What it’s like to stand here
LP 791-18 d
weight
0.85 g
sun
9.1× wider
sky
dim red

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

Rocky world

LP 791-18 d

LP 791-18 d is a confirmed rocky exoplanet 86.4 ly from Earth in the constellation Crater, discovered in 2023 by Spitzer Space Telescope.

Transit: spotted by the tiny, repeating dip in its star’s light each time the planet crosses in front of it.

LP 791-18
host star
1.03 R⊕
radius
0.91 M⊕
mass · measured
2.8 days
orbital period
122°C (252°F)
avg temp
Human scale

Standing on LP 791-18 d, you would weigh about 15% less than you do on Earth. Its red dwarf looks 9.1× wider than ours, bathing the surface in dim red 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 122°C (252°F) it is warm.

0.85 g
your weight (measured mass)
2.8 days
one year, in Earth time
9.1× wider
how big its sun looks vs ours
dim red
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 LP 791-18 d
Earth Similarity Index0.69#159 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 0.85 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 122°C (252°F), sound would travel roughly 17% 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 ≈ 399 m/s · 1.17× 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 122°C (252°F), well above anything you would call comfortable.
  • Surface gravity is close to Earth's, 0.85 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 LP 791-18 d’s measured and computed values, not a real advisory.

How long to get there · 86.4 ly away
Jet airliner
104 million years
dies en route1000-yr cryo: fails
Parker Solar Probethe fastest craft ever built
134,762 years
dies en route1000-yr cryo: fails
Light speed
86 years
dies en route1000-yr cryo: survives
Warp 10
32 days
arrives thriving
Folding spacetimeinstant, plus 1 hr of paperwork
1 hour
arrives thriving
Size vs Earth
EarthLP 791-18 d is about the size 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 16.9
ConstellationCrater
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 LP 791-18 d?

LP 791-18 d's surface gravity is about 0.85 times Earth's.

How much would you weigh on LP 791-18 d?

Someone who weighs 150 pounds on Earth would weigh about 128 pounds on LP 791-18 d.

How far is LP 791-18 d from Earth?

LP 791-18 d lies about 86.4 light-years from Earth.

How long would it take to get to LP 791-18 d?

At the speed of NASA's Parker Solar Probe, the fastest craft ever built, the journey would take about 134,762 years.

How hot is LP 791-18 d?

LP 791-18 d's equilibrium temperature, the balance it reaches from its star's light alone before any greenhouse warming, is about 122°C (252°F).

How long is a year on LP 791-18 d?

LP 791-18 d completes one orbit of its star in 2.8 days.

Illustration generated from LP 791-18 d's confirmed parameters, not a photograph.