Exoplanet GJ 3378b, located 25 light-years away, is more similar to Earth than previously thought, according to a study published in The Astrophysical Journal.
How did the mass of GJ 3378b change?
Astronomers first identified GJ 3378b in 2024 orbiting the red dwarf star Gliese 3378. Initial analyses estimated the planet’s mass at 5.26 times that of Earth with an orbital period of 24.73 days. However, Robertson’s team used the Hobby-Eberly Telescope and the WIYN Telescope to refine these figures.
The updated data lowers the mass to 2.3 Earth masses and the orbital period to 21 days. This correction suggests a rocky, Earth-like composition. A lower mass means the planet is less likely to possess a suffocatingly thick atmosphere.
Can GJ 3378b support life?
The planet resides in the “habitable zone,” meaning it receives a moderate amount of stellar radiation. While this makes liquid water possible, the planet’s position is precarious. According to the research team, GJ 3378b sits on the “life-and-death boundary” regarding atmospheric retention.
This placement is compared to Mars in our own solar system. The team notes an increased risk that the host star’s radiation could strip away the planet’s atmosphere entirely. Currently, researchers cannot confirm if an atmosphere exists.
| Metric | Initial 2024 Estimate | Updated Findings |
|---|---|---|
| Mass (Earths) | 5.26x | 2.3x |
| Orbital Period | 24.73 days | 21 days |
| Composition | Larger/Unknown | Likely Rocky |
What happens next in the search for biosignatures?
GJ 3378b has been added to the list of candidate planets capable of supporting life, but direct confirmation requires next-generation hardware. The research team points to the future operation of the Giant Magellan Telescope and the Extremely Large Telescope.
These facilities will allow astronomers to observe the planet directly. Only through such direct observation can scientists search for liquid water, biological signatures, or other indicators of life.
Frequently Asked Questions
How far is GJ 3378b from Earth?
It is located approximately 25 light-years away.
Is GJ 3378b definitely habitable?
No. While it is in the habitable zone and likely rocky, researchers are unsure if it has an atmosphere or if that atmosphere has been stripped by its star.
Who conducted the new observations?
A team led by Paul Robertson from the University of California, Irvine.
What do you think about the possibility of life on red dwarf planets? Let us know in the comments below or subscribe to our newsletter for more space discoveries.
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