A solar explosion called a coronal mass ejection is poised to graze Earth on Friday or Saturday (Jan. 24 or Jan. 25), potentially triggering colorful auroras over the northern U.S.
Continent-size islands deep inside Earth's mantle could be more than a billion years old, a new study finds. Known as large low-seismic-velocity provinces (LLSVPs), these blobs are both hotter and ...