- weight
- 0.39 g
- sun
- 12.3× wider
- sky
- deep orange
Illustration computed from this world’s measured and derived values, not a photograph.
AU Mic b
AU Mic b is a confirmed Neptune-like exoplanet 31.7 ly from Earth in the constellation Microscopium, discovered in 2020 by Transiting Exoplanet Survey Satellite (TESS).
Transit: spotted by the tiny, repeating dip in its star’s light each time the planet crosses in front of it.
AU Mic b is a giant ball of gas with no solid surface to stand on; you would simply sink into ever-thicker cloud. Its red dwarf looks 12.3× wider than ours, bathing the cloud tops in deep orange light. A year passes in just 8.5 days, and at an estimated 282°C (539°F) it is blistering.
How closely this world matches Earth in size and warmth, from 0 to 1 (Earth = 1.0). Computed by gravityfinder. See every world ranked →
What these mean: surface gravity · tidal locking · equilibrium temperature · Earth similarity
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 0.4 times Earth's 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 demo
Your voice would sound a thin, helium-fast squeak.
There is no surface to stand on; this is the sound at the cloud tops, where the air is mostly hydrogen and helium, the lightest gases there are. Sound races through them at about 1,676 metres per second, 4.9 times its Earth speed, flipping a voice into a thin, cartoon-helium squeak. The temperature behind that number is this world's computed equilibrium temperature; its real atmosphere is unknown. The demo plays the shift capped at 1.8x; the real effect would be even stronger.
A real voice sample, pitch-shifted (tempo held constant) to suggest the acoustics: a playful approximation, not a precise simulation. Voice: Lingua Libre / Vealhurl, CC BY-SA 4.0.
- !Blistering at about 282°C (539°F), far too hot for liquid water on the surface.
- !There is nowhere to land: no ground, no deck, only cloud that thickens into crushing pressure.
A playful read of AU Mic b’s measured and computed values, not a real advisory.
How long to get there · 31.7 ly away
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.
What is the gravity on AU Mic b?
AU Mic b is a gas giant with no solid surface to stand on. At its cloud tops, gravity pulls about 0.39 times as hard as Earth's.
How far is AU Mic b from Earth?
AU Mic b lies about 31.7 light-years from Earth.
How long would it take to get to AU Mic b?
At the speed of NASA's Parker Solar Probe, the fastest craft ever built, the journey would take about 49,454 years.
How hot is AU Mic b?
AU Mic b's equilibrium temperature, the balance it reaches from its star's light alone before any greenhouse warming, is about 282°C (539°F).
How long is a year on AU Mic b?
AU Mic b completes one orbit of its star in 8.5 days.
Illustration generated from AU Mic b's confirmed parameters, not a photograph.