Rare exoplanet 45 EP

GJ 1148 b

RA 175.4326° · Dec 42.7516° · exoplanet

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Score breakdown

· 4 badges

45 pts · Rare

Rare 46 pts → Epic

In the habitable zone +30
Multi-planet system +6
Confirmed exoplanet +5
Gas giant +4

Total score 45

1 more point to reach Epic.

Badges

Confirmed exoplanet · +5
In the habitable zone · +30
Gas giant · +4
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. ≈ 631.3 thousand years at Voyager 1's speed (17 km/s).
Fastest probe ever. ≈ 56.1 thousand years even at the Parker Solar Probe's 192 km/s.
At 10% light speed. ≈ 359 years in a starship at a tenth of light speed.
Distance. 35.9 light-years from Earth.

Look-back time

Look-back time. The light you'd see left around the year 1990.

Saying hello

Say hello. A radio message and its reply would take 71.8 years round-trip.

Standing on it

A year here. A full year lasts just 41.4 Earth days.

By the numbers

Size. About 11.9× the width of Earth.
Volume. About 1685 Earths could fit inside it.
Mass. Roughly 96.7× Earth's mass — about 0.3 Jupiters.
Your weight. You'd weigh about 0.7× your Earth weight standing here.
Density. Less dense than water — drop it in a big enough ocean and it would float.
Temperature. A frigid -40°C — colder than dry ice.

How we found it

Discovery. Found by W. M. Keck Observatory using the radial velocity method.

Cosmic context

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

Properties

density gcc: 0.315
discovery facility: W. M. Keck Observatory
discovery method: Radial Velocity
dist ly: 35.9238
eccentricity: 0.38
eq temp k: 232.94
habitable zone: yes
insolation: 0.4906
mass earth: 96.7
name: GJ 1148 b
orbital period days: 41.38
radius earth: 11.9
sys num planets: 2

About GJ 1148 b

GJ 1148 b is a rare exoplanet. It lies about 35.9 light-years from Earth, has an equilibrium temperature near 233 K, spans roughly 11.9 Earth radii and weighs about 96.7 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 1148 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 GJ 1148 b is a rare exoplanet

GJ 1148 b scores 45 points on Spacedle's rarity scale, which places it in the rare tier. Another 1 point would lift it into a rarer tier.

That score comes from 4 science badges — Confirmed exoplanet, In the habitable zone, Gas giant 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.