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Common exoplanet 21 EP

K2-209 b

RA 14.6903° · Dec 1.3828° · exoplanet

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Score breakdown

· 2 badges
21 pts · Common
Common 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. ≈ 4.4 million years at Voyager 1's speed (17 km/s).
  • Fastest probe ever. ≈ 389.6 thousand years even at the Parker Solar Probe's 192 km/s.
  • At 10% light speed. ≈ 2495 years in a starship at a tenth of light speed.
  • Distance. 250 light-years from Earth.

Look-back time

  • Look-back time. The light you'd see left around the year 1776.

Saying hello

  • Say hello. A radio message and its reply would take 499 years round-trip.

Standing on it

  • A year here. A full year lasts just 2.1 Earth days.

By the numbers

  • Size. Around 87% of Earth's width.
  • Mass. About 0.6× the mass of Earth.
  • Your weight. You'd weigh about 0.8× your Earth weight standing here.

How we found it

  • Discovery. Found by K2 using the transit method.

Properties

density gcc
4.92
discovery facility
K2
discovery method
Transit
dist ly
249.5048
mass earth
0.586
name
K2-209 b
orbital period days
2.0806
radius earth
0.8685
sys num planets
1

About K2-209 b

K2-209 b is a common exoplanet. It lies about 249.5 light-years from Earth, spans roughly 0.87 Earth radii, weighs about 0.59 Earth masses and completes an orbit every 2.08 days.

Around 87% of Earth's width.

How to see it

Like any astronomical target, K2-209 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 K2-209 b is a common exoplanet

K2-209 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.

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.