Redshift

Redshift is a kind of telescope. It lets us see really far away things, like stars and galaxies. Instead of using regular light like we use to see things close up, it uses light waves that are more red, which helps us see things that are far away because the red light waves can travel farther than other colors. So when astronomers point the telescope at a distant object, they see the red light that it gives us and can use it to study the object like a scientist!