Astronomers have identified a new exoplanet, GJ 3378b, which they describe as Earth's "next-door neighbor." Located approximately 25 light-years away, the planet is about twice the size of Earth and orbits within its star's habitable zone, also known as the Goldilocks zone. This region is defined as the area around a star where temperatures are suitable for liquid water to exist on a planet's surface.
"This one's exciting," Paul Robertson of the University of California, Irvine, stated. "It's one of our closest cosmic neighbors." He added that while 25 light-years may seem distant, it is relatively close within the vastness of the Milky Way galaxy.
The potential habitability of GJ 3378b hinges on whether it can retain an atmosphere. Scientists are assessing this using a metric that considers the planet's gravity in relation to the radiation it receives from its star. "If you scale the Earth down to the size of an apple, its atmosphere would be about as thick as the skin of the apple," Robertson explained. "That's just enough to maintain the kinds of surface pressures where you can have liquid water." Such an atmosphere could also provide a degree of protection from space radiation.
Further observations are needed to confirm the presence and composition of an atmosphere. Gogod James, a UC Irvine student involved in the study, noted that detecting an atmosphere would warrant more in-depth research for biosignatures, liquid water, or other indicators of life.
NASA plans to deploy the Habitable Worlds Observatory in the coming two decades, which is expected to aid in the search for such atmospheric chemicals. This mission aims to advance the search for life beyond Earth.