Ask An Earth and Space Scientist
Ask An Earth and Space Scientist is an educational resource for students, teachers, parents, and life-long learners. We encourage anyone interested in earth and space to make use of its content.
There are millions of galaxies in our Universe. How do we organize them so that we can compare them to each other and learn new things?
Today, the air we breathe has lots of oxygen – over 20 percent! But that wasn’t always the case.