasers and cannons gets kudos for realizing there isn’t any sound in space, as does the action-adventure game that understands that just because space is a vacuum doesn’t necessarily mean it’s absolutely cold absolutely everywhere.
Mass Effect 2, unfortunately, still has a few of those tropes in the game, but there is one thing that they definitely got right, and that’s the positioning of each planet for the year the game takes place (which is 2185 for you lore nuts).
Of course, the position of the planets doesn’t remain static for the entire year. As everyone knows, the Earth rotates around the sun every 365.25 days. The specific date represented is roughly January 30th, 2185.
There are naturally a few problems with Mass Effect 2’s representation of the solar system. First, some planets do move fast enough that the few days it takes to travel from the Mass Effect Relay to any specific planet would cause them to move with respect to the Sun and other planetoids. Mercury, for example, whips around the Sun for a full rotation every 88 days.
Conversely, a few planets are super slow-moving in comparison to the smaller planets. Neptune takes over 164 years to complete one circuit of the Sun.
There is one planet (or should we say “dwarf planet”) that doesn’t match the simulation, and that’s Pluto. However, Mass Effect can claim a few intervening factors. First, Pluto has a highly elliptical orbit that makes predicting exact positions almost impossible. Second, Charon, Pluto’s largest moon, gets melted to reveal the Mass Effect Relay in the universe, further perturbing Pluto’s orbit.
There are a few things that Mass Effect missed, such as Ceres, the dwarf planet inside the Asteroid Belt, and Eris, another dwarf planet with an elliptical orbit that brings it way outside the normal bounds of our solar system. But hey, at least they were trying.