Pine lichen and crescent moon

Fluorescent lichens and moss on a pine tree by illuminating with UV light.

Lichens on trees are usually completely harmless and are not a sign of disease. They only use the tree as a foothold and do not take nutrition from it. The lichens indicate clean air and serve as homes for insects, which attracts small birds.

Key facts about lichens on trees:

No harm: Lichens do not penetrate the bark, do not cause rot and do not harm the growth of the tree.

Epiphytes: They grow as so-called epiphytes, mainly on older trees, and get nutrition from water and air.

Air quality: Abundant occurrence of lichens is a sign of a good air environment.

Common types: Examples are leaf lichens such as lung lichen, beard lichen and crust lichen.

Ecological benefit: Lichens provide habitat for small animals, which benefits bird life.

In the sky, a slightly overexposed crescent moon with thin clouds in front.

Double Arc of Aurora

An aurora arc (northern lights arc) is the most classic and stable form of the northern lights. It looks like a luminous bridge spanning the sky, usually in a faint green color.

Characteristics and origin

Shape: The arc follows the Earth's magnetic latitudes. When you see an arc, you are actually looking at a small part of the giant aurora oval that surrounds the Earth's magnetic pole.

Color: The most common color is yellow-green, which is created when electrons collide with oxygen atoms at an altitude of about 100–150 km.

Development: A quiet arc is often the starting point. If geomagnetic activity increases, the arc begins to "dance", form folds (curtains) or split into several bands

A double aurora arc (aurora borealis double arc) occurs when the northern lights split into two or more parallel bands that stretch across the sky from horizon to horizon. The phenomenon is particularly captivating because it creates a symmetrical and structured view of the otherwise often chaotic light show.

How they are formed:

Magnetic field lines: Particles from the sun are guided by the Earth's magnetic field down towards the poles. A double arc often forms when geomagnetic activity increases, causing the aurora oval to expand and split into several discrete bands.

Geomagnetic substorms: During the most active phases of a "substorm", a single arc can quickly split into several parallel arcs.

Perspective: To an observer on the ground, the aurora appears as an arc due to the curvature of the Earth and the distance from the light show.

On the left, the constellations Cygnus and Cepheus run through one of the most star-dense and interesting parts of the Milky Way in the northern sky. These areas are particularly popular for both observation and astrophotography.

The "Handle" of the Big Dipper is seen at the top right, consisting of three bright stars that form a curved line. These stars are part of the larger constellation Ursa Major.Here are the three stars in the handle, counting from the dipper outwards:Alioth: The brightest star in the entire dipper. It is closest to the "dipper" itself.Mizar: The middle star. It is known to be a double star. If you have good eyesight (or binoculars), you can see a smaller, fainter star right next to it called Alcor.Alkaid: The star that sits at the far end of the handle.

Moon & planets

A cold, colorful afternoon in Vallentuna, Sweden. In the sky, a thin crescent moon with earthshine is visible, and to the left of the moon, the planet Saturn, and to the lower right, the planet Mercury.

Earthshine is an astronomical phenomenon in which sunlight is reflected from the Earth onto the dark night side of the moon, making the entire lunar disk faintly visible even when only a thin crescent is directly illuminated by the sun.

Mercury is the smallest planet in the solar system and the one closest to the sun. It is a rocky, so-called terrestrial planet with a surface filled with craters, which makes it very reminiscent of our moon.

Saturn is the second largest planet in the solar system and is best known for its spectacular and complex ring system. It is a gas giant that consists mainly of hydrogen and helium.

Where life once evolved.

 A clear and cold night by the sea on planet Earth. In the sky, the constellation Orion is visible with the star factory Orion Nebula under Orion's belt, visible to the naked eye. Our star Sun was probably created from a similar star factory long ago. The Orion Nebula (M42) consists primarily of gas and dust, where the absolutely dominant elements are hydrogen and helium. It is an emission nebula that shines because young, hot stars ionize the gas.

The Earth formed about 4.6 billion years ago from a rotating disk of gas and dust that surrounded the young Sun. By clumping together pebbles and cosmic dust, the planet grew. Originally, the Earth was a red-hot melt that cooled and formed a solid crust. Water was added later, probably via comet impacts. The theory of the origin of life is that life on Earth arose in the ocean about 3.5–3.8 billion years ago, probably in close proximity to hot springs on the seafloor where amino acids and simple bacteria were formed. The ocean served as a protective environment for the first organisms before oxygen and the ozone layer made life on land possible. The oldest traces of life are 3.5–3.7 billion years old and are found in marine environments. Early theories focused on the "primordial soup" in shallow sea bays, while more recent research often points to hot springs (hydrothermal vents) in deep water. Complex organic molecules (amino acids) formed in the water and assembled into simple bacteria. These first organisms were independent of oxygen, but later began to produce it through photosynthesis. Evolution started with simple microorganisms, followed by algae, and later the first multicellular animals developed in the sea. The picture shows algae and seaweed that fluoresce via UV light. They are clearly visible thanks to the current record low sea level. Algae contain chlorophyll for photosynthesis. When chlorophyll is hit by UV light or blue light, it absorbs the energy, but cannot use it all. The excess energy is emitted as a red or pink glow. This is called fluorescence and can often be seen underwater with special lighting or when analyzing algae. Under Orion, light pollution from civilization is seen, life has developed into an intelligent species Homo Sapiens Sapiens that eventually invented electricity. The place where the picture was taken, Nothamn Sweden, is known for its geology, 1.9 billion years ago there were explosive volcanoes here that spewed ash and lava over a shallow sea that covered the area. Early forms of life, microorganisms, lived on the seabed, which together built up limestone layers. Iron precipitated in the limestone and layers of iron ore were formed, something that is common throughout Bergslagen. Deep down, beneath the volcanoes, large magma chambers have solidified into the rocks diorite and gabbro. So the rocks in the picture were created during this time.

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!

The lonely pine cone

Finally some starry skies! Orion is beautifully high in the sky with the bright planet Jupiter to its left. Took a walk in the woods and saw this pine cone lying on the ground. Took a close-up of it and the starry sky. The pine cone is the spruce's equivalent of a flower. It acts as a protection for the tree's seeds and reacts to humidity by opening when dry and closing when wet.

Quick facts:

Seed bank: A single pine cone can contain up to 200 seeds.

Maturation: The cones mature during their first autumn and release the seeds during sunny spring and winter days.

Who eats them? Squirrels often gnaw them clean, while woodpeckers wedge them into the bark to get to the seeds.

Cone year: The spruce produces abundant cones about every five to seven years, which is called a cone year.

Lichens with Jupiter and lightpollution

Bright planet Jupiter in the night sky on this clear and cold evening. In the foreground is a birch with lava in different colors as I have used UV light to create fluorescence. Lichens on birch are usually harmless, superficial organisms that use the bark as a base without damaging the tree, often a sign of clean air. Common species include blue lichen and various crust lichens. Lichens do not penetrate the bark, do not cause rot and can benefit biodiversity by offering food to insects. The bright night sky is due to light pollution, caused by excessive or misdirected artificial night lighting, disrupting ecosystems, disrupting the circadian rhythm of humans and animals and obscuring the starry sky. It is a rapidly increasing environmental problem that negatively affects biodiversity, insect and bird migration patterns, and can be counteracted by targeted, warm white lighting, motion sensors and timers