The planet Neptune has a dim planetary ring system which is made up of several separate rings and some "ring arcs". The "rings arcs" are part of the outer ring called the Adams ring and are not to be seen anywhere else. The ring "particles" (small parts) are unusually dark colored, and have large amounts of microscopic dust. Neptune has thirteen known moons. Four of them orbit the planet inside the outermost rings.
The rings around Neptune could not be seen from Earth with strong telescopes. The evidence that they were there was first seen when scientists were watching the planet as it passed between the Earth and a star. (When this happens, the light of the star is blocked. This is called "stellar occulation".) Scientists watched this happen 50 times, and on five of those times in the early 1980s they saw the star give a little "blink" just before or after the planet covered it. This meant that rings around the planet were blocking the light, but the rings were not complete.
In 1989 the unmanned spacecraft "Voyager 2" flew by Neptune. "Voyager 2" sent back pictures that gave most of the information that scientists now have about the rings of Neptune. The pictures also help scientists to know why the rings looked incomplete. Not only did the pictures give a closer view, but they also showed the rings in a way that cannot ever be seen from earth. From earth the rings are always seen with the light of the sun shining "towards" them. When the spacecraft went past the planet, it took pictures with the sun shining "behind" the rings, as well. Big "particles" in the rings looked dark against the sunlight, but all tiny dust "particles" (microscopic dust) shone brightly when the sun was behind it. This allowed the scientists to work out what the rings were made of, and how all the particles were arranged.
As better types of telescopes have been developed, scientists can now see some of the rings from earth. The brightness of Neptune makes it hard to see the rings, which are much dimmer and the faintest rings still cannot be seen, even with vey powerful telescopes.
The most famous of Neptune's rings is the thin outer Adams ring, although by comparison with the rings of the planets Saturn or Uranus, it is very hard to see. It was originally named as "1989 N1R". The reason that the Adams ring is famous is that it has a feature that has not been seen on any other planetary rings. These are three long narrow ""arcs"" which are much brighter and look more solid than the rest of the ring system. Each one spans from 4-10° of the whole ring. All the arcs are close to each other, spanning under 40° of longitude, only about 1/8th of the edge of the ring. It has been a puzzle to understand why the stuff in these arcs does not spread out evenly through the whole ring.
The three arcs have been named with French names "Liberté", "Égalité", and "Fraternité". These names came from the famous saying of the French Revolution, which translates into English as "Liberty, Equality and Brotherhood!". These names were suggested by the scientists who discovered them during "stellar occultations" in 1984 and 1985.
Four of Neptune's 13 moons are inside the ring system. The one that is nearest to the Adam's ring is called Galatea. It is a lumpy mass of rock that orbits around the planet at about the same speed as the planet is rotating. It is about 1000 kilometers inside the ring.
Many scientists now think that it is the effect of the moon Galatea that is causing the three arcs in the Adam's ring. The ring also has 42 wiggles, which are like waves 30 kilometers high. Scientists are able to use this information to work out the mass of the moon Galatea. .
The best photos that came back from Voyager 2 showed that there are clumps of particles in the rings, but no-one can tell whether they are made of fine dust, or if there may be bigger particles in the clumps as well. All of Neptune's rings have a lot of "microscopic dust" but particularly the arcs of the Adam's ring. Scientists know this because they looked very bright in the photos that Voyager 2 took with the sun shining behind them.
The Adams ring is very red. The background particles that make up the ring look twice as bright near the three arcs as they do on the side of the ring that is opposite the arcs.
With the arrival of the Hubble Space Telescope and adaptive optics ground-based telescopes the ring arcs have been re-examined several times, starting in July 1998.
In addition to the outer Adams Ring, the other ring arrangements in the direction of Neptune's surface are:
Voyager pictures appear to also suggest a wide disc of scattered material extending inside of the 50,000 km radius which surrounds the Galle ring, but is difficult to tell apart from Neptune's brightness, and for this reason its existence is uncertain.
The rings are named after astronomers who made important discoveries to the study of Neptune.
Four of Neptune's moons: Naiad, Thalassa, Despina, and Galatea orbit inside the ring system.
Igor Diakonov
Igor Mikhailovich Diakonov (December 30, 1914 (January 12, 1915), Petrograd – May 2, 1999, St Petersburg) was a Russian historian, linguist, and translator who should be ranked among the greatest authorities on Ancient Near East and its languages.
Baudouin I of Belgium
Baudouin I (French: "Baudouin Albert Charles Léopold Axel Marie Gustave" or Dutch: "Boudewijn Albert Karel Leopold Axel Marie Gustaaf") (7 September 1930 – 31 July 1993) was the King of the Belgians from 1951 to 1993.
The king was the oldest son of King Leopold III (1901-1983) and his first wife, Princess Astrid of Sweden (1905-1935).
On 15 December 1960, Baudouin was married in Brussels to Doña Fabiola de Mora y Aragón. The King and Queen had no children. All of the Queen's five pregnancies ended in miscarriage. Badouin died of heart failure. Having had no children, the crown passed on to his brother, Albert II of Belgium, following his death.
During Baudouin's reign the colony of Belgian Congo became independent.
Core
Core generally is the heart or inner part of a thing, as of a column, wall, rope, of a boil, etc.; especially, the central part of fruit, containing the kernels or seeds; as, the core of an apple or quince.
Core could mean:
In media:
In science and academics:
In computers and technology:
Acronyms:
Mesocyclone
A mesocyclone is a vortex of air, about 2 to 10 km in diameter (the mesoscale of meteorology), inside a convective storm.
That is, it is air that rises and rotates around a vertical axis, usually in the same direction as low pressure systems in a given hemisphere. They are most often cyclonic, that is, related with a localized low pressure area inside a severe thunderstorm. Such storms can create strong surface winds and a lot of hail. Mesocyclones often happen together with updrafts in supercells, where tornadoes may form.
Mesocyclones are normally relatively very small in size; they lie between the synoptic scale (hundreds of kilometers) and small scale (hundreds of meters).
Florida International University
Florida International University (FIU) is a public research university in Miami, Florida in the United States. the University is the largest university in South Florida and also the fifth-largest university in Florida, and the thirteenth-largest university in the country. FIU's programs in law, architecture and business are amongst its most well-ranked and most known programs. The mascot of FIU is a panther, named Roary, and students and fans of the university's athletic teams are often called "Panthers".
On March 15, 2018, a pedestrian bridge at the university collapsed and killed six people.
Sash