Menaris is the second planet inward of the Canopus system. Because of similarities of size and orbit, Menaris and Extaris are informally referred to as "the Twins." Their combination is responsible for the highly eccentric orbit of the third planet, Arrakis. It is much larger in radius than Seban.
Because of the above, the planet nearly rolls in its orbit with contrasting seasonal effects, one hemisphere eternally hot and the other eternally cold although the atmosphere mitigates the temperature effects to some extent.
Menaris possesses a dense atmosphere of carbon dioxide with traces of nitrogen dioxide (which is responsible for the yellow brown tint). Largely because of its oxidizing atmosphere, there are no known life forms on Menaris.
Sources: Dune Encyclopedia?,
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