Common exoplanet 22 EP

Kepler-138 d

RA 290.3814° · Dec 43.2931° · exoplanet

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Score breakdown

· 4 badges

22 pts · Common

Common 24 pts → Uncommon

Super-Earth +8
Multi-planet system +6
Confirmed exoplanet +5
Found by Kepler +3

Total score 22

2 more points to reach Uncommon.

Badges

Confirmed exoplanet · +5
Super-Earth · +8
Multi-planet system · +6
Found by Kepler · +3

Trivia

Could we get there?

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

Getting there

Aboard Voyager 1. ≈ 3.8 million years at Voyager 1's speed (17 km/s).
Fastest probe ever. ≈ 340.5 thousand years even at the Parker Solar Probe's 192 km/s.
At 10% light speed. ≈ 2181 years in a starship at a tenth of light speed.
Distance. 218 light-years from Earth.

Look-back time

Look-back time. The light you'd see left around the year 1808.

Saying hello

Say hello. A radio message and its reply would take 436 years round-trip.

Standing on it

A year here. A full year lasts just 23.1 Earth days.

By the numbers

Size. About 1.5× the width of Earth.
Mass. About 2.1× the mass of Earth.
Your weight. You'd weigh about 0.9× your Earth weight standing here.
Temperature. A scorching 72°C on average.

How we found it

Discovery. Found by Kepler using the transit method.

Cosmic context

Crowded system. One of at least 4 planets orbiting its star.

Properties

density gcc: 3.6
discovery facility: Kepler
discovery method: Transit
dist ly: 218.0757
eccentricity: 0.01
eq temp k: 345
insolation: 3.4
mass earth: 2.1
name: Kepler-138 d
orbital period days: 23.0923
radius earth: 1.51
sys num planets: 4

About Kepler-138 d

Kepler-138 d is a common exoplanet. It lies about 218.1 light-years from Earth, has an equilibrium temperature near 345 K, spans roughly 1.51 Earth radii and weighs about 2.1 Earth masses.

One of at least 4 planets orbiting its star.

How to see it

Like any astronomical target, Kepler-138 d 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 Kepler-138 d is a common exoplanet

Kepler-138 d scores 22 points on Spacedle's rarity scale, which places it in the common tier. Another 2 points would lift it into a rarer tier.

That score comes from 4 science badges — Confirmed exoplanet, Super-Earth, Multi-planet system and Found by Kepler — 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.