- weight
- 2.04 g
- sun
- 22.1× wider
- sky
- warm white
Illustration computed from this world’s measured and derived values, not a photograph.
Kepler-221 b
Kepler-221 b is a confirmed sub-Neptune exoplanet 1,256 ly from Earth in the constellation Cygnus, discovered in 2014 by Kepler.
Transit: spotted by the tiny, repeating dip in its star’s light each time the planet crosses in front of it.
Standing on Kepler-221 b, you would weigh about 104% more than you do on Earth. Its yellow, Sun-like star looks 22.1× wider than ours, bathing the surface in warm white light. It is likely tidally locked, so that sun never moves in the sky: one hemisphere in endless day, the other in permanent night. A year passes in just 2.8 days, and at an estimated 817°C (1502°F) it is furnace-hot.
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
Heavier than home, at 2.0 times Earth's gravity. A child would end up markedly shorter and powerfully built, about 0.87x as tall as on Earth: a 5 ft 10 in adult could stand nearer 5 ft 1 in. Bones, muscle, and heart would all grow heavier just to stand and move.
- Bones
- Thick and dense
- More weight to bear forces the skeleton to grow denser and stronger all through childhood.
- Heart
- Large and powerful
- Pushing blood upward against stronger gravity demands a bigger, harder-working heart.
- Movement
- Low and deliberate
- A fall under this gravity lands hard, so movement stays slow, planted, and careful.
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 high and thin, almost cartoonish.
Assuming Earth-like air at this world's temperature of about 817°C (1502°F), sound would travel roughly 95% faster than on Earth, so your voice would sound high and thin, almost cartoonish. The real atmosphere is unknown, so this is a best guess.
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.
- !Furnace-hot at around 817°C (1502°F), with no liquid water and no shade anywhere.
- !Noticeably heavy, 2.0 times Earth's gravity.
- !Its star delivers about 309 times the sunlight Earth gets, a blinding, sterilizing glare.
- !Earth-similarity index 0.11: this world has almost nothing in common with our own.
- !Likely tidally locked: one hemisphere in endless day, the other in permanent night.
A playful read of Kepler-221 b’s measured and computed values, not a real advisory.
How long to get there · 1,256 ly away
Zoom out: star → system → (soon) galaxy arm, host black hole, and a real image of the host galaxy.
Matched telescope & eyepiece recommendations are coming. Any product links will carry a clear affiliate disclosure.
What is the gravity on Kepler-221 b?
Kepler-221 b's surface gravity is about 2.0 times Earth's.
How much would you weigh on Kepler-221 b?
Someone who weighs 150 pounds on Earth would weigh about 306 pounds on Kepler-221 b.
How far is Kepler-221 b from Earth?
Kepler-221 b lies about 1,256 light-years from Earth.
How long would it take to get to Kepler-221 b?
At the speed of NASA's Parker Solar Probe, the fastest craft ever built, the journey would take about 2.0 million years.
How hot is Kepler-221 b?
Kepler-221 b's equilibrium temperature, the balance it reaches from its star's light alone before any greenhouse warming, is about 817°C (1502°F).
How long is a year on Kepler-221 b?
Kepler-221 b completes one orbit of its star in 2.8 days.
Illustration generated from Kepler-221 b's confirmed parameters, not a photograph.