From July to September 1989, "Voyager 2" discovered six new moons of Neptune. Of these, Proteus is the second most massive Neptunian moon. It has only one quarter of 1% of the mass of Triton. Neptune's closest four moons, Naiad, Thalassa, Despina, and Galatea, orbit close enough to be inside Neptune's rings. The next farthest out, Larissa was originally discovered in 1981 when it had occulted a star. The moon was credited for causing Neptune's ring arcs when "Voyager 2" observed Neptune in 1989. Five new unusual moons discovered between 2002 and 2003 were announced in 2004. The latest moon, Hippocamp, was discovered from examining Hubble Telescope images on 16 July 2013.
Neptune cannot be seen with naked eye alone, since Neptune's normal brightness are between magnitudes +7.7 and +8.0. It can be out-shined by Jupiter's Galilean moons, the dwarf planet Ceres, and the asteroids 4 Vesta, 2 Pallas, 7 Iris, 3 Juno and 6 Hebe. A telescope or strong binoculars will show Neptune as a small blue dot that looks similar to Uranus. The blue color comes from the methane in its atmosphere. Its small obvious size has made it difficult to study visually. Most telescopic data was quite limited until the arrival of the Hubble Space Telescope and large ground-based telescopes with adaptive optics.
With an orbital period (sidereal period) of 164.88 Julian years, Neptune was returning to the same place in the sky where it was discovered in 1846. In August 2011, it completed its first full orbit of the Sun. It happened three different times, also with a fourth in which it came very close to being at that position. This is explained by the idea of retrogradation.
Currently, only one spacecraft has visited Neptune. NASA's "Voyager 2" probe made a quick flyby of the planet with its closest encounter on 25 August 1989. It was the last planet to have been visited by a spacecraft.
One of "Voyager 2"'s important discoveries was its very close fly-by of Triton where took pictures of several parts of the moon. The probe also discovered the Great Dark Spot. However, it had now disappeared after the Hubble Space Telescope took pictures of Neptune in 1994. Originally thought to be a large cloud or cyclonic storm system. It was later guessed to be a hole in the visible cloud deck.
The pictures sent back to Earth from "Voyager 2" in 1989 became the basis of a PBS all-night program called "Neptune All Night".
After the "Voyager 2" flyby mission comes "Flagship orbital mission". This hypothetical mission is not possible until the late 2020s or early 2030s.
"Neptune Odyssey" is the current mission concept for a Neptune orbiter. NASA's possible large strategic science mission would launch in 2033 and arrive at Neptune in 2049.
Negative
Negative may mean:
Now
Now is the time span between the past and the future. It can be long (like an eon in geologic time) or short (like a picosecond) but it is almost always used to refer to the span between the present instant to some time horizon when a decision must be made. It can be used to ask or demand that someone make a decision even if they want to delay.
"I want to know what you think, now."
"What do you think now?"
"Now is the time for all good people to come to the aid of their country."
Mathematics and measurement assume that everything used in one equation equals the same quantities at the beginning of calculation or axiomatization as at the end. That means it is mathematically correct to say that the idea of "equal" means "equal from the time the process starts to the time it ends." In General Semantics and E Prime the words equal, remain (for the past until now) and become (for now into the future) replace the verb "to be" for this reason.
Algebra is now often called snapshot algebra or algebra of seeing because of this dependence on time. If any action or event were possible between steps in algebraic analysis, then, in theory, one would have to start over as if one had no knowledge of the new state at all. For these reasons the idea of statistics and also knowledge and knowledge management are sometimes questioned, for instance, in the book "Lies, Damn Lies, and Statistics". A major issue is the comparing of numbers gathered in the past, and now, after some key conditions change.
New York City
New York City (NYC) or simply New York (NY) is the largest city by population in the United States, located in the state of New York. New York’s population is similar to London in the United Kingdom with over 8 million people currently living in it, and over 22 million people live in the bigger New York metropolitan area. It is in the south end of the state of New York, which is in the northeastern United States. It is the financial capital of the US since it is home to the nation's stock market, Wall Street, and the One World Trade Center. A leading global city; New York exerts culture, media and capital internationally, as well as attracting great numbers of international travelers. It is also the home of the United Nations Headquarters.
Being on one of the world's largest natural harbors, New York City is made up of five boroughs, each of which is a county of the State of New York. The five boroughs—Brooklyn, Queens, Manhattan, the Bronx, and Staten Island—were combined into one city in 1898. The city and its metropolitan area are an important place for legal immigration to the United States. As many as 800 languages are spoken in New York, making it the most linguistically diverse city in the world. New York has more than 3.2 million people born outside the United States, the biggest foreign-born population of any city in the world as of 2016.
New York City started as a trading post created by colonists from the Dutch Republic in 1624 on Lower Manhattan; the post was named New Amsterdam in 1626. In 1664, the English controlled the city and the areas around it, and were renamed "New York" after King Charles II of England gave the lands to his brother, the Duke of York. New York was the capital of the United States from 1785 until 1790, and has been the biggest U.S. city since 1790. The Statue of Liberty welcomed millions of immigrants as they came to the U.S. by ship in the late 19th and early 20th centuries, and it is a symbol of the U.S. and its ideals of liberty and peace. In the 21st century, New York has grew into a global hub of creativity and entrepreneurship and environmental sustainability, and as a symbol of freedom and cultural diversity. In 2019, New York was voted the best city in the world in a survey of over 30,000 people from 48 cities worldwide, because of its cultural diversity.
Many districts and landmarks in New York City are well known, including three of the world's ten most visited tourist places in 2013. A record 62.8 million tourists came to New York City in 2017. Times Square is the colorful area of the Broadway Theater District, one of the world's busiest pedestrian intersections, and a famous area for the world's entertainment industry. Many of the city's landmarks, skyscrapers, and parks are known around the world. Manhattan's real estate market is one of the most expensive in the world. New York has more ethnic Chinese people outside of Asia than anywhere else in the world, with many Chinatowns across the city. The New York City Subway is the biggest single-operator rapid transit system worldwide, with rail stations. The city has over 120 colleges and universities, including Columbia University, New York University, Rockefeller University, and the City University of New York system, which is the biggest urban public university system in the United States. The world's two largest stock exchanges, the New York Stock Exchange, located on Wall Street in the Financial District of Lower Manhattan, and NASDAQ, headquartered in Midtown Manhattan, are both in Manhattan.