Hi, I'm Sonia,
I have been into astronomy since 1997 when I was 11 years old when comet Hale Bopp was around. I remember being in the back garden with my dad and he was showing me how to take a photo of it with his old Fujica camera, that I still have now.
Ever since then I've been fascinated with space. I started with a very cheap Tasco telescope from Argos to look at the moon, went onto a Meade goto etx 90 telescope, which unfortunately due to age stopped working.
For a very long time and currently using a skywatcher 10" Dobsonian, to mostly photograph the moon and also the planets with a moon filter. Seestar S50 which has now got me into deep sky imaging which I love! And lastly a Coronado PST for solar imaging.
I have two BscHons open degrees in Introducing Astronomy and the planets.
Elected in 2023 to become a Fellow of the Royal Astronomical Society, Vice President for the Manchester Astronomical Society.
Currently a freelancer for the BBC sky at night magazine.
Clear Skies
Sonia
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Gofororbit - Own work Sweden , CC BY-SA 4.0
Noctilucent Cloud: The mysterious night shiners of the sky!
It’s now prime season for Noctilucent clouds, that can be seen from end of May to start of August.
High above the Earth’s surface, shimmering like ghostly veils against the twilight sky, Noctilucent clouds (Known as NLC’s and night shining clouds) are among the rarest and most beautiful atmospheric phenomena. Their name is derived from Latin, meaning “night shining” and they live up to that title by glowing with a soft, silvery-blue light just after sunset or before Sunrise.
But what are they?
Noctilucent clouds are extremely high-altitude clouds that form in the Mesosphere, approximately 76-85km (47-53 miles) above Earth’s surface, but they have been known to be lower than this. Unlike ordinary clouds, which form in the troposphere (the lowest layer of clouds) they are made of tiny ice crystals that condense on particles of dust – possibly from meteors, volcanic ash, or pollution.
Discovery, study and evolving significance:
Early Observation:
First sighting was in 1885 after the eruption of Krakatoa in 1883 in Indonesia. In 1885, observers in Northern Europe
began recording unusual glowing cloud formations in the twilight sky, thought to be a side effect of volcanic dust.
Late 19th Century scientists began finding these clouds to be from other atmospheric phenomena, they were much
higher in the atmosphere, known as the mesosphere.
1920s-1930: The term noctilucent is a Latin name for night-shining which became widely used. It was then that
Researchers began to photograph and study their seasonal and latitude patterns.
Modern Research and scientific Importance:
1960s onward: Satellite and high-altitude research. Using high altitude balloons, scientists gained better tools to study
NLCs. Confirming them to be tiny ice crystals formed under specific cold conditions.
2000s-present: Climate change connections
NLCs are now to be considered a potential indicator of climate change. Increasing Occurrences and lower-latitude
Sightings may be linked to:
Increased methane emissions, produce more water vapour at high altitudes.
Changes in upper-atmosphere temperature due to greenhouse gas effects.
So..how do they form?
The formation of NLCs requires three main ingredients:
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Extremely cold temperatures: The mesosphere must drop below -120C. However, this happens during summer due to atmospheric circulation that causes this upper layer to cool.
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Water Vapour: Even though the Mesosphere is dry, there is a small amount of water vapour that can rise to this level, especially in the Summer months.
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Dust Particles: The dust particles act as a nuclei for the water vapour to condense and freeze, forming Ice Crystals.
Once all these conditions are met, NLCs can form and becomes visible when the sun is just below the horizon. About 6 -11 degrees. The sun illuminates the clouds from below while the ground and lower atmosphere are in shadow.
What do they look like:
They appear as thin, wispy electric blue streaks or web like patterns in the twilight sky.
Where and when can they be seen?
Best time is around 45-60 minutes after sunset or before sunrise in the Northerly direction.
The best locations for them are high-latitude regions such as: Northern Europe, Scandinavia, the UK, Canada, Northern United States. Southern tips of Australia, New Zealand or Chile (for the southern Hemisphere season)
Why are they important?
NLCs are more than just a beautiful display, they may also be indicators of climate change. Since they form at the edge of space, they are sensitive to changes in the upper atmosphere. Scientists have observed an increase in the frequency and intensity of the NLCs over recent decades which could be due to:
Increased water vapour, more dust particles in the mesosphere and changing atmospheric circulation patterns.
How to take photos of them.
So the next time you are out during the Summer Twilight in the northern latitude, look up! You might just catch a glimpse of the sky’s most elusive glow.
Sonia Turkington, Stockport, Single Drone Shot.
Clear Skies, Sonia
