Rare exoplanet 36 EP

Proxima Cen d

RA 217.3935° · Dec -62.6762° · exoplanet

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Score breakdown

· 3 badges

36 pts · Rare

Rare 46 pts → Epic

Stellar next door (<10 ly) +25
Multi-planet system +6
Confirmed exoplanet +5

Total score 36

10 more points to reach Epic.

Badges

Confirmed exoplanet · +5
Multi-planet system · +6
Stellar next door (<10 ly) · +25

Trivia

What makes it special

Next-door neighbour. One of the closest objects of its kind to the Sun.

Could we get there?

Verdict. A multi-generation starship could one day attempt the crossing.

Getting there

Aboard Voyager 1. ≈ 74.6 thousand years at Voyager 1's speed (17 km/s).
Fastest probe ever. ≈ 6626 years even at the Parker Solar Probe's 192 km/s.
At 10% light speed. ≈ 42.4 years in a starship at a tenth of light speed.
Distance. 4.2 light-years from Earth.

Look-back time

Look-back time. The light you'd see left around the year 2022.

Saying hello

Say hello. A radio message and its reply would take 8.5 years round-trip.

Standing on it

A year here. A full year lasts just 5.1 Earth days.

By the numbers

Size. Around 69% of Earth's width.
Mass. About 0.3× the mass of Earth.
Your weight. You'd weigh about 0.5× your Earth weight standing here.
Temperature. A surprisingly temperate 9°C average.

How we found it

Discovery. Found by La Silla Observatory using the radial velocity method.

Cosmic context

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

Properties

density gcc: 4.31
discovery facility: La Silla Observatory
discovery method: Radial Velocity
dist ly: 4.2439
eccentricity: 0
eq temp k: 282
insolation: 1.814
mass earth: 0.26
name: Proxima Cen d
orbital period days: 5.1234
radius earth: 0.692
sys num planets: 2

About Proxima Cen d

Proxima Cen d is a rare exoplanet. It lies about 4.2 light-years from Earth, has an equilibrium temperature near 282 K, spans roughly 0.69 Earth radii and weighs about 0.26 Earth masses.

One of the closest objects of its kind to the Sun.

How to see it

Like any astronomical target, Proxima Cen 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 Proxima Cen d is a rare exoplanet

Proxima Cen d scores 36 points on Spacedle's rarity scale, which places it in the rare tier. Another 10 points would lift it into a rarer tier.

That score comes from 3 science badges — Confirmed exoplanet, Multi-planet system and Stellar next door (<10 ly) — 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.