The youngest planet discovered is less than one million years old.

A team of astrophysicists led by Italian researcher Andrea Bernardi has discovered the youngest planet ever observed, named Elias 2-24 b. It is less than a million years old, has a mass similar to Jupiter, and orbits a star 450 light-years away, within the disk of gas and dust where it formed.

The discovery, published in The Astrophysical Journal Letters, was made possible by analyzing archival observations from the W. M. Keck Observatory in Hawaii. The planet was found precisely within a gap in the protoplanetary disk, the location where theoretical models predict planets form. The researchers emphasize that this young planet challenges current models of planetary formation.

"Elias 2-24 b shows us that even our best models still do not account for some fundamental processes," said study co-author Lucas Cieza. The study offers a unique glimpse into what our Solar System might have looked like in its earliest stages.

The search for planets outside our Solar System, called exoplanets, is a rapidly evolving field in astronomy. For decades, scientists theorized their existence, but the first confirmation only came in 1992, with the discovery of planets around a pulsar. The breakthrough arrived in 1995 with the discovery of the first exoplanet around a Sun-like star, 51 Pegasi b.

Since then, thousands of exoplanets have been discovered, but finding very young ones is extremely rare and complex. Before Elias 2-24 b, the youngest known planets were over 5 million years old and orbited the stars PDS 70 and WISPIT 2. These already posed a puzzle for scientists, as their existence challenged the timelines predicted by formation models.

The discovery of a planet less than a million years old further pushes the boundary and forces a revision of theories on how gas giants like Jupiter can form so quickly. Studying these young systems is like using a time machine to observe the origins of planetary systems, including our own. New telescopes, like the future NASA Nancy Grace Roman Space Telescope, will make this research more accessible.