An international team of scientists has announced the discovery of Gliese 12 b, a temperate Earth-sized exoplanet just 40 light-years away, 378 trillion kilometers from Earth, a relatively close neighborhood.

Researchers from around the world, including significant support from researchers at McGill University and Western University, worked together to find Gliese 12 b as part of the Subaru Infrared Doppler Strategic Program (IRD-SSP), which searches for planets in the habitable zones around red dwarfs.

An international team discovered the planet’s existence using a combination of advanced telescopes and observational techniques, and the discovery opens up exciting opportunities for a deeper understanding of worlds beyond our solar system.

A planet around a red dwarf

Gliese 12 b orbits a central star called Gliese 12, which belongs to a type of star known as a red dwarf. Red dwarfs are smaller, cooler and more common than G-type stars like our Sun.

Planets orbiting red dwarf stars are prime candidates for the search for life beyond Earth. Much effort has been devoted to searching for planets orbiting red dwarfs, as terrestrial worlds around these stars are easier to detect than those around larger stars like our Sun.

Gliese 12 is one of two red dwarf stars (the other is TRAPPIST-1) orbiting Earth-sized planets with relatively little stellar radiation, located less than 100 light-years from Earth.

TRAPPIST-1’s high activity (such as high-energy explosions) likely compromises the planets’ habitability because recent observations suggest that TRAPPIST-1 b and c have almost no atmospheres.

Highly active stars flare more frequently and intensely than inactive stars, and emit life-threatening high-energy radiation. In contrast, Gliese 12 is a highly inactive red dwarf, meaning its planets face much less adverse conditions.

Barely warming starlight

What makes Gliese 12 b particularly interesting is its size and location. It is approximately the same size as Earth, suggesting it may have a similar composition and surface environment. However, more observations and simulations are needed to confirm this.

Gliese 12 b’s location near the inner edge of the habitable zone makes it particularly interesting. The habitable zone, often referred to as the “Goldilocks zone,” is the region around a star where conditions are just right for liquid water to exist on the planet’s surface. Since water is essential for life as we know it, finding a planet in this zone is a big step in the search for life.

Gliese 12 b receives enough starlight to be slightly closer to the inner edge of the red dwarf’s habitable zone, but the actual existence of liquid water depends on the atmosphere and surface conditions.

However, the amount of starlight it receives is between the amount that Earth and Venus receive from the Sun. Further study of Gliese 12 b could shed light on the fundamental differences between the habitable Earth and the inhospitable Venus.

Close view

Another interesting aspect of Gliese 12 b is that its relatively close location to Earth allows for more detailed study of its surface environment. A particularly useful method of studying Gliese 12 b, which is not possible for non-transiting planets, is atmospheric transmission spectroscopy. This involves analyzing the starlight passing through the planet’s atmosphere during the transit.

By examining changes in the light spectrum, scientists can infer the composition of a planet’s atmosphere by identifying gases such as oxygen, water, methane and carbon dioxide, which can indicate biological processes. The discovery of Gliese 12b is another step toward finding potentially habitable planets and understanding the conditions that make life possible.

Existing and future telescopes, such as the James Webb Space Telescope and ground-based Extremely Large Telescopes, will play a crucial role in further studies, allowing scientists to make more detailed studies of Gliese 12 b’s atmosphere and surface conditions.

The discovery of Gliese 12 b, a potentially habitable exoplanet nearby, is an exciting development in the search for Earth-like planets and possibly extraterrestrial life. As we continue to explore space, each new discovery brings us one step closer to the answer to the eternal question: Are we alone in the universe? For now, Gliese 12 b serves as a beacon of hope and wonder, inviting us to learn more about the possibilities beyond our solar system.