(This planet is in the same universe as Cauldron, Cryolith, Phobis Terra,
and Behemoth, but is not something I'd plan to make a main part of the
actual mod, if it ever gets made. This description is more for my own
enjoyment, and hopefully yours.)
Basic Description
This is the second planet out from the main star in this system, orbiting between Griddle and Cauldron. It is about a third the mass of Earth, but with a much greater proportion of radioactive materials. The planet's atmosphere is much like that of Venus, a hot, thick, carbon dioxide dominated atmosphere, although not as dense, with a covering of sulfuric acid aerosol clouds.
The surface is mostly Volcanic, with some erosion, with large sections covered by a series of lava channels and pools.
Interior
The inside of this planet, like most Rocky planets, has a metal core in the center and a rocky mantle surrounding it. The interior contains far more radioactive material than found in equivalent rocks on Earth, and as a result the interior is hotter and more active. Most activity is in the form of plumes, both upwelling and downwelling.
Surface
The atmospheric greenhouse and closer distance to the star keep the surface extremely hot throughout the planet. Some volcanoes on this planet release magma that stays liquid at these temperatures, resulting in large river systems and some floodplains and lakes of lava. Other magma releases form tunnels, which form fields of hump like formations. Most of the lava in these formations forms from highland areas, flowing from the volcanoes that form over the interior plumes, resulting in systems that look similar to Earth river systems, flowing into something similar to salt lakes.\
Most of the planet is relatively flat, with highlands and mountain ranges covering areas over plumes. These mountains are jagged, clifflike structures, with numerous volcanic features and lava flows. Within mountain ranges, lava is more likely to pool and form lakes, while in plains areas, lava flows go for far longer, forming longer river like features until the lava decomposes or reacts with the surrounding air and ground.
Atmosphere
The atmosphere of Kiln is much like Venus, mostly high pressure carbon dioxide, with sulfur compounds formed in the atmosphere. However, water escapes more easily from the atmosphere than on Venus, and as a result the clouds are filled less with Sulfuric acid and more with other sulfur materials. Pure sulfur forms a large fraction of the clouds, and in some high altitude areas, reaches the surface and coats it occasionally. Carbon dioxide is released in greater amounts by volcanoes, and by the decomposition of low temperature lavas, but also escapes more easily due to lower gravity.
The planet does not have a strong magnetic field, and the atmosphere is constantly escaping into space. The large amount of volcanic activity has maintained the atmosphere over time.
Explanation
This planet is effectively a smaller, more volcanic Venus. This planet is me imagining another planet to follow the pattern of Cauldron, with greater amounts of radioactive materials towards the center of this solar system. The lava lakes are an attempt to make the planet somewhat more interesting, although I've still largely written a copy of Venus.
The lava flows are based on two theories of formation of lava Channels on Venus. Since the "standard" types of lava would freeze too quickly to form the long channels seem (The freezing point is still above Venus's temperature, and the high density of the atmosphere carries heat away very quickly, more than compensating for the increased temperature), some people think the Venusian channels were formed by something called Carbonatites, which freeze at relatively low temperatures for lava, and has the right physical properties, others think that the lava is a more "standard" type, that formed an insulating covering that kept the lava liquid for long distances. Here are some links describing the theories involved:
http://www.sfu.ca/~glynwj/pdfs/JGR%2798-Venus.pdf
http://books.google.com/books?id=b93lEgkPquoC&pg=PA1213&lpg=PA1213&dq=komatiites+venus&source=bl&ots=QROD1nYNA2&sig=awB1TTGnFUC4so1YBvnM81Otmk0&hl=en&sa=X&ei=lSkPUYb6DuzAyQH704CQDg&ved=0CGcQ6AEwCA#v=onepage&q=komatiites%20venus&f=false
