A major astronomical event occurs Wednesday -- a total solar eclipse in which the moon's shadow blocks Earth-bound views of the sun from Brazil to Mongolia. In Wednesday's event, a total eclipse lasting up to 4 minutes will be visible over a path beginning in Brazil and extending across the Atlantic Ocean, Northern Africa and Central Asia where it ends at sunset in Northern Mongolia. A partial eclipse will be seen in the much broader path of the moon's shadow, including the northern two-thirds of Africa, Europe and Asia.