What it’s like to stand here
8 UMi b
weight
≥ 2.88 g
sun
23.1× wider
sky
amber-orange

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

8 UMi b

8 UMi b is a confirmed gas-giant exoplanet 530 ly from Earth in the constellation Ursa Minor, discovered in 2015 by Bohyunsan Optical Astronomical Observatory.

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

8 UMi
host star
13.50 R⊕
radius
524 M⊕
mass · minimum (m·sin i)
93 days
orbital period
853°C (1568°F)
avg temp
Human scale

8 UMi b is a giant ball of gas with no solid surface to stand on; you would simply sink into ever-thicker cloud. Its orange dwarf looks 23.1× wider than ours, bathing the cloud tops in amber-orange light. A year passes in just 93 days, and at an estimated 853°C (1568°F) it is furnace-hot.

≥ 2.88 g
surface gravity (no solid surface · minimum mass only)
93 days
one year, in Earth time
23.1× wider
how big its sun looks vs ours
amber-orange
midday sky tint
0.3×
how high you could jump vs Earth
normal
day/night cycle (not tidally locked)
Calculate your exact weight on 8 UMi b
Earth Similarity Index0.11#4,943 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 2.9 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 2,388 metres per second, 7 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.

sound speed ≈ 2388 m/s · 7.02× 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
  • !Furnace-hot at around 853°C (1568°F), with no liquid water and no shade anywhere.
  • !There is nowhere to land: no ground, no deck, only cloud that thickens into crushing pressure.
  • !Its star delivers about 248 times the sunlight Earth gets, a blinding, sterilizing glare.
  • !Earth-similarity index 0.11: this world has almost nothing in common with our own.

A playful read of 8 UMi b’s measured and computed values, not a real advisory.

How long to get there · 530 ly away
Jet airliner
636 million years
dies en route1000-yr cryo: fails
Parker Solar Probethe fastest craft ever built
826,863 years
dies en route1000-yr cryo: fails
Light speed
530 years
dies en route1000-yr cryo: survives
Warp 10
194 days
arrives thriving
Folding spacetimeinstant, plus 1 hr of paperwork
1 hour
arrives thriving
Size vs Earth
Earth8 UMi b 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
BINOCULARS NEEDED
Host-star brightnessmag 6.8
ConstellationUrsa Minor
To see the host star50 mm binoculars
Gear bridge

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

Common questions

What is the gravity on 8 UMi b?

8 UMi b is a gas giant with no solid surface to stand on. At its cloud tops, gravity pulls at least 2.9 times as hard as Earth's.

How far is 8 UMi b from Earth?

8 UMi b lies about 530 light-years from Earth.

How long would it take to get to 8 UMi b?

At the speed of NASA's Parker Solar Probe, the fastest craft ever built, the journey would take about 826,863 years.

How hot is 8 UMi b?

8 UMi b's equilibrium temperature, the balance it reaches from its star's light alone before any greenhouse warming, is about 853°C (1568°F).

How long is a year on 8 UMi b?

8 UMi b completes one orbit of its star in 93 days.

Illustration generated from 8 UMi b's confirmed parameters, not a photograph.