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Epic exoplanet 46 EP

K2-18 b

RA 172.5601° · Dec 7.5878° · exoplanet

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Score breakdown

· 4 badges
46 pts · Epic
Epic 68 pts → Anomaly
  • In the habitable zone +30
  • Multi-planet system +6
  • Confirmed exoplanet +5
  • Sub-Neptune +5
Total score 46

22 more points to reach Anomaly.

Badges

  • Confirmed exoplanet · +5
  • In the habitable zone · +30
  • Sub-Neptune · +5
  • Multi-planet system · +6

Trivia

What makes it special

  • Goldilocks zone. Sits where it's neither too hot nor too cold — liquid water could exist.

Could we get there?

  • Verdict. Hopelessly far for any craft humanity can build today.

Getting there

  • Aboard Voyager 1. ≈ 2.2 million years at Voyager 1's speed (17 km/s).
  • Fastest probe ever. ≈ 193.7 thousand years even at the Parker Solar Probe's 192 km/s.
  • At 10% light speed. ≈ 1240 years in a starship at a tenth of light speed.
  • Distance. 124 light-years from Earth.

Look-back time

  • Look-back time. The light you'd see left around the year 1902.

Saying hello

  • Say hello. A radio message and its reply would take 248 years round-trip.

Standing on it

  • A year here. A full year lasts just 32.9 Earth days.

By the numbers

  • Size. About 2.4× the width of Earth.
  • Volume. About 13.3 Earths could fit inside it.
  • Mass. About 8.9× the mass of Earth.
  • Your weight. You'd weigh about 1.6× your Earth weight standing here.
  • Temperature. A surprisingly temperate 11°C average.

How we found it

  • Discovery. Found by K2 using the transit method.

Cosmic context

  • Crowded system. One of at least 2 planets orbiting its star.

Properties

density gcc
4.11
discovery facility
K2
discovery method
Transit
dist ly
124.026
eccentricity
0.2
eq temp k
284
habitable zone
yes
insolation
1.005
mass earth
8.92
name
K2-18 b
orbital period days
32.9396
radius earth
2.37
sys num planets
2

About K2-18 b

K2-18 b is an epic exoplanet. It lies about 124 light-years from Earth, has an equilibrium temperature near 284 K, spans roughly 2.37 Earth radii and weighs about 8.92 Earth masses.

Sits where it's neither too hot nor too cold — liquid water could exist.

How to see it

Like any astronomical target, K2-18 b 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 K2-18 b is an epic exoplanet

K2-18 b scores 46 points on Spacedle's rarity scale, which places it in the epic tier. Another 22 points would lift it into a rarer tier.

That score comes from 4 science badges — Confirmed exoplanet, In the habitable zone, Sub-Neptune and Multi-planet system — 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.

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Sky imagery and survey data courtesy of Aladin Lite & CDS, Strasbourg. Object data from the NASA Exoplanet Archive, JPL Small-Body Database, and the ATNF Pulsar Catalogue.