A team led by Andrea Bernardi of Chile's Universidad Diego Portales has confirmed Elias 2-24 b as the youngest known planet, less than 1 million years old. Using Keck Observatory coronagraph data, with supporting observations from ALMA and the Very Large Telescope, they found a roughly Jupiter-mass world still forming in the dust and gas disk around its star, about 450 light-years away. The result was published Sept. 16 in The Astrophysical Journal Letters.
The planet orbits at about 55 times Earth's distance from the Sun, farther than Neptune. Current models say a Jupiter-size planet needs about 5 million years to form at Jupiter's distance, and longer the farther out it sits. Previous record holders were all more than 5 million years old.
Team member Lucas Cieza said the planet shows that even the best formation models are "still missing some important processes." Astronomers also see it as a rare window on how planetary systems, including our own, take shape.