Red giant will begin to expand into a subgiant. Eventually, the pressure builds up so much that the core will begin to fuse helium, and will expand even more into a red giant. At its largest, its surface (photosphere) will approximately reach the current orbit of Earth. It will then lose its atmosphere completely; its outer layers forming a planetary nebula and the core a white dwarf. The evolution of the Sun into and through the red-giant phase has been extensively modelled, but it remains unclear whether Earth will be engulfed by the Sun or will continue in orbit. The uncertainty arises
Red and white giant flying squirrel found in mountain areas, they nest in hollow trees. They move between the trees of their ecosystem by gliding by use of a patagium, typically over distances of 10–20 meters although glides of up to 400 meters longer have been observed when they happen to be traveling downhill. This species has a wide distribution and a presumed large population, it occurs in many protected areas, and the International Union for Conservation of Nature has rated it as being of "least concern". Red and white giant flying squirrel The red and white giant flying squirrel ("Petaurista alborufus") is a species of