About ROXs 12 b
ROXs 12 b is an epic exoplanet. It lies about 445.7 light-years from Earth, has an equilibrium temperature near 13 K, spans roughly 12.2 Earth radii and weighs about 5,085 Earth masses.
A deep-frozen world far from its star's warmth.
Epic exoplanet 60 EP
ROXs 12 b
RA 246.6168° · Dec -25.4467° · exoplanet
Score breakdown
· 6 badgesEpic 68 pts → Anomaly
- Denser than iron +18
- Directly imaged +16
- Eccentric orbit +9
- Frozen world +8
- Confirmed exoplanet +5
- Gas giant +4
Total score 60
8 more points to reach Anomaly.
Badges
- Confirmed exoplanet · +5
- Gas giant · +4
- Frozen world · +8
- Eccentric orbit · +9
- Denser than iron · +18
- Directly imaged · +16
Trivia
What makes it special
- Frozen world. A deep-frozen world far from its star's warmth.
- Heavyweight. Packed denser than solid iron.
Could we get there?
- Verdict. Hopelessly far for any craft humanity can build today.
Getting there
- Aboard Voyager 1. ≈ 7.8 million years at Voyager 1's speed (17 km/s).
- Fastest probe ever. ≈ 695.9 thousand years even at the Parker Solar Probe's 192 km/s.
- At 10% light speed. ≈ 4457 years in a starship at a tenth of light speed.
- Distance. 446 light-years from Earth.
Look-back time
- Look-back time. The light you'd see left around the year 1580.
Saying hello
- Say hello. A radio message and its reply would take 891 years round-trip.
By the numbers
- Size. About 12.2× the width of Earth.
- Volume. About 1816 Earths could fit inside it.
- Mass. Roughly 5085× Earth's mass — about 16 Jupiters.
- Your weight. You'd weigh about 34.2× your Earth weight standing here.
- Density. Denser than solid iron.
- Temperature. A frigid -260°C — colder than dry ice.
How we found it
- Discovery. Found by W. M. Keck Observatory using the imaging method.
Cosmic context
- Wild orbit. Its highly elliptical path swings between scorching and frozen each lap.
Properties
- density gcc
- 15.4
- discovery facility
- W. M. Keck Observatory
- discovery method
- Imaging
- dist ly
- 445.6922
- eccentricity
- 0.83
- eq temp k
- 13.23
- insolation
- 0
- mass earth
- 5085
- name
- ROXs 12 b
- radius earth
- 12.2
- sys num planets
- 1
How to see it
Like any astronomical target, ROXs 12 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 ROXs 12 b is an epic exoplanet
ROXs 12 b scores 60 points on Spacedle's rarity scale, which places it in the epic tier. Another 8 points would lift it into a rarer tier.
That score comes from 6 science badges — Confirmed exoplanet, Gas giant, Frozen world, Eccentric orbit, Denser than iron and Directly imaged — 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.