Astronomers Find a New “Almost-Earth” Just Around the Corner in Space!
Quick Summary
Astronomers have discovered a rocky planet about twice the size of Earth orbiting a nearby star — just 25 light-years away! The planet, called GJ 3378b, sits in the “Goldilocks zone” around its star, where temperatures might be just right for liquid water. Scientists are excited, but there are still big questions to answer.
What Happened?
Astronomers have discovered a rocky exoplanet about twice Earth’s size just 25 light-years away, orbiting in the habitable zone of its parent star, Gliese 3378.
Gliese 3378, also known as GJ 3378, is a red dwarf star located 25 light-years away in the northern constellation of Camelopardalis. Red dwarfs are the most common type of star in our galaxy — smaller and cooler than our Sun, and they glow with a faint reddish-orange light.
The newfound planet, Gliese 3378b, has a mass about 2.3 times that of Earth and an orbital period of 21.45 days. It sits inside its host star’s habitable zone — the “Goldilocks” region around a star where a planet receives just the right amount of radiation so that water could exist as a liquid on its surface.
“This super-Earth gets about 90 percent of the radiation from its host star as Earth gets from its sun, so it’s right in the sweet spot,” said Dr. Paul Robertson of the University of California, Irvine.
The discovery was made using two powerful instruments: the Habitable-zone Planet Finder on the Hobby-Eberly Telescope in Texas and the NEID Spectrometer on the WIYN Telescope at Kitt Peak National Observatory in Arizona.
However, there is one big mystery remaining: does GJ 3378b have an atmosphere? That doesn’t mean GJ 3378b is habitable. Any liquid water exposed to the vacuum of space will evaporate — for a planet to have liquid surface water, it needs an atmosphere. We currently have no way of knowing if GJ 3378b has an atmosphere.
Scientists may have to wait until the 2040s before they can study GJ 3378b in greater detail. NASA’s planned Habitable Worlds Observatory is expected to be able to directly image planets like this one and determine whether they have atmospheres.
Why Does It Matter?
Every time astronomers find a planet in the habitable zone of a nearby star, it’s a huge step forward in one of humanity’s biggest questions: are we alone in the universe? GJ 3378b is what we call a super-Earth — larger than Earth, but small enough for a rocky composition similar to the only planet in the universe known to host life: ours. Even if this particular planet turns out to be barren, learning to spot these worlds helps scientists build a map of our cosmic neighborhood — and find the best targets to search for signs of life.
Big Words
- Exoplanet — A planet that orbits a star other than our Sun
- Super-Earth — A rocky planet larger than Earth but smaller than the ice giants Uranus and Neptune
- Habitable zone — The “Goldilocks” distance from a star where temperatures may allow liquid water on a planet’s surface
- Red dwarf — A small, cool, long-lived star that glows reddish-orange; the most common type of star in the Milky Way
- Atmosphere — The layer of gases surrounding a planet; on Earth, it gives us air to breathe and helps keep temperatures stable
Fun Fact
25 light-years sounds far, but the Milky Way galaxy is 100,000 light-years wide. That means GJ 3378 is essentially our next-door neighbor on the galactic scale — like a house just down the street from ours in an enormous city!
Think About It
If we eventually discover that GJ 3378b does have an atmosphere and liquid water, what would be the next step scientists should take — and what tools might they need to look for signs of life there?
Sources
- ScienceAlert — “Potentially Habitable Super-Earth Found Just 25 Light-Years Away” (July 3, 2026)
- Space.com — “Astronomers discover a potentially habitable planet just 25 light-years away” (July 2, 2026)
- Sci.News — “Astronomers Find Potentially Habitable Super-Earth Just 25 Light-Years Away” (July 1, 2026)
- The Astrophysical Journal (peer-reviewed publication)