Oort Cloud

I live far, far away, past all the planets you know. Imagine a giant, sparkly bubble that wraps all around your Sun and its family of planets. It is very cold and very dark out here where I am. I am filled with trillions and trillions of sleeping, icy snowballs, just floating quietly in the dark. You can't see me, not even with a big telescope, but I am always here, watching over everything from far away.

My name is the Oort Cloud. A very smart man named Jan Oort dreamed me up a long, long time ago, in the year 1950. He thought that I must be the cozy home for all the comets that take long trips through space. My icy snowballs are really comets, and they float around me very slowly, like they are napping. But sometimes, something gives one of my comets a gentle nudge, like a little push on a swing. That tiny push sends the sleepy comet on a big adventure toward the bright, warm Sun.

When one of my comets gets close to the Sun, it wakes up from its long sleep. The Sun's warmth gives it a beautiful, glowing tail that stretches across the sky. Sometimes, you can see it from your home on Earth, like a special visitor sparkling in the night. That is my way of saying hello to you. So, when you look up at the stars, remember me, the big, icy bubble sending you sparkly greetings from the edge of space.