Orion Nebula in Oxygen, Hydrogen, and Sulfur Image Credit Copyright: César Blanco González The Orion Nebula is among the most intensely studied celestial features.The nebula has revealed much about the process of how stars and planetary systems are formed from collapsing clouds of gas and dust. Astronomers have directly observed protoplanetary disks, brown dwarfs, intense and turbulent motions of the gas, and the photo-ionizing effects of massive nearby stars in the nebula.
Venus is one unique planet when it comes to rotational motion. It takes Venus 243 Earth days to completely rotate on its axis, but just 225 days to orbit the sun. Venus also is one of two planets that rotates in reverse, a phenomenon called retrograde motion, which according to most theories is due to an ancient planetary collision.