the Northern Lights
often get questions about:
- What website
gives the best information about space weather and aurora observing
usually look at the Space
site and pull down the right side menu - Space Weather Now
option which shows a view from the
POLAR satellite of the so-called auroral oval. If you see a
bright ring on the image, then you know that an
aurora is going on right now. The more intense (redder) the
oval, the stronger the display.
Stronger ovals tend to expand further equatorially and
therefore become more visible in the Lower-48.
The Kp Index helps you
determine aurora visibility.
despite an active sun which
heads towards the earth, not all CMEs create aurora. As noted
by the left hand dial, the Bz component needs to be negative
(have a southward
deflection) for the solar energy to be drawn into the earth's upper
be made visible. The more negative the better. A positive Bz
all but guarantees that the energy that creates the northern lights is
deflected away from the earth and therefore will not cause
any aurora to form. The higher the speed of the solar wind,
the more energetic the aurora will be if it reaches the earth (middle
dial). The right dial measures how dense the solar energy is.
higher the better for viewing the lights.
- What is the best time of
year and day to
view the Northern Lights?
from Yerkes Observatory during a 55 year period spanning 5
sunspot cycles did confirm that September and March are the most
frequent months for auroras and January and July the least likely. This
correlation was also apparently described by Mairan in 1733. Most of
the solar activity
comes from regions of the sun outside the solar equatorial band +/- 10
degrees to either side of the solar equator. The Earth in its orbit is
this equatorial band during January and July, and when it is at its
heliographic latitudes in September and March, the Earth is in the zone
of solar activity.
the fact that most of the United States is located well
below the zone of most activity near latitudes of 68 degrees, we get
a number of Aurora Borealis sightings, even as far south as Arizona!
From Fairbanks, Alaska, because of the midnight sun, all night twilight is too bright for the aurora
to be seen from about 15 April to 15 August.
Typically in Fairbanks,
a display lasts a few minutes and occurs a few times per night. Auroral
activity is usually highest during the hours near midnight. During a
moderate to large auroral display, which can last up to three hours,
the amount of energy released is roughly equivalent to that of a small
list that is culled from back issues of Sky
and Telescope magazine:
events and photos since 2000, see Spaceweather.com Aurora
- Is there a forecast for when
the aurora will be visible?
to Northern Lights Photos and Movies
- Latest Science About the Aurora
- The Aurora Watcher's Handbook by Neil Davis
- Documentary Film - Dance of the Auroras by Maida Withers