What it’s like to stand here
K2-239 d
weight
≈ 1.13 g
sun
5.3× wider
sky
deep orange

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

Rocky world

K2-239 d

K2-239 d is a confirmed rocky exoplanet 101 ly from Earth in the constellation Sextans, discovered in 2018 by K2.

ESI 0.69101 lyDiscovered 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.

K2-239
host star
1.10 R⊕
radius
1.37 M⊕
mass · estimated from radius
10 days
orbital period
126°C (259°F)
avg temp
Human scale

Standing on K2-239 d, you would weigh roughly about 13% more than you do on Earth. Its red dwarf looks 5.3× 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 10 days, and at an estimated 126°C (259°F) it is warm.

≈ 1.13 g
your weight (mass estimated from size)
10 days
one year, in Earth time
5.3× wider
how big its sun looks vs ours
deep orange
midday sky tint
0.9×
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 K2-239 d
Earth Similarity Index0.69#148 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≈ 0.98xEARTH-RAISEDRAISED HERE
much like Earth height

Gravity close to Earth's, at about 1.1 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 noticeably higher and reedier.

Assuming Earth-like air at this world's temperature of about 126°C (259°F), sound would travel roughly 18% faster than on Earth, so your voice would sound noticeably higher and reedier. The real atmosphere is unknown, so this is a best guess.

sound speed ≈ 400 m/s · 1.18× 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
★★★★
Recommended, with reservations
  • !Persistently hot at around 126°C (259°F), well above anything you would call comfortable.
  • Surface gravity is close to Earth's, about 1.13 times, so you would move much as you do here.
  • !Likely tidally locked: one hemisphere in endless day, the other in permanent night.

A playful read of K2-239 d’s measured and computed values, not a real advisory.

How long to get there · 101 ly away
Jet airliner
122 million years
dies en route1000-yr cryo: fails
Parker Solar Probethe fastest craft ever built
158,121 years
dies en route1000-yr cryo: fails
Light speed
101 years
dies en route1000-yr cryo: survives
Warp 10
37 days
arrives thriving
Folding spacetimeinstant, plus 1 hr of paperwork
1 hour
arrives thriving
Size vs Earth
EarthK2-239 d is 1.1× 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
FAINT: LARGE TELESCOPE NEEDED
Host-star brightnessmag 14.6
ConstellationSextans
To see the host star10"+ (250 mm) telescope, dark sky
Gear bridge

Matched telescope & eyepiece recommendations are coming. Any product links will carry a clear affiliate disclosure.

Common questions

What is the gravity on K2-239 d?

K2-239 d's surface gravity is about 1.1 times Earth's, estimated from its size.

How much would you weigh on K2-239 d?

Someone who weighs 150 pounds on Earth would weigh about 170 pounds on K2-239 d.

How far is K2-239 d from Earth?

K2-239 d lies about 101 light-years from Earth.

How long would it take to get to K2-239 d?

At the speed of NASA's Parker Solar Probe, the fastest craft ever built, the journey would take about 158,121 years.

How hot is K2-239 d?

K2-239 d's equilibrium temperature, the balance it reaches from its star's light alone before any greenhouse warming, is about 126°C (259°F).

How long is a year on K2-239 d?

K2-239 d completes one orbit of its star in 10 days.

Illustration generated from K2-239 d's confirmed parameters, not a photograph.