Saturday, March 13, 2010
William Herschel announces discovery of Uranus
It was on this day in 1781 that the astronomer William Herschel announced he had discovered the planet Uranus — only at first he was cautious and did not call it a "planet."
European astronomers went to work trying to confirm the planethood of Uranus, making calculations about things like its Earth-Sun distance and the shape of its orbit. Soon, everyone agreed that what Herschel reported was a planet, and in 1783 — two years after he first spotted the celestial object from his garden in Bath, England — William Herschel announced humbly but formally that he'd discovered a planet.
A German astronomer, Bode, proposed the planet be named "Uranus," after the Greek god of the sky. Astronomers generally prefer to pronounce the planet's name with the emphasis on the first syllable, as in "YUR uh nuhs," which is the way it's said in Latin. But English speakers have adopted the pronunciation with emphasis on the second syllable.
Uranus is the seventh planet from the Sun. Its equator is four times longer than Earth's equator, and its mass is about 14½ times greater than Earth's. It takes 84 Earth years to make one complete orbit around the Sun. Its day — the amount of time it takes to make a full spin on its axis — is just 17 hours and 14 minutes, compared with Earth's 24 hours.
It is known as one of the "ice giants," and its atmosphere is the coldest in the solar system, with a temperature of about negative 215 degrees Celsius, and is made up mostly of hydrogen and helium gases. Most of what we know about Uranus comes from an unmanned NASA expedition, Voyager 2, in the mid-1980s. The spacecraft flew within about 50,000 miles of the planet's top layer of clouds, taking pictures and collecting data.
Uranus, (YUR uh nuhs or yu RAY nuhs), is the seventh planet from the sun. Only Neptune and Pluto are farther away. Uranus is the farthest planet that can be seen without a telescope. Its average distance from the sun is about 1,784,860,000 miles (2,872,460,000 kilometers), a distance that takes light about 2 hours 40 minutes to travel.
Uranus is a giant ball of gas and liquid. Its diameter at the equator is 31,763 miles (51,118 kilometers), over four times that of Earth. The surface of Uranus consists of blue-green clouds made up of tiny crystals of methane. The crystals have frozen out of the planet's atmosphere. Far below the visible clouds are probably thicker cloud layers made up of liquid water and crystals of ammonia ice. Deeper still -- about 4,700 miles (7,500 kilometers) below the visible cloud tops -- may be an ocean of liquid water containing dissolved ammonia. At the very center of the planet may be a rocky core about the size of Earth. Scientists doubt Uranus has any form of life.
Uranus was the first planet discovered since ancient times. British astronomer William Herschel discovered it in 1781. Johann E. Bode, a German astronomer, named it Uranus after a sky god in Greek mythology. Most of our information about Uranus comes from the flight of the United States spacecraft Voyager 2. In 1986, that craft flew within about 50,000 miles (80,000 kilometers) of the planet's cloud tops.
Orbit and rotation
Uranus travels around the sun in an elliptical (oval-shaped) orbit, which it completes in 30,685 Earth days, or just over 84 Earth years. As it orbits the sun, Uranus also rotates on its axis, an imaginary line through its center. The planet's interior (ocean and core) takes 17 hours 14 minutes to spin around once on its axis. However, much of the atmosphere rotates faster than that. The fastest winds on Uranus, measured about two-thirds of the way from the equator to the south pole, blow at about 450 miles per hour (720 kilometers per hour). Thus, this area toward the south pole makes one complete rotation every 14 hours.
Uranus is tilted so far on its side that its axis lies nearly level with its path around the sun. Scientists measure the tilt of a planet relative to a line at a right angle to the orbital plane, an imaginary surface touching all points of the orbit. Most planets' axes tilt less than 30¡. For example, the tilt of Earth's axis is about 23 1/2. But Uranus's axis tilts 98 degrees, so that the axis lies almost in the orbital plane. Many astronomers think that a collision with an Earth-sized planet may have knocked Uranus on its side soon after it was formed.
Uranus has a mass (quantity of matter) 14 1/2 times larger than that of Earth. However, the mass of Uranus is only about 1/20 as large as that of the largest planet, Jupiter.
Uranus has an average density of 1.27 grams per cubic centimeter, or about 1 1/4 times the density of water. Density is the amount of mass in a substance divided by the volume of the substance. The density of Uranus is 1/4 that of Earth, and is similar to that of Jupiter.
The force of gravity at the surface of Uranus is about 90 percent of that at the surface of Earth. Thus, an object that weighs 100 pounds on Earth would weigh about 90 pounds on Uranus.
The atmosphere of Uranus is composed of about 83 percent hydrogen, 15 percent helium, 2 percent methane, and tiny amounts of ethane and other gases. The atmospheric pressure beneath the methane cloud layer is about 19 pounds per square inch (130 kilopascals), or about 1.3 times the atmospheric pressure at the surface of Earth. Atmospheric pressure is the pressure exerted by the gases of a planet's atmosphere due to their weight.
The visible clouds of Uranus are the same pale blue-green all over the surface of the planet. Images of Uranus taken by Voyager 2 and processed for high contrast by computers show very faint bands within the clouds parallel to the equator. These bands are made up of different concentrations of smog produced as sunlight breaks down methane gas. In addition, there are a few small spots on the planet's surface. These spots probably are violently swirling masses of gas resembling a hurricane.
The temperature of the atmosphere is about -355 degrees F (-215 degrees C). In the interior, the temperature rises rapidly, reaching perhaps 4200 degrees F (2300 degrees C) in the ocean and 12,600 degrees F (7000 degrees C) in the rocky core. Uranus seems to radiate as much heat into space as it gets from the sun. Because Uranus is tilted 98¡ on its axis, its poles receive more sunlight during a Uranian year than does its equator. However, the weather system seems to distribute the extra heat fairly evenly over the planet.
Uranus has 21 known satellites. Astronomers discovered the 5 largest satellites between 1787 and 1948. Photographs by Voyager 2 in 1985 and 1986 revealed 10 additional satellites. Astronomers later discovered more satellites by using Earth-based telescopes.
Miranda, the smallest of the five large satellites, has certain surface features that are unlike any other formation in the solar system. These are three oddly shaped regions called ovoids. Each ovoid is 120 to 190 miles (200 to 300 kilometers) across. The outer areas of each ovoid resemble a race track, with parallel ridges and canyons wrapped about the center. But in the center, ridges and canyons crisscross one another randomly.
Uranus has a strong magnetic field. The axis of the field (an imaginary line connecting its north and south poles) is tilted 59 degrees from the planet's axis of rotation.
The magnetic field has trapped high-energy, electrically charged particles -- mostly electrons and protons -- in radiation belts around the planet. As these particles travel back and forth between the magnetic poles, they send out radio waves. Voyager 2 detected the waves, but they are so weak that they cannot be detected on Earth.
Uranus in science fiction [the arts] is sparse. This is the only film devoted to a trip to Uranus and other than showing up now and then in pulp scifi magazines doesn't appear to be a favorite place for adventure.
Journey to the Seventh Planet was a 1962 science fiction film. It was shot in Denmark with a budget of only US $75,000. The seventh planet is, of course, Uranus, and a crew is being dispatched there by the United Nations on a mission of space exploration. The film's ideas of astronauts exploring outer space only to confront their inner mindscapes and memories precede the similar-themed Solaris by a full decade (Although the novel Solaris precedes this film by a year). It is also reminiscent of Ray Bradbury's 1948 short story Mars is Heaven! that appeared in the 1950 book The Martian Chronicles.
During their journey to the planet an alien presence briefly assumes control of the crew's minds. They awaken safely but notice that an unexplained long period of time has passed by.
Upon landing on Uranus, they find a forested land oddly like our own (rather than the cold, bleak world they were expecting.) This forest is surrounded by a mysterious barrier. One of the crew pushes his arm through the barrier, only to have it frozen.
New features and forms begin to appear each time they are imagined by the crew. Soon, however, the crew discover that they have been the victim of mind-control by a one-eyed brain living in a cave. Naturally the alien brain plans to possess the astronaut's bodies and have them take it back to Earth where it will, of course, implement a plan for global domination. The crew finally outwits the supposedly mind-reading creature.
Japanese anime developed Sailor Uranus.
Sailor Uranus...is one of the central characters in the Sailor Moon metaseries. Her real name is Haruka Tenoh,or Amara Tenoh in the English anime, a masculine schoolgirl who can transform into one of the series' specialized heroines, the Sailor Senshi.
Haruka is one of the most famous out lesbians in the anime fandom. Her masculine persona (by shōjo standards) is one of the standard archetypes in yuri.
Haruka is a stubborn, protective individual, but is also strong-willed, capable, charming, and occasionally even doting. She is formally introduced in the third story arc, although she appears in silhouette alongside Sailor Neptune in the final episode of Sailor Moon R.
Haruka is a racecar driver, even though she is barely sixteen years old when she appears. However, the timing of her birthday to the Japanese school year means she is one grade ahead of the Guardian Senshi.
Among fans in North America, Haruka and Michiru are among the most famous out lesbian characters in anime. Haruka is also extremely flirtatious and loves to tease pretty girls who sometimes mistake her gender due to Haruka's tomboyish behavior. In the manga, she even kisses Usagi. Throughout the manga, she is lightly flirting with Usagi, either out of habit from the first arc she appeared in or just for fun, and eventually Usagi would occasionally flirt back out of pure playfulness.
Although her relationship with Michiru is not implicitly sexual until later in the series, their romantic situation is referred to early on and generally understood by most of the metaseries' characters fairly quickly. It is sometimes a source of good natured humor, particularly because few of the other Senshi have serious romantic prospects in comparison and because the otherwise flirtatious Haruka finds it impolite to discuss romantic matters in public. All fan rumors about Haruka being a man, the reincarnation of one, or a hermaphrodite, are untrue. Naoko Takeuchi has explicitly stated that "Haruka has always been a girl. Always will be."
She further complicates the perception of her gender by appearing as a "Tuxedo Mask" instead of a Sailor Senshi in the first appearance. This form is never mentioned again.
Besides her relationship with Michiru, Haruka is also close friends with Setsuna, because the three of them work closely together as Outer Senshi. Following the destruction of the Death Busters and the rebirth of Sailor Saturn as an infant, they vow to be her family and care for her. Later story arcs show that the four live together happily for some time. Nothing about Haruka's family life is ever discussed, although she and Michiru Kaioh appear noticeably wealthy by unknown means. In the manga, Haruka says that she and Michiru have "wealthy patrons." Haruka is the target of sexism in episode 98 of the anime, but never of homophobia.
The anime and manga versions of the character are reasonably interchangeable, although her standoffishness is more pronounced in the anime. Like the other Outer Senshi, Haruka is sometimes considered colder and almost unfeeling. Aside from a brief vignette in a special, Haruka and the others do not return after the third season until the final fifth season, generally retaining the same personalities.
In the Sailor Moon musicals (Seramyu), Haruka and Michiru's relationship remains largely unchanged; they are always shown together, which is consistent with both manga and anime, and while their romance in the musicals is usually kept low-key, the actresses for the two do kiss on stage in the omake of Kaguya Shima Densetsu Kaiteiban. They are also the only two Senshi to engage in physical combat with Galaxia. The other Senshi only use their powers to combat her. As in the anime, however, neither Uranus or Neptune are capable of harming Galaxia in combat. It is seen that Uranus could sense Neptune's death when Galaxia gravely injures Neptune, who had been weakened while protecting Sailor Mars. Otherwise, the two are shown to be more willing to work as a team with the Guardian Senshi in the musicals than in the anime, except where plot-lines are directly drawn from the anime, such as their pretended betrayal of the other Senshi in Stars.
Haruka's greatest dream, prior to becoming a Sailor Senshi, was to be a professional racer. Thereafter it is still a well-loved hobby, and driving is listed in the manga as her best skill. She is also a skilled runner, belonging to the track-and-field club at school. On occasion, Haruka can be seen playing piano in accompaniment during Michiru's violin performances. While Physical Education is her best class, Modern Japanese is her worst. Haruka is highly private, able to tease others while becoming flustered if teased herself, and has difficulty with confessions. Her favorite food is salad, and her least favorite is natto (fermented soybeans); she also likes the color gold. According to Michiru, Haruka has had trouble with popular men on more than one occasion. Haruka denies this, but it clearly annoys her.
Haruka and the other Outer Senshi appear in the SuperS movie, although this conflicts with the general timeline of the series in several ways. Notably, they are more overtly friendly and helpful than they had been when they last met and Sailor Pluto is present (in contradiction of certain events in the third series).
Wikipedia [edited] offers a list of venues where Uranus has appeared.
An anonymous author writing as a Mr. Vivenair published A Journey Lately Performed Through the Air in an Aerostatic Globe, Commonly Called an Air Balloon, From This Terraquaeous Globe to the Newly Discovered Planet, Georgium Sidus in 1784.
In the Buck Rogers series (1928), Uranus is portrayed as having biodomes and robots.
In Stanley G. Weinbaum's 1935 story "The Planet of Doubt", Uranus' North pole is shrouded in a perpetual fog.
R. R. Winterbotham's "Clouds over Uranus" was published by Astounding in March 1937.
Fritz Leiber's 1962 short story "Snowbank Orbit" has three Earth-ships, fleeing from interstellar invaders, attempt a desperate aero-braking maneuver in the atmosphere of Uranus at 100 miles per second.
In Ramsey Campbell's The Insects from Shaggai (1964), a Cthulhu Mythos story, Uranus is known as L'gy'hx and is inhabited by cubical metallic many-legged creatures who worship Lrogg. They entered in religious conflict with the Shan.
Uranus is the source of radio signals investigated by Chris Godfrey and his team in First Contact, written by Hugh Walters and published in 1971.
The novels #5 ("Push towards Uranus") and #22 ("Position Oberon") in the Mark Brandis SF book series take place on and around Uranus.
In Larry Niven's novel A World Out of Time (1976), Uranus is outfitted with a massive fusion motor and used to gently move the Earth outward from an artificially brightening sun caused by a civil war between Earth and its colonies.
Geoffrey A. Landis's short story "Into the Blue Abyss," part of his short-story collection Impact Parameter and other Quantum Fictions (2001) discussed an expedition to Uranus in search of life.
Film and television
In the 1962 film Journey to the Seventh Planet, astronauts on Uranus encounter a strange intelligence.
In Space Patrol (1962) episode: "The Dark Planet" - Professor Heggerty and his daughter Cassiopeia are baffled by a plant sample from Uranus with a mind of its own. Following the disappearance of a 20 strong survey team on Uranus, Colonel Raeburn dispatch the Space Patrol crew to locate larger versions of the plant, where they discover the adult specimens of the plant are far from friendly.
In Space Patrol (1962) episode: "The Invisible Invasion"- On Uranus, the Duo's are planning to seize power on Earth by taking over the minds of everyone at Space Headquarters, including Colonel Raeburn. The one person seemingly unaffected by the Duo's power is Professor Heggerty, who is installed beneath his electronic hair-restorer!
In the Doctor Who (1963) serial "The Daleks' Master Plan", Uranus is described as being the only location in the universe where the mineral Taranium can be acquired.