Norii de pe Saturn

[Dreamy]

Tehnica LANTERNEI CHINEZESTI ajuta la urmarirea norilor de pe Saturn

   In imagine: Planeta Saturn - Se poate observa la poli aurora. (Foto: Hubble/NASA)

O noua imagine a planetei Saturn demonstreaza o tehnica ce creaza efectul "lanternei chinezesti", aratand silueta norilor lui Saturn in contrast cu interiorul cald. Vazut astfel, interiorul lui Saturn arata o activitate surprinzatoare cuprinzand o larga varietate de nori de diferite marimi si forme.

Deoarece norii din nivelele superioare acopera acesti nori in lumina vizibila, redarea de imagini cu norii de pe Saturn nu este posibil cu ajutorul camerelor care au nevoie de lumina pentru a captura imagini. Cateva imagini capturate de Cassini cu ajutorul spectrometrului visual si infrarosu au fost combinate astfel incat sa evidentieze norii mai aproape de suprafata planetei pe fondul radiatei generate de interiorul lui Saturn. Literalmente, acest procedeu "aprinde" planeta din interior spre exterior ca o lanterna.
Norii din emisfera nordica a lui Saturn sunt ceva mai subtiri decat cei din emisfera sudica. Se crede ca acesta este un efect de anotimp; idea va fi testata cand va veni primavera peste cativa ani in emisfera nordica.

Partile colorate in rosu aprins indica zone care nu prezinta nori josi sau particule, in timp ce zonele de un rosu mai inchis sunt mai innorate.

Sursa: NASA/Jet Propulsion Laboratory 

P.S. ce crezi Ciuciulete... am vreo sansa cu telescopul meu sa vad asa ceva???  :roll:

[DepthOfField]

P.S. ce crezi Ciuciulete... am vreo sansa cu telescopul meu sa vad asa ceva??

numai daca telescopul tau este Hubble... :evil:
Eu am vazut si fotografiat ceva similar ca in atasament (nu dispun de pozele originale acum), cu o improvizatie de binoclu, lentile foto, tuburi si camera web cu obiectivul scos (evident si PC) plus scaun si alte obiecte de sprijin plus ceva contorsionistica si muuulta rabdare  :-D (mai ales ca la mariri mari, o sa observi, obiectul vizat fuge repede din vizor....datorita rotatiei Pamantului).
Totusi, inelele lui Saturn, chiar si asa, au fost o experienta deosebita pt mine atunci cand le-am vazut pt prima data (inainte de faza cu web-camul) si nu ma asteptam sa le pot vedea. Si pentru tine va fi la fel. Din pacate, telescopul va trebui folosit .. afara, fie cat de frig, pentru ca prin geamul ferestrei vei distorsiona imaginile. In perioada asta poti incerca sa vezi Saturn dimineata inainte de a se ilumina, Saturn fiind undeva spre sud-est pe la 50..60 grade inaltime fata de orizont.. si luna, restul planetelor fiind cam absente in perioada asta a anului. Poti incerca si petele solare, dar ATENTIE, numai daca stii sa te protejezi de lumina solara. daca nu, las-o balta cu soarele!!, ca poti orbi, mai ales cu telescoapele astea!

[maya]

chiar vazand poza asta cu Saturn m-am gandit ca si Saturn, Jupiter etc, ar avea un Soare Central care sa le creeze efectul de aurora...de ce nu? ca doar sistemele astea sunt in esenta fractali... :roll:
De ce nu se spune nimic(de "savanti") despre gigantica structura artificiala care orbiteaza in jurul Terei si creeaza efectul de Curcubeu?
Ne tot indoapa cu "explicatii stiintifice" multe fara justificari reale...

[Dreamy]

Salut Ciuciulete!!

Multam mult pentru toate informatiile pe care mi le-ai dat....iti imaginezi ca deja sunt "abonata" pe situl Observatorului Astronomic...sorb fiecare stire astronomica..
Ce ma surprisns cel mai mult la observatiile facute pana acum prin telescop este viteza uluitoare cu care se invarte Pamantul...ai scris si tu chestia asta undeva pe un topic, incredibil cat de repede dispar astrele din obicetiv si cat de putin percepem cu ochiul liber miscarea de rotatie ...
Cat despre Soare, stiu ca este fff periculos, am observat ca totusi telescopul are dispozitivele necesare de protectie in cazul observatiei solare...inca nu am incercat...nici n-am avut ocazia...dimineata la job cand ajung deja e seara.. :|
Cat despre observatia prin geam...deja sunt racita din cauza geamului deschis :cry:..insa MERITA sacrificiul. :-D
Abia astept sa am ocazia sa-l pun la treaba undeva in afara orasului, unde influentele luminilor din oras nu ajung...poate am ocazia sa prind un fenomen Iridium Flare.
Multumesc inca o data si sigur o sa va tin la curent cu observatiile.
Apropos ai ideepe ce data in Decembrie se vad Perseidele...am auzit ca sunt mult mai spectaculoase decat cele din vara.

[DepthOfField]

Dreamy a spus:

Multumesc inca o data si sigur o sa va tin la curent cu observatiile.

Pentru a nu fi off-topici fata de subiectele curente, poate e bine sa creezi un topic nou, (de exemplu: "astronomie - experiente personale" sau ceva de genul asta)  :wink:

Maya a spus:

De ce nu se spune nimic(de "savanti") despre gigantica structura artificiala care orbiteaza in jurul Terei si creeaza efectul de Curcubeu?

nu stiam despre asta, e vre-un topic pe aici in acest sens?! (apropo: curcubeu poti crea si tu in camera cu o sursa de lumina si o prizma de sticla)

Ne tot indoapa cu "explicatii stiintifice" multe fara justificari reale...

cred ca e destul de departe de a fi astfel. De cele mai multe ori pur si simplu noi, nespecialistii, nu intelegem mare lucru din explicatiile stiintifice, caci nu-i nici unul dintre noi sa le stie pe toate.

legat de topic, omenirea are de vreo 2 ani o sonda automata in misiune pe orbita in jurul lui Saturn, misiunea Cassini-Huygens, care trimite informatii si imagini spectaculoase si in premiera de acolo. (plus ca a si trimis o mini-sonda sa aterizeze pe suprafata inghetata (-170 grade) a satelitului Titan, de unde a transmis imagini in premiera pana sa inghete definitiv in atmosfera inospitaliera (mi se pare ca sonda fiind mai "calduta", a topit metanul solidificat pe care aterizase, si gazele expulzate au defectat-o rapid - oricum nu fusese proiectata sa reziste unor asemenea conditii). Detalii si imagini ale misiunii inca in desfasurare aici: http://saturn.jpl.nasa.gov/home/index.cfm  (iar direct sectiunea de imagini aici: http://saturn.jpl.nasa.gov/multimedia/images/index.cfm)

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency.

[DepthOfField]

spuneam in postul anterior de misiunea Cassini-Huygens ..
azi pe "Astronomy Picture of the Day " au dat o imagine (si film!) despre norii de pe Saturn..de fapt un urias ciclon, probabil prezent acolo de milioane de ani, si de o diomensiune mai mare decat TERRA noastra....

Explanation: What's happening at the south pole of Saturn? To find out, scientists sent the robot Cassini probe now orbiting Saturn directly over the lower spin axis of the ringed giant. Cassini found there a spectacular massive swirling storm system with a well developed eye-wall, similar to a hurricane here on Earth. One image of the storm is shown above, while several frames from the overpass have been made into a movie that shows the huge vortex rotating. The storm is slightly larger than the entire Earth and carries winds that reach 550 kilometers per hour, twice the velocity of a Category 5 hurricane. This pole vortex on Saturn might have been raging for billions of years and is not expected to drift off the pole.

poza aici: http://antwrp.gsfc.nasa.gov/apod/ap061113.html
iar mai multe poze distantate in timp si adunate intr-un fiilmulet, aici: http://ciclops.org/media/ir/2006/2313_6310_4.mpg

[sxn_b]

Primul uragan de pe Saturn
Vineri 10 Noiembrie 2006
Un fenomen neobiºnuit are loc în aceste zile pe planeta Saturn. Este vorba despre o furtunã, prima de acest fel detectatã vreodatã de pe Pãmânt. Furtuna are dimensiuni gigant de 8.000 de km.
Uraganul este foarte diferit de cele care au loc pe planeta noastrã. Rafalele de vânt depãºesc 350 de km pe orã, iar centrul ciclonului este foarte bine definit fiind mãrginit de nori care se desfãºoarã pe o înãlþime de 75 de km, aproximativ de 5 ori mai mult decât norii uraganelor terestre. Se pare cã spirala descrisã de ciclon este cãt douã treimi din suprafaþa totalã a planetei noastre. Cercetãtorii au declarat cã, deºi aratã ca un uragan, se comportã diferit. Furtuna pare sã se fi oprit chiar deasupra polului sud al planetei, acolo unde este cel mai cald ºi unde atmosfera este puternic rarefiatã. Ea nu se deplaseazã aºa cum s-ar întampla pe Terra.
O altã premierã constã în faptul cã furtunile care au loc pe alte planete ale sistemului solar nu au acel ochi specific perturbaþiilor terestre. Prezenþa acelei deschideri reprezintã pentru cercetãtori o fereastrã prin care se pot apropia mai mult de suprafaþa planetei Saturn. E greu sã ne imaginam ce s-ar fi întâmplat dacã un asemenea turbion s-ar fi format în atmosfera terestrã. Pare mai degrabã un scenariu science fiction.
Sursa:http://www.realitatea.net/23337_Primul-uragan-de-pe-Saturn-.html

[Dreamy]

Misiunea de cercetare Cassini-Huygens a descoperit recent un un masiv lant muntos pe Titan, satelitul natural a lui Saturn!!
Mai multe informatii puteti afla pe:
http://saturn.jpl.nasa.gov/news/press-release-details.cfm?newsID=709

[Dreamy]

Existenta unor lacuri si oceane de metan lichid pe Titan, luna lui Saturn, a fost prezisa cu 20 de ani in urma. Insa nu s-a reusit confirmarea lor, asta pana pe 22 iulie 2006, cand prin dreptul lui Titan a trecut sonda Cassini.

Imaginile radar luate de Cassini dovedesc prezenta unor largi mase de lichid. Intensitatea din imaginea colorata este proportionala cu luminozitatea intoarsa de radar. Culorile nu sunt o imagine a ceea ce ar vedea ochiul uman.

Lacurile, care apar mai intunecate decat terenul din jur, sunt accentuate de regiunile slab colorate din jurul lor. Regiunile care apar luminoase pe radar sunt de culoare cafenie in imagine. Aceasta imagine a fost facuta de instrumentele sondei Cassini pe 22 iulie, 2006. Imaginea este centrata la aproximativ 80 de grade nord, 35 de grade vest si cuprinde o arie de 140 de kilometri.

Sursa: NASA/Jet Propulsion Laboratory

[pri3st3ss]

nu e o imagine surprinsa de SPITZER sau HUBBLE, ci de Cassini, insa ramane  la fel de frumoasa...



"The Cassini probe has imaged a huge cloud system covering the north pole of Titan, Saturn's largest moon. Is it from such clouds that methane "rain" falls on to the surface of Titan? Cassini has already spotted lakes that appear to be filled with liquid hydrocarbons like methane and ethane."

[pri3st3ss]

nu e despre saturn.....

Martian moon 'could be key test'

(fig 1   Image: Esa/DLR/FU Berlin/G.Neukum)

Mars' moon Phobos could be the target for a technology trial that would seek to return rock samples to Earth.
A UK team is developing a concept mission that aims to land a spacecraft on the potato-shaped object and grab material off its surface.
These small rock fragments would then be despatched to Earth in a capsule.
"It is being seen as a technological demonstrator for an eventual Mars sample return," said Dr Andrew Ball from the Open University.
Those aspects of the mission that worked well could be incorporated into a full-scale assault on the Red Planet.
Both Europe and the US have made the objective of bringing back Martian rocks to Earth laboratories a top priority for their space programmes. A joint venture is likely to occur within the next 15-20 years.
But getting on and off a large planet will be extremely difficult, and the British satellite manufacturer Astrium is proposing to test the required technologies on the low-gravity target of Phobos first.
"It would be a three-year mission. We're looking at a 2016 launch," said Marie-Claire Perkinson, a principal mission systems engineer at the Stevenage company.

Many links

Even so, the Phobos concept has a number of challenging steps, all of them capable of killing the mission if a single element goes wrong.
It is envisaged that a "mothership", powered by an ion engine, would fly into orbit around Mars where it would release a lander craft down on to the surface of the moon.
This robot vehicle might do some in-situ experiments but its main task would be to core, drill, or scoop up surface "soil" into a sealed vessel.
Then, it would lift off from Phobos using chemical thrusters to attempt to dock with, or be captured by, the passing mothership. If that succeeds, the sample vessel would be transferred across and packaged inside an additional bio-secure sealed-container ready for the trip home.
Close to Earth, this capsule would be jettisoned into the atmosphere to make a hard landing; it would need no parachute assistance.
"It's really the sample transfer chain which is the critical issue - right from landing on Phobos and taking the sample, and then passing it through the various vehicles to return to Earth," explained Ms Perkinson.
"It's challenging because it requires a lot of new technology development, and it's reliant on a lot of mechanisms, which is something we usually try to avoid."  ( fig 2 )



The concept is being considered by the European Space Agency (Esa) under its Aurora programme for Solar System exploration.

Already approved and in development is a robot rover that will trundle across the surface of the Red Planet to look for signs of past or present life; and Astrium is working on the vehicle's chassis. (The Aurora programme is committed to a rover project)
A precursor Mars-sample-return mission could get the go-ahead from Esa in the next couple of years. French industry is interested in leading this project and is preparing its own, competing concept.
Whoever is chosen may well have to watch the Russians give it a go first. They are currently working on a project known as Phobos-Grunt, which could fly as early as 2009.
But leading out of the box is not a guarantee of success. Getting down on to a small low-gravity body has its own difficulties. The wrong approach could crush landing legs or even result in the vehicle bouncing straight back off into space.
Such problems were amply demonstrated by the recent Japanese attempts to grab samples off the surface of an asteroid.
It is still not clear whether the Hayabusa spacecraft managed to capture any material and the probe's return to Earth is still haunted by uncertainty.

Moon 'death' ( fig 3)

For Dr Ball, a consultant on the Astrium proposal, Phobos represents a fascinating subject for study in its own right, over and above any eventual objective of getting down to the surface of the Red Planet.
The moon, like its sister Deimos, is asteroid-like in appearance - in fact, these two satellites are very probably "primitive" asteroids that were captured into Mars' orbit by its gravity.

Close study should also refine estimates for the expected "death" of Phobos. Its orbit around Mars is shrinking and in a few tens of millions of years it will either fall on to the planet or, more likely, shatter under tidal forces into countless pieces and form a ring.

One of the moon's most notable features is the system of grooves that cross its surface. These are assumed to be the result of collisions with rocks blasted off the surface of Mars by space impacts.

This raises the intriguing prospect that Phobos may actually be littered with Martian material.
"So, with this mission, you could get two for one," said Dr Ball.
"When there's a large impact on Mars, ejecta-debris gets thrown up, and some of that can hit Phobos. Over billions of years, Phobos should have accumulated some fraction of Martian soil in its surface.

"In doing this mission, we'd not only be demonstrating many of the technologies required for a Mars sample return, but we may even get some Martian material itself."

The size of the Phobos sample would not need to be very large.
Some 200g would be enough to keep current astro-labs busy and have a portion in reserve for future analysis using yet-to-be developed techniques - a standard approach when dealing with scarce extra-terrestrial material.


pt fig 2:
(1) The spacecraft could leave in 2016 when Earth and Mars are in a favourable alignment, reducing the mission length to three years
(2) Cruise phase would use a solar-electric engine. This relies on solar power to accelerate xenon ions to produce forward thrust
(3) The mothership would go into orbit around Mars; the lander would be ejected to make its own way down to the surface of Phobos
(4) The lander could do some in-situ experiments, but its primary objective would be to package away surface material
(5) After lift-off, the lander would dock with, or be captured by, the mothership - a key test for Mars sample return technology
(6) The Phobos samples will be transferred to a sealed and bio-secure re-entry capsule for the journey home:
(7) After ejection and Earth re-entry, the capsule would crash-land; no parachute would be used to slow its fall

pt fig 3
Measures 27 x 22 x 18km; could be a captured asteroid
Orbits less than 6,000km above Mars; slowly falling inwards
First high-res probe images taken by Mariner 7 in 1971
Dedicated Soviet probes, Phobos 1 & 2, failed en route
10km-wide Stickney crater (above) records huge impact


sursa : http://news.bbc.co.uk/

[pri3st3ss]

Saturn moon's cosmic graffiti art


Saturn's moon Enceladus is a "cosmic graffiti artist", with geysers which spray out material that eventually settles over other satellites.
Hubble Space Telescope observations show how material from Enceladus alters the appearance of its neighbours.
One of Saturn's rings - the E ring - is largely made up of icy material from Enceladus' volcanic plumes.
These particles then collide with other moons that orbit within the E ring, coating their surfaces with material.
Anne Verbiscer from the University of Virginia and colleagues measured the reflectivity, or "albedo" of the saturnian satellites.
They concluded that interactions with E ring particles, ultimately from Enceladus' plumes, produced high albedos on the moons Tethys, Mimas, Dione and Rhea.
With a diameter of 500km (310 miles), Enceladus is a relatively small moon.
"Inevitably, material from Enceladus impacts all satellites orbiting within the E ring, enhancing their albedos at the hands of a diminutive giant," the researchers write in Science.
Enceladus is thought to have reservoirs of near-surface liquid water that erupt to form geysers.
These jets have been observed erupting from a "hot spot" in the moon's south polar region.
"We knew the E ring had a considerable extent from Mimas to beyond Tethys. So naturally, satellites orbiting within there are going to get coatings of this icy material," said Professor Carl Murray, from Queen Mary in London, who was not an author on the Science paper.
Prof Murray, who is a co-investigator on the Cassini-Huygens mission, added: "Anything more we can find out about the E ring is important because it is the material that came from under the surface of Enceladus. We believe there is a source of liquid water under the surface."

The Cassini spacecraft reached Saturn in July 2004 to study the planet, its rings and its moons.
On a flyby of Enceladus, it was able to sample and analyse material ejected by the south polar volcanic plume.

-The heat emission is associated with the tiger stripe features which mark the southern pole. The temperatures are in Kelvin (zero K equals -273C)

sursa:  http://news.bbc.co.uk/
mai multe si aici :   http://news.bbc.co.uk/2/shared/spl/hi/sci_nat/04/cassini/html/introduction.stm

[sxn_b]

Nava spaþialã Cassini a descoperit un nou inel în jurul planetei Saturn. Cercul este subtil ºi are ca marcã distinctã o cruce neagrã. Se pare cã noul inel a apãrut în urma impactului unui meteorit care a lovit suprafaþa a douã luni saturniene. Lunile Janus ºi Epimetheus sunt prea mici pentru a putea susþine praful produs de explozia meteoritului, de aceea particulele au fost dislocate în spaþiu. Subtilul inel coincide cu orbita celor douã luni, de aceea specialiºtii cred cã ele sunt responsabile de apariþia noului cerc.

Cercetãtorii au fãcut descoperirea în urma unui eveniment destul de neobiºnuit: o eclipsã solarã a lãsat nava spaþialã Cassini în umbra lui Saturn pentru 12 ore. În acest interval au putut vedea foarte clar toate cercurile din jurul planetei-gigant, Saturn.
Sursa - Antena 3

[xennon_2000]

Daca ati vazut filmul: "Masina timpului"...in care se presupunea ca luna daca ar exploda s-ar  transforma in inel al terrei! O buna ipoteza de luat in calcul si in cazul: Saturn

[pri3st3ss]

The Cassini space probe pictures three of Saturn's small moons in conjunction with its immense ring system. Prometheus and Pandora, on the right, are "shepherd moons" whose gravity keeps the edge of the F-ring sharp. Janus is the third moon pictured. (Image: Nasa/JPL/Space Science Institute)