Confirmed exoplanet · Database record + computed analysis
GJ 3378 b
A confirmed world orbiting GJ 3378, 25.2 light-years away.
A super-Earth
1.32 Earth radii. Worlds between Earth and Neptune in size are the most common in the galaxy, yet our Solar System has none, which is why each one matters. With 2.3 Earth masses packed into that size, its density points to rock and iron rather than gas.
The orbit
Its year, one full orbit, takes just 21.4 Earth days.
Temperature and starlight
Its equilibrium temperature (the airless-world estimate) is about -1 °C. In the range where, with the right atmosphere, liquid water is conceivable; a real atmosphere could shift the true surface figure a lot (Earth's equilibrium value is −18 °C, yet we average +15 °C). It receives 0.91 times Earth's starlight, the same order as our own world.
Its sun
Its star is a red dwarf (3,340 K surface), type M4 V: small, dim, flare-prone, and destined to outlive the Sun many times over.
How far is that, really?
At 25 light-years, tonight's light from this system left it around the year 2000. That is close by galactic standards, which makes it a prime target for follow-up telescopes. A Voyager-speed probe would need roughly 445,645 years to get there.
How we found it
It was found by the radial-velocity method: the planet's gravity swings its star in a small circle, and that wobble shows up as a rhythmic Doppler shift in the starlight. The wobble's size gives the planet's minimum mass. The discovery was announced in 2026 from Mauna Kea Observatory.
Everything above is computed from the archive’s measured values for this planet. Where a quantity is missing, the statement is omitted rather than guessed.
About this record
The measured values come from the NASA Exoplanet Archive, and any missing value has not been determined yet; the Atlas never fills gaps with guesses. More standout worlds: Proxima b, TRAPPIST-1e, K2-18 b, 55 Cancri e, and the detection methods that found them all.