- weight
- ≈ 0.72 g
- sun
- 23.1× wider
- sky
- deep orange
Illustration computed from this world’s measured and derived values, not a photograph.
K2-257 b
K2-257 b is a confirmed rocky exoplanet 209 ly from Earth in the constellation Virgo, discovered in 2018 by K2.
Transit: spotted by the tiny, repeating dip in its star’s light each time the planet crosses in front of it.
Standing on K2-257 b, you would weigh roughly about 28% less than you do on Earth. Its orange dwarf looks 23.1× wider than ours, bathing the surface in deep orange 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 1.6 days, and at an estimated 516°C (961°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
Lighter than home, at about 0.72 times Earth's gravity. A child raised here would likely grow taller and more slender than their Earth-raised parents, about 1.1x taller than on Earth: a 5 ft 10 in adult could stand nearer 6 ft 3 in.
- Bones
- Light and slender
- With little weight to carry, the growing skeleton lays down far less bone, the way astronauts' bones thin in months of low gravity.
- Movement
- Bounding and springy
- So little weight means each step would carry the body up and forward in long, floating strides.
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 516°C (961°F), sound would travel roughly 66% 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 516°C (961°F), with no liquid water and no shade anywhere.
- Surface gravity is close to Earth's, about 0.72 times, so you would move much as you do here.
- !Its star delivers about 89 times the sunlight Earth gets, a blinding, sterilizing glare.
- !Likely tidally locked: one hemisphere in endless day, the other in permanent night.
A playful read of K2-257 b’s measured and computed values, not a real advisory.
How long to get there · 209 ly away
No other confirmed planets here yet. New ones auto-appear as telescopes report.
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 K2-257 b?
K2-257 b's surface gravity is about 0.72 times Earth's, estimated from its size.
How much would you weigh on K2-257 b?
Someone who weighs 150 pounds on Earth would weigh about 108 pounds on K2-257 b.
How far is K2-257 b from Earth?
K2-257 b lies about 209 light-years from Earth.
How long would it take to get to K2-257 b?
At the speed of NASA's Parker Solar Probe, the fastest craft ever built, the journey would take about 325,586 years.
How hot is K2-257 b?
K2-257 b's equilibrium temperature, the balance it reaches from its star's light alone before any greenhouse warming, is about 516°C (961°F).
How long is a year on K2-257 b?
K2-257 b completes one orbit of its star in 1.6 days.
Illustration generated from K2-257 b's confirmed parameters, not a photograph.