Janssen — The Twilight Zone
The exoplanet Janssen (scientific name 55 Cancri e) is tidally locked (it has the same rotational period as its orbital period around its Sun-like partner — like the Moon is tidally locked to the Earth), the place where the sun never rises, nor it sets. Janssen is a two-faced super-Earth with the dayside of the planet molten from the heat of its star Copernicus and its nightside plunged permanently into darkness. You might think you’d survive in the twilight or “terminator” zone of Janssen the farthest and the most “private” one in its planetary system, where the day and night sides meet. Where pollution dusk is eternal. But the year on this exoplanet is astonishingly enough — only 18 hours long. What does this mean? Well, here’s the thing — backside of the planet is just cool enough to harden the dayside’s boiling hellish world of possible lava flows. So, basically, Janssen has only bad, hellish sides. At least, its name honors the spectacle maker and telescope pioneer Zacharias Janssen.
LICH Zombie Worlds
Nothing can live in this most inhospitable corner of the galaxy. An astronaut who flew to the planetary system Lich would find himself or herself in the midst of three dead planet cores shambling through the twisted magnetic fields of their corpse star. Disturbing much? Like the decaying ruins of a once-great house, the pulsar PSR B1257+12 aka Lich is named after a powerful, fictional undead creature. This scary pulsar is actually the collapsed core of an exploded star and has a planetary system of three known planets.
Besides Poltergeist, there’s Draugr and Phobetor. But that’s not the creepiest part of this planetary graveyard. Lich has twin-spinning beams of radiation spinning faster than you can blink (hence the name pulsar), which can instantly destroy any spaceship. Oh yes, and the radiation constantly rains down on Poltergeist and its neighboring worlds, creating silent nights, possibly lit with sickly irradiated auroras. If your supernatural reflexes can get you to a planetary surface, good luck. Planet Draugr (PSR B1257+12 b) is a Norse undead creature and the world Phobetor (PSR B1257+12 d) is named after the Greek deity of nightmares.
KOI-55 — Kepler’s Inferno
The shrills scream of damned souls being burned alive might be heard traveling faintly through space. The world Kepler-70b (KOI-55) could well be another circle of hell as its average temperature is hotter than the surface of the sun. A year on this rocky planet only takes five hours, but a trip to its surface would be much shorter. A spaceship wouldn’t even have time to melt in its extreme heat but would vaporize. Even more unnerving is the fact that Kepler-70b used to be a Jupiter-size giant until it spent some time inside its now-dead star…a trip that destroys most worlds, but left this one a Freddy Krueger-like burnt survivor smaller than Earth. At about 12,000 degrees Fahrenheit (6,800 Celsius), it holds the dubious honor of the hottest planet discovered so far. In fact, the planet itself is evaporating, soon to be another victim.
TrEs-2b — Eternal Darkness
Afraid of the dark? Ready to demolish that fear? No? Nevermind, TrEs-2b is a scary and dark world indeed, but is, at least, 750 light-years away from our solar system. Welcome to the planet of eternal night, found by NASA’s Kepler space telescope. The darkest planet ever discovered orbiting a star, this alien world is less reflective than coal. For instance, while Mercury is reflecting 10% of the light, this planet doesn’t even reflect 1% of it. Inside its atmosphere, you’d be flying blind in the dark. Some scientists think an eerie deep red glow would emanate from its burning atmosphere. The air of this planet is the same temperature as the hottest lava, like an infernal nightlight to light your way. TrES-2b may even represent a whole new class of exoplanet whose maybe more appropriate nickname would be Erebus, Ancient Greece’s God of Darkness.