Saturn-Sized Rogue Planet Found Drifting Alone Through the Galaxy
Astronomers have identified a Saturn-sized planet drifting alone through the galaxy. The world no longer orbits a star and travels freely through interstellar space. Scientists believe the planet once formed around a star. However, a violent breakup likely flung it away. As a result, the planet became what researchers call a rogue planet.
A Rare Measurement Breakthrough
This discovery stands out for one key reason. Astronomers measured both the planet’s mass and distance. They achieved this by observing the same event from Earth and space. Ground-based telescopes worked alongside the Gaia space observatory. Therefore, researchers gained two viewpoints. This rare setup helped unlock details that usually remain hidden.
How Microlensing Reveals Rogue Worlds
Rogue planets emit almost no light. Because of this, astronomers rely on gravity to find them. For example, microlensing occurs when a planet bends light from a distant star.The effect creates a brief brightening. However, microlensing alone rarely shows distance. As a result, scientists often struggle to calculate a planet’s true mass.
Earth and Space Working Together
In this case, timing differences made the difference. Light reached Earth and Gaia at slightly different moments. These delays allowed scientists to calculate microlensing parallax.Researchers then paired the data with advanced modeling. In addition, they confirmed the planet’s Saturn-like mass.The team also pinpointed its location within the galaxy.Rogue planets reveal how chaotic planetary systems can be. Many likely form near stars before violent ejections. Therefore, they help scientists understand planet formation across the galaxy.Only a small number of rogue planets are known today. However, discoveries should increase soon. NASA’s Nancy Grace Roman Space Telescope, launching in 2027, will play a major role.
