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Massive Solid Planets
A mega-Earth is a proposed neologism for a massive terrestrial exoplanet that is at least ten times the mass of Earth. Mega-Earths would be substantially more massive than super-Earths (terrestrial and ocean planets with masses around 5–10 Earths). The term "mega-Earth" was coined in 2014, when Kepler-10c was revealed to be a Neptune-mass planet with a density considerably greater than that of Earth, though it has since been determined to be a typical volatile-rich planet weighing just under half that mass. Examples Kepler-10c was the first exoplanet to be classified as a mega-Earth. At the time of its discovery, it was believed to have a mass around 17 times that of Earth () and a radius around 2.3 times Earth's (), giving it a high density that implied a mainly rocky composition. However, several follow-up radial velocity studies produced different results for Kepler-10c's mass, all much below the original estimate. In 2017, a more careful analysis using data from multiple dif ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Exoplanet Comparison Kepler-10 C
An exoplanet or extrasolar planet is a planet outside the Solar System. The first confirmed detection of an exoplanet was in 1992 around a pulsar, and the first detection around a main-sequence star was in 1995. A different planet, first detected in 1988, was confirmed in 2003. In 2016, it was recognized that the first possible evidence of an exoplanet had been noted in 1917. In collaboration with ground-based and other space-based observatories the James Webb Space Telescope (JWST) is expected to give more insight into exoplanet traits, such as their composition, environmental conditions, and potential for life. 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PSR J1719−1438 B
PSR J1719−1438 b is an extrasolar planet that was discovered on August 25, 2011, in orbit around PSR J1719−1438, a millisecond pulsar. The pulsar planet is most likely composed largely of crystalline carbon but with a density far greater than diamond. PSR J1719-1438 b orbits so closely to its host star that its orbit would fit inside the Sun. The existence of such carbon planets had been theoretically postulated. Observational history PSR J1719−1438 was first observed in 2009 by a team headed by Matthew Bailes of Swinburne University of Technology in Melbourne, Australia. The orbiting planet was published in the journal ''Science'' on August 25, 2011. The planet was confirmed through pulsar timing, in which small modulations detected in the highly regular pulsar signature are measured and extrapolated. Observatories in Britain, Hawaii, and Australia were used to confirm these observations. Host star PSR J1719−1438 is a pulsar some away from Earth in the Serpens Cauda ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Terrestrial Planets
A terrestrial planet, tellurian planet, telluric planet, or rocky planet, is a planet that is composed primarily of silicate, Rock (geology), rocks or metals. Within the Solar System, the terrestrial planets accepted by the IAU are the inner planets closest to the Sun: Mercury (planet), Mercury, Venus, Earth and Mars. Among astronomers who use the geophysical definition of a planet, two or three planetary-mass moon, planetary-mass satellites – Earth's Moon, Io (moon), Io, and sometimes Europa (moon), Europa – may also be considered terrestrial planets. The large rocky asteroids 2 Pallas, Pallas and 4 Vesta, Vesta are sometimes included as well, albeit rarely. The terms "terrestrial planet" and "telluric planet" are derived from Latin words for Earth (''Terra'' and ''Tellus''), as these planets are, in terms of structure, ''Earth-like''. Terrestrial planets are generally studied by geologists, astronomers, and geophysicists. Terrestrial planets have a solid planetary surface, ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Super-Neptune
A super-Neptune is a planet that is more massive than the planet Neptune. These planets are generally described as being around 5–7 times as large as Earth with estimated masses of 20–80 ; beyond this they are generally referred to as gas giants. A planet falling within this mass range may also be referred to as a sub-Saturn. There have been relatively few discoveries of planets of this kind. The mass gap between Neptune-like and Jupiter-like planets is thought to exist because of "runaway accretion (astrophysics), accretion" occurring for protoplanets of more than —once this mass threshold is crossed, they accumulate much additional mass (due to gravity increasing with mass and the presence of material in an accretion disk) and grow into planets the size of Jupiter or super-Jupiter, even larger. Known examples include Kepler-101b, HAT-P-11b, and K2-33b. Mass-radius relationship Through modelling, and analysis of discovered exoplanets, the relationship between mass and rad ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sub-Neptune
The term sub-Neptune can refer to a planet with a smaller radius than Neptune even though it may have a larger mass or to a planet with a smaller mass than Neptune even though it may have a larger radius like a super-puff and both meanings can even be used in the same publication. Neptune-like planets are considerably rarer than sub-Neptune sized planets, despite being only slightly bigger. Edwin S. Kite, Bruce Fegley Jr., Laura Schaefer, Eric B. Ford, 5 Dec 2019 This "radius cliff" separates sub-Neptunes (radii < 3 Earth radii) from Neptunes (radii > 3 Earth radii). This radius cliff is thought to arise because during formation when gas is accreting, the atmospheres of planets that size reach the pressures required to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reuters
Reuters ( ) is a news agency owned by Thomson Reuters. It employs around 2,500 journalists and 600 photojournalists in about 200 locations worldwide writing in 16 languages. Reuters is one of the largest news agencies in the world. The agency was established in London in 1851 by Paul Reuter. The Thomson Corporation of Canada acquired the agency in a 2008 corporate merger, resulting in the formation of the Thomson Reuters Corporation. In December 2024, Reuters was ranked as the 27th most visited news site in the world, with over 105 million monthly readers. History 19th century Paul Julius Reuter worked at a book-publishing firm in Berlin and was involved in distributing radical pamphlets at the beginning of the Revolutions of 1848. These publications brought much attention to Reuter, who in 1850 developed a prototype news service in Aachen using homing pigeons and electric telegraphy from 1851 on, in order to transmit messages between Brussels and Aachen, in what today is Aa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diamond
Diamond is a Allotropes of carbon, solid form of the element carbon with its atoms arranged in a crystal structure called diamond cubic. Diamond is tasteless, odourless, strong, brittle solid, colourless in pure form, a poor conductor of electricity, and insoluble in water. Another solid form of carbon known as graphite is the Chemical stability, chemically stable form of carbon at Standard temperature and pressure, room temperature and pressure, but diamond is metastable and converts to it at a negligible rate under those conditions. Diamond has the highest Scratch hardness, hardness and thermal conductivity of any natural material, properties that are used in major industrial applications such as cutting and polishing tools. Because the arrangement of atoms in diamond is extremely rigid, few types of impurity can contaminate it (two exceptions are boron and nitrogen). Small numbers of lattice defect, defects or impurities (about one per million of lattice atoms) can color ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Density
Density (volumetric mass density or specific mass) is the ratio of a substance's mass to its volume. The symbol most often used for density is ''ρ'' (the lower case Greek letter rho), although the Latin letter ''D'' (or ''d'') can also be used: \rho = \frac, where ''ρ'' is the density, ''m'' is the mass, and ''V'' is the volume. In some cases (for instance, in the United States oil and gas industry), density is loosely defined as its weight per unit volume, although this is scientifically inaccurate this quantity is more specifically called specific weight. For a pure substance, the density is equal to its mass concentration. Different materials usually have different densities, and density may be relevant to buoyancy, purity and packaging. Osmium is the densest known element at standard conditions for temperature and pressure. To simplify comparisons of density across different systems of units, it is sometimes replaced by the dimensionless quantity "relative den ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pulsar Planet
Pulsar planets are planets that are orbiting pulsars. The first such planets to be discovered were around a millisecond pulsar in 1992 and were the first extrasolar planets to be confirmed as discovered. Pulsars are extremely precise clocks and even small planets can create detectable variations in pulsar traits; the smallest-known exoplanet is a pulsar planet. They are extremely rare, with only half a dozen listed by the NASA Exoplanet Archive. Only special processes can give rise to planet-sized companions around pulsars, and many are thought to be exotic bodies, such as planets made of diamond, that were formed through the partial destruction of a companion star. The intense radiation and winds consisting of electron-positron pairs would tend to strip atmospheres away from such planets, thus making them unlikely abodes for life. Formation The formation of planets requires the existence of a protoplanetary disk, most theories also require a "dead zone" within it where there ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kepler-277c
Kepler-277c (also known by its Kepler Objects of Interest designation KOI-1215.02) is the third most massive and second-largest rocky planet ever discovered, with a mass about 64 times that of Earth. Discovered in 2014 by the Kepler Space Telescope, Kepler-277c is a Neptune-sized exoplanet with a very high mass and density for an object of its radius, suggesting a composition made mainly of rock with some amounts of water. Along with its sister planet, Kepler-277b, the planet's mass was determined using transit-timing variations (TTVs). Characteristics Size and temperature Kepler-277c was detected using the transit method and TTVs, allowing for both its mass and radius to be determined to some level. It is approximately 3.36 , close to the size of Neptune. At that radius, most planets should be gaseous Mini-Neptunes with no solid surface. However, the mass of Kepler-277c is extremely high for its size. Transit-timing variations indicate a planetary mass of about 64.2 , close to S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neologism
In linguistics, a neologism (; also known as a coinage) is any newly formed word, term, or phrase that has achieved popular or institutional recognition and is becoming accepted into mainstream language. Most definitively, a word can be considered a neologism once it is published in a dictionary. Neologisms are one facet of lexical innovation, i.e., the linguistic process of new terms and meanings entering a language's lexicon. The most precise studies into language change and word formation, in fact, identify the process of a "neological continuum": a '' nonce word'' is any single-use term that may or may not grow in popularity; a '' protologism'' is such a term used exclusively within a small group; a ''prelogism'' is such a term that is gaining usage but is still not mainstream; and a ''neologism'' has become accepted or recognized by social institutions. Neologisms are often driven by changes in culture and technology. Popular examples of neologisms can be found in science, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
