Seasons first Aurora

The sun has been very active lately with several CMEs creating auroras around midnight in my hometown. It doesn't get dark until midnight, but then a green arc and some pillars were visible at times. The moonrise was beautiful too.

Bedrock and night sky

1.9 billion-year-old bedrock, limestone, and marble. Limestone bedrock refers to bedrock that is dominated by limestone, a sedimentary rock that primarily consists of the mineral calcite (calcium carbonate). This type of bedrock creates unique conditions for both plant life and landscape forms. Limestone is a relatively soft and water-soluble rock. When acidic rainwater penetrates the soil, it dissolves the limestone, creating various types of cavities. 

The image at the bottom shows something called Boudinage. It is a geological structure that occurs when a relatively stiff (competent) rock is stretched and broken into smaller pieces within a more easily deformable surrounding. The result often resembles sausages lying in a row, which gave rise to the name (from the French boudin, meaning blood sausage).

In the sky, the colors of dusk can be seen, but the northern lights also emerge along with the Milky Way.

Fantastic Aurora display

A magical night in the Swedish mountains. It started as a green glow in the north that developed into an arc that then increased in strength and went higher in the sky, finally to the zenith with curving green waves of light. The green glow flashed across the entire sky as if the atmosphere was shaking.

The northern lights (aurora borealis) affect the Earth's atmosphere, mainly in the upper layers such as the thermosphere and the ionosphere. The phenomenon occurs when charged particles from the sun collide with oxygen and nitrogen in the atmosphere at the magnetic poles. Main effects of the northern lights on the atmosphere: Energy input and heating: The northern lights are the result of an enormous energy input from the solar wind to the atmosphere. This causes local heating in the upper layers of the atmosphere. Electric currents: In connection with the northern lights, strong electric currents arise in the atmosphere, so-called auroral electrojet streams. These currents can affect the Earth's magnetic field. Ionosphere disturbances: Aurora activity can affect the ionosphere (the part of the atmosphere that is ionized), which in turn can disrupt radio communications and satellite navigation. Faint moonlight via a fine crescent moon and bright planet Jupiter also visible.

Cabin Aurora

A week's stay in the family's mountain cabin where the starry sky is very dark. One night the northern lights played fantastically beautifully and went high up in the sky above the cabin. The Big Dipper is seen in the middle of the picture, upside down. It almost forms a corona of the northern lights just above. Earlier in the evening I was able to witness a corona right in the zenith, pictures will come later.

 

Aurora Show in Stockholm

Last night, nature put on a fantastic spectacle! For being in the Stockholm area, this was really nice, even the northern lights at zenith. The northern lights, or aurora borealis, are a light phenomenon that occurs when charged particles from the sun collide with gas atoms in the Earth's atmosphere. It is mainly visible in the polar regions (such as northern Sweden, Norway and Iceland) between September and March, often as dancing green, purple or red lights at an altitude of 80–500 km.

Colors: Yellow-green is most common (oxygen at an altitude of 100–140 km). Red and violet tones also occur, depending on the type of atom that collides with the particles.

Shape: They can look like arches, curtains or rays dancing across the sky.

Origin: The northern lights are caused by geomagnetic storms that affect the Earth's magnetic field.

Low water level in a icy landscape

The Baltic Sea is currently experiencing historically low water levels. During February 2026, persistent high pressure and strong northeasterly winds pushed enormous amounts of water – almost 300 cubic kilometers – through the Öresund and the Belts towards the North Sea.

Historical levels: Several measuring stations have approached or broken previous records for low water levels.

Cause: A strong and stationary high pressure combined with cold winds has acted as a "pump" that has drained the sea of ​​water.

Good news for the environment: The extremely low water level creates a "place" in the Baltic Sea. When the weather turns, this can pave the way for a strong influx of salt and oxygen-rich water from the Western Sea, which is crucial for saving oxygen-poor seabeds.

So why not head out to the east coast on a starry night! And indeed, the water level was very low. I could see barnacles on the rocks where the water's edge used to be. Amazing ice formations everywhere and when I shone UV light many interesting things under the ice fluoresced in different colors. I have no idea what it was, but probably algae, seaweed and minerals.

And on top of all this beauty the Northern Lights appeared with a nice spectacle!

Colors in the dark from a burial ground

The view from the ground, the small things. Standing at a historical site, old burial ground from the Iron Age. The stoned ones moved by the people creating the burial ground. At the stones moss and lichens grow, some very colorful in UV light. 

What are lichens?

Lichens are miniature ecosystems made of fungus and an algae and/or cyanobacteria. These different life forms work so closely together that the algae or cyanobacteria actually sits inside the fungus. The algae or cyanobacteria provide the fungus with sugars made from sunlight, and the fungus provides the home. Lichens look like spots or clumps of colour, like someone has splashed paint onto a branch of a tree. Their colours range from green to brown to white to russet red. Even in these colours, lichens can be understated additions to tree trunks and rocks, and you might miss them at first glance. There are many types of lichen but they only grow in three ways. They can be branched like tiny shrubs, they can have crinkly little leaves or they can grow like a crust on a surface.

Mosses are small, non-vascular, flowerless plants that form dense green clumps or mats, usually in damp places, lacking true roots, stems, and leaves but having root-like rhizoids and simple leaf-like structures. They absorb water and nutrients directly through their surfaces, reproduce via spores, and are vital for soil stabilization, water retention, and creating microhabitats, acting as an important link in ecosystems.

In the sky a faint green light visible below the Big Dipper. According to Spaceweather.com it is SOLSTICE STORM IN PROGRESS: A minor G1-class geomagnetic storm is in progress on Dec. 21st. Why? Earth's magnetic field is connecting to the sun's (SWx jargon: "BsubZ is pointing south"), giving the solar wind an unimpeded path into our magnetosphere. Arctic sky watchers should be alert for auroras.

A closer look at cliff and stones in fluorescence, also lichens. The blue stones are probably fluorite, the orange cliff is feldspar and golden lichens. Lichens fluoresce in "gold" (yellow/orange) due to natural pigments like xanthones and atranorin, especially under UV light, revealing hidden colors not seen in daylight. Feldspars crystallize from magma, this area was vulcanic 1,9 billion years ago.

In the sky bright planet Jupiter and a lot of airglow, even some faint aurora borealis.

 

Airglow Aurora and Big Dipper

Heavy airglow and faint aurora borealis with the big dipper in the sky.

On planet earth you see fluorescence in water and lichens.

Airglow is a faint emission of light by a planetary atmosphere. In the case of Earth's atmosphere, this optical phenomenon causes the night sky never to be completely dark, even after the effects of starlight and diffused sunlight from the far side are removed. This phenomenon originates with self-illuminated gases and has no relationship with Earth's magnetism or sunspot activity, causing aurorae.

The Big Dipper is an asterism consisting of seven bright stars of the constellation Ursa Major six of them are of second magnitude and one, Megrez, of third magnitude. Four define a "bowl" or "body" and three define a "handle" or "head". It is recognized as a distinct grouping in many cultures. The North Star (Polaris), the current northern pole star and the tip of the handle of the Little Dipper (Little Bear), can be located by extending an imaginary line through the front two stars of the asterism, Merak and Dubhe. This makes it useful in celestial navigation.

 

Ocean's purification plant and night sky

Mussels play a super important role as the ocean's purification plant by filtering enormous amounts of water, combating eutrophication (nitrogen/phosphorus), creating habitats (biodiversity) and providing healthy food for people (protein, vitamins), making them a climate-smart and nutritious resource for a sustainable future in Sweden's aquatic environments and other aquatic environments.

Ecological roles Water purification: Mussels filter plankton and particles, purify the water and combat eutrophication by binding nutrients such as nitrogen and phosphorus. Habitat and biodiversity: Mussel beds serve as protection and substrate for many small animals, which increases biodiversity. Key species in the food web: They connect benthic life with free aquatic life, and some freshwater mussels use fish to disperse their larvae.

Some mussels washed up at the shore a clear night by the coast. Faint Aurora and airglow visible in the sky in this macro widefield photo.

Golden lichens and colorful moss in fluorescence, a macro view and in the north Aurora Borealis.

Caloplaca marina, the orange sea lichen, is a crustose, placodioid lichen. It has wide distribution, and can be found near the shore on rocks or walls.

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A lovely photo session by the coast

 A clear and calm night by the ocean. Photogenic Aurora in the north and fluorescent sea weed and lichen on stones. Planet Jupiter rising below Castor and Pollux, green airglow visible too and a nice starry sky.

Strong Aurora Borealis with a rare SAR ARC (and comet Lemmon)

 Me and my son went for a drive to darker skies to see comet Lemmon a little bit better. But when we arrived a big green bow was visible. We went very fast to put up the gear and photograph and the show just went on. Dring the session we noticed a bow in the south, we thought that it was aurora too but it was actually Surprise: Some Red Auroras are *not* Auroras | Spaceweather.com

Spaceweather.com Time Machine

A lovely session with comet Lemmon visible too but much more faint because of the Aurora.