The James Webb Space Telescope (JWST) has made a groundbreaking discovery: for the first time since its 2021 launch, it has identified an alien planet — or exoplanet — that was previously unknown, marking a historic milestone in the hunt for worlds beyond our solar system.
According to Reuters, this newly found planet is a young gas giant roughly the size of Saturn and orbits a small star located approximately 110 light-years from Earth in the constellation Antlia. The discovery, revealed by a team of international astronomers and published Wednesday in the journal Nature, opens new doors for the exploration of distant planetary systems.
A Rare Direct Imaging Breakthrough
What makes this discovery particularly notable is that the planet was detected through direct imaging, a method that has been used to identify fewer than 2% of the nearly 5,900 known exoplanets. Most exoplanets have been found using indirect methods, like monitoring the dimming of starlight when a planet transits in front of its star.
“This is the least massive planet ever observed using direct imaging — 10 times less massive than the previous record holder,” said astronomer Anne-Marie Lagrange of France’s CNRS and LIRA/Observatoire de Paris, the lead author of the study.
The feat was made possible by a French-developed coronagraph installed on Webb’s Mid-Infrared Instrument (MIRI). This device blocks the overwhelming glare of the host star, allowing the telescope to capture faint planetary signatures nearby.
Meet TWA 7 b: A Baby Planet Orbiting a Young Star
The host star, known as TWA 7, is much smaller than our sun and, along with its newly discovered planet, is considered a cosmic newborn — just 6 million years old. For comparison, our solar system is approximately 4.5 billion years old.
The gas giant orbits TWA 7 at a distance 52 times greater than Earth’s distance from the Sun, making it one of the more distant exoplanets observed to date. By contrast, Neptune, the farthest planet in our solar system, orbits at 30 times Earth’s solar distance.
Due to the favorable angle of observation — looking down at the planetary system rather than from the side — researchers were also able to study the structure of the protoplanetary disk surrounding TWA 7. This disk features two wide, dusty rings and a narrower ring in which the planet is embedded, providing valuable insight into early planet formation.
The Future of Exoplanet Discovery with Webb
While this gas giant is still much larger than Earth and unlikely to host life, the discovery is a critical step forward in understanding the diversity and evolution of planetary systems.
“Webb opens a new window in terms of mass and the distance of a planet to the star — regions that had not been accessible before,” said Lagrange. “This is important to explore how planetary systems form and evolve.”
Researchers have yet to determine the chemical composition of the planet’s atmosphere, or whether it is still growing by accumulating nearby material. These mysteries may be resolved in future Webb observations.
Though JWST currently lacks the sensitivity to directly image Earth-sized exoplanets, this discovery fuels optimism that future missions may one day detect rocky planets that could harbor life.
“Looking forward, I do hope the projects of direct imaging of Earth-like planets and searches for possible signs of life will become a reality,” Lagrange said.
