- weight
- ≥ 1.01 g
- sun
- 2.9× wider
- sky
- dim red
Illustration computed from this world’s measured and derived values, not a photograph.
Proxima Cen b
Proxima Cen b is a confirmed rocky exoplanet 4.2 ly from Earth in the constellation Centaurus, discovered in 2016 by European Southern Observatory.
★ Closest known exoplanetThe closest known exoplanet to Earth is Proxima Cen b, about 4.2 light-years away.
Radial Velocity: spotted by the gravitational wobble the planet tugs in its star.
Standing on Proxima Cen b, you would weigh roughly almost exactly what you weigh on Earth. Its red dwarf looks 2.9× 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 11 days, and it sits squarely in the habitable zone, among the more Earth-like worlds known.
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
Gravity close to Earth's, at about 1.0 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 deeper and fuller.
Assuming Earth-like air at this world's temperature of about -55°C (-67°F), sound would travel roughly 13% slower than on Earth, so your voice would sound deeper and fuller. 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.
- !Cold at about -55°C (-67°F), survivable only fully suited and heated.
- Surface gravity is close to Earth's, at least 1.01 times, so you would move much as you do here.
- A high Earth-similarity index of 0.89, among the more Earth-like worlds known.
- It orbits within the habitable zone, where a world could in principle hold liquid water.
- !Likely tidally locked: one hemisphere in endless day, the other in permanent night.
A playful read of Proxima Cen b’s measured and computed values, not a real advisory.
How long to get there · 4.2 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 Proxima Cen b?
Proxima Cen b's surface gravity is at least 1.0 times Earth's, and possibly more: its mass is only a lower bound.
How much would you weigh on Proxima Cen b?
Someone who weighs 150 pounds on Earth would weigh at least 152 pounds on Proxima Cen b.
How far is Proxima Cen b from Earth?
Proxima Cen b lies about 4.2 light-years from Earth.
How long would it take to get to Proxima Cen b?
At the speed of NASA's Parker Solar Probe, the fastest craft ever built, the journey would take about 6,619 years.
How hot is Proxima Cen b?
Proxima Cen b's equilibrium temperature, the balance it reaches from its star's light alone before any greenhouse warming, is about -55°C (-67°F).
Is Proxima Cen b habitable?
Proxima Cen b orbits inside its star's habitable zone, the range of distances where liquid water could be stable, and its Earth-similarity index is 0.89. 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 Proxima Cen b?
Proxima Cen b completes one orbit of its star in 11 days.
Illustration generated from Proxima Cen b's confirmed parameters, not a photograph.