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Rare exoplanet 37 EP

WASP-18 c

RA 24.3545° · Dec -45.6778° · exoplanet

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Score breakdown

· 6 badges
37 pts · Rare
Rare 50 pts → Epic
  • Lava world +14
  • Multi-planet system +6
  • Confirmed exoplanet +5
  • Gas giant +4
  • Blasted by starlight +4
  • Found by TESS +4
Total score 37

13 more points to reach Epic.

Badges

  • Confirmed exoplanet · +5
  • Gas giant · +4
  • Lava world · +14
  • Multi-planet system · +6
  • Blasted by starlight · +4
  • Found by TESS · +4

Trivia

What makes it special

  • Lava world. Its surface is almost certainly an ocean of molten rock, kept liquid by the star it hugs.

Hard to believe

  • It would float. It is less dense than water. Drop it in a big enough ocean and the whole world would bob on the surface.

What it actually is

  • Hugging its star. It orbits closer to its star than Mercury does to the Sun, completing a lap in less time than Mercury takes.
  • What it is made of. Lighter than Neptune — a puffed-up ball of hydrogen and helium with no surface anywhere on it to stand on.
  • Crowded system. One of at least 2 planets orbiting its star.

Sense of scale

  • In perspective. Far away by human standards, yet still a local address inside the Milky Way's spiral arms.

Find it in the sky

  • Southern sky. It rides the southern half of the sky — an easier target the further south you are.
  • Best time of year. It stands highest in the middle of the night around October — that's when to go looking.

Properties

density gcc
0.48
discovery facility
Transiting Exoplanet Survey Satellite (TESS)
discovery method
Transit Timing Variations
dist ly
402.7472
eccentricity
0.015
eq temp k
1829.5
insolation
1865.3061
mass earth
55.2
name
WASP-18 c
orbital period days
2.1558
radius earth
8.58
sys num planets
2

Nearby objects

About WASP-18 c

WASP-18 c is a rare exoplanet. It lies about 402.7 light-years from Earth, has an equilibrium temperature near 1,830 K, spans roughly 8.58 Earth radii and weighs about 55.2 Earth masses.

Its surface is almost certainly an ocean of molten rock, kept liquid by the star it hugs.

How to see it

Like any astronomical target, WASP-18 c is best seen from a dark site away from city lights, and when it is above the horizon depends on your latitude and the time of year. The visibility panel above works out tonight's viewing window for your saved location.

Why WASP-18 c is a rare exoplanet

WASP-18 c scores 37 points on Spacedle's rarity scale, which places it in the rare tier. Another 13 points would lift it into a rarer tier.

That score comes from 6 science badges — Confirmed exoplanet, Gas giant, Lava world, Multi-planet system, Blasted by starlight and Found by TESS — each earned for a real, measurable property of the object. Rarity on Spacedle is never random: the more remarkable an object's astrophysics, the more badges it collects, the higher it scores, and the rarer it ranks.