| Neptune | |
| Facts: Mass: 2.27 x 1026 lbs. Diameter: 30, 775 miles Mean Density: 102 lbs./ ft 3 Escape Velocity: 52,600 mph Average distance from sun: 2,794 million miles Rotation period: 16 Earth hours Revolution period: 165 Earth years Mean temperature: -370 F Atmospheric components: 79 % Hydrogen, 18% Helium, 3% Methane Rings: There are six rings that surround Neptune. They are narrow and contain concentrations of particles called ring arcs. |
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Within a century of Uranus’ discovery scientists
began to realize that the predicted orbit did not match up with the actual
orbit. Two astronomers named John Couch Adams and Urban Leverrier independently
calculated that in order for Uranus to have the orbit currently observed
something would have to be acting on it. That “something” was believed to
be another planet beyond Uranus. Leverrier ended up getting a German astronomer
named Johann Galle at the Berlin Observatory to examine the night sky for
such a planet. This was done in the fall of 1846. The first night Galle examined
the night sky the new planet had been discovered. Neptune is named for the God of the Sea. It is colored by the methane gas in its atmosphere (just like Uranus), which causes it to appear blue. Neptune, however, is not covered up by a thick haze but contains a rather incredibly diverse atmosphere. Of the four gas giants, it is the most distant from the sun |
| In 1982, Voyager 2 flew past Neptune and captured
images of a dark blue spot in its atmosphere. It was named the Great Dark
Spot. Roughly the size of the Pacific Ocean, scientists believe that it was
once a giant storm system that created a “hole” in Neptune’s upper clouds.
This would allow us to peer even further into the planet’s atmosphere where
we would see darker blue clouds. Neptune’s Great Dark Spot is a storm in
the planet’s atmosphere similar to Jupiter’s Great Red Spot. Voyager 2 also discovered what came to be known as the Small Dark Spot, Wizard’s Eye, and the Scooter. The Wizard’s Eye got its name from the white clouds made of methane ice crystals that appear similar to the cirrus clouds found here on Earth. Another white cloud was given the name of the Scooter because it traveled around Neptune at a faster speed than any other cloud observed on the planet. Voyager also discovered blizzards of frozen natural gas. They’re made up of enormous clouds of methane ice crystals that stretch for thousands of miles. |
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New images from the Palomar Mountain Observatory
reveal a massive cloud about the size of Europe, as well as several smaller
clouds. With these new images, scientists will be able to determine the composition
and altitude of the clouds. Neptune holds the title for the fastest winds
in the solar system. Neptune’s jet streams clock in at 1,400 miles per hour,
which is 400 more than Saturn, which comes in second place, and Jupiter as
well at 300 miles per hour. When the Hubble Space Telescope (HST) was finally refurbished in 1994 it gave astronomers here on Earth some close-up views of Neptune. What it showed was amazing. Since the last Voyager 2mission in 1989 the Great Dark Spot had disappeared from the planets Northern Hemisphere but a new, immense dark storm had emerged in the Southern Hemisphere. Not only that but the Wizard’s Eye and the Scooter had also vanished! What Hubble Space Telescope showed astronomers was that Neptune could undergo dramatic changes, in some cases in as little as a few weeks. |
| It is believed that Galileo may have been the first
discoverer of Neptune. In his notebooks he sketched Jupiter and its four
largest satellites along with what he thought was a star. Had he observed
the “star” more attentively he would have recognized that it moved from night
to night. Galileo would have discovered the eighth planet before ever discovering
the seventh. Neptune has so far eight identified moons and
has six dark rings. Triton, it’s the largest moon, orbits the planet clockwise.
It orbits opposite to all the sun's planets and all the major moons as well.
There is however, a possible explanation for this. Triton was once captured
by the gravity of Neptune when it came to close. The varying landscape of
Triton makes it a very intriguing moon. The components of Triton are rock
and ice. Its surface has large amounts of frozen water including frozen
lakes that measure up to 300 miles across, dry ice, methane, nitrogen, and
carbon monoxide. It also contains valleys of ice criss crossing past cratered
terrain and an entire hemisphere appearing so weird that scientists have
referred to it as the “cantaloupe terrain”. |
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In the moon’s opposite hemisphere there are dark
streaks that are several miles long. These dark streaks were later discovered
to be geysers blasting nitrogen at least 8 miles into the sky. The strong
winds later cover the landscape in long black streaks.
Triton is the coldest place known in our solar system with a temperature around –400 F. Its icy surface also reflects more than 90 percent of the sun light that reaches it, which makes it also one of the brightest spots in the solar system. |