File photo: VCG

A discovery that caught the attention of Chinese netizens on Sunday was that astronomers have confirmed an exoplanet named GJ3378b, located within the habitable zone of a red dwarf star about 25 light-years from Earth, may possess conditions suitable for life, making it one of the closest potentially habitable worlds known to date, as reported by the Science and Technology Daily (STD).

The planet lies in the direction of the constellation Camelopardalis and orbits a faint red dwarf star. The findings, published in the latest issue of The Astrophysical Journal, mark another significant step in the search for habitable worlds beyond the solar system.

GJ3378b was first identified by French astronomers in 2024. Initial estimates suggested it had a mass of 5.26 times that of Earth, leading scientists to classify it as a gaseous mini-Neptune. However, a team from the University of California in the US, using the WIYN 3.5-meter Telescope at Kitt Peak National Observatory and other facilities, revised that assessment. New observations indicate the planet has a mass of just 2.3 Earth masses, placing it in the category of rocky "super-Earths."

"The significance of this discovery lies first in the fact that, while 25 light-years is still an enormous distance by human standards, it is actually very close on the scale of our galaxy, which spans roughly 100,000 light-years," a postdoctoral researcher in astrophysics surnamed Wei, told the Global Times on Sunday. "The planet is also located within its star's habitable zone, where temperatures may be just right for liquid water to exist."

The discovery quickly sparked lively discussions among Chinese netizens, with many joking about the immense distance involved despite its relative "proximity" in astronomical terms.

"Even traveling at half the speed of light, it would still take 50 years to get there," one netizen wrote.

Others referenced the Chinese sci-fi blockbuster The Wandering Earth, noting that reaching Proxima Centauri, just 4.24 light-years away, takes about 2,500 years in the film. Some also calculated that, using current human technology, it would take roughly 30 million years by commercial airplane, 440,000 years by rocket, or  Voyager 1, the 1977-launched uncrewed deep-space probe for the outer solar system. Netizens joked that humanity should first figure out how to overcome the light-year barrier or achieve space-time travel.

While many netizens focused on the planet's potential habitability, astronomers are more interested in determining whether it is capable of supporting life.

Scientists initially believed GJ3378b completed one orbit around its host star every 25 days. Updated observations shortened that period to just 21 days. Although this means the planet is closer to its star than previously thought, it remains within the habitable zone, where temperatures could allow liquid water to persist on the surface. The planet receives about 90 percent as much stellar radiation as Earth receives from the sun, placing it in what researchers consider an ideal location for habitability.

"Based on the latest observations, its mass is also relatively close to Earth's, and planetary mass is one of the key indicators of whether a planet is likely to be rocky," Wei said. "Planets with masses exceeding about five Earth masses tend to accumulate thick gaseous envelopes and evolve into mini-Neptunes, while those below that threshold are more likely to have solid surfaces."

At the same time, the planet's orbit around a red dwarf presents challenges. Such stars frequently emit intense stellar winds and high-energy radiation that can strip away a planet's atmosphere. Moreover, because GJ3378b does not transit in front of its host star from Earth's perspective, astronomers cannot analyze its atmosphere using transit spectroscopy with space telescopes, according to the STD report.

For now, scientists are looking ahead to NASA's proposed Habitable Worlds Observatory, expected to launch in the 2040s. The telescope may be capable of directly detecting GJ3378b's atmosphere and potentially identifying signs of life.

Despite the many uncertainties, astronomers remain cautiously optimistic. GJ3378b appears to orbit near the outer edge of the region most severely affected by stellar radiation, meaning it may have avoided the harshest conditions and retained an atmosphere conducive to habitability, according to the report.