What it’s like to stand here
GJ 3512 c
weight
≥ 0.70 g
sun
0.08× as wide
sky
dim red

Illustration computed from this world’s measured and derived values, not a photograph.

GJ 3512 c

GJ 3512 c is a confirmed gas-giant exoplanet 30.9 ly from Earth in the constellation Ursa Major, discovered in 2020 by Multiple Observatories.

Radial Velocity: spotted by the gravitational wobble the planet tugs in its star.

GJ 3512
host star
14.30 R⊕
radius
144 M⊕
mass · minimum (m·sin i)
6.4 years
orbital period
-230°C (-382°F)
avg temp
Human scale

GJ 3512 c 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 0.08× as wide as ours, bathing the cloud tops in dim red light. A year here lasts 6.4 Earth years, and at an estimated -230°C (-382°F) it is colder than almost anywhere in the solar system.

≥ 0.70 g
surface gravity (no solid surface · minimum mass only)
6.4 years
one year, in Earth time
0.08× as wide
how big its sun looks vs ours
dim red
midday sky tint
1.4×
how high you could jump vs Earth
normal
day/night cycle (not tidally locked)
Calculate your exact weight on GJ 3512 c
Earth Similarity Index0.06#5,491 of 5,788 ranked worlds

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
NO GROUND: A DRIFTER, NOT A WALKER

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 about 0.7 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 466 metres per second, 1.4 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.

sound speed ≈ 466 m/s · 1.37× Earth

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.

The journey
Cosmic travel advisory
☆☆☆☆
Do not travel
  • !Cryogenic at roughly -230°C (-382°F), cold enough to freeze most gases solid.
  • !There is nowhere to land: no ground, no deck, only cloud that thickens into crushing pressure.
  • !Earth-similarity index 0.06: this world has almost nothing in common with our own.

A playful read of GJ 3512 c’s measured and computed values, not a real advisory.

How long to get there · 30.9 ly away
Jet airliner
37.1 million years
dies en route1000-yr cryo: fails
Parker Solar Probethe fastest craft ever built
48,255 years
dies en route1000-yr cryo: fails
Light speed
31 years
arrives middle-aged
Warp 10
11 days
arrives thriving
Folding spacetimeinstant, plus 1 hr of paperwork
1 hour
arrives thriving
Size vs Earth
EarthGJ 3512 c is 14× the width of Earth
Explore from here · roam the neighborhood

Zoom out: star → system → (soon) galaxy arm, host black hole, and a real image of the host galaxy.

Can you see it tonight? · observe
FAINT: LARGE TELESCOPE NEEDED
Host-star brightnessmag 15.2
ConstellationUrsa Major
To see the host star10"+ (250 mm) telescope, dark sky
Gear bridge

Matched telescope & eyepiece recommendations are coming. Any product links will carry a clear affiliate disclosure.

Common questions

What is the gravity on GJ 3512 c?

GJ 3512 c is a gas giant with no solid surface to stand on. At its cloud tops, gravity pulls at least 0.70 times as hard as Earth's.

How far is GJ 3512 c from Earth?

GJ 3512 c lies about 30.9 light-years from Earth.

How long would it take to get to GJ 3512 c?

At the speed of NASA's Parker Solar Probe, the fastest craft ever built, the journey would take about 48,255 years.

How hot is GJ 3512 c?

GJ 3512 c's equilibrium temperature, the balance it reaches from its star's light alone before any greenhouse warming, is about -230°C (-382°F).

How long is a year on GJ 3512 c?

GJ 3512 c completes one orbit of its star in 6.4 years.

Illustration generated from GJ 3512 c's confirmed parameters, not a photograph.