Moons in the context of "List of tumblers (small Solar System bodies)"

Venus is the second planet from the Sun. It is often called Earth's "twin" or "sister" among the planets of the Solar System for its orbit being the closest to Earth's, both being rocky planets, and having the most similar and nearly equal size, mass, and surface gravity. Venus, though, is significantly different, especially as it has no liquid water, and its atmosphere is far thicker and denser than that of any other rocky body in the Solar System. The atmosphere is composed mostly of carbon dioxide and has a thick cloud layer of sulfuric acid that spans the whole planet. At the mean surface level, the atmosphere reaches a temperature of 737 K (464 °C; 867 °F) and a pressure 92 times greater than Earth's at sea level, turning the lowest layer of the atmosphere into a supercritical fluid. From Earth, Venus is visible as a star-like point of light, appearing brighter than any other natural point of light in the sky, and as an inferior planet always relatively close to the Sun, either as the brightest "morning star" or "evening star".

The orbits of Venus and Earth make the two planets approach each other in synodic periods of 1.6 years. In the course of this, Venus comes closer to Earth than any other planet, in contrast to Mercury which stays closer over the course of an orbit to Earth than any other planet, due to its orbit being closer to the Sun. In interplanetary spaceflight from Earth, Venus is frequently used as a waypoint for gravity assists, offering a faster and more economical route. Venus has no moons and a very slow retrograde rotation about its axis, a result of competing forces of solar tidal locking and differential heating of Venus's massive atmosphere. As a result, a Venusian day is 116.75 Earth days long, about half a Venusian solar year, which is 224.7 Earth days long.

The orbital period (also revolution period) is the amount of time a given astronomical object takes to complete one orbit around another object. In astronomy, it usually applies to planets or asteroids orbiting the Sun, moons orbiting planets, exoplanets orbiting other stars, or binary stars. It may also refer to the time it takes a satellite orbiting a planet or moon to complete one orbit.

For celestial objects in general, the orbital period is determined by a 360° revolution of one body around its primary, e.g. Earth around the Sun.

Scott Sander Sheppard (born 1977) is an American astronomer and a discoverer of numerous moons, comets and minor planets in the outer Solar System.

He is an astronomer in the Department of Terrestrial Magnetism at the Carnegie Institution for Science in Washington, DC. He attended Oberlin College as an undergraduate, and received his bachelor in physics with honors in 1998. Starting as a graduate student at the Institute for Astronomy at the University of Hawaiʻi at Mānoa, he was credited with the discovery of many small moons of Jupiter, Saturn, Uranus, and Neptune. He has also discovered the first known trailing Neptune trojan, 2008 LC18, the first named leading Neptune trojan, 385571 Otrera, and the first high inclination Neptune trojan, 2005 TN53. These discoveries showed that the Neptune trojan objects are mostly on highly inclined orbits and thus likely captured small bodies from elsewhere in the Solar System.