NEW YORK, June 26: Since its launch in 2021, the James Webb Space Telescope (JWST) has not only provided extensive insights into the early universe but also gathered important data on known exoplanets — planets beyond our solar system. Now, for the first time, JWST has directly discovered a previously unknown exoplanet.

The telescope captured an image of a young gas giant roughly the size of Saturn, orbiting a star smaller than the Sun about 110 light-years away in the constellation Antlia. (A light-year is the distance light travels in one year, approximately 5.9 trillion miles or 9.5 trillion kilometers.)

Most of the approximately 5,900 exoplanets found since the 1990s have been detected using indirect techniques, such as the transit method, which measures the slight dimming of a star's light when a planet crosses in front of it. Less than 2% of exoplanets have been directly imaged, making this discovery notable.

Although this planet is large compared to those in our solar system, it is actually the least massive exoplanet ever detected by direct imaging, being ten times lighter than the previous smallest one discovered. This highlights the remarkable sensitivity of Webb’s instruments.

This achievement was made possible by a French-built coronagraph—a device that blocks the intense light from a star—integrated into Webb’s Mid-Infrared Instrument (MIRI).

"Webb opens a new window in terms of detecting planets of smaller mass and at greater distances from their stars, previously inaccessible to observation," said astronomer Anne-Marie Lagrange of France's CNRS and LIRA/Observatoire de Paris, who led the study published in Nature. "This is key to exploring the diversity of planetary systems and understanding their formation and evolution."

The newly found planet orbits its star, known as TWA 7, at a distance about 52 times that between Earth and the Sun. To provide perspective, Neptune—the outermost planet in our solar system—circles the Sun at about 30 times Earth’s distance. The transit method excels at finding planets close to their stars, but imaging is essential for detecting and analyzing those orbiting farther away.

Planetary systems begin with the collapse of a large molecular cloud of gas and dust under gravity, forming a central star surrounded by a protoplanetary disk of leftover material that eventually forms planets.

Both the star TWA 7 and its planet are very young—around 6 million years old—compared to the Sun’s age of roughly 4.5 billion years. Viewing the system nearly face-on, researchers could identify the structure of the disk, which contains two wide concentric rings of rocky and dusty material, along with a narrow ring where the planet resides.

The composition of the planet’s atmosphere remains unknown, but future JWST observations may shed light on this. Scientists also aren’t sure whether the young planet is still growing by accumulating nearby material.

While this is the smallest exoplanet directly imaged to date, it is still far more massive than rocky planets like Earth, which are prime targets in the search for extraterrestrial life. Despite JWST’s powerful near- and mid-infrared capabilities, it currently cannot directly image Earth-sized exoplanets.

“Looking ahead, I hope that direct imaging of Earth-like planets and the search for signs of life will become achievable,” Lagrange concluded.