What it’s like to stand here
HD 20868 b
weight
≥ 2.12 g
sun
0.80× as wide
sky
amber-orange

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

Gas giant · likely temperate

HD 20868 b

HD 20868 b is a confirmed gas-giant exoplanet 156 ly from Earth in the constellation Fornax, discovered in 2008 by La Silla Observatory.

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

HD 20868
host star
13.70 R⊕
radius
397 M⊕
mass · minimum (m·sin i)
381 days
orbital period
-66°C (-87°F)
avg temp
Human scale

HD 20868 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 0.80× as wide as ours, bathing the cloud tops in amber-orange light. A year here lasts 381 days, and at an estimated -66°C (-87°F) it is deeply frozen.

≥ 2.12 g
surface gravity (no solid surface · minimum mass only)
381 days
one year, in Earth time
0.80× as wide
how big its sun looks vs ours
amber-orange
midday sky tint
0.5×
how high you could jump vs Earth
normal
day/night cycle (not tidally locked)
Calculate your exact weight on HD 20868 b
Earth Similarity Index0.37#1,532 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 · habitable zone

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 2.1 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 1,024 metres per second, 3 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 ≈ 1024 m/s · 3.01× 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
  • !Cold at about -66°C (-87°F), survivable only fully suited and heated.
  • !There is nowhere to land: no ground, no deck, only cloud that thickens into crushing pressure.
  • It orbits within the habitable zone, where a world could in principle hold liquid water.

A playful read of HD 20868 b’s measured and computed values, not a real advisory.

How long to get there · 156 ly away
Jet airliner
187 million years
dies en route1000-yr cryo: fails
Parker Solar Probethe fastest craft ever built
242,752 years
dies en route1000-yr cryo: fails
Light speed
156 years
dies en route1000-yr cryo: survives
Warp 10
57 days
arrives thriving
Folding spacetimeinstant, plus 1 hr of paperwork
1 hour
arrives thriving
Size vs Earth
EarthHD 20868 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
SMALL TELESCOPE NEEDED
Host-star brightnessmag 9.9
ConstellationFornax
To see the host star4-6" (100-150 mm) telescope
Gear bridge

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

Common questions

What is the gravity on HD 20868 b?

HD 20868 b is a gas giant with no solid surface to stand on. At its cloud tops, gravity pulls at least 2.1 times as hard as Earth's.

How far is HD 20868 b from Earth?

HD 20868 b lies about 156 light-years from Earth.

How long would it take to get to HD 20868 b?

At the speed of NASA's Parker Solar Probe, the fastest craft ever built, the journey would take about 242,752 years.

How hot is HD 20868 b?

HD 20868 b's equilibrium temperature, the balance it reaches from its star's light alone before any greenhouse warming, is about -66°C (-87°F).

Is HD 20868 b habitable?

HD 20868 b orbits inside its star's habitable zone, the range of distances where liquid water could be stable, and its Earth-similarity index is 0.37. That makes it worth studying, but it is not evidence of life: we have no measurement of its atmosphere, water, or surface.

How long is a year on HD 20868 b?

HD 20868 b completes one orbit of its star in 381 days.

Illustration generated from HD 20868 b's confirmed parameters, not a photograph.