Just 40 light-years away, astronomers have unveiled a fascinating new world: Gliese 12 b. This newly discovered exoplanet, or planet outside our solar system, has caused a stir because of its size – it falls right between Earth and Venus. This discovery, announced in May 2024, opens doors for further exploration into the possibility of life beyond Earth.
The findings were made by a team of astronomers utilizing NASA’s Transiting Exoplanet Survey Satellite (TESS). TESS detects dips in a star’s brightness, which can occur when a planet passes before it, briefly blocking some light. By analyzing these dips, scientists can estimate the size and orbital period of the planet.
Gliese 12 b is estimated to be roughly 1.1 times the width of Earth. This places it in a size range similar to Venus, our solar system’s hottest planet. However, unlike Venus, Gliese 12 b orbits a much more relaxed and smaller star – a red dwarf called Gliese 12. This more excellent star means the planet could lie within its habitable zone, the Goldilocks zone.
The Goldilocks zone is the region around a star where conditions might be favorable for liquid water to exist on a planet’s surface. While Gliese 12 b orbits its star every 12.8 days, much faster than Earth’s year, the star’s cooler temperature could compensate for its proximity. However, the planet’s actual habitability depends heavily on its atmosphere.
“We don’t know yet if the planet has an atmosphere,” explains Dr. Amelia Palethorpe, lead author of one of the research papers on the discovery. “If it has no atmosphere, the surface temperature would likely be around 107 degrees Fahrenheit (42 degrees Celsius), which is quite hot but not outside the realm of possibility for life.”
The presence or absence of an atmosphere is crucial. A thick atmosphere could trap heat, creating a runaway greenhouse effect similar to Venus, where temperatures soar to over 800 degrees Fahrenheit (462 degrees Celsius). Conversely, a thin or nonexistent atmosphere would expose the planet to harsh stellar radiation and leave the surface frigid.
The discovery of Gliese 12 b is significant for a few reasons. Firstly, its size range falls within the realm of potentially habitable planets. Secondly, its proximity to Earth, at a mere 40 light-years, makes it a prime candidate for further study. With future telescopes like the James Webb Space Telescope, scientists hope to gather more information about the planet’s atmosphere and potential for life.
“This discovery is exciting because it allows us to potentially study a world that’s more like Earth than anything we’ve found before,” says Dr. Li Wang, a co-author of the research. “The fact that it’s relatively close makes it an even more intriguing target for future observations.”
While Gliese 12 b may not be a perfect Earth replica, its discovery opens a new chapter in the search for extraterrestrial life. It highlights the potential for habitable worlds around red dwarf stars, the most common type of star in our galaxy. Gliese 12 b reminds us that Earth-like planets might be more common than we ever imagined as we continue to explore the cosmos.