Table of Contents
observing and photographing aurora borrealis and aurora australis
see also:
introduction
- a prominent aurora display can be an awesome visual event in dark skies and makes a great photographic subject.
- unfortunately, to see them one must be in the right place at the right time with clear skies
- the chance of seeing one depends upon:
- the strength of the storm - this is measured by its Kp value (0-9 with 9 being the max)
- your latitude
- clear skies away from light pollution
- that usually means the far northern hemisphere at latitudes around the +60deg region or in the south (-50 to 60deg latitude)
- with extreme magnetic storms, brief events may be visible from southern parts of Australia but they are no where near as dramatic as at higher latitudes, so if you want the best displays, one must go in winter or preferably around the times of the equinoxes (eg. Sept or March) to very cold places such as Iceland, Scaninavia, Alaska or Canada (summer is no good at such latitudes as the long summer twilight interferes with visibility)
- best quality images usually require a modern full frame dSLR with manual focus and magnified Live View, 24mm f/1.4 lens or Zeiss ZE 21mm f2.8 if you need wider, tripod and you may still need ISO 1600. If your lens is not great in the corners wide open, you may need to stop down to f/2.8.
- aurora displays can be very short-lived lasting only 10-20 minutes so you must be well prepared
- solar storms pose a massive risk to the network of low earth orbiting satellites
- a “close approach”, defined as two satellites passing by each at less than 1km separation, occurs every 22 seconds. For Starlink alone, that number is once every 11 minutes.
- for Starlink, on average, each of the thousands of satellites have to perform 41 maneuvers per year to avoid running into other objects in their orbit.
- storms they heat up the atmosphere causing increased drag, as well as positional uncertainty for some of the satellites. Increasing their drag causes them to use more fuel to maintain their orbit, but also to initiate evasive maneuvers if their path might cross that of another satellite.
- During the “Gannon Storm” of May 2024 (which, unfortunately, appears not to be named after the Zelda villain) over half of all satellites in LEO has to use up at least some of their fuel on these repositioning maneuvers
- storms can take out the navigational and communications systems of satellites themselves. This would make them unable to maneuver out of harm's way, and, combined with the increased drag and uncertainty caused by the heated atmosphere, could least to an immediate catastrophe.
- if satellite operators were to lose their ability to send commands for avoidance maneuvers, there would be a catastrophic collision in around 2.8 days1)
- if operators lose control for even just 24 hours, there’s a 30% chance of a catastrophic collision that could act as the seed case for the decades-long process of Kessler syndrome
solar storms
solar particle storms
- stars similar to the Sun produce a gigantic outburst of radiation on average about once every hundred years per star. Such superflares release more energy than a trillion hydrogen bombs and make all previously recorded solar flares pale in comparison. “It is unclear whether gigantic flares are always accompanied by coronal mass ejections and what is the relationship between superflares and extreme solar particle events.” 2)
- solar particle storms are rare, but when they occur, they bombard Earth with an enormous amount of high-energy particles.
- solar particle storms can greatly enhance the normal production of cosmogenic isotopes like radiocarbon (14C) in the atmosphere by galactic cosmic rays. These can be detected as Miyake events in tree rings
- 12350BC: strongest solar event ever detected - 18% stronger than the notorious AD 775 event and over 500 times more intense than the 2005 storm
- other large known solar particle storms have occurred around 994 AD, 663 BC, 5259 BC and 7176 BC
solar electromagnetic storms from solar flares
- these are the relatively common events which cause aurorae to appear on earth
- the famous Carrington event in 1859 was not accompanied by a solar particle storm and only had ~1% of the energy of a superflare, but the telegraph network collapsed in large parts of northern Europe and North America.
Aurora Borrealis
- the “Northern Lights”
For some awesome photographs:
- from Iceland, see Olgeir Andrésson's website or Flickr set.
Aurora Australis
- the “Southern Lights”
In Victoria, you need a Kp of 8-9 to have any chance of seeing one:
image courtesy of http://www.aurora-service.net/aurora-forecast/
It is seen best from Antarctica such as this one from Mawson base in 2003.
In an extreme event, the aurora australis may be seen as far north as -35deg latitude, such as this image by Adam Marsh taken in Tocumwal, NSW, Australia in March 2012 at ISO 1600, f/3.5 and 30sec exposure:
10 minutes of this approx. 20 minute event on March 12th 2012 was captured and animated by Michael Mattiazzo in Castlemaine, Victoria using 25 frames of 15 sec exposures at ISO 800 using an 18mm focal length on a Canon 300D:
