Breakthrough Listen is like using a really big ear to listen to sounds from outer space. Scientists use telescopes to collect signals from space to see if any aliens might be trying to communicate with us.
Think of it like this: Say you go to the playground and want to find your friend hiding somewhere. You listen for clues like their giggles or footsteps. That's what scientists are doing with Breakthrough Listen - they're listening for signals to see if there are any aliens out there trying to say "hello!"
But just like it's really hard to hear your friend when it's really noisy at the playground, it's hard for scientists to hear anything in space because there's a lot of noise out there like stars and other things. So they use special equipment and computers to try and filter out that noise so they can hear any possible alien signals.
Overall, Breakthrough Listen is a project that helps scientists search for any possible sounds from aliens in space. It's like they are using a really big ear to listen to space!