What it’s like to stand here
HD 153950 b
weight
≥ 5.38 g
sun
about the same
sky
bright white

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

Gas giant · likely temperate

HD 153950 b

HD 153950 b is a confirmed gas-giant exoplanet 158 ly from Earth in the constellation Scorpius, discovered in 2008 by La Silla Observatory.

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

HD 153950
host star
13.20 R⊕
radius
938 M⊕
mass · minimum (m·sin i)
499 days
orbital period
22°C (72°F)
avg temp
Human scale

HD 153950 b is a giant ball of gas with no solid surface to stand on; you would simply sink into ever-thicker cloud. Its yellow-white star looks about the same size as ours, bathing the cloud tops in bright white light. A year here lasts 499 days, and at an estimated 22°C (72°F) it is warm.

≥ 5.38 g
surface gravity (no solid surface · minimum mass only)
499 days
one year, in Earth time
about the same
how big its sun looks vs ours
bright white
midday sky tint
0.2×
how high you could jump vs Earth
normal
day/night cycle (not tidally locked)
Calculate your exact weight on HD 153950 b
Earth Similarity Index0.45#872 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 5.4 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 1,222 metres per second, 3.6 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 ≈ 1222 m/s · 3.59× 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
  • Surface temperatures near 22°C (72°F) fall in the range where liquid water is at least possible.
  • !There is nowhere to land: no ground, no deck, only cloud that thickens into crushing pressure.

A playful read of HD 153950 b’s measured and computed values, not a real advisory.

How long to get there · 158 ly away
Jet airliner
190 million years
dies en route1000-yr cryo: fails
Parker Solar Probethe fastest craft ever built
246,478 years
dies en route1000-yr cryo: fails
Light speed
158 years
dies en route1000-yr cryo: survives
Warp 10
58 days
arrives thriving
Folding spacetimeinstant, plus 1 hr of paperwork
1 hour
arrives thriving
Size vs Earth
EarthHD 153950 b is 13× 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 7.4
ConstellationScorpius
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 HD 153950 b?

HD 153950 b is a gas giant with no solid surface to stand on. At its cloud tops, gravity pulls at least 5.4 times as hard as Earth's.

How far is HD 153950 b from Earth?

HD 153950 b lies about 158 light-years from Earth.

How long would it take to get to HD 153950 b?

At the speed of NASA's Parker Solar Probe, the fastest craft ever built, the journey would take about 246,478 years.

How hot is HD 153950 b?

HD 153950 b's equilibrium temperature, the balance it reaches from its star's light alone before any greenhouse warming, is about 22°C (72°F).

Is HD 153950 b habitable?

HD 153950 b orbits near its star's habitable zone, the range of distances where liquid water could be stable, and its Earth-similarity index is 0.45. 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 153950 b?

HD 153950 b completes one orbit of its star in 499 days.

Illustration generated from HD 153950 b's confirmed parameters, not a photograph.