Sky gazers have been counting down to today: a "ring of fire" annular solar eclipse is here to darken the skies over the Americas! Solar eclipses happen when the moon passes between the sun and Earth, casting parts of Earth into shadow. In an annular solar eclipse, a halo effect is created when the moon blocks out most but not all, of the sun"s light. An annulus—or ring—of light remains visible. Seen here from Doha, Qatar, in 2019, the phenomenon will appear today over the United States—traveling from Oregon to Texas before continuing to Central America and ending in South America. While the "ring of fire" is visible only in certain areas, partial eclipses will grace parts of all 50 states.