- weight
- 0.62 g
- sun
- 5.4× wider
- sky
- dim red
Illustration computed from this world’s measured and derived values, not a photograph.
TRAPPIST-1 d
TRAPPIST-1 d is a confirmed rocky exoplanet 40.5 ly from Earth in the constellation Aquarius, discovered in 2016 by La Silla Observatory.
Transit: spotted by the tiny, repeating dip in its star’s light each time the planet crosses in front of it.
Standing on TRAPPIST-1 d, you would weigh about 38% less than you do on Earth. Its red dwarf looks 5.4× 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 4.0 days, and at an estimated 13°C (55°F) it is cold.
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 · habitable zone
If your children grew up herea playful thought experiment
Lighter than home, at 0.62 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 5 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 much as it does on Earth.
Assuming Earth-like air at this world's temperature of about 13°C (55°F), sound would travel close to its Earth speed, so your voice would sound much as it does on Earth. The real atmosphere is unknown.
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.
- Surface temperatures near 13°C (55°F) fall in the range where liquid water is at least possible.
- !Low gravity, 0.62 times Earth's, would hold only a thin, unbreathable atmosphere at best.
- A high Earth-similarity index of 0.85, among the more Earth-like worlds known.
- !Likely tidally locked: one hemisphere in endless day, the other in permanent night.
A playful read of TRAPPIST-1 d’s measured and computed values, not a real advisory.
How long to get there · 40.5 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 TRAPPIST-1 d?
TRAPPIST-1 d's surface gravity is about 0.62 times Earth's.
How much would you weigh on TRAPPIST-1 d?
Someone who weighs 150 pounds on Earth would weigh about 94 pounds on TRAPPIST-1 d.
How far is TRAPPIST-1 d from Earth?
TRAPPIST-1 d lies about 40.5 light-years from Earth.
How long would it take to get to TRAPPIST-1 d?
At the speed of NASA's Parker Solar Probe, the fastest craft ever built, the journey would take about 63,228 years.
How hot is TRAPPIST-1 d?
TRAPPIST-1 d's equilibrium temperature, the balance it reaches from its star's light alone before any greenhouse warming, is about 13°C (55°F).
Is TRAPPIST-1 d habitable?
TRAPPIST-1 d orbits near its star's habitable zone, the range of distances where liquid water could be stable, and its Earth-similarity index is 0.85. That makes it worth studying, but it is not evidence of life: we have no measurement of its atmosphere, water, or surface.
How long is a year on TRAPPIST-1 d?
TRAPPIST-1 d completes one orbit of its star in 4.0 days.
Illustration generated from TRAPPIST-1 d's confirmed parameters, not a photograph.