Neptune, discovery

Newtons law of gravitation played that ideal role for planetary astronomy during the eighteenth century. Once a planetary orbit had been calculated, based on the ideal relation between a planet and the sun, any deviation from the calculated path was immediately seen as a challenge to the law and became a focus of concerned attention to seek an explanation, usually found in the gravitational effects of other planets. The most spectacular example of this was the discovery of the planet Neptune from the deviations in the orbit of Uranus. 

It is, therefore, noteworthy that almost immediately upon Welsh and associates discovery of collision-induced absorption in hydrogen [128, 129, 420], Herzberg found the first direct evidence of the H2 molecule in the atmospheres of the outer planets [181, 182], He was able to reproduce in the laboratory the unidentified diffuse feature at 827.0 nm observed by Kuiper in the spectra of Uranus and Neptune, using an 80 m path of hydrogen at 100 atmospheres pressure and a temperature of 78 K. The feature is the S3(0) line of the 3 — 0 collision-induced rotovibrational band of the H2 molecule [182]. 

Look up an account of the discovery of the planet Neptune. What can be said about the effectiveness of the factors in the models that described the motions of the planets other than Neptune What can be said about the lack of fit of these models to the available astronomical data How was the lack of fit accounted for ... 

Neptune s largest moon, Triton, was discovered within weeks of the discovery of the planet itself. It is one of the most distant objects in the solar system. Even the outermost planet, Pluto, and its moon, Charon, spend considerable time on their eccentric orbits closer to the Sun than Triton. Its nature remained a mystery until the advent of new astronomical methods in the 1970s and 1980s and the flyby of the Voyager 2 spacecraft in 1989. In many ways, it is a planetary body on the edge —on the outer edge of the main part of the solar system, and the inner edge of the realm of comets and the recently discovered Kuiper belt objects. As such, it shares some of the characteristics of the icy satellites of the rest of the outer solar system with some of the nature of the colder, more distant, cometary bodies. 

J. (1996) Triton s plumes discovery, characteristics and models. In Neptune and Triton (ed. D. Cruikshank). University of Arizona Press, Tucson, pp. 949—990. 

Neptune is in a nearly circular orbit around the Sun at a 30.1 astronomical unit (a.u.) mean distance (4,500,000,000 km) from it, making it the most distant known Jovian planet (and probably the most distant known major planet, since recent findings indicate that the Pluto-Charon system is too small to be considered a major planet) from the Sun. Kepler s third law gives 165 years for Neptune s period of revolution around the Sun. Therefore, Neptune will not have made one complete revolution around the Sun since its discovery until 2011. 

Soon after its discovery, it was found that Triton s orbit around Neptune is retrograde, meaning that, as seen from above Neptune s north pole, Triton revolves around... 

In the next century, scientists realized that anomalies in the orbit of Uranus could be accounted for by the presence of another planet. In 1846, after a search marked by total confusion (in keeping with the nature of the planet), European astronomers identified that unknown body and named it Neptune A third discovery further expanded the solar system in 1930, when Clyde Tombaugh, a 23-year-old amateur who was hired to examine photographic plates of the night sky, found what he was looking for A tiny, distant body, which is now named Pluto. 

Elusive Neptune, the planet of inspiration, is your ruler, no matter what your Sun sign is. Its position in your chart by house, by sign, and by aspect, indicates an area of ideals, creativity, and spiritual fulfillment. You also have a co-ruler Jupiter, the planet associated with Pisces prior to the discovery of Neptune in 1846. 

Neptunium was named after Neptune and was the second element to be named after a planet. Uranium had been named in 1789 in honor of the discovery of the planet Uranus eight years earlier. 

Geocentric model based on religious beliefs, but explains observed phenomena. Careful observations (Brahe, 9 planets eventually Kepler) point to discovered. Discovery of Heliocentric Model first Neptune confirms Newton s suggested by Copernicus. theory of universal Telescope confirms model. gravitation. Anomaly in orbit of Mercury resists solution with Newton s laws. Precession of Mercury s orbit is solved by Einstein s Theory of General Relativity. Theory and observations agree. Pluto is demoted to non-planet status (4). 

In 1940, Edwin M. McMillan (1907-91) and Philip H. Abelson (1913-2004), working in Berkeley, bombarded uranium with cyclotron-produced neutrons, producing element 93, neptunium (Np). Neptunium was the first transuranium element to be reported. It is one beyond uranium in atomic number, hence the name, after the planet Neptune which is the one beyond Uranus. In the same year Glenn T. Seaborg (1912-99) and others in the Berkeley group discovered element 94, plutonium (Pu). Its potential for nuclear fission was soon apparent and the discovery was only... 

Not until 1942 would they officially propose a name for the new element that fissioned like U235 but could be chemically separated from uranium. But Seaborg already knew what he would call it. Q>nsistent with Martin Klaproth s inspiration in 1789 to link his discovery of a new element with the recent discovery of the planet Uranus and with McMillan s suggestion to extend the scheme to Neptune, Seaborg would name element 94 for Pluto, the ninth planet outward from the sun, discovered in 1930 and named for the Greek god of the underworld, a god of the earth s fertiUty but also the god of the dead plutonium. 

The four largest satellites of Jupiter - Ganymede, Callisto, lo, and Europa - are known as the Galilean satellites after their discovery by Galileo in 1610. Ganymede is the largest natural satellite in the solar system and is in tact larger than Mercury it is followed by Titan (Saturn), Callisto (Jupiter), lo (Jupiter), the moon (earth), Europa (Jupiter), and Triton (Neptune). 

Duke MB (1965) Discovery of Neptune Mountains iron meteorite, Antarctica Meteorit Bull No. 34 2-3 Duprat J, Maurette M, Engrand C, Matrajt G, Immel G, GouneUe... 

Lakatos emphasis on corroboration can be viewed as turning Popper s asymmetry into a dichotomy, indeed symmetry, of falsification and corroboration. This follows from what Popper (1974 1005ff) identified as Lakatos central thesis, which is that exactly the most admired scientific theories simply fail to forbid any observable state of affairs (Lakatos 1974 100). Lakatos proceeds to recount the story of an imaginary account of planetary misbehavior in support of his thesis (the story is a variation of the discovery of Neptune). Ironically, this story is built on the class of forbidden statements derived from Newtonian mechanics (why else would this be a case of planetary misbehavior ), and merely portrays a researcher who is unwilling to concede, or accept, the occurrence of a forbidden instance. Popper (1974 1005ff) took very serious issue with, and refuted, Lakatos central thesis. 

The discovery of transiting planets with masses below 10 MEanh and radii consistent with rocky planetary models answered the important question as to whether planets more massive than Earth could be rocky. 10 Mgarth and 2 Earth radii are used as estimates from planet formation theories as the upper limit for rocky planet mass and size. For comparison, Uranus has about 14.5 MEanh and about 4 Earth radii. Above about 10 Earth masses a planet is thought to accumulate a substantial amount of gas that makes it akin to a gas giant with a substantial atmosphere, not a rocky planet with a thin outgassed atmosphere. Where exactly such a cut-off mass is that distinguishes rocky Super-Earths and gaseous Mini-Neptunes - if it exists at all - is an open question that mean density measurements of detected exoplanets currently explore. 

Recent discoveries by ground based observations, as well as the Corot and Kepler space-missions, found planets with masses below 10 MEarth and densities akin to Neptune as well as Earth, suggesting that there is not one cut-off mass above which a planet is like Neptune and below which it is rocky like Earth or Venus. Note that the term Mini-Neptune is used for small extrasolar giant planets, not mini-Uranus, even though Uranus is the less massive planet (17.1 and 14.5 Earth masses. 

But perhaps the pivotal event of nineteenth-century celestial mechanics was the successful prediction of the orbit of Neptune through the analysis of orbital perturbations on Uranus. Accomplished by Adams and Le Verrier, the discovery in 1846 of this hitherto unknown planet served to inspire much of the revived interest in orbital dynamies and the detailed exploration of perturbation theory. Significant contributions were made by Delaunay, Hill, Hansen, Brown, and Airy in this regard, especially concerning the motion of the moon (a problem that had even perplexed... 

Super-Earth planets are planets with masses between 1 and 10 Earth masses. Such masses are still beyond the mass of the gas giants, e.g. the mass of Neptune is 17 MEarth- The atmospheres of such objects may be different from atmospheres for typical terrestrial planets. Some of them may possess hydrogen rich atmospheres. These objects should show strong H2O features in their spectra. Objects that have lost most of their hydrogen could exhibit strong CO2 features. Generally, this type of objects seems to represent a transition between rocky objects and Neptune-like planets. The discovery of super-Earths was discussed e.g. in Elkins-Tanton and Sea-ger, 2008 [120]. They argue that there are three ways how such objects may obtain atmospheres ... 

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