ObserveTheSky
ObserveTheSky › Everything in the sky › Proxima Centauri b
exoplanet · orbiting Proxima Centauri

Proxima Centauri b compared to Earth

Nearest known exoplanet, probably a rocky world, in Proxima Centauri’s habitable zone.

Can you see it?

As of 2026, no telescope can show this one; it is here to be understood, not spotted.

How long is a year on Proxima Centauri b compared to Earth?

Proxima Centauri b takes about 11 Earth days to go once round Proxima Centauri.

How much mass does Proxima Centauri b have compared to Earth?

Proxima Centauri b has at least the mass of Earth.

Worth knowing about Proxima Centauri b

Anything light from there tells us is news 4.246 years old.

Why it stands out
It is the nearest planet known outside the solar system — and still, nobody has seen it.
What it is like
Probably rocky; at least 1.07 Earth masses.
How we know: Found via the radial-velocity (Doppler wobble) method, watching starlight shift as the planet’s gravity tugs the star back and forth.
How it moves
Orbits Proxima Centauri every 11.19 days, inside the star’s habitable zone.
Proxima Centauri b — A model, seen from the Earth, with north up.
The numbers
Distance from us4.246 light-years
Once round its orbit11.19 days

Where it sits

It belongs to Proxima Centauri, 4.246 light-years away.

How anyone knows this

Things like it

Proxima Centauristar150 mm telescopeTRAPPIST-1eexoplanetBeyond a 150 mm telescope51 Pegasi bexoplanetBeyond a 150 mm telescope

Games it appears in

Show Proxima Centauri b in the model📖 How the Milky Way fits together🌙 Plan an evening outside