A new study co-led by the Smithsonian and the University of Arizona offers the most detailed glimpse yet of how Earth’s ...

A planet swings in front of its star, dimming the starlight we see. Events like these, called transits, provide us with ...

It is almost 100 years since scientists discovered the universe is expanding. In the decades that followed, the accuracy of ...

Astronomers study stars by looking at the different colors of light they emit—colors they capture and analyze using ...