A Good Week For Northern Lights? Fall Equinox Puts Earth In The Perfect Position For Aurora
Sep 20, 2019, 01:00am
Jamie Carter Contributor
A sky-covering aurora as seen from the Hurtigruten ship the m/s Nordnorge near Tromso, Norway (Photo by: VW Pics/Universal Images Group via Getty Images)UNIVERSAL IMAGES GROUP VIA GETTY IMAGES
Fall can be green, too. The coming of the equinox on Monday brings the start of astronomical fall or autumn in the northern hemisphere, a season known for browns, reds and yellows in the foliage, but did you know it can also bring greens to the night skies?
Those on or around the Arctic Circle are more likely to experience increased Northern Lights around the equinox. Why is that, and what is equinox, anyway?
When is fall/autumnal equinox?
In 2019 the equinox occurs on Monday, September 23 at precisely 7.50 a.m. Universal Coordinated Time. It’s a global event that happens for everyone on the planet at the same time. However, some sample locations times are as follows:
Sydney 17:50 p.m.
Tokyo 16:50 p.m.
Singapore, Manila, Beijing, Shanghai & Hong Kong 15:50 p.m.
Dhaka 13:50 p.m.
Mumbai 13:20 p.m.
Karachi 12:50 p.m.
Istanbul & Moscow 10:50 a.m.
Capetown, Paris & Madrid 09:50 a.m.
London 08:40 a.m.
Sao Paulo 04:50 a.m.
New York 03:50 a.m.
Lima & Mexico City 02:50 a.m.
Los Angeles 00.50 a.m.
Honolulu 21:50 p.m. (Sunday, September 22)
The fall/autumnal equinox–know as the spring or vernal equinox in the southern hemisphere–always occurs between September 21 and September 24 each year. But what is it?
What is the fall equinox?
The fall or autumnal equinox marks that point in Earth's annual orbit when the sun crosses the celestial equator heading south to create shorter, cooler days as the northern hemisphere begins to tilt away the sun. It’s also known as the southward equinox. It's the point halfway between the summer solstice and the winter solstice, and when the day and night are of almost identical length. After all, equinox means 'equal night', and on Monday (and for a few days either side) there will be more or less equal hours of daylight and darkness (in practice, atmospheric refraction and the fact that the Sun is massive preclude perfectly equal day and night). However, light and dark are not the only visible signs of the fall equinox.
More:
https://www.forbes.com/sites/jamiecartereurope/2019/09/20/a-good-week-for-northern-lights-fall-equinox-puts-earth-in-the-perfect-position-for-a-light-show/#54bb8af945e9