Suojelija

Suojelija is the fourth and largest planet in the Aurinko System. It is a gas giant with an average radius of slightly under 8 Earths. Despite its size, it has a density slightly lower than water of about 0.956 g/cm3. It orbits at a distance of 2.84 AU with an orbital period of about 3.4 years. It also has the most number of moons in the system, at least 87, 3 of which are major moons named (from inside to out) Takertuva, Keskellä and Pieru. The outer most major moon, Pieru, produces gysers of water ice, creating a very faint ring around Suojelija which is only visible when backlit.

Nomenclature

Suojelija is Finnish for "protector" as it deflects comets and asteroids away from the inner system, and maintains the orbits of many objects in its lagrange points, keeping the inner system free from disturbances.

General characteristics

Suojelija is a gas giant, composed mostly of hydrogen and helium. It has a solid core, though it is not known what the composition of the core is. Due to its high rotation speed of about 7 and a half hours, it is an oblate spheroid, with its eqautorial radius being about 15% larger than the polar radius.

Metallic hydrogen is thought to exist within Suojelija due to high pressures and temperatures near the core. Helium rain may also exist near Suojelija's core.

Suojelija's atmosphere has a banded pattern of blue, gray and white. Water vapor clouds are the most common cloud type in Suojelija's atmosphere, which gives it is grayish-blue color, making it a Class II gas giant, however it is unknown why a Class II planet exists this far from the host star. One theory suggests that Suojelija formed slightly closer to Aurinko (possibly 1-1.5 AU) where ammonia was less abundant but a sufficent amount of water was available. Another suggests that ammonia was simply less abundant in general in the protoplanetary disk.

A notable feature of Suojelija is its "Blue Hat", a pale blue vortex on the northern hemisphere. It has also been noted that this is the warmest area of Suojelija being about 30-40°C warmer than the rest of the planet, but it is unknown why. The heat could also be responsible for the blue color.

Backlit image showcasing Suojelija's rings.

A water ice ring is present around Suojelija, which is produced by gysers on Pieru, though it is not usually visible and requires the viewer to be in the planets shadow to see it.

Moons

Suojelija has 87 known moons. 3 major moons named Takertuva, Keskellä and Pieru make up 90% of the mass in orbit around Suojelija, and are in a 1:2:4 orbital resonance, making them extremely stable in long timescales. They are mostly made of water ice and all likely have subsurface oceans due to tidal heating. Pieru is the largest, and hence likely has the largest subsurface ocean. Gysers have been observed ejecting highly salty water into Suojelija orbit, forming the very faint ring.