**First Exoplanet Discovery: 51 Pegasi b Revolutionizes Our Understanding**

# Astronomy Tonight Podcast This is your Astronomy Tonight podcast. Today, June 11th, marks a truly remarkable date in our cosmic history—the anniversary of one of the most thrilling discoveries in modern astronomy! On June 11, 1995, Michel Mayor and Didier Queloz announced the discovery of the first exoplanet orbiting a sun-like star. They found **51 Pegasi b**, a gas giant circling the star 51 Pegasi, located about 50 light-years away in the constellation Pegasus. Now, you might think "just another planet," but this was absolutely *revolutionary*. For centuries, humanity wondered: are we alone? Are there other worlds out there? And this discovery provided the first concrete answer—a resounding YES! What makes 51 Pegasi b particularly wild is that it completely upended our assumptions. This Jupiter-sized world orbits incredibly close to its star—much closer than Mercury orbits our Sun—meaning it's absolutely *baked*, making it a "hot Jupiter." Scientists hadn't expected this! It challenged our theories about how planetary systems form and migrate, sparking decades of new research and refinement in our understanding of planetary architecture across the cosmos. Today, we've discovered over 5,600 exoplanets, and it all traces back to this one pivotal moment on June 11th, 1995. Not bad for a couple of Swiss astronomers with a good spectrograph! Be sure to **subscribe to the Astronomy Tonight podcast**! For more information, check out **Quiet Please dot AI**. Thank you for listening to another **Quiet Please Production**.