Rogue Planet's Mass & Distance Measured: A First for Starless Worlds

• Astronomers for the first time measured both the mass and distance of a rogue planet, a starless world drifting alone in the Milky Way.
• The planet, about 22% the mass of Jupiter and 9,785 light-years away, likely formed in a planetary system before being ejected.
• Its detection on May 3, 2024, used gravitational microlensing, observed by ground-based telescopes and the Gaia space telescope.
• Gaia's unique position 1.5 million km from Earth was crucial, enabling distance calculation from differing observation times.
• This discovery supports theories that rogue planets originate from unstable early systems, with future telescopes like Nancy Grace Roman set to find more.

Why It Matters: Scientists precisely measured a rogue planet's mass and distance, revealing insights into its origin.