PIX4632751: Archean stromatolites - Illustration showing the shores of an ancient sea 3 billion years ago. In the foreground, stromatolites, aggregation of sediments and cyanobacteries. Stromatoliths have undoubtedly contributed to our dioxygen-rich atmosphere and the ozone layer that allowed the development of a more complex terrestrial and oceanic life. Dome - shaped stromatolites, averaging three feet high and four feet wide, populate the shallow shore of an ancient sea 3 billion years ago. The Moon looms near the horizon, much closer to the Earth than it is now and therefore appearing considerably larger, but otherwise looking much like the moon we know today. 3 billion years ago the first macro evidence of life on Earth may have appeared in the form of large aggregations of microorganisms and associated sediments known as stromatolites. Cyanobacteria (AKA blue - green algae) were likely one of the primary contributors to these aggregations. During the Archean Eon the Earth's atmosphere contained very little oxygen. Cyanobacteria would have thrived during this time as they employ photosynthesis to combine water, carbon dioxide, and sunlight to create their food, while the byproducts of this process are oxygen and calcium carbonate. Billions of years of photosynthetic processes by cyanobacteria other living organisms are likely the primary source of the oxygen we breathe. They also provided the oxygen that forms the protective ozone layer, filtering the shorter wavelengths of ultraviolet light from the Sun that are harmful to most forms of life. Varieties of stromatolites still flourish to this day with well - known formations in parts of Australia, Brazil, and the Bahamas / Bridgeman Images
PIX4627431: Eclipse totale de Soleil 02/1998 - Composite Image, Total Eclipse of the Sun - 1998 - The different phases of the total eclipse of the Sun of 26 February 1998. February 26, 1998 Total Eclipse of the Sun. Partial phases and corona during mid totality. A total eclipse of the Sun occurs when the orbits of the Sun and Moon line up and the Moon moves in front to the Sun, totally blocking its light from reaching a narrow path on the Earth / Bridgeman Images
PIX4596026: Apollo 11: E. Aldrin on the Moon - Apollo 11: Portrait of E. Aldrin - Portrait of Edwin Aldrin on the Moon. Neil Armstrong and the LEM are visible in reflection on the visor of his helmet. 20/07/1969. N.B. of the black was added in height and the horizon was straightened from the original photo e - apo11 - 30042. Portrait of E. Aldrin. Armstrong's reflection in visor. Jul 20 1969. N.B. image has been rotated and black has been added in height. See the original photo e - apo11 - 30042 / Bridgeman Images