Space photo of the week: James Webb and Hubble telescopes unite to solve 'impossible' planet...

Why it's so special: This James Webb Space Telescope (JWST) image has helped astronomers untangle a long-standing mystery about how planets form. The mystery arose more than 20 years ago, when the Hubble Space Telescope spotted the universe's oldest known planet, which formed earlier in the universe's history than scientists thought was possible.

Stars form in large clouds of gas and dust called molecular clouds. Any remaining gas and dust gather in disks around the stars. Planets, in turn, form from these disks. Scientists believed that early stars didn't have planets because there was a lack of heavier elements, such as carbon and iron, which are created by stars' nuclear fusion and supernova deaths. They thought that these heavier elements were essential for planet-forming disks to exist long enough for planets to form.