Recent astronomical surveys have reshaped the view of our Milky Way. What once seemed like a handful of nearby worlds has become a vast census of planets scattered across the galaxy. Today, the Milky Way is understood to host billions of Earth-like planets, far more than was imagined a generation ago. These discoveries come from long-term observations and advances in planet hunting, revealing a galaxy teeming with rocky worlds and diverse planetary systems.
By watching planets pass in front of their stars, a method known as transit detection, researchers have found that roughly 17 percent of Sun-like stars host a rocky planet that orbits it. These findings come from extensive transit campaigns and refined data analysis, uncovering tiny, rocky worlds that orbit stars much like our Sun.
The Milky Way is now estimated to contain between 100 and 400 billion stars, which means the galaxy could host tens of billions of rocky Earth-like planets in addition to many gas giants and icy worlds. Even with conservative counts, the total number of planets in the Milky Way runs into the hundreds of billions when all planetary types are included.
DID YOU KNOW?
- Historic telescope observations confirmed the Milky Way is composed of countless stars. Citation: space science data.
- Spiral-like arms extend from the Milky Way’s center, winding through the disk and shaping the visible pattern seen in the galaxy. Citation: space science data.
- The Sun completes an orbit around the Milky Way roughly every 230 million years. Citation: space science data.
- The Milky Way consists of a disk with young stars, a central bulge with older stars, and a halo that contains dark matter and globular clusters. Citation: space science data.