NASA’s James Webb Space Telescope has directly imaged two infant gas giant planets orbiting a young sun-like star offering a rare glimpse into the early stages of planetary formation. The star, known as YSES-1, lies approximately 310 light years away in the constellation Musca and is estimated to be just 16 million years old, making it a cosmic newborn compared to our 4.5-billion-year-old Sun.
The two planets, both significantly more massive than Jupiter, are at different developmental stages a surprising find that deepens the mystery of how planetary systems, including our own, come into being. The inner planet, with a mass 14 times that of Jupiter, is surrounded by a disk of fine dust. This suggests it may still be coalescing, or that a recent collision or moon formation may be underway. Webb also detected water and carbon monoxide in its atmosphere.
Meanwhile, the outer planet, about six times Jupiter’s mass, lacks a surrounding disk but possesses an atmosphere thick with silicate clouds unlike anything seen in our solar system’s gas giants. Methane, water, carbon monoxide, and carbon dioxide were also identified in its atmosphere.
The extreme orbital distances 160 and 320 times farther from their star than Earth is from the Sun challenge existing theories of planet formation. According to lead researcher Kielan Hoch of the Space Telescope Science Institute, “Theoretically, the planets should be forming around the same time… yet they show striking differences.” This anomaly raises critical questions about the environments in which planets form and whether all giant planets undergo similar developmental paths.
Since becoming operational in 2022, Webb has revolutionized our understanding of exoplanets by observing them in infrared wavelengths, revealing atmospheric details previously invisible. With over 5,900 exoplanets discovered to date, fewer than 2% have been directly imaged making this observation a milestone in the study of planetary origins.
These findings, published in Nature, underscore how much we still have to learn about the birth of planetary systems and may ultimately help us better understand our own place in the universe.
