What it’s like to stand here

UKIRT-2017-BLG-001L b

weight: 2.17 g

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

UKIRT-2017-BLG-001L b

UKIRT-2017-BLG-001L b is a confirmed gas-giant exoplanet 20,548 ly from Earth in the constellation Sagittarius, discovered in 2018 by Mauna Kea Observatory.

20,548 lyDiscovered in 2018 by Mauna Kea Observatory

Microlensing: spotted when its gravity briefly magnified the light of a more distant star.

UKIRT-2017-BLG-001L →

host star

13.70 R⊕

radius · estimated

407 M⊕

mass · microlensing (model-dependent)

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orbital period

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avg temp

Human scale

UKIRT-2017-BLG-001L b is a giant ball of gas with no solid surface to stand on; you would simply sink into ever-thicker cloud.

2.17 g

surface gravity (no solid surface · measured mass)

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one year, in Earth time

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sun size, needs orbit

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sky color, needs star temp

0.5×

how high you could jump vs Earth

normal

day/night cycle (not tidally locked)

Calculate your exact weight on UKIRT-2017-BLG-001L b →

What these mean: surface gravity · tidal locking · equilibrium temperature

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 2.2 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, and we have no temperature for this world, so its cloud-top acoustics cannot be modelled. In hydrogen-helium air sound races, so a voice would leap to a thin, almost cartoonish squeak.

The journey

Cosmic travel advisory

★☆☆☆☆

Do not travel