Question: A home-schooled student observes that two asteroids orbit a star every 15 and 25 Earth days. After how many days will they align at the same point in their orbits?

Mon, 04 May 2026 16:44:46 +0000

**A home-schooled student observes that two asteroids orbit a star every 15 and 25 Earth days. After how many days will they align at the same point in their orbits?** Why questions like this are trending in science circles—and why a curious student might wonder when they’ll truly meet again. With the rise of accessible astronomy education, young learners across the U.S. are diving into orbital mechanics, fascinated by the rhythm of planetary motion echoed in asteroid paths. This isn’t just schoolwork—it’s part of a growing culture of scientific curiosity. Using basic math, this alignment puzzle comes down to finding the least common multiple (LCM) of 15 and 25. These orbital periods represent cycles—how often each asteroid completes its path. Alignment happens when both have completed whole cycles and return to the starting position relative to their star. **How Does Orbital Alignment Work?**
At the core, orbital periods describe how many days one full orbit takes. When two objects orbit a star, they cycle repeatedly. The star acts as a reference point, so alignment—also called “conjunction”—occurs when their positions repeat at the same moment. Mathematically, this occurs when both have completed integer numbers of orbits, resulting in a shared position. The LCM of 15 and 25 reveals the first day both asteroids meet at that common point.