Helios is the fourth planet from Sol. It is a terrestrial world, similar in size to Tellus. Helios is notable for having very similar makeup to Tellus, and likely being somewhat habitable, with a similar atmospheric composition and density. At the surface, temperatures range from 21 to 50 degrees celsius. These conditions are somewhat warmer then Tellus, but are still habitable for Tellurian life.
Helios, being a terrestrial world, contains a core, mantle and crust. it has a moderately strong magnetic field, somewhat weaker then Tellus. The planet is known to have plate tectonics, and is fairly volcanically active. Helios has 2 moons. Eos, and Selene, one of the largest moons in the inner planets. Conditions on the planet are favorable for some plant life to exist, which is believed to be similar to tropical regions of Tellus.
The Rotation of Helios is slower then Tellus, causing a day to be around 36 hours instead of 24. The planet is also closer to the sun, making the year only last around 270 Tellurian days.