Epic exoplanet 65 EP

WASP-121 b

RA 107.6002° · Dec -39.0973° · exoplanet

Loading sky survey…

🌌 View in 3D star map

Tonight’s visibility

Computing the sky for your location…

Score breakdown

· 6 badges

65 pts · Epic

Epic 68 pts → Anomaly

Ultra-hot Jupiter +26
Puffy low-density world +12
Hot Jupiter +10
Blasted by starlight +8
Confirmed exoplanet +5
Gas giant +4

Total score 65

3 more points to reach Anomaly.

Badges

Confirmed exoplanet · +5
Gas giant · +4
Hot Jupiter · +10
Ultra-hot Jupiter · +26
Puffy low-density world · +12
Blasted by starlight · +8

Trivia

What makes it special

Ultra-hot Jupiter. So hot that iron vaporises and rains back down as molten metal.
Cotton-candy planet. So low-density it would float on water.

Could we get there?

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

Getting there

Aboard Voyager 1. ≈ 15.5 million years at Voyager 1's speed (17 km/s).
Fastest probe ever. ≈ 1.4 million years even at the Parker Solar Probe's 192 km/s.
At 10% light speed. ≈ 8803 years in a starship at a tenth of light speed.
Distance. 880 light-years from Earth.

Look-back time

Look-back time. The light you'd see left around the year 1146.

Saying hello

Say hello. A radio message and its reply would take 1761 years round-trip.

Standing on it

A year here. A full year lasts just 1.3 Earth days.

By the numbers

Size. About 19.5× the width of Earth.
Volume. About 7445 Earths could fit inside it.
Mass. Roughly 372× Earth's mass — about 1.2 Jupiters.
Your weight. You'd weigh about 1.0× your Earth weight standing here.
Density. Less dense than water — drop it in a big enough ocean and it would float.
Temperature. Around 2409 K — hot enough to vaporise iron.

How we found it

Discovery. Found by SuperWASP using the transit method.

Properties

density gcc: 0.275
discovery facility: SuperWASP
discovery method: Transit
dist ly: 880.2885
eccentricity: 0
eq temp k: 2409
insolation: 6216.41
mass earth: 371.8592
name: WASP-121 b
orbital period days: 1.2749
radius earth: 19.526
sys num planets: 1

About WASP-121 b

WASP-121 b is an epic exoplanet. It lies about 880.3 light-years from Earth, has an equilibrium temperature near 2,409 K, spans roughly 19.53 Earth radii and weighs about 371.86 Earth masses.

So hot that iron vaporises and rains back down as molten metal.

How to see it

Like any astronomical target, WASP-121 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 WASP-121 b is an epic exoplanet

WASP-121 b scores 65 points on Spacedle's rarity scale, which places it in the epic tier. Another 3 points would lift it into a rarer tier.

That score comes from 6 science badges — Confirmed exoplanet, Gas giant, Hot Jupiter, Ultra-hot Jupiter, Puffy low-density world and Blasted by starlight — 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.