Epic exoplanet 46 EP

GJ 3998 d

RA 259.0021° · Dec 11.0562° · exoplanet

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Score breakdown

· 4 badges

46 pts · Epic

Epic 68 pts → Anomaly

In the habitable zone +30
Multi-planet system +6
Confirmed exoplanet +5
Sub-Neptune +5

Total score 46

22 more points to reach Anomaly.

Badges

Confirmed exoplanet · +5
In the habitable zone · +30
Sub-Neptune · +5
Multi-planet system · +6

Trivia

What makes it special

Goldilocks zone. Sits where it's neither too hot nor too cold — liquid water could exist.

Could we get there?

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

Getting there

Aboard Voyager 1. ≈ 1 million years at Voyager 1's speed (17 km/s).
Fastest probe ever. ≈ 92.4 thousand years even at the Parker Solar Probe's 192 km/s.
At 10% light speed. ≈ 592 years in a starship at a tenth of light speed.
Distance. 59.2 light-years from Earth.

Look-back time

Look-back time. The light you'd see left around the year 1967.

Saying hello

Say hello. A radio message and its reply would take 118 years round-trip.

Standing on it

A year here. A full year lasts just 41.8 Earth days.

By the numbers

Size. About 2.3× the width of Earth.
Volume. About 12.8 Earths could fit inside it.
Mass. About 6.1× the mass of Earth.
Your weight. You'd weigh about 1.1× your Earth weight standing here.
Temperature. A surprisingly temperate 19°C average.

How we found it

Discovery. Found by Multiple Observatories using the radial velocity method.

Cosmic context

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

Properties

density gcc: 2.6
discovery facility: Multiple Observatories
discovery method: Radial Velocity
dist ly: 59.1839
eccentricity: 0
eq temp k: 292.23
habitable zone: yes
insolation: 1.2
mass earth: 6.07
name: GJ 3998 d
orbital period days: 41.78
radius earth: 2.34
sys num planets: 3

About GJ 3998 d

GJ 3998 d is an epic exoplanet. It lies about 59.2 light-years from Earth, has an equilibrium temperature near 292 K, spans roughly 2.34 Earth radii and weighs about 6.07 Earth masses.

Sits where it's neither too hot nor too cold — liquid water could exist.

How to see it

Like any astronomical target, GJ 3998 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 GJ 3998 d is an epic exoplanet

GJ 3998 d scores 46 points on Spacedle's rarity scale, which places it in the epic tier. Another 22 points would lift it into a rarer tier.

That score comes from 4 science badges — Confirmed exoplanet, In the habitable zone, Sub-Neptune and Multi-planet system — 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.