"solar wind around itself called the magnetosphere, which the wind cannot penetrate. The magnetosphere can be much larger than the planet itself. In contrast, non-magnetized planets have only small magnetospheres induced by interaction of the ionosphere with the solar wind, which cannot effectively protect the planet. Of the eight planets in the Solar System, only Venus and Mars lack such a magnetic field. In addition, the moon of Jupiter Ganymede also has one. Of the magnetized planets the magnetic field of Mercury is the weakest, and is barely able to deflect the solar wind. Ganymede's magnetic field is several times"
"giant Jupiter's sidereal day is only 9 hours and 56 minutes. However, it is not just the sidereal rotation period which determines the length of a planet's day-night cycle but the length of its orbital period as well - Venus has a rotation period of 224.7 days, but a day-night cycle just 116.75 days long due to its retrograde rotation and orbital motion around the Sun. Mercury has the longest day-night cycle as a result of its 3:2 resonance between its orbital period and rotation period - this resonance gives it a day-night cycle 176 days long. A planet may"
"on September 1, 2008. Gliese 832 b Gliese 832 b (Gl 832 b or GJ 832 b) is an extrasolar planet located approximately 16 light-years from our sun in the constellation of Grus, orbiting the red dwarf star Gliese 832. The planet takes 3416 days to revolve at an orbital distance of 3.4 AU; this is the longest-period Jupiter-like planet orbiting a red dwarf. The brightness of the faint parent star at that distance corresponds to the brightness of the Sun from 80AU (or a 100 times brighter than a full Moon as seen from Earth). The planet was discovered"
"the planet a circular orbit. In comparison, planet Mercury orbits the Sun at .3871 AU every 87.97 days. Mercury also has an elliptical orbit, with an eccentricity of .2056. Kepler-8 Kepler-8 is a star located in the constellation Lyra in the field of view of the Kepler Mission, a NASA-led operation tasked with discovering terrestrial planets. The star, which is slightly hotter, larger, and more massive than the Sun, has one gas giant in its orbit, Kepler-8b. This gas giant is larger than Jupiter, but is less massive, and thus more diffuse. The planet's discovery was announced to the public"
"word tranquility is mentioned in this somewhat famous quote — ""Houston, Tranquility Base Here. The Eagle Has Landed"". Moon Landing Day has 20 hours, 18 minutes, and 1.2 seconds Before Tranquility and 3 hours, 41 minutes, 58.8 seconds After Tranquility. The calendar year has 13 months each with 28 days (divided in exactly 4 weeks) plus an extra day at the end of the year not belonging to any month (and so 365 days). The months are named after famous scientists: Archimedes, Brahe, Copernicus, Darwin, Einstein, Faraday, Galileo, Hippocrates, Imhotep, Jung, Kepler, Lavoisier, and Mendel. The 365th day is called"
"Gliese 832 b Gliese 832 b (Gl 832 b or GJ 832 b) is an extrasolar planet located approximately 16 light-years from our sun in the constellation of Grus, orbiting the red dwarf star Gliese 832. The planet takes 3416 days to revolve at an orbital distance of 3.4 AU; this is the longest-period Jupiter-like planet orbiting a red dwarf. The brightness of the faint parent star at that distance corresponds to the brightness of the Sun from 80AU (or a 100 times brighter than a full Moon as seen from Earth). The planet was discovered in the Anglo-Australian Observatory"
"in a really close torch orbit around the star, making this planet extremely hot (in the order of a thousand kelvins). The distance from the star is roughly 20 times smaller than that of Earth from the Sun, which places the planet roughly 8 times closer to its star than Mercury is from the Sun. The “year” on this planet lasts only 3 days, 1 hour, 49 minutes, and 54 seconds, compared with Earth's 365 days, 6 hours, 9 minutes, and 10 seconds in a sidereal year. HAT-P-8b HAT-P-8b is an extrasolar planet located approximately 720 light years away in"
"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"
"it appears from Earth, and its total brightness is more than 6 times as great. Because of the planet's eccentric orbit, the Sun's apparent diameter in the sky would vary from 2.2 times that from Earth at aphelion (with total brightness 4.8 times as great), to 3.2 times at perihelion (with total brightness 10.2 times as great). Mercury has a 3:2 spin–orbit resonance. This means that although a sidereal day (the period of rotation) lasts around 58.7 Earth days, a solar day (the length between two meridian transits of the Sun) lasts around 176 Earth days. (In contrast, the difference"
"Lunar day A lunar day is the period of time for Earth's Moon to complete one rotation on its axis with respect to the Sun. Due to tidal locking, it is also the time the Moon takes to complete one orbit around Earth and return to the same phase. A lunar month is the period between two new moons.A lunar month lasts about 29.5 solar days on earth. Relative to the fixed stars on the celestial sphere, the Moon takes 27 Earth days, 7 hours, 43 minutes, and 12 seconds to complete one orbit; however, since the Earth–Moon system advances"
"with a period of 4,323 days, over 400 times the period of the second-furthest planet, WASP-117b with a period of 10.02 days. Measurements of WASP-8b's radius and mass give it an estimated density of 2.53 g/cm, about twice the density of Jupiter. WASP-8 WASP-8 is a magnitude 9.9 main-sequence yellow dwarf star. It is reported to be a G-type star of temperature 5600 K, mass of 0.93 solar masses, radius of 0.93 solar radius, and a luminosity of 0.79 of solar luminosity. There is a companion star located 4 arcseconds away with the same proper motion indicating a stellar binary"
"This period (1,951 days or 5.34 years) is among the dozen longest exoplanet periods known, as of 2009. Follow-up studies with the Hipparcos satellite further constrained the predicted mass of the companion, providing a best estimate of . HD 131664 HD 131664 is an 8th magnitude star in the southern constellation of Apus with an orbiting brown dwarf companion. Parallax measurements by the Gaia space observatory provide an estimated distance of 172.5 light years from the Earth. The system is moving further away with a baseline heliocentric radial velocity of +35 km/s. The stellar component is an ordinary G-type main-sequence"
"on Earth. Combined with a 3:2 spin–orbit resonance of the planet's rotation around its axis, it also results in complex variations of the surface temperature. The resonance makes a single solar day on Mercury last exactly two Mercury years, or about 176 Earth days. Mercury's orbit is inclined by 7 degrees to the plane of Earth's orbit (the ecliptic), as shown in the diagram on the right. As a result, transits of Mercury across the face of the Sun can only occur when the planet is crossing the plane of the ecliptic at the time it lies between Earth and"
"planet or brown dwarf that orbits 1 AU from a Sun-like star. In the case of Gliese 876 b, the orbital period would have to be no greater than a week (7 days) in order to have a stable orbit. Tidal effects could also allow the moon to sustain plate tectonics, which would cause volcanic activity to regulate the moon's temperature and create a geodynamo effect which would give the satellite a strong magnetic field. To support an Earth-like atmosphere for about 4.6 billion years (the age of the Earth), the moon would have to have a Mars-like density and"
"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 Venus is the second planet from the Sun, orbiting it every 224.7 Earth days. It has the longest rotation period (243 days) of any planet in the Solar System and rotates in the opposite direction to most other planets (meaning the Sun would rise in the west and set in the east). It does not have any natural satellites. It is named after the Roman goddess of love and beauty. It is the second-brightest natural object in the night sky after the Moon, reaching an apparent magnitude of −4.6 – bright enough to cast shadows at night and, rarely,"
"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,"
"day is approximately 24 hours, whereas a mean Martian 'sol' is 24 hours, 39 minutes, and 35.244 seconds. The English weekday name ""Sunday"" stems from Old English (""Sunnandæg""; ""Sun's day"", from before 700) and is ultimately a result of a Germanic interpretation of Latin ""dies solis"", itself a translation of the Greek ἡμέρα ἡλίου (""hēméra hēlíou""). Solar deities play a major role in many world religions and mythologies. The ancient Sumerians believed that the sun was Utu, the god of justice and twin brother of Inanna, the Queen of Heaven, who was identified as the planet Venus. Later, Utu was"
"is a member of the artisan ""d'jarra"", even though she was a member of the military, and she explained that the different styles of earring no longer signified anything. Bajor () is the homeworld of the Bajorans. Bajor is a Class M planet that has five moons. A day on Bajor has 26 hours. Bajor's atmosphere has a greenish tint; as a result, oceans viewed from space will appear more green than blue. Bajor, the seventh planet in the system, orbits the star Bajor-B'hava'el in the Bajoran sector. Other inhabited planets in the Bajoran star system include Andros (Bajor VIII),"
"the Sun. It has a Jupiter-sized planet with an orbital period of 280 days that was discovered by the radial velocity method. WASP-7 is a star of spectral type F5V with an apparent magnitude of 9.54, about 1.28 times as massive as the Sun. Its hot Jupiter planet—WASP-7b—was discovered by transit method and found to orbit the star every 4.95 days. HD 202628 is a sunlike star of spectral type G2V with a debris disk that ranges from 158 to 220 AU distant. Its inner edge is sharply defined, indicating a probable planet orbiting between 86 and 158 AU from"
"a Martian day is 24 hours 37 minutes long, meaning that Phobos can create two eclipses per Martian day. These are annular eclipses, because Phobos is not quite large enough or close enough to Mars to create a total solar eclipse. Deimos is too small (about ) and too far from Mars to cause an eclipse. The best an observer on Mars would see is a small spot crossing the Sun's disc. Both moons are too small to cast a shadow on Mars that can be seen from Earth. However, shortly after the first artificial satellites were placed in orbit"
"Earth, Kepler-8 is an extremely dim star. It cannot be seen with the naked eye. Kepler-8b is the only planet that has been discovered in the orbit of Kepler-8. With a mass of .603 M and a radius of 1.419 R, the planet is 60% the mass of, but 42% larger than planet Jupiter. The planet is diffuse, with a density of .261 grams/cc, especially in comparison to Jupiter and its density of 5.515 grams/cc. At a distance of .0483 AU, Kepler-8b orbits its star every 3.5225 days. The eccentricity of Kepler-8 is assumed to be 0, which would give"
"Earth rotates nearly 24 hours, but its position at the sky is only in one position as it never changes as it does with some other moons (or satellites) in other planets or dwarf planets and a few asteroids even inside the solar system but are very rare in the outer part of the solar system. The last solar eclipse on the Moon was a total eclipse on July 27, 2018, with the whole Nearside and the tiny surroundings of the Farside seeing totality. Unlike the Earth which sees its eclipse for up to 2 1/2 hours the longest in"
"dwarfs); a single strong flare appeared near the end of the observation period. The observed flaring activity possibly changes the atmospheres of the orbiting planets on a regular basis, making them less suitable for life. The star has a rotational period of 3.3 days. High-resolution speckle images of TRAPPIST-1 were obtained and revealed that the M8 star has no companions with a luminosity equal to or brighter than a brown dwarf. This determination that the host star is single confirms that the measured transit depths for the orbiting planets provide a true value for their radii, thus proving that the"
"of only 2.6 days. XO-4 is an F-type main sequence star that is a little hotter and more massive than the Sun that has a hot Jupiter orbiting with a period of around 4.1 days. XO-5 is a Sun-like star with a hot Jupiter about as massive as Jupiter that takes around 4.2 days to complete an orbit. WASP-13, a Sun-like star that has begun to swell and cool off the main sequence, had a transiting planet discovered by the SuperWASP program in 2009. The planet is around half as massive as Jupiter and takes 4.35 days to complete a"
"days will remain safely bound to a massive giant planet or brown dwarf that orbits 1 AU from a Sun-like star. In the case of Upsilon Andromedae d, the orbital period would have to be no greater than 120 days (around 4 months) in order to have a stable orbit. Tidal effects could also allow the moon to sustain plate tectonics, which would cause volcanic activity to regulate the moon's temperature and create a geodynamo effect which would give the satellite a strong magnetic field. To support an Earth-like atmosphere for about 4.6 billion years (the age of the Earth),"
"3–6"", use the modern reading of Thai numerals, as do all remaining months. Months 3–6, alternate between 29-day hollow months and 30-day full months. Month 7, ""duean 7"", a hollow month is normally 29 days long in years of 354 days, but adds an extra day ( ) when required for 355-day-long years (, ). The eighth month, ""duean 8"", is a 30-day full month. Athikamat (, )) is the extra month needed for a 384-day-long ""pi athikamat"" (extra-month year; , ). Month 8 repeats as เดือน ๘/๘ or Month 8/8, variously read as ""duean paet thab paet"" () Months"
"unit of time in SI units. In 1967–68, during the 13th CGPM (Resolution 1), the International Bureau of Weights and Measures (BIPM) redefined a second as … the duration of 9 192 631 770 periods of the radiation corresponding to the transition between two hyperfine levels of the ground state of the caesium 133 atom. This makes the SI-based day last exactly 794 243 384 928 000 of those periods. Mainly due to tidal effects, the Earth's rotational period is not constant, resulting in minor variations for both solar days and stellar ""days"". The Earth's day has increased in length"
"Narn The Narn are a fictional alien race in the universe of the ""Babylon 5"" television series. Their homeworld is also called Narn. Narn is the homeworld of the Narn and the Narn Regime. Its day is 31 hours long. Prior to the Centauri's first invasion, Narn was a healthy green planet. Now it has the look of a slightly more habitable Mars. The surface temperature can fluctuate by at least 60 degrees Fahrenheit on any given day. Before the Centauri invasion the planet was dominated by primordial jungles and forests, teeming with animal life. Craggy mountains and small, landlocked"
"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"
"the number of hours in a day (25, giving him an extra hour in bed and a few minutes every day adjusting his watch, a task he greatly enjoys) and the number of days in a year (about 300, so the year doesn't drag on). The planet is mostly unknown, so few space travellers ever taste the superbly made sandwiches that would be the planet's claim to fame. Magrathea is an ancient planet located in orbit around the twin suns Soulianis and Rahm in the heart of the Horsehead Nebula. Magrathea is a planet whose economy was based on the"
"Neptune Neptune is the eighth and farthest known planet from the Sun in the Solar System. In the Solar System, it is the fourth-largest planet by diameter, the third-most-massive planet, and the densest giant planet. Neptune is 17 times the mass of Earth and is slightly more massive than its near-twin Uranus, which is 15 times the mass of Earth and slightly larger than Neptune. Neptune orbits the Sun once every 164.8 years at an average distance of . It is named after the Roman god of the sea and has the astronomical symbol ♆, a stylised version of the"
"the heavens. In Hawaiian, its name is ""Hele‘ekala"", a loanword for the discoverer Herschel. In Māori, its name is ""Whērangi"". Uranus orbits the Sun once every 84 years. Its average distance from the Sun is roughly . The difference between its minimum and maximum distance from the Sun is 1.8 AU, larger than that of any other planet, though not as large as that of dwarf planet Pluto. The intensity of sunlight varies inversely with the square of distance, and so on Uranus (at about 20 times the distance from the Sun compared to Earth) it is about 1/400 the"