Astronomical unit
An astronomical unit is like the ruler we use in school to measure things, but it's much bigger because it's used to measure things in space. One astronomical unit (AU) is the distance from the Earth to the Sun.
You know how when you see the sun during the day, it looks big and really bright? That's because it's really close to us! In fact, it's only about 93 million miles away from us. That's so far that it would take a really long time to travel there even in a rocket ship.
Scientists use the AU as a way to measure distance in space because everything in space is super far away from us. For example, the next closest star to us is over four light-years away. That's a really long distance!
To make it easier, they use the AU to measure things that are inside our own solar system. It's a way to help us understand how far planets are from each other, how long it takes for them to travel around the sun, and other important things like that.
You know how when you see the sun during the day, it looks big and really bright? That's because it's really close to us! In fact, it's only about 93 million miles away from us. That's so far that it would take a really long time to travel there even in a rocket ship.
Scientists use the AU as a way to measure distance in space because everything in space is super far away from us. For example, the next closest star to us is over four light-years away. That's a really long distance!
To make it easier, they use the AU to measure things that are inside our own solar system. It's a way to help us understand how far planets are from each other, how long it takes for them to travel around the sun, and other important things like that.
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