APOD: Two Hours Before Neptune (2010 Aug 08)

[APOD Robot]

Two Hours Before Neptune

Explanation: Two hours before closest approach to Neptune in 1989, the Voyager 2 robot spacecraft snapped this picture. Clearly visible for the first time were long light-colored cirrus-type clouds floating high in Neptune's atmosphere. Shadows of these clouds can even be seen on lower cloud decks. Most of Neptune's atmosphere is made of hydrogen and helium, which is invisible. Neptune's blue color therefore comes from smaller amounts of atmospheric methane, which preferentially absorbs red light. Neptune has the fastest winds in the Solar System, with gusts reaching 2000 kilometers per hour. Speculation holds that diamonds may be created in the dense hot conditions that exist under the cloud tops of Uranus and Neptune.

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[garrymaxfield]

How can the atmosphere of Neptune be dense and hot being so far away from the Sun? What is the current theory of how the heat is generated? Obviously there has been no probe to exactly measure the temperature so this must be speculation.

Garry Maxfield

[orin stepanek]

Nice serene movie of Neptune! http://www.youtube.com/watch?v=PSJub1A1aIk
I'd like to see a probe dropped on Neptune to learn more about it. 2000 km wind gusts must suggest pressure differentials on the planet.

[rstevenson]

How can the atmosphere of Neptune be dense and hot being so far away from the Sun? What is the current theory of how the heat is generated? Obviously there has been no probe to exactly measure the temperature so this must be speculation.

Being far from the sun is not, apparently, inconsistent with being hot. Here's a quote from the Wikipedia article about the planet...

Because of its great distance from the Sun, Neptune's outer atmosphere is one of the coldest places in the Solar System, with temperatures at its cloud tops approaching −218 °C (55 K). Temperatures at the planet's centre, however, are approximately 5,400 K (5,000 °C).

There is a section further down that Wiki entry regarding Neptune's Internal Heat which states that the exact reason is not known, but there are theories.

Rob

[neufer]

Nice serene movie of Neptune! http://www.youtube.com/watch?v=PSJub1A1aIk

I'd like to see a probe dropped on Neptune to learn more about it.

I'd liketh to see a Probst droppest on Neptune to learneth more about it.

[Ann]

Ah, Neptune, the blue planet! Of course, it is no match for the blue planet!



Art???? Am (Bist???) I just stupidest or ignorantest?

Ann

[León]

That sample provided by the solar system, planets and satellites with unique and unrepeatable, like each of us, with its mysteries and secrets, as following a cosmic law which prevents repeated and at the same time maintain an individuality incompatible.

Neptune is in retreat against all logic to allow the approach of Uranus, in the near-surface winds protects your privacy, and keeps in his heart who knows how many other relics for knowledge as our oceans are still in reserve depths held by the same god.



The heat from the depths is a remnant, I would say old star, who has also captured a satellite, Triton, which is characteristic of a planet with retrograde orbits and geologically active.

[rstevenson]

Must every thread descend into banter? Is that what the Asterisk is becoming -- a sand box for the slightly silly?

Rob

[neufer]

The heat from the depths is a remnant, I would say old star, who has also captured a satellite,
Triton, which is characteristic of a planet with retrograde orbits and geologically active.

<<Triton (Τρίτων) is a mythological Greek god, the messenger of the sea. He is the son of Poseidon, god of the sea, and Amphitrite, goddess of the sea, whose herald he is. He is usually represented as a merman, having the upper body of a human and the tail of a fish, "sea-hued", according to Ovid "his shoulders barnacled with sea-shells". Like his father, Poseidon, he carried a trident. However, Triton's special attribute was a twisted conch shell, on which he blew like a trumpet to calm or raise the waves. Its sound was so terrible, that when loudly blown, it put the giants to flight, who imagined it to be the roar of a mighty wild beast. A family of large sea snails, the shells of some of which have been used as trumpets since antiquity, are commonly known as "tritons."

According to Hesiod's Theogony, Triton dwelt with his parents in a golden palace in the depths of the sea; Homer places his seat in the waters off Aegae. The story of the Argonauts places his home on the coast of Libya. When the Argo was driven ashore in the Gulf of Syrtes Minor, the crew carried the vessel to the "Tritonian Lake", Lake Tritonis, whence Triton, the local deity euhemeristically rationalized by Diodorus Siculus as "then ruler over Libya", welcomed them with a guest-gift of a clod of earth and guided them through the lake's marshy outlet back to the Mediterranean.

Triton was the father of Pallas and foster parent to the goddess Athena. Pallas was killed by Athena during a fight between the two goddesses. Triton is also sometimes cited as the father of Scylla by Lamia. Triton can sometimes be multiplied into a host of Tritones, daimones of the sea.
...................................................

<<During an episode of Survivor: Prehistoric Ethiopia, the contestants from the "Oooga" tribe were pitted against the "Booga" tribe in a footrace. In order to attain victory, and create an unfair advantage, the "Oooga" tribe conspired to destroy the village of the "Booga" tribe. Seconds before the raid on the village, a trumpet was played by Survivor host Jeff Probst. The "Oooga" tribe was given kerosene and matches, created the first controlled fire, and won immunity.>>

...................................................
In Wordsworth's sonnet "The World Is Too Much with Us" (ca 1802), the poet regrets the prosaic humdrum modern world, yearning for

• glimpses that would make me less forlorn;
  Have sight of Proteus rising from the sea;
  Or hear old Triton blow his wreathèd horn.

The name Triton is associated in modern industry with tough hard-wearing machines such as the Ford Triton engine and Mitsubishi Triton pickup truck. In a new SpongeBob SquarePants special, Spongebob releases him from a cage and Triton attacks Bikini Bottom.>>

The Triton Fountain by Gian Lorenzo Bernini, in Piazza Barberini, Rome The fountain has a base of four dolphins that entwine the papal tiara with crossed keys and the heraldic Barberini bees in their scaly tails.

---

<<The Triton Fountain (Italian Fontana del Tritone) is a 17th century fountain in Rome, by the well-known Baroque sculptor Gian Lorenzo Bernini. Commissioned by his patron, Pope Urban VIII, the fountain is located in the Piazza Barberini, near the entrance to the Palazzo Barberini. The Triton Fountain is one of those evoked in Ottorino Respighi's Fontane di Roma.

The fountain was executed in travertine in 1642–43. At its centre rises an larger than lifesize muscular Triton, a minor sea god of ancient Greco-Roman legend, depicted as a merman kneeling on the sum of four dolphin tailfins. His head is thrown back and his arms raise a conch to his lips; from it a jet of water spurts, formerly rising dramatically higher than it does today.

The Tritone, the first of Bernini's free-standing urban fountains, was erected to provide water from the Acqua Felice aqueduct which Urban had restored, in a dramatic celebration. It was Bernini's last major commission from his great patron who died in 1644. At the Triton Fountain, Urban and Bernini brought the idea of a sculptural fountain, familiar from villa gardens, decisively to a public urban setting for the first time; previous public fountains in the city of Rome had been passive basins for the reception of public water.

Bernini has represented the triton to illustrate the triumphant passage from Ovid's Metamorphoses book I, evoking godlike control over the waters and describing the draining away of the Universal Deluge. The passage that Urban set Bernini to illustrate, was well-known to all literate Roman contemporaries:

He called Tryton to him straight, his trumpetter, who stoode
In purple robe on shoulder cast, aloft upon the floode, ...
And bade him take his sounding Trumpe and out of hand to blow
Retreat, that all the streames might heare, and cease from thence to flow.
He tooke his Trumpet in his hand, hys Trumpet was a shell
Of some great Whelke or other fishe, in facion like a Bell
That gathered narrow to the mouth, and as it did descende
Did waxe more wide and writhen still, downe to the nether ende:
When that this Trumpe amid the Sea was set to Trytons mouth,
He blew so loude that all the streames both East, West, North and South,
Might easly heare him blow retreate, and all that heard the sounde
Immediatly began to ebbe and draw within their bounde.
Then gan the Sea to have a shore, and brookes to finde a banke,
And swelling streames of flowing flouds within hir chanels sanke.
Then hils did rise above the waves that had them overflow,
And as the waters did decrease the ground did seeme to grow.
And after long and tedious time the trees did shew their tops
All bare, save that upon the boughes the mud did hang in knops.
— free translation by Edward de Vere>>

[Ann]

Rob, thank you for posting that link to possible causes for the internal heat of Neptune. If you can put up with my silliness, I must confess that I have a particularly soft spot for Neptune because of its blue color (well, I'm not called the Color Commentator for nothing). Favoring a planet because of its color is silly, but I'm truly interested in why Neptune produces so much heat, too. It's definitely good to be serious during discussions of astronomy, but I hope you can put up with a bit of silliness, too. To me the threads that mix seriousness with a bit of jokes are the best.

Thank you for standing up for the seriousness that we need and reminding us of the unanswered questions out there, Rob.

Ann

[biddie67]

I was fascinated by the delicate blue color of Neptune also. And then how could the core be so hot as suggested? Leon's suggestion of an ancient star remnant encased inside is interesting - what a possibility to explore by more probes (( not of the Probst-kind - altho' possibly he should experience some of his show's challenges to prove his worth )).

But back to Big Blue, it seems quite possible, that on Neptune, diamonds aren't for forever.

[neufer]

I was fascinated by the delicate blue color of Neptune also.

The Planetary Society Blog By Emily Lakdawalla
Dec. 31, 2009 | 10:06 PST | 18:06 UTC

Uranus (left) _&_ Neptune (right)

The images for these two color composites were obtained by the same spacecraft through the same sets
of filters and processed in the same way, so should accurately represent the relative colors of Uranus
and Neptune at the times that Voyager 2 passed by them. Credit: NASA / JPL / Bjorn Jonsson

<<Really, [Uranus & Neptune} are VERy, VERy similar. We don't have
one blue-green world and one blue one, as the two are so often depicted.
They're pretty much the same METHANE BLUE;
Uranus just had more high haze, making it whiter (not greener) than Neptune.
Now that the Uranian equinox is past and atmospheric circulation is producing storms
I'll bet they'd look even more similar from up close.>>

Click to play embedded YouTube video.

[mexhunter]

Title: Little Symphony for One Wind Instrument.
There is no best trumpet player in the world. However, everyone has Their own styles.
Regards
Cesar

[Don Lund]

What's all this blue stuff?? When I looked at Neptune many moons ago through my Skyscope, it was greenish.

[Chris Peterson]

What's all this blue stuff?? When I looked at Neptune many moons ago through my Skyscope, it was greenish.

Your eyes are more sensitive to green light than blue. So astronomical targets that are just bright enough to stimulate color vision often look green. As they get brighter, their "true" hue starts being apparent. This is why very red objects like the Orion nebula appear green to the eye of those with sensitive enough vision to see any color at all.

[neufer]

The "happy face" Martian crater is named for J.G. Galle.

<<Johann Gottfried Galle (9 June 1812 – 10 July 1910) was a German astronomer at the Berlin Observatory who, with the assistance of student Heinrich Louis d'Arrest, was the first person to view the planet Neptune, and know what he was looking at (23 September 1846). He used the calculations of Urbain Le Verrier to know where to look. Born in Radis, Galle started to work as an assistant to Johann Franz Encke in 1835 immediately following the completion of the Berlin observatory.

Galle's Ph.D. thesis, finished in the year of 1845, was a reduction and critical discussion of Ole Rømer's observation of meridian transits of stars and planets on the days from 20 October to 23 October 1706. Around 1845 he sent a copy of his thesis to Urbain Le Verrier, but only received an answer a year later on 18 September 1846. It reached Galle on 23 September and in it Le Verrier asked him to look at a certain region of sky to find a predicted new planet, which would explain the perturbations of the planet Uranus. The same night, after Encke gave him the permission against his own judgment, an object fitting the description was found, and it was confirmed as being a planet over the next two evenings.

In 1851 he moved to Breslau to become professor of astronomy and the director of the local observatory. Throughout his career he studied comets, and in 1894 (with the help of his son Andreas Galle) he published a list with 414 comets. He died in Potsdam at age 98. The asteroid 2097 Galle, and a ring of Neptune, have been named in his honor.>>