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.
