PIX4632789: The First Trees on Earth - Artist View - First Trees - Artist view - 385 million years ago, in the upper Devonian, the first trees began to appear on Earth. In this illustration, the archaeopteris, considered the first tree, is present at different stages of its evolution, with on the left a young specimen of 6 metres, in the centre a tree twice as large, on the right, an even older specimen. At the extreme right, a strain of an old Archaeopteris collapse. 385 million years ago, near the end of the Devonian period, the first trees began to populate the Earth. Considered the first modern trees, the Archaeopteris were a part of the Earth's primitive forests for the next 25 million years. Unlike the trees we know today, Archaeopteris was in fact a primitive fern that reproduced by means of spores instead of seeds. While terrestrial plants had been around for 130 million years prior to Archaeopteris, this was the first plant to solve the biomechanical challenges of supporting and nurturing ever larger sizes, enabling these Archaeopteris to grow to heights of 70 feet and more, over twice the height of the Calamites. In this image, four stages of the life of the Archaeopteris are illustrated. On the far left nearest our vantage point is a young, 20 - foot Archaeopteris, and in the center at twice that height is a medium - aged Archaeopteris, and on the right is a fully mature specimen. Furthest right is the collapsed and decaying trunk of a mature tree, a contribution the biomassy that will eventually become the oil, coal and natural gas we exploit today / Bridgeman Images
PIX4580041: Ice on the Moon - Illustration - Lunar ice - Illustration - Artist's view of ice on the surface of a crater that remains perpetually in the shade of the Sun, near the poles. Water from an encounter with an icy comet has collected in the perpetual shade of a deep crater where the temperature is a constant - 380o F. In 1998, the unmanned Lunar Prospector probe discovered evidence for water ice on the surface of the moon. Some scientists believe that as much as 10 to 300 million tons of ice may reside at the moon's North and South poles. The source of the ice is thought to be from one or more comets that struck the moon's surface four billion years ago. (It is thought that Earth's water may have come from comets as well.) Unfortunately, the moon's small size and lack of an atmosphere caused it to lose almost all of its accumulated water to space. Any water that does remain on the moon would likely be on the poles, hidden in craters and depressions shaded from the Sun / Bridgeman Images
PIX4574285: Andromede Galaxy - The Andromeda Galaxy (M31) - The Andromede galaxy is located about 2.3 million light years away from Earth. Two satellite galaxies accompany it: M32 (NGC 221) at the top left of the nucleus, and M110 (NGC 205) at the bottom. Like the lactee path, the Andromede galaxy belongs to the local group, making up about thirty galaxies. M31, the Great galaxy in Andromeda, is a gigantic collection of more than 300 billion stars and is located about 2 million light years from Earth. Companion dwarf elliptical galaxies M32 and M110 are also visible. M31 and its companions are part of our local group of galaxies, which includes the Milky Way and Magellanic Clouds, and M33. The Andromeda Galaxy is headed towards our Milky Way Galaxy and is expected to collide with it and possibly merge into a gigantic elliptical galaxy in about 3 billion years / Bridgeman Images
PIX4591805: Constellation of the male Hydra - Constellation Hydrus - Constellation of the southern hemisphere between the galaxies of the Small and Large Magellan Clouds. The bright star below is Achernar, in the constellation Eridan. Southern hemisphere constellation between the Small and the Large Magellic clouds galaxies. The bright star on the bottom of the image is Achernar, located in the constellation Eridanus / Bridgeman Images