Download - The Twin Planets (Uranus and Neptune)
THE TWIN
ICE GIANTS
URANUS Discovery: 1781, William
Herschel Name: Greek sky god, first ruler of the Titans
Average Distance from Sun: 1,783,939,400 miles
2,870,972,200 km 19.2
Astronomical Units Mass: 14.4 times Earth's mass
Equatorial Diameter: 31,764 miles 51,118 km Length of Day: 17 hours, 14
minutes Length of Year: 84 Earth years
Surface Gravity: 0.86 that of Earth (If you weigh 100 pounds, you would weigh about 86 pounds on Uranus)
Known Moons: 27 as of January 2006
Significant Dates: 1787-1851
• Four Uranian moons are discovered and named Titania,
Oberon, Ariel, and Umbriel.
1948•Another moon, Miranda,
is discovered.
1977• Scientists discover nine
faint rings of Uranus while observing a distant
star pass behind the planet.
1986• Voyager 2 discovers 10
moons and two additional rings during
its historic flyby
2007• Uranus reaches
equinox.
2003-2005• The Hubble Space
Telescope images two delicate rings far
from the planet, and two new moons.
1997-2005• Astronomers
discover more tiny moons.
THE 27 MOONS OF URANUS:
Cordelia Ophelia
Bianca Cressida
DesdemonaJuliet
PortiaRosalind Mab
Belinda Perdita Puck Cupid Miranda Francisco
ArielUmbriel Titania
Oberon
Caliban Stephano
Trinculo
Sycorax
Margaret
ProsperoSetebosFerdinand
Blue-Green GiantUranus is the seventh planet from the sun in our solar system. This giant ball of gas and liquid is about four times as large as Earth, and it's covered by methane clouds. It is believed that Uranus is covered in ammonia and water oceans surrounding a rocky core believed to be the size of Earth. In 1986, Voyager 2 passed by the planet, illuminating the blue-green gas giant as never before.
Uranus in Color
Uranus is in some ways most like its neighbor Neptune, but in others it is fantastically different. While Neptune was the first planet to be discovered by mathematical prediction, Uranus was the first planet to be discovered by telescope. It was first revealed in March 1781 by English astronomer Sir William Herschel. Here the top picture shows Uranus as the human eye sees it. The bottom picture shows Uranus through ultraviolet, violet and orange filters to illustrate the contrast of gases.
High-level haze on Uranus
This computer-enhanced photo taken by Voyager 2 shows the high levels of haze in Uranus' upper atmosphere. While the planet closely resembles Neptune in composition, Uranus emits less colorful wavelengths, making it a somewhat bland planet in comparison. NASA believes this is because the planet's internal heat is lower than the other gas giants. Because Neptune is at such an extreme axial tilt, the planet experiences different and sometimes violent seasons.
Hubble finds many bright clouds on UranusThis image was taken in 2007 by the Hubble Space Telescope. It shows the cloud bands, rings and moons of the planet. These are theplanet's four major rings and 10 of its many known satellites. The five main satellites of Uranus are called Miranda, Ariel, Umbriel, Titania and Oberon. Uranus also has the most unique positioning among all the planets, as it tilts almost completely on its side. Where most planets have its equator, Uranus has its north and south poles.
Miranda as seen by Voyager 2The moon Miranda is named for the daughter of Prospero in "The Tempest." It is seen here in a photo taken from Voyager 2 in 1986. It is the smallest of Uranus' largest satellites, but it is considered perhaps one of the most intriguing moons in the solar system. Made of ice and rock, Miranda's surface is made up of ancient and newer surfaces, a rarity in planetary geology. Some experts believe this combination of surfaces was caused by partly melted ice upwells forced new surfaces into existence while other experts think that Miranda may have literally shattered and reformed itself over the centuries.
Crescent UranusThis photo, taken by Voyager 2, shows a color composite of three photographs taken through blue, green and orange filters. Voyager 2, launched in 1977, photographed Jupiter in 1979, Saturn in 1981, Uranus in 1986 and Neptune in 1989. What it did not clarify was the pronunciation of Uranus, which can cause some giggles. Some astronomers stress the first syllable of the word: in other words, yoor-uh-nuhs. However, it is acceptable to pronounce the name of the planet with an emphasis on the second syllable as well.
A rare eclipse on UranusIn 2006, the Hubble Space Telescope caught a rare view of an eclipse on Uranus. Uranus has an extremely strong magnetosphere. Its atmosphere is comprised mostly of hydrogen and smaller amounts of helium and methane. Further, it averages around 2,870,972,200 kilometers (1,783,939,400 miles) from the Sun. And while its atmosphere is extremely cold, experts estimate that the oceans can reach a temperature as high as 4,200 degrees F (2,300 degrees C).
Voyager 2's final image of UranusThis photo, taken in 1986, was the final image released by NASA of Uranus before the spacecraft began its journey to Neptune. Uranus also has the distinction of being the only planet named after a god from Greek mythology, as opposed to Roman. In the 18th century, German astronomer Johann Bode suggested that the planet be named for the father of Saturn, as Saturn is named for the father of Jupiter. In 1850, the name Uranus became the universal tag for the planet.
FACTS ABOUT URANUS:
Uranus is the coldest planet in the Solar System
Uranus is turned over on its side
Summer on Uranus lasts one long day – 42 years
Uranus is the second least dense planet
Uranus has rings
The atmosphere of Uranus is boring… or is it?
Uranus was the first planet discovered in the modern age
•You can see Uranus with the unaided eye•Uranus has only been visited once•You can see Uranus with the unaided eye•Uranus has only been visited once•You can see Uranus with the unaided eye•Uranus has only been visited once•You can see Uranus with the unaided eye•Uranus has only been visited once•You can see Uranus with the unaided eye•Uranus has only been visited once•You can see Uranus with the unaided eye•Uranus has only been visited once•You can see Uranus with the unaided eye
You can see Uranus with the unaided eye
Uranus has only been visited once
Space Probes: Launched in 1973, some of the most important Uranian
discoveries of
Voyager 2 are:
Uranus’s ring system
Uranus’s highly inclined magnetosphere
Ten satellites, with more discovered later from the same data
NEPTUNE Discovery: 1846, Johann Galle
Name: Roman god of the sea
Average Distance from Sun:
2,795,084,800 miles 498,252,900 km
30.1 Astronomical Units Mass: 17.1 times Earth's mass
Equatorial Diameter: 30,776
miles49,528 km
Length of Day: 16 hours, 7 minutes
Length of Year: 164.8 Earth years
Surface Gravity: 1.1 that of Earth
(If you weigh 100 pounds, you
would weigh about 110 pounds on Neptune Known Moons: 13 as of January
2006; Largest: Triton
Significant Dates:
1846: • Using mathematical calculations, astronomers discover
Neptune, increasing the number of known planets to eight. Neptune's largest moon, Triton, is found the same year.
1984:• Astronomers find evidence for the existence of a ring
system around Neptune.
1989:Voyager 2 becomes the first and only spacecraft to visit Neptune, passing about 4,800 km (2,983 miles) above the planet's North Pole. 1998:
• Scientists using telescopes on Earth and in space image Neptune's rings and ring arcs
for the first time.
2011: • Neptune completes its first 165-year orbit
of the sun since its discovery in 1846.
2003:• Using improved observing techniques, astronomers discover five new moons
orbiting Neptune.
2005: • Scientists using the Keck Observatory image the outer rings and find that some of the ring
arcs have deteriorated.
Naiad
Thalassa
Despina
Nereid
GalateaLarissa Proteus
Triton
S/2002 N1S/2002 N2. S/2002 N3
S/2002 N4
Psamathe
THE 13 MOONS OF N NEPTUNE:
The blue planet
The beautiful blue orb of Neptune, named for the Roman god of the sea, is the eighth and farthest planet in our solar system from the sun. This honor used to reside with Pluto until it was demoted from planet status by the International Astronomical Union. Neptune's equator is four times as long as Earth's. It is 17 times as heavy, though not as dense. We have one moon, while Neptune has 13. And now, thanks to the Voyager 2 spacecraft and the Hubble Space Telescope, we can see Neptune as never before.
Hubble captures dynamic atmosphere
Neptune is one of two planets not visible to Earth by the naked eye. This is perhaps the main reason why it was the first planet to be discovered by mathematical prediction. It was separately discovered in the mid-19th century by English astronomer John C. Adams and French mathematician Urbain Le Verrier. The planet is covered by thick clouds that move rapidly. NASA reports that Neptune's winds move at speeds up to 700 mph. This color-enhanced photo taken by the Hubble telescope in 2005 shows Neptune as never seen before.
HurricanesHere two great hurricanes can be seen spinning on Neptune's surface. This photo was taken in August 1989 by Voyager 2, the only spacecraft to travel to Neptune. The Great Dark Spot is seen to the north, while Great Spot 2, with its white center, is more to the south. The white clouds in between were nicknamed "The Scooter" by NASA. The storms were thought to be swirling masses of gases similar to hurricanes on Earth. But when Hubble turned its telescope on Neptune in 1994, the storms had disappeared.
On Triton's horizonVoyager 2 generated this computer image of Neptune as seen from its moon, Triton. Triton is Neptune's largest satellite and is the only moon in the solar system to orbit opposite of its planet. Experts believe that Triton may have been a large comet that orbited the sun but got caught in Neptune's gravitational pull. Triton boasts the coldest known temperatures in the solar system, at minus 390 degrees F (that's minus 235 degrees C). NASA has discovered evidence of ammonia and water volcanoes on Triton.
Crescents of Triton and Neptune
When Voyager 2 took this image, it "was plunging southward at an angle of 48 degrees to the plane of the ecliptic," according to NASA. Besides its 11 satellites, Neptune also boasts a planetary ring system. The three main rings are named for Neptune's first researchers, the Adams ring, the La Verrier ring and the Galle ring. But recent evidence shows that the rings are unstable and may be deteriorating in spots.
Great Dark SpotVoyager 2 took this photo of Neptune's gigantic anti-cyclonic storm in 1989. Considered to be much like Jupiter's Red Spot, the storm was thought to span 8,000 by 4,100 miles. It was believed to have a vortex structure. When Hubble turned its lens on Neptune in 1994, the Great Dark Spot was found to have vanished. A new storm just like it was found roaming the northern hemisphere of the planet.
Mosaic of TritonThis global color mosaic of Triton was taken by Voyager 2 in 1989. Like Earth, Triton is thought to have a nitrogen-rich atmosphere, and it is the only satellite in the solar system that has a nitrogen ice surface. The blue-green band across Triton is thought to be nitrogen frost, while the pink is thought to be methane ice.
CloudsVoyager 2 took this image of Neptune in 1989, two hours before it made its closest approach to the planet. Neptune's surface is not like Earth's. While these thick clouds cover the surface, the interior of the planet is made up of heavy, compressed gases. Its core is composed of rock and ice. What does the future hold for Neptune and its moons? In 2005, a team of researchers backed by NASA came up with a plan to land a team of explorers on Triton.
FACTS ABOUT NEPTUNE:
Neptune May Be a Giant Diamond and Oil Factory.
Like Saturn, Neptune Has Rings.
It Would Take a Long Time to Get to NeptuneIf There Were Radio Stations on Neptune, the Reception Would Be Pretty Bad.
Neptune Has Really, Really Nasty Weather.
Nobody Knows Why Neptune Is Such a Vivid Shade of Blue.
Neptune Has a Lot of Moons.
In Certain Regions of Neptune, the Length of the Day Varies by as Much as Six Hours.
A Year on Neptune Is a Long Time.
Neptune Almost Was Named "Le Verrier.“
Neptune Has Really, Really Nasty Weather.
Nobody Knows Why Neptune Is Such a Vivid Shade of Blue.
Launched in 1973, Voyager 2, actually sixteen days before the Voyager 1, the probe passed by Jupiter, Saturn, and Uranus, finally reaching Neptune twelve years after its launch. Some of the most important Neptunian discoveries of Voyager 2 are: Neptune's highly inclined
magnetosphere Six satellites (moons) Auroral zones.Two new rings circling the planet Storms were discovered, particularly the Great Dark Spot.
Ricardo Abapo