About K2-129 b
K2-129 b is a common exoplanet. It lies about 90.7 light-years from Earth, has an equilibrium temperature near 419 K, spans roughly 1.04 Earth radii and weighs about 1.12 Earth masses.
Almost exactly Earth-sized.
Common exoplanet 21 EP
K2-129 b
RA 289.1485° · Dec -25.6463° · exoplanet
Score breakdown
· 2 badgesCommon 24 pts → Uncommon
- Earth-sized +16
- Confirmed exoplanet +5
Total score 21
3 more points to reach Uncommon.
Badges
- Confirmed exoplanet · +5
- Earth-sized · +16
Trivia
Could we get there?
- Verdict. Hopelessly far for any craft humanity can build today.
Getting there
- Aboard Voyager 1. ≈ 1.6 million years at Voyager 1's speed (17 km/s).
- Fastest probe ever. ≈ 141.6 thousand years even at the Parker Solar Probe's 192 km/s.
- At 10% light speed. ≈ 907 years in a starship at a tenth of light speed.
- Distance. 90.7 light-years from Earth.
Look-back time
- Look-back time. The light you'd see left around the year 1935.
Saying hello
- Say hello. A radio message and its reply would take 181 years round-trip.
Standing on it
- A year here. A full year lasts just 8.2 Earth days.
By the numbers
- Size. Almost exactly Earth-sized.
- Mass. About 1.1× the mass of Earth.
- Your weight. You'd weigh about 1.0× your Earth weight standing here.
- Temperature. A scorching 146°C on average.
How we found it
- Discovery. Found by K2 using the transit method.
Properties
- density gcc
- 5.47
- discovery facility
- K2
- discovery method
- Transit
- dist ly
- 90.6573
- eccentricity
- 0.13
- eq temp k
- 419.19
- insolation
- 4.5
- mass earth
- 1.12
- name
- K2-129 b
- orbital period days
- 8.2395
- radius earth
- 1.04
- sys num planets
- 1
How to see it
Like any astronomical target, K2-129 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 K2-129 b is a common exoplanet
K2-129 b scores 21 points on Spacedle's rarity scale, which places it in the common tier. Another 3 points would lift it into a rarer tier.
That score comes from 2 science badges — Confirmed exoplanet and Earth-sized — 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.