aurora

Coloured light in the night sky near the Earth's magnetic poles, called aurora borealis (‘northern lights’) in the northern hemisphere and aurora australis (‘southern lights’) in the southern hemisphere. Although auroras are usually restricted to the polar skies, fluctuations in the solar wind occasionally cause them to be visible at lower latitudes. An aurora is usually in the form of a luminous arch with its apex towards the magnetic pole, followed by arcs, bands, rays, curtains, and coronae, usually green but often showing shades of blue and red, and sometimes yellow or white. Auroras are caused at heights of over 100 km/60 mi by a fast stream of charged particles from solar flares and low-density ‘holes’ in the Sun's corona. These are guided by the Earth's magnetic field towards the north and south magnetic poles, where they enter the upper atmosphere and bombard the gases in the atmosphere, causing them to emit visible light.

The French philosopher Pierre Gassendi coined the term ‘northern dawn’ (the literal meaning of ‘aurora borealis’) in 1621.

Aurora

In Roman mythology, goddess of the dawn (Greek Eos). Preceded by her sons, the fresh morning winds, she would fly or drive a chariot across the sky to announce the approach of Apollo's chariot bearing the sun.

Descriptions of Aurora refer to her rosy fingers and saffron-yellow robe.

Aurora

City in three counties (Arapahoe, Adams, and Douglas) in central Colorado, USA, 10km/6mi east of Denver, of which it is mainly a residential suburb; population (2000 est) 276,400. Founded in 1891 as Fletcher, it was renamed after the Roman goddess of the dawn when it was incorporated as a city in 1907. It is the third city of Colorado, after Denver and Colorado Springs. Its industries include telecommunications and aerospace equipment, fishing tackle, and travel goods. Aurora is a main gateway to winter-sports centres and other tourist attractions in the Rocky Mountains.

A community college, Lowry Air Force Base, and Fitzsimons Army Hospital are located here.

Aurora

City in Kane and Du Page counties, northeast Illinois, USA; population (2000) 143,100. It is located on the Fox River, 60 km/37 mi west-southwest of Chicago. An important regional economic centre, it manufactures and distributes such products as auto parts, office furniture and equipment, electrical and pneumatic tools, clothing, pumps, toys, tractors, and road paving machinery. Local institutions include Aurora University (1893) and the Bellarmine School of Theology of Loyola University.

Aurora was founded in 1834 as McCarty's Mills, a fur trading post and sawmill near a Potawatomi village; it was incorporated as a city in 1857. An important stagecoach stop on the road leading west from Chicago, it boomed when the Chicago, Burlington and Quincy Railroad built its construction and repair yards here in the 1850s. Aurora was a pioneer in the use of electric streetlights (1881).

Aurora

Province of northwest Luzon Island in the Philippines; population (1995) 160,000. The capital is Baler. It is a rugged, rocky province in the typhoon zone, containing important forest resources, many of which are conservation areas. Fishing and subsistence agriculture are carried out. Surfing attracts some tourism. It is home to the Dumagat and Ilongot peoples.

It became the 73rd province of the Philippines in 1978. Aurora province is named after Aurora Aragon, the wife of Manuel Luis Quezon (the first president of the Philippines). Some key scenes in the film Apocalypse Now were shot here.