Uranus

Imagine a giant blue marble spinning in space, but this marble is tilted way, way over! That's Uranus! It's the seventh planet from the Sun, and it's super cold.

It's an ice giant, which means it's made of icy stuff like water, methane, and ammonia, all wrapped up in a thick atmosphere. It looks a bit plain compared to other planets, but it has a cool secret: it spins on its side! Scientists think something big might have bumped into it a long, long time ago, knocking it over.

Most planets spin like tops, standing up straight as they go around the Sun. But Uranus is different! It spins on its side, almost like it's rolling along its path.

This means its poles, the very top and bottom of the planet, point towards the Sun for a long time, and then away from the Sun for a long time. This makes for very strange seasons, with each pole getting 42 years of sunlight and then 42 years of darkness!

Uranus is a beautiful blue color because of a gas called methane in its atmosphere. Methane is the same stuff that makes campfires burn! When sunlight hits the methane, it absorbs red light and reflects blue light, making the planet look like a giant sapphire.

It's so far from the Sun that it's incredibly cold, much colder than even your freezer! The temperature can be as low as -371 degrees Fahrenheit (-224 degrees Celsius).

Uranus wasn't always known. For thousands of years, people only knew about the planets they could see with their eyes. But in 1781, a musician and astronomer named William Herschel was looking through his telescope and found something new!

He didn't know it was a planet at first, but it was the first planet ever discovered using a telescope. It was a huge discovery that changed how we understood our solar system.