Anyone who's looked at the night sky knows there's a lot of stars, but how many are there? I reached out to Professor Kim McLeod for help.

Hi, my name is Kim McLeod, and I'm a professor at Wellesley College, which is in Massachusetts, just outside of Boston.

And in my work here at Wellesley, I use a telescope right here to help NASA discover planets around other stars.

But you asked how many stars are in space.

Here's what I can tell you, Kellan.

Some kids like to know how many stars they can see in the sky.

If you live in a city, a big city like Boston or New York, there's a lot of lights from the city, and kids can't see very many stars at all.

But astronomers are also really good at other math tricks of counting, things like estimation, um, and I was wondering if you could talk a little bit about that.