Look up at the night sky. Ever wonder how we can be so sure Halley’s Comet will swing by again in 2061? Or how NASA can launch a rover from Earth and nail a landing on a specific crater on Mars months later, a planet that never stops moving? It feels like some kind of cosmic magic trick. It’s not. It’s science. Specifically, it’s the science of celestial mechanics. Figuring out how celestial mechanics predict orbits is like discovering the universe’s secret code, one written in the elegant language of math and physics. This is the story of how we…
Author: Šinko Jurica
Ever find yourself staring into the sky, feeling the sun’s warmth, and just… wondering? We all know the Earth is spinning, hurtling through the vastness of space. We also know that giant, fiery star is the heart of it all, its immense gravity holding our entire cosmic family together. It’s a thought that can sneak up on you, a question as simple as it is profound: why don’t planets fall into the sun? It’s a fair question. It feels like they should. The sun is a gravitational behemoth, a monster 333,000 times more massive than our own world. Its pull…
Look up on a clear night. You’re seeing more than just twinkling stars. You’re looking into a cosmic highway, full of silent travelers. I’m talking about comets, with their spectacular tails, and asteroids, the leftover rubble from when our solar system was born. They aren’t just drifting. Not at all. Every move they make is guided by an invisible, powerful force. Getting a handle on the trajectory of comets and asteroids isn’t just for astronomers. It helps us understand the huge, intricate dance happening right over our heads. It’s a story about gravity, pure speed, and every now and then,…
Have you ever watched an ice skater mid-spin, arms outstretched, and then witnessed the sudden, breathtaking acceleration as they pull their arms in? It’s a moment of pure magic. A human transformation into a blur. But it’s not magic at all. That simple, elegant action is a perfect demonstration of a law that governs the entire universe. It’s the same rule that flattens galaxies into majestic spirals, that forges stars and planets from shapeless clouds of dust, and that locks our own world into a stable, life-sustaining orbit. This powerful, invisible architect is the conservation of angular momentum in space.…
What do you see when you picture the solar system? For most of us, it’s a tidy, predictable model. The Sun sits in the middle, and the planets spin around it on what looks like a single, flat cosmic record. Mercury, Venus, Earth, Mars, and the gas giants beyond—they all follow the rules, orbiting on a level playing field. And then there’s Pluto. Pluto is the cosmic rebel. It doesn’t just march to a different beat; it dances to a symphony playing in another room entirely. The heart of its strangeness, and what makes it endlessly fascinating, is the orbital…
Growing up, you were probably told a simple story: the Moon orbits the Earth. It paints a clean picture, right? A big blue-and-white marble with a smaller gray one circling it forever. And for the most part, that picture works. But reality, as it often does, is a little messier and a whole lot more interesting. The Earth and Moon are locked in a cosmic dance, and they aren’t dancing around the center of the Earth. Not even close. Instead, they both revolve around a shared, invisible point in space. This is the barycenter of Earth and Moon, the real…
Picture this: you’re standing in an open field. You wind up and throw a ball as hard as you can, watching it carve a perfect arc against the sky. For a split second, you’ve just created a tiny orbit. Gravity always wins that particular game, pulling the ball back down. But what if it didn’t? Imagine throwing that ball with such incredible force that it just kept going, falling all the way around the Earth. You’ve just achieved orbit. When we think of orbits, most of us picture a perfect circle. We see a planet waltzing around its star in…