An aurora (plural: auroras or aurorae) is a natural light display in the sky, particularly in the polar regions, caused by the collision of charged particles directed by the Earth's magnetic field. An aurora is usually observed at night and typically occurs in the ionosphere. It is also referred to as a polar aurora or, collectively, as polar lights. These phenomena are commonly visible between 60 and 72 degrees north and south latitudes, which place them in a ring just within the Arctic and Antarctic polar circles. Auroras do occur deeper inside the polar regions, but these are infrequent and often invisible to the naked eye.
In northern latitudes, the effect is known as the aurora borealis (or the northern lights), named after the Roman goddess of dawn, Aurora, and the Greek name for the north wind, Boreas, by Pierre Gassendi in 1621. Auroras seen near the magnetic pole may be high overhead, but from farther away, they illuminate the northern horizon as a greenish glow or sometimes a faint red, as if the Sun were rising from an unusual direction. The aurora borealis most often occurs near the equinoxes. The northern lights have had a number of names throughout history. The Cree call this phenomenon the "Dance of the Spirits". In Europe, in the Middle Ages, the auroras were commonly believed a sign from God.
- With gentle hand, as seeming oft to pause,
The purple curtains of the morn she draws.
- For night's swift dragons cut the clouds full fast,
And yonder shines Aurora's harbinger;
At whose approach ghosts, wandering here and there,
Troop home to churchyards.
- The wolves have prey'd: and look, the gentle day,
Before the wheels of Phœbus, round about,
Dapples the drowsy east with spots of grey.
- At last, the golden orientall gate
Of greatest heaven gan to open fayre,
And Phœbus, fresh as brydegrome to his mate,
Came dauncing forth, shaking his dewie hayre;
And hurls his glistring beams through gloomy ayre.
- Edmund Spenser, The Faerie Queene (1589-96), Book I, Canto V, Stanza 2.
- You cannot rob me of free nature's grace,
You cannot shut the windows of the sky
Through which Aurora shows her brightening face.
- James Thomson, Castle of Indolence (1748), Canto II, Stanza 3.
Hoyt's New Cyclopedia Of Practical QuotationsEdit
- Quotes reported in Hoyt's New Cyclopedia Of Practical Quotations (1922), p. 46.
- Aurora had but newly chased the night,
And purpled o'er the sky with blushing light.
- John Dryden, Palamon and Arcite, Book I, line 186.
- But when Aurora, daughter of the dawn,
With rosy lustre purpled o'er the lawn.
- Homer, Odyssey, Book III, line 621. Pope's translation.
- Night's son was driving
His golden-haired horses up;
Over the eastern firths
High flashed their manes.
- Charles Kingsley, The Longbeards' Saga.
- Zephyr, with Aurora playing,
As he met her once a-Maying.
- John Milton, L'Allegro, line 19.