What it’s like to stand here
Kepler-139 b
weight
0.81 g
sun
10.2× wider
sky
warm white

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

Kepler-139 b

Kepler-139 b is a confirmed sub-Neptune exoplanet 1,275 ly from Earth in the constellation Lyra, discovered in 2014 by Kepler.

ESI 0.291,275 lyDiscovered 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.

Kepler-139
host star
2.94 R⊕
radius
7.00 M⊕
mass · measured
16 days
orbital period
479°C (894°F)
avg temp
Human scale

Standing on Kepler-139 b, you would weigh about 19% less than you do on Earth. Its yellow, Sun-like star looks 10.2× 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 16 days, and at an estimated 479°C (894°F) it is furnace-hot.

0.81 g
your weight (measured mass)
16 days
one year, in Earth time
10.2× wider
how big its sun looks vs ours
warm white
midday sky tint
1.2×
how high you could jump vs Earth
likely
likely tidally locked: probably eternal day on one side, night on the other
Calculate your exact weight on Kepler-139 b
Earth Similarity Index0.29#2,608 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

If your children grew up herea playful thought experiment
EARTH HEIGHT≈ 1.0xEARTH-RAISEDRAISED HERE
much like Earth height

Gravity close to Earth's, at 0.81 times. A child would grow up much as they would back home.

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 479°C (894°F), sound would travel roughly 62% 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.

sound speed ≈ 550 m/s · 1.62× Earth · assumes Earth-like air

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
  • !Furnace-hot at around 479°C (894°F), with no liquid water and no shade anywhere.
  • Surface gravity is close to Earth's, 0.81 times, so you would move much as you do here.
  • !Its star delivers about 65 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 Kepler-139 b’s measured and computed values, not a real advisory.

How long to get there · 1,275 ly away
Jet airliner
1.5 billion years
dies en route1000-yr cryo: fails
Parker Solar Probethe fastest craft ever built
2.0 million years
dies en route1000-yr cryo: fails
Light speed
1,275 years
dies en route1000-yr cryo: fails
Warp 10
1 year
arrives, just older
Folding spacetimeinstant, plus 1 hr of paperwork
1 hour
arrives thriving
Size vs Earth
EarthKepler-139 b is 2.9× 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
MID-SIZE TELESCOPE NEEDED
Host-star brightnessmag 12.8
ConstellationLyra
To see the host star8-10" (200-250 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 Kepler-139 b?

Kepler-139 b's surface gravity is about 0.81 times Earth's.

How much would you weigh on Kepler-139 b?

Someone who weighs 150 pounds on Earth would weigh about 121 pounds on Kepler-139 b.

How far is Kepler-139 b from Earth?

Kepler-139 b lies about 1,275 light-years from Earth.

How long would it take to get to Kepler-139 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-139 b?

Kepler-139 b's equilibrium temperature, the balance it reaches from its star's light alone before any greenhouse warming, is about 479°C (894°F).

How long is a year on Kepler-139 b?

Kepler-139 b completes one orbit of its star in 16 days.

Illustration generated from Kepler-139 b's confirmed parameters, not a photograph.