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.

Aurora Corona

When the northern lights are really strong, you might be lucky enough to see them at their zenith, overhead like a corona. The picture shows the beginning of a corona last week.

An aurora corona is a spectacular form of aurora that occurs when you are directly under the magnetic field lines.

It looks as if all the light rays are radiating from a single point high in the sky (the zenith).

Why? It's a perspective effect, just like when parallel train tracks appear to meet on the horizon. In reality, the aurora rays are parallel and follow the Earth's magnetic field, but from the ground they appear to form a "crown" (corona in Latin).

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.

The dark spots you see on the moon are actually giant, solidified lava fields called maria. These were formed billions of years ago when huge amounts of liquid lava gushed out of the moon's interior and filled large craters after meteorite impacts.

Composition: The fields are mainly composed of basalt, a dark, iron-rich volcanic rock similar to that found on the ocean floor here on Earth.

Volcanic activity: It was long thought that volcanism on the moon died out billions of years ago, but new analyses of lunar samples suggest that there may have been active volcanoes as recently as 120 million years ago.

Lava tubes: Beneath the surface are hollow lava tunnels, or lava tubes. These giant caverns are considered ideal locations for future lunar bases because they protect against radiation and extreme temperatures.

Asymmetry: There are significantly more and larger lava fields on the side of the moon that faces Earth than on the far side, which is because the crust is thinner on the front side.

Worm Moon HDR

Today's full moon, called a worm moon, photographed with a telescope and several images stitched together into one image.

At a full moon, the sun illuminates the lunar surface directly from the front, which hides shadows and makes it more difficult to distinguish topographical details such as craters and mountain walls. The use of HDR photography (High Dynamic Range) and stacking (combining many images) is therefore crucial to highlight geological contrasts and mineral variations that are otherwise lost in the bright light.

Geological details at a full moon

Beam systems: At a full moon, bright beam systems appear most clearly, for example from the crater Copernicus. These consist of material (ejecta) that was thrown out during a meteorite impact.

Albedo and minerals: The contrast between the light, calcium-rich highlands (anorthosite) and the dark, iron-rich oceans (basaltic maria) becomes extremely clear. By saturating the colors in an HDR image (so-called "Mineral Moon"), chemical differences in the soil can be visualized.

Bright Craters: Craters with high albedo, such as Aristarchus, shine brightly and can even be seen with the naked eye.

99% moon and the bird

The full moon is slowly rising in the sky, well, almost full, 99% behind a tree with a blackbird sitting at the top.

Tomorrow, 3/3, a total lunar eclipse will occur. The eclipse will be completely visible over northeastern and northwestern North America and the central Pacific Ocean and will be visible rising over large parts of Asia and Australia and setting over North and South America, unfortunately not from Sweden.