← Back to dex
Epic exoplanet 47 EP

Kepler-129 c

RA 285.3112° · Dec 47.8485° · exoplanet

Loading sky survey…
🌌 View in 3D star map
Tonight’s visibility

Computing the sky for your location…

Score breakdown

· 6 badges
47 pts · Epic
Epic 68 pts → Anomaly
  • Denser than iron +18
  • Distant (>1000 ly) +10
  • Multi-planet system +6
  • Confirmed exoplanet +5
  • Sub-Neptune +5
  • Found by Kepler +3
Total score 47

21 more points to reach Anomaly.

Badges

  • Confirmed exoplanet · +5
  • Sub-Neptune · +5
  • Denser than iron · +18
  • Multi-planet system · +6
  • Found by Kepler · +3
  • Distant (>1000 ly) · +10

Trivia

What makes it special

  • Heavyweight. Packed denser than solid iron.

Could we get there?

  • Verdict. Impossible with our current technology — and the next millennium of it.

Getting there

  • Aboard Voyager 1. ≈ 23.4 million years at Voyager 1's speed (17 km/s).
  • Fastest probe ever. ≈ 2.1 million years even at the Parker Solar Probe's 192 km/s.
  • At 10% light speed. ≈ 13.3 thousand years in a starship at a tenth of light speed.
  • Distance. 1333 light-years from Earth.

Look-back time

  • Look-back time. The light you'd see left around the year 693.

Saying hello

  • Say hello. A radio message and its reply would take 2667 years round-trip.

Standing on it

  • A year here. A full year lasts just 82.2 Earth days.

By the numbers

  • Size. About 2.5× the width of Earth.
  • Volume. About 16 Earths could fit inside it.
  • Mass. About 43× the mass of Earth.
  • Your weight. You'd weigh about 6.8× your Earth weight standing here.
  • Density. Denser than solid iron.
  • Temperature. A scorching 252°C on average.

How we found it

  • Discovery. Found by Kepler using the transit method.

Cosmic context

  • Crowded system. One of at least 3 planets orbiting its star.

Properties

density gcc
14.8
discovery facility
Kepler
discovery method
Transit
dist ly
1333.4725
eccentricity
0.2
eq temp k
525
insolation
17.554
mass earth
43
name
Kepler-129 c
orbital period days
82.2
radius earth
2.52
sys num planets
3
spacedle A daily roll through the real universe. © 2026 spacedle. Buy me a coffee

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.