Discover the cosmos!Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.
Discover the cosmos!Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. To view this video please enable JavaScript, and consider upgrading to a web browser thatsupports HTML5 video Explanation:Jupiter is one of the least lonely planets in the Solar System, at least when it comes tonatural satellites.115 moonshave been discovered orbiting Jupiter so far! (Saturn has the most with 293, butwho’s counting.)GanymedeandIo, two of Jupiter’sGalilean moons, met in the sky on October 20th, 2026. Today’s video captures the meeting, withGanymedebriefly blockingIofrom view. This event, when an astronomical object passes in front of another and either completely or partially blocks it, is called a mutual occultation. Themutual occultations of Galilean moonsare rare to witness because they require Earth’s edge-on view of their orbits. This occurs once every 6 years when Jupiter reachesits equinoxand appears less “tilted”. Ganymede is alsocasting its shadowon Jupiter’s right side. Anyfictional Jovian specieswithin the shadow would experience asolar eclipse!Tomorrow's picture:a planet grows horns