"Inferior and superior planets In the Solar System, a planet is said to be inferior or interior with respect to another planet if its orbit lies inside the other planet's orbit around the Sun. In this situation, the latter planet is said to be superior to the former. In the reference frame of the Earth, in which the terms were originally used, the inferior planets are Mercury and Venus, while the superior planets are Mars, Jupiter, Saturn, Uranus and Neptune. Dwarf planets like Ceres or Pluto and most asteroids are 'superior' in the sense that they almost all orbit outside"
"planets. These usually are limited to the planets from Mercury to Saturn, although some include Uranus. The light sources for the planets are projected onto mirrors which are geared to a motor which drives the images on the dome. Typically the Earth will circle the Sun in one minute, while the other planets will complete an orbit in time periods proportional to their actual motion. Thus Venus, which takes 224.7 days to orbit the Sun, will take 37 seconds to complete an orbit on an orrery, and Jupiter will take 11 minutes, 52 seconds. Some planetariums have taken advantage of"
"planets in the solar system, Jupiter and Saturn, take approximately 12 and 30 years to orbit the Sun respectively. Using $120 as an example again, it would become 10° and 4°, which are 10° and 4° Aries in terms of zodiac. Gann also uses a scale of $0.07 ($1/15) to 1 degree, which is based on the Earth’s rotation in 24 hours (for 24 times 15° is 360°). Using $120 as an example, $120 times 15 will be 1800°, and when it is divided by 360°, the remainder is 0. Therefore, it will become 0° Aries in the zodiac. Here"
"Earth and the Sun. For comparison, Mercury, our Solar System's innermost planet, takes 88 days to orbit at a distance of about 0.38 AU. The size of TRAPPIST-1 and the close orbit of TRAPPIST-1d around it means that the star as seen from the planet appears 5.5 times as large as the Sun from the Earth. While a planet at TRAPPIST-1d's distance from our Sun would be a scorched world, the low luminosity of TRAPPIST-1 means that the planet gets only 1.043 times the sunlight that Earth receives, placing it within the inner part of the conservative habitable zone. The"
"into an elliptical orbit, then chemical rockets will fire to deposit the mapper probe into a circular orbit. Both probes will operate for one terrestrial year. The mapper probe carries an array of spectrometers similar to those on ""MESSENGER"", and will study the planet at many different wavelengths including infrared, ultraviolet, X-ray and gamma ray. Mercury (planet) Mercury is the smallest and innermost planet in the Solar System. Its orbital period around the Sun of 87.97 days is the shortest of all the planets in the Solar System. It is named after the Roman deity Mercury, the messenger of the"
"Mercury (planet) Mercury is the smallest and innermost planet in the Solar System. Its orbital period around the Sun of 87.97 days is the shortest of all the planets in the Solar System. It is named after the Roman deity Mercury, the messenger of the gods. Like Venus, Mercury orbits the Sun within Earth's orbit as an ""inferior planet"", and never exceeds 28° away from the Sun. When viewed from Earth, this proximity to the Sun means the planet can only be seen near the western or eastern horizon during the early evening or early morning. At this time it"
"excess of . K2-229b has one of the shortest orbital periods known, with one full orbit taking just 0.584 days (14 hours) to complete. The planet orbits its host star at a distance of 0.012888 AU, nearly 100 times closer in than Earth. For comparison, our Solar System's innermost planet, Mercury, takes 88 days to orbit at 0.39 AU. K2-229b has an orbital eccentricity of 0 and is most likely tidally locked with its host star. K2-229 orbits the orange dwarf star K2-229. It is about 79% the radius and 84% the mass of the Sun, with a temperature of"
"could still lead to collisions. The great orbits of the planets take longer than the shorter: Saturn and Jupiter take many years, Mars two, whereas the moon takes only a month. Jupiter's moons take even less. This is not changed if the earth rotates every day, but if the earth is stationary then we suddenly find that the sphere of the fixed stars rotates in 24 hours. Given the distances, that would more reasonably be thousands of years. In addition some of these stars have to travel faster than others: if the Pole Star was precisely at the axis, then"
"Solar eclipses on Mars The two moons of Mars, Phobos and Deimos, are much smaller than the Moon, greatly reducing the frequency of solar eclipses on that planet. Neither moon's apparent diameter is large enough to cover the disk of the sun, and therefore they are annular solar eclipses and can also be considered transits. Due to the small size of Phobos (about ) and its rapid orbital motion, an observer on the surface of Mars would never experience a solar eclipse for longer than about thirty seconds. Phobos also takes only 7 hours 39 minutes to orbit Mars, while"
"by the Apollo program. </math>, where ""m"" is the mass of Earth, ""a"" is an astronomical unit, and ""M"" is the mass of the Sun. So the radius in AU is about formula_1.</ref> Earth Earth is the third planet from the Sun and the only astronomical object known to harbor life. According to radiometric dating and other sources of evidence, Earth formed over 4.5 billion years ago. Earth's gravity interacts with other objects in space, especially the Sun and the Moon, Earth's only natural satellite. Earth revolves around the Sun in 365.26 days, a period known as an Earth year."
"the Drake equation, which estimates the number of intelligent, communicating civilizations that exist in the Milky Way. There are exoplanets that are much closer to their parent star than any planet in the Solar System is to the Sun, and there are also exoplanets that are much farther from their star. Mercury, the closest planet to the Sun at 0.4 AU, takes 88 days for an orbit, but the shortest known orbits for exoplanets take only a few hours, e.g. Kepler-70b. The Kepler-11 system has five of its planets in shorter orbits than Mercury's, all of them much more massive"
"Earth Earth is the third planet from the Sun and the only astronomical object known to harbor life. According to radiometric dating and other sources of evidence, Earth formed over 4.5 billion years ago. Earth's gravity interacts with other objects in space, especially the Sun and the Moon, Earth's only natural satellite. Earth revolves around the Sun in 365.26 days, a period known as an Earth year. During this time, Earth rotates about its axis about 366.26 times. Earth's axis of rotation is tilted with respect to its orbital plane, producing seasons on Earth. The gravitational interaction between Earth and"
"planets in smaller orbits than Mercury's. Neptune is 30 AU from the Sun and takes 165 years to orbit it, but there are exoplanets that are thousands of AU from their star and take tens of thousands of years to orbit, e.g. GU Piscium b. The radial-velocity and transit methods are most sensitive to planets with small orbits. The earliest discoveries such as 51 Peg b were gas giants with orbits of a few days. These ""hot Jupiters"" likely formed further out and migrated inwards. The ""Kepler"" space observatory has found planets with even shorter orbits of only a few"
"just four times the star's radius. The second planet, HD 3167 c, has an orbital period of 29.8454 days and an eccentricity of less than 0.267. The semimajor axis is . It has and , giving it a low bulk density of . This suggests either a mini-Neptune with a gaseous envelope consisting mainly of hydrogen and helium, or a planet consisting of mostly water. The incident flux from the host star is around 16 times the amount the Earth receives from the Sun, and it is less susceptible to atmospheric stripping than HD 3167 b. The proximity of the"
"Kepler-20e Kepler-20e is an exoplanet orbiting Kepler-20. The planet is notable as it is the first planet with a smaller radius than Earth found orbiting a Sun-like star. The planet is second-closest to the star after Kepler-20b, and at , it is far too hot to have liquid water on its surface. Along with the other four planets in the system, Kepler-20e was announced on 20 December 2011. With a semimajor axis of 0.0507 AUs, Kepler-20e's orbit has a period of 6.098 days (with an extremely small margin of error). The orbit has an inclination of 87.50°, making its transits"
"situation is quite different for Mercury and Venus. Mercury's sidereal day is about two-thirds of its orbital period, so by the prograde formula its solar day lasts for two revolutions around the Sun— three times as long as its sidereal day. Venus rotates retrograde with a sidereal day lasting about 243.0 Earth days, or about 1.08 times its orbital period of 224.7 Earth days; hence by the retrograde formula its solar day is about 116.8 Earth days, and it has about 1.9 solar days per orbital period. By convention, rotation periods of planets are given in sidereal terms unless otherwise"
"Venus for the seventh and last time, decreasing its period to 88 or 89 days and allowing it to approach closer to the Sun. The perihelion distances above are from the center of the Sun. For altitude above the surface, subtract one solar radius ≈ 0.7 Gm.<br> By way of comparison, the planet Mercury orbits the Sun at a distance varying from about 46.0 Gm (46,001,200 km) at its closest to about 69.8 Gm (69,816,900 km) at its farthest. Parker Solar Probe Parker Solar Probe (previously Solar Probe, Solar Probe Plus, or Solar Probe+, abbreviated PSP) is a NASA robotic"
"and Spacecraft B will take 387 days. The A spacecraft/Sun/Earth angle will increase at 21.650 degree/year. The B spacecraft/Sun/Earth angle will change −21.999 degrees per year. Given that the length of Earth's orbit is around 940 million kilometres, both craft have an average speed, in a rotating geocentric frame of reference in which the sun is always in the same direction, of about 1.8 km/s, but the speed varies considerably depending on how close they are to their respective aphelion or perihelion (as well as on the position of Earth). Their current locations are shown here. Over time, the STEREO"
"the poles and is lower than the surface gravity of Earth. However, the equatorial escape velocity of nearly is much higher than that for Earth. Saturn is the only planet of the Solar System that is less dense than water—about 30% less. Although Saturn's core is considerably denser than water, the average specific density of the planet is due to the atmosphere. Jupiter has 318 times Earth's mass, and Saturn is 95 times Earth's mass. Together, Jupiter and Saturn hold 92% of the total planetary mass in the Solar System. Despite consisting mostly of hydrogen and helium, most of Saturn's"
"Jupiter"", a planet with a mass half that of Jupiter and orbital distance only 1/24th that of Earth from the Sun. One revolution around the star takes a little over three days to complete. The planet is slightly larger than Jupiter, probably due to the heat from the star. OGLE-TR-10 was identified as a promising candidate by the OGLE team during their 2001 campaign in three fields towards the Galactic Center. The possible planetary nature of its companion was based on spectroscopic follow-up. A reported a tentative radial velocity semi-amplitude (from Keck-I/HIRES) of 100±43 m/s, and a mass for the"
"the planet would be thick and misty, covering much of the surface as viewed from space. The planet takes 385 Earth days to orbit its star. Its radius is 50% bigger than Earth's, and lies within the conservative habitable zone of its parent star. It has an equilibrium temperature of , a little warmer than Earth. The host star, Kepler-452, is a G-type star that is about the same mass of the Sun, only 3.7% more massive and 11% larger. It has a surface temperature of 5757 K, nearly the same as the Sun, which has a surface temperature of"
"Beta Pictoris b orbits its host star every 21 years at a distance of 9.2 AU (about the same as Saturn's distance, which is about 9.55 AU). It receives 11% of the amount of sunlight that Earth does from the Sun. In 2014, the rotation period of Beta Pictoris b was calculated from the broadening of its carbon monoxide infrared absorption line. This makes it, , the first extrasolar planet to have its rotation rate measured. With a rotation period of 8.1 hours, it is the fastest-spinning planet known. Its rotation period is faster than that of Jupiter, which has"
"of Earth and orbits approximately every 21 days at a distance of just under 0.14 AU. Kepler-37d is about twice the diameter of Earth. It orbits in around 40 days at a distance of nearly 0.21 AU. Neither is able to support water due to their proximity to Kepler-37. The periods of the three inner planets are close (within one per cent) to a 5:8:15 mean-motion resonance relationship. The Kepler planets were discovered in September 2012 with the aid of transit events detected by the Kepler space telescope, and announced to the public in February 2013. Computer simulation was used"
"two planets gravitationally interact: modelling the planets assuming their masses are the same as the empirically-determined lower limits, they exchange eccentricities on a timescale of 2700 years, and their arguments of periastron precess on a timescale of 2300 years. HD 155358 b has mass little bit less than Jupiter but more than Saturn. HD 155358 c has mass half that of Jupiter. However, more accurate masses were needed when inclinations will eventually become known. HD 155358 b orbits at 0.628 AU while c orbits at 1.224 AU. HD 155358 HD 155358 is a low metallicity yellow dwarf star approximately 43"
"Venus and Mercury which are easily seen to rotate about the sun. Mars must also go about the sun (as well as the earth) since it is never seen horned, unlike Venus now seen through the telescope; similarly with Jupiter and Saturn. Earth, which is between Mars with a period of two years and Venus with nine months, has a period of a year which may more elegantly be attributed to motion than a state of rest. Sagredo brings up two other common objections. If the earth rotated, the mountains would soon be in a position that one would have"
"the Sun, which it orbits every 87.97 days. Kepler-9d Kepler-9d, formerly known as KOI-377.03, is a planet in orbit around the sunlike star Kepler-9. Initially discovered by Kepler spacecraft, a terrestrial planet-searching satellite built and operated by NASA, Kepler-9d is most likely a Super-Earth, with an estimated radius approximately 60% larger than that of Earth's, although its exact mass cannot be determined. Kepler-9d orbits Kepler-9 every 1.56 days at a distance of .0273 AU from its star, an extremely close distance. Although Kepler-9d is the closest planet to its star in its system, it is named Kepler-9d instead of Kepler-9b"
"As seen from Earth, the planet's orbital prograde motion makes the Sun appear to move with respect to other stars at a rate of about 1° (or a Sun or Moon diameter every 12 hours) eastward per solar day. Earth's orbital speed averages about 30 km/s (108,000 km/h; 67,000 mph), which is fast enough to cover the planet's diameter in 7 minutes and the distance to the Moon in 4 hours. From a vantage point above the north pole of either the Sun or Earth, Earth would appear to revolve in a counterclockwise direction around the Sun. From the same"
"the Sun, although it is approximately three quarters of a billion years younger and is slightly less metal-rich. Kepler-8b has a mass of .603 M, but a radius of 1.419 R. This means that although Kepler is approximately 60% the mass of planet Jupiter, it is more diffuse, as it is 41.9% wider. Based on its size and the distance from its star, Kepler-8b is a Hot Jupiter planet, orbiting Kepler-8 from a distance of .0483 AU every 3.52254 days. To compare, planet Mercury orbits the Sun at an average distance of .3871 AU every 87.97 days. With an equilibrium"
"hours. Due to this motion, on average it takes 24 hours—a solar day—for Earth to complete a full rotation about its axis so that the Sun returns to the meridian. The orbital speed of Earth averages about , which is fast enough to travel a distance equal to Earth's diameter, about , in seven minutes, and the distance to the Moon, , in about 3.5 hours. The Moon and Earth orbit a common barycenter every 27.32 days relative to the background stars. When combined with the Earth–Moon system's common orbit around the Sun, the period of the synodic month, from"
"System orbit the Sun in a counterclockwise direction as viewed from above Earth's north pole. Most planets also rotate on their axes in an anti-clockwise direction, but Venus rotates clockwise in retrograde rotation once every 243 Earth days—the slowest rotation of any planet. Because its rotation is so slow, Venus is very close to spherical. A Venusian sidereal day thus lasts longer than a Venusian year (243 versus 224.7 Earth days). Venus's equator rotates at , whereas Earth's rotates at . Venus's rotation has slowed down in the 16 years between the ""Magellan"" spacecraft and ""Venus Express"" visits; each Venusian"
"to have a hot Jupiter-type planet that has a minimum mass of 48% of Jupiter's, and takes only 3.49 days to complete an orbit. WASP-34 is a sunlike star of spectral type G5V that has 1.01 ± 0.07 times the mass and 0.93 ± 0.12 times the diameter of the Sun. It has a planet 0.59 ± 0.01 times as massive as Jupiter that takes 4.317 days to complete an orbit. The system is 432 ± 3 light-years distant from Earth. The Crater 2 dwarf is a satellite galaxy of the Milky Way, located approximately 380,000 light-years from Earth. NGC"
"is one third of the Sun. Kepler-42 has an appreciable proper motion of up to 431±8 mas/yr. Due to its small size and low temperature, the star's habitable zone is much closer to the star than Earth is to the Sun. On 10 January 2012, using the Kepler Space Telescope three transiting planets were discovered in orbit around Kepler-42. These planets' radii range from approximately those of Mars to Venus. The Kepler-42 system is only the second known system containing planets of Earth's radius or smaller (the first was the Kepler-20 system pictured at left). These planets' orbits are also"
"have a planetary system—echoing the fate of the Solar System in a few billion years as the Sun ages and becomes a giant. Conversely, HD 45364 is a star 107 light-years distant that is a little smaller and cooler than the Sun, of spectral type G8V, which has two planets discovered in 2008. With orbital periods of 228 and 342 days, the planets have a 3:2 orbital resonance, which helps stabilise the system. HD 47186 is another sunlike star with two planets; the inner—HD 47186 b—takes four days to complete an orbit and has been classified as a Hot Neptune,"