"Designated 55 Cancri e, Janssen is a super-Earth that orbits a sunlike star far too closely for life to exist. What’s intriguing is its extreme density. The planet is twice the size of Earth, but 9 times more massive. That means it’s terrestrial, but made of what?"
Imagine a sea of lava bejeweled with diamonds and bathed by a liquidy-gas atmosphere. The planet’s extreme density suggests a carbon core mixed with iron and other heavy elements under intense pressure. Pressurized carbon takes the form of graphite and diamond.
Generator Unlocked
Tidal Lock
One molten side of Janssen faces its star at all times in what’s called a tidal lock. On the dark side, clouds of molecular minerals condense into rain, made sparkly by the glowing lava below. Planets like Earth that are not tidally locked are more hospitable to life.
Diamond Crust
Achievements[]
Icon
Name
Description
Requires
Soot Line
In a baby star system, the soot line marks a carbon-rich zone in the protoplanetary disk where carbon stays solid instead of vaporizing. That’s where Janssen was born—but not Earth. Despite being populated by carbon-based life forms, our planet is carbon poor.
Janssen Rank 3
Prime Location
LHS 1140 b is a dense super-Earth, like Janssen, but in a prime location. It orbits a red dwarf squarely in the habitable zone, the life-friendly distance from a star where water stays liquid. Bathed in moderate heat and light, it’s a planet ripe for further study.
Janssen Rank 6
Trivia[]
Hypothetical image of 55 Cancri e (Janssen).
55 Cancri e (formally named Janssen) is an exoplanet in the orbit of its Sun-like host star 55 Cancri A.