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GJ1214b
Gliese 1214 b (often shortened to GJ 1214 b) is an exoplanet that orbits the star Gliese 1214, and was discovered in December 2009. Its parent star is 48 light-years from the Sun, in the constellation Ophiuchus. As of 2017, GJ 1214 b is the most likely known candidate for being an ocean planet. For that reason, scientists have nicknamed the planet "the waterworld". It is a super-Earth, meaning it is larger than Earth but is significantly smaller (in mass and radius) than the gas giants of the Solar System. After CoRoT-7b, it was the second super-Earth to have both its mass and radius measured and is the first of a new class of planets with small size and relatively low density. GJ 1214 b is also significant because its parent star is relatively near the Sun and because it transits (crosses in front of) that parent star, which allows the planet's atmosphere to be studied using spectroscopic methods. In December 2013, NASA reported that clouds may have been detected in the a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Super-Earth
A super-Earth is an extrasolar planet with a mass higher than Earth's, but substantially below those of the Solar System's ice giants, Uranus and Neptune, which are 14.5 and 17 times Earth's, respectively. The term "super-Earth" refers only to the mass of the planet, and so does not imply anything about the surface conditions or habitability. The alternative term "gas dwarfs" may be more accurate for those at the higher end of the mass scale, although " mini-Neptunes" is a more common term. Definition In general, super-Earths are defined by their masses, and the term does not imply temperatures, compositions, orbital properties, habitability, or environments. While sources generally agree on an upper bound of 10 Earth masses (~69% of the mass of Uranus, which is the Solar System's giant planet with the least mass), the lower bound varies from 1 or 1.9 to 5, with various other definitions appearing in the popular media. The term "super-Earth" is also used by astronomers t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gliese 1214
Extrasolar PlanetsEncyclopaedia Gliese 1214 is a dim M4.5 red dwarf in the constellation Ophiuchus with an apparent magnitude of 14.7. It is located at a distance of approximately 47 light years from Earth. The star is about one-fifth the radius of the Sun with a surface temperature estimated to be . Its luminosity is only 0.35% that of the Sun. The estimate for the stellar radius is 15% larger than predicted by theoretical models. It also shows a 1% intrinsic variability in the near-infrared probably caused by stellar spots. The star is rotating slowly, with a period that is most likely an integer multiple of 53 days. It is probably at least three billion years old and a member of the old thin disk of the Milky Way. Although GJ 1214 has a low to moderate level of magnetic activity, it does undergo flares and is a source of X-ray emission with a base luminosity of . The temperature of the stellar corona is estimated to be about . Planetary system In mid-December ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GJ 1214
Extrasolar PlanetsEncyclopaedia Gliese 1214 is a dim M4.5 red dwarf in the constellation Ophiuchus with an apparent magnitude of 14.7. It is located at a distance of approximately 47 light years from Earth. The star is about one-fifth the radius of the Sun with a surface temperature estimated to be . Its luminosity is only 0.35% that of the Sun. The estimate for the stellar radius is 15% larger than predicted by theoretical models. It also shows a 1% intrinsic variability in the near-infrared probably caused by stellar spots. The star is rotating slowly, with a period that is most likely an integer multiple of 53 days. It is probably at least three billion years old and a member of the old thin disk of the Milky Way. Although GJ 1214 has a low to moderate level of magnetic activity, it does undergo flares and is a source of X-ray emission with a base luminosity of . The temperature of the stellar corona is estimated to be about . Planetary system In mid-Decemb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Earth
Earth is the third planet from the Sun and the only astronomical object known to harbor life. While large volumes of water can be found throughout the Solar System, only Earth sustains liquid surface water. About 71% of Earth's surface is made up of the ocean, dwarfing Earth's polar ice, lakes, and rivers. The remaining 29% of Earth's surface is land, consisting of continents and islands. Earth's surface layer is formed of several slowly moving tectonic plates, which interact to produce mountain ranges, volcanoes, and earthquakes. Earth's liquid outer core generates the magnetic field that shapes the magnetosphere of the Earth, deflecting destructive solar winds. The atmosphere of the Earth consists mostly of nitrogen and oxygen. Greenhouse gases in the atmosphere like carbon dioxide (CO2) trap a part of the energy from the Sun close to the surface. Water vapor is widely present in the atmosphere and forms clouds that cover most of the planet. More sola ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clouds
In meteorology, a cloud is an aerosol consisting of a visible mass of miniature liquid droplets, frozen crystals, or other particles suspended in the atmosphere of a planetary body or similar space. Water or various other chemicals may compose the droplets and crystals. On Earth, clouds are formed as a result of saturation of the air when it is cooled to its dew point, or when it gains sufficient moisture (usually in the form of water vapor) from an adjacent source to raise the dew point to the ambient temperature. They are seen in the Earth's homosphere, which includes the troposphere, stratosphere, and mesosphere. Nephology is the science of clouds, which is undertaken in the cloud physics branch of meteorology. There are two methods of naming clouds in their respective layers of the homosphere, Latin and common name. Genus types in the troposphere, the atmospheric layer closest to Earth's surface, have Latin names because of the universal adoption of Lu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CoRoT-7b
CoRoT-7b (previously named CoRoT-Exo-7b) is an exoplanet orbiting the star CoRoT-7 in the constellation of Monoceros, from Earth. It was first detected photometrically by the French-led CoRoT mission and reported in February 2009. Until the announcement of Kepler-10b in January 2011, it was the smallest exoplanet to have its diameter measured, at 1.58 times that of the Earth (which would give it a volume 3.95 times Earth's) and the first potential extrasolar terrestrial planet to be found. The exoplanet has a very short orbital period, revolving around its host star in about 20 hours. Combination of the planet's diameter derived from transit data with the planet's mass derived from radial velocity measurements means that the density of CoRoT-7b is about the same as that of Earth; therefore, CoRoT-7b is a terrestrial planet like Earth and not a gas giant like Jupiter. The radial velocity observations of CoRoT-7 also detected a second super-Earth, CoRoT-7c, which has a mass 8.4 tim ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Astronomical Transit
In astronomy, a transit (or astronomical transit) is a phenomenon when a celestial body passes directly between a larger body and the observer. As viewed from a particular vantage point, the transiting body appears to move across the face of the larger body, covering a small portion of it. The word "transit" refers to cases where the nearer object appears smaller than the more distant object. Cases where the nearer object appears larger and completely hides the more distant object are known as ''occultations''. However, the probability of seeing a transiting planet is low because it is dependent on the alignment of the three objects in a nearly perfectly straight line. Many parameters of a planet and its parent star can be determined based on the transit. In the Solar System One example of a transit involves the motion of a planet between a terrestrial observer and the Sun. This can happen only with inferior planets, namely Mercury and Venus (see transit of Mercury ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spectroscopy
Spectroscopy is the field of study that measures and interprets the electromagnetic spectra that result from the interaction between electromagnetic radiation and matter as a function of the wavelength or frequency of the radiation. Matter waves and acoustic waves can also be considered forms of radiative energy, and recently gravitational waves have been associated with a spectral signature in the context of the Laser Interferometer Gravitational-Wave Observatory (LIGO) In simpler terms, spectroscopy is the precise study of color as generalized from visible light to all bands of the electromagnetic spectrum. Historically, spectroscopy originated as the study of the wavelength dependence of the absorption by gas phase matter of visible light dispersed by a prism. Spectroscopy, primarily in the electromagnetic spectrum, is a fundamental exploratory tool in the fields of astronomy, chemistry, materials science, and physics, allowing the composition, physical structure an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NASA
The National Aeronautics and Space Administration (NASA ) is an independent agency of the US federal government responsible for the civil space program, aeronautics research, and space research. NASA was established in 1958, succeeding the National Advisory Committee for Aeronautics (NACA), to give the U.S. space development effort a distinctly civilian orientation, emphasizing peaceful applications in space science. NASA has since led most American space exploration, including Project Mercury, Project Gemini, the 1968-1972 Apollo Moon landing missions, the Skylab space station, and the Space Shuttle. NASA supports the International Space Station and oversees the development of the Orion spacecraft and the Space Launch System for the crewed lunar Artemis program, Commercial Crew spacecraft, and the planned Lunar Gateway space station. The agency is also responsible for the Launch Services Program, which provides oversight of launch operations and countdown m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Exoplanet
An exoplanet or extrasolar planet is a planet outside the Solar System. The first possible evidence of an exoplanet was noted in 1917 but was not recognized as such. The first confirmation of detection occurred in 1992. A different planet, initially detected in 1988, was confirmed in 2003. There are many methods of detecting exoplanets. Transit photometry and Doppler spectroscopy have found the most, but these methods suffer from a clear observational bias favoring the detection of planets near the star; thus, 85% of the exoplanets detected are inside the tidal locking zone. In several cases, multiple planets have been observed around a star. About 1 in 5 Sun-like starsFor the purpose of this 1 in 5 statistic, "Sun-like" means G-type star. Data for Sun-like stars was not available so this statistic is an extrapolation from data about K-type stars. have an "Earth-sized"For the purpose of this 1 in 5 statistic, Earth-sized means 1–2 Earth radii. planet in the habitable ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nature (journal)
''Nature'' is a British weekly scientific journal founded and based in London, England. As a multidisciplinary publication, ''Nature'' features peer-reviewed research from a variety of academic disciplines, mainly in science and technology. It has core editorial offices across the United States, continental Europe, and Asia under the international scientific publishing company Springer Nature. ''Nature'' was one of the world's most cited scientific journals by the Science Edition of the 2019 '' Journal Citation Reports'' (with an ascribed impact factor of 42.778), making it one of the world's most-read and most prestigious academic journals. , it claimed an online readership of about three million unique readers per month. Founded in autumn 1869, ''Nature'' was first circulated by Norman Lockyer and Alexander Macmillan as a public forum for scientific innovations. The mid-20th century facilitated an editorial expansion for the journal; ''Nature'' redoubled its efforts in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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