- sky
- icy blue-white
Illustration computed from this world’s measured and derived values, not a photograph.
ZTF J1828+2308 b
ZTF J1828+2308 b is a confirmed gas-giant exoplanet 658 ly from Earth in the constellation Hercules, discovered in 2025 by Zwicky Transient Facility.
Transit: spotted by the tiny, repeating dip in its star’s light each time the planet crosses in front of it (what that means).
ZTF J1828+2308 b is a giant ball of gas with no solid surface to stand on; you would simply sink into ever-thicker cloud. Bathing the cloud tops in icy blue-white light. A year passes in just 2.7 hours.
Catalog values (NASA Exoplanet Archive): mass 6,357 M⊕, radius 11.13 R⊕. Its catalog mass and radius imply a density of 25.4 g/cm³, denser than compressed iron, so they cannot both be right, and gravityfinder does not use ZTF J1828+2308 b in gravity rankings or weight calculations.
What these mean: surface gravity · tidal locking · equilibrium temperature
If your children grew up herea playful thought experiment
There is no ground here to grow up on, only bottomless sky. A child could never stand, walk, or even fall to a surface, because there isn't one. Under crushing gravity and pressure that only climbs the deeper you go, anything built for this world would not look human at all: picture something closer to a deep-sea creature than a person, broad and buoyant, drifting through the cloud decks with no need for legs and no floor to land on.
- Body plan
- Floating, not upright
- With no surface and no fixed up or down, a skeleton built for standing would be useless; a drifting, gas-filled body would not.
- Build
- Broad and pressure-hardened
- Pressure rises without limit toward the interior, so anything alive would have to be built like a deep-sea animal, not a land one.
A playful thought experiment from this world’s gravity, not a prediction about any real person. No human has ever grown up off Earth, so no one truly knows; the direction (taller in low gravity, shorter and stockier in high) follows how growing bodies respond to weight.
Hear how a voice sounds herea computed acoustic demoEXPERIMENTAL · just for fun
Your voice would sound a thin, helium-fast squeak.
There is no surface to stand on, and we have no temperature for this world, so its cloud-top acoustics cannot be modelled. In hydrogen-helium air sound races, so a voice would leap to a thin, almost cartoonish squeak.
- !There is nowhere to land: no ground, no deck, only cloud that thickens into crushing pressure.
A playful read of ZTF J1828+2308 b’s measured and computed values, not a real advisory.
How long to get there · 658 ly awayCALCULATED
No other confirmed planets here yet. New ones auto-appear as telescopes report.
Zoom out: star → system → (soon) galaxy arm, host black hole, and a real image of the host galaxy.
Matched telescope & eyepiece recommendations are coming. Any product links will carry a clear affiliate disclosure.
How far is ZTF J1828+2308 b from Earth?
ZTF J1828+2308 b lies about 658 light-years from Earth.
How long would it take to get to ZTF J1828+2308 b?
At the speed of NASA's Parker Solar Probe, the fastest craft ever built, the journey would take about 1.0 million years.
How long is a year on ZTF J1828+2308 b?
ZTF J1828+2308 b completes one orbit of its star in 2.7 hours.
Illustration generated from ZTF J1828+2308 b's confirmed parameters, not a photograph.