ASTRONOMIJA

[corolla02]

@NIN; super odgovor i hvala za tumacenje svih relativnih mjerila u svezi promjene kretanja Zemlje i Mjeseca;

Sve sto sam trazio jeste potvrdu o nacinu kako covjek primjecuje sve te promjene i sve to za neki svoj relativno kratak period zivota. Znamo da ljudi nisu savrseni te su skloni grijesiti. Time i sama tehnologija nije savrsena, pa i sam Njutn je bio covjek, te uopste nema garancije da za nekih 20 godina unaprijed nece se naci neko ko ce pobiti ovaj ili onaj zakon ili vjerovanje, npr. Pluton danas vise nije planeta mada se to smatrao dugim nizom godina. Sva ova nova saznanja se pogotovo mogu dogoditi na polju Astronomije i Kosmosa kako technologija dalje bude isla naprijed, dok istovremeno taj covjek je jos uvijek toliko mali u poredjenju sa Kosmosom te i dalje osta kratak da poimuje pravu velicinu tog istog Universuma.

[NIN]

Naravno da ljudi nisu savrseni - rat, glad, pohlepa i jos mnogo toga. Ali ljudi su ipak jedinstveni u prirodi i u kosmosu, doduse, kosmosu koji nam je dostupan. Razlog nase jedinstvenosti je alat kojeg smo izumili, a to je nauka. Jedan od najbitnijih faktora nauke kao konstrukta je mjerenje. Svi dosadasnji naucni pronalasci i zakljucci proizasli iz promatranja su bazirani bas na tom mjerenju bez kojeg nauka ne bi imala smisla.

Recimo, Einstein je teoretski, tacnije, matematicki dokazao da su prostor i vrijeme relativni pojmovi (teorija relativiteta). Kada bacimo matematicke formule na papir rezultati koje dobijamo nedvosmisleno kazuju da je ova teorija tacna, bez obzira sto nasa percepcija govori suprotno. U pocetku, akademska zajednica je bas iz tog intuitivnog razloga odbijala ovu ideju relativiteta sve dok se nije doslo do mjerenja. koliko se sjecam, nekada tokom Hladog rata izvrsio se ekperiment sa dva sinhronizirana atomska sata (dakle, nepogresive tacnosti, da tako kazem). Jedan sat je smjesten u mlazni avion dok je kontrolni ostao na zemlji. Nakon leta dva sata su uporedjena gdje je ustanovljen otklon jednog od satova sto je potvrdilo da je teorija relativiteta koja govori o vremenu tacna.

Poenta je da svaki prirodni fenomen ostaje u domenu fenomena sve dok se isti ne izmjeri. Na slican nacin je izmjereno i samo usporavanje zemljine rotacije, i to mnogo puta (jer je za potvrdu hipoteze potrebno mnogo vise od jednog mjerenja, kao sto je uostalom bio slucaj i sa teorijom relativiteta).

Pozdrav...

[NIN]

Crveni planet nekoć je bio plav!



Veliki ocean nekada je prekrivao trećinu Marsa, tvrde znanstvenici, što uvelike povećava mogućnosti da je postojao život na četvrtom planetu od Sunca.
Uz pomoć novog softvera znanstvenici su analizirali površinu Marsa, te su pronašli putove kojima su nekada rijeke tekle do oceana. Korita su prvi puta uočena 1971. godine, a dodatnim analizama, uz pomoć moderne tehnologije, gotovo u potpunosti su otkrivene trase kojima su tekle do oceana. Znanstvenici NASA-e tvrde da su rijeke tekle s visokog juga Marsa prema ogromnom oceanu na sjeveru. Svi do sada prikupljeni dokazi o Crvenom planetu pokazuju kako je Mars prije nekoliko bilijuna* godina imao klimatološke uvjete slične današnjima na Zemlji.

T.J.|Net.hr
24.11.2009.


* Novinarski lapsus - vjerovatno pogresan prijevod novinara jer bi nasa milijarda na engleskom bila billion, dok je nas bilion ustvari hiljadu milijadi, a znamo da je svemir star tek nekih 15-tak milijardi godina.

[ljubav_aha]

Mjesece se konstatno udaljava os Zemlje,a isto tako,rotiranje Zemlje se usporava,stoga dani postaju duzi

Najjednostavniji odgovor bi bio: Njutnovi zakoni.

I da, naravno da je ovaj fenomen stvaran. Skolska fizika. Naime, posrijedi je gravitaciona interakcija Zemlje i Mjeseca. Recimo, i nas se Mjesec prije vise stotina miliona godina okretao oko svoje osi pa je vremenom, pod uticajem zemljine gravitacije, njegova rotacija usporavala da bi danas potpuno nestala (ne bas potpuno ali sa naseg zemaljskog aspekta uvijek je samo jedna mjeseceva strana okrenuta prema Zemlji, sto nije bio slucaj u proslosti, pa otud i Dark side of the Moon).

Kada su dva tijela u uzajamnoj gravitacijskoj interakciji oni fakticki djeluju jedni na druge svojom masom. Recimo, direktna posljedica mjeseceve gravitacije na Zemlji je plima i oseka. Da kojim slucajem postoje mora na Mjesecu, razlika razine mora izmedju plime i oseke bila bi desetine puta veca nego kod nas na Zemlji jer, kako je Zemlja 81 puta masivnija od Mjeseca gravitacione konsekvence na manjem tijelu bi bile kudikamo jaceg opsega. E sada, isti taj gravirtacioni mehanizam koji je odgovoran za plimu i oseku odgovoran je i za usporavanje rotacije tijela. Sto je sila koja djeluje na odredjeno tijelo veca rotacija istog ce se brze i usporavati i vice versa. To je razlog zasto je rotacija Mjeseca mnogo prije zaustavljena od rotacije nase planete - jer je djelovanje mjeseceve gravitacije dosta manjeg intenziteta. Ipak, ono djeluje sto ima za posljedicu, osim plime i oseke i to da se zemljina rotacija polako usporava.

Mada, nema potreba za panikom niti nekim senzacionalizmom jer su u pitanju milioniti dijelovi sekunde na odredjen vremenski period sto govori da bi rotacija nase planete trebala biti zaustavljena za vise milijardi godina, ako tada uopste Zemlja bude i postojala (prije ce nasa planeta biti progutana od strane nase zvijezde jer se Sunce polako ali sigurno siri kako crpi svoje gorivo, tako postajuci crveni div).

nin,nesto sma znala,ali sam nesto i novo naucila,hvala

[statix]

Evo, kome se da gleda
'A Universe From Nothing' by Lawrence Krauss

[mala_truba]

http://www.nasa.gov/mission_pages/chand ... 9-103.html

[statix]

Sudara galaksija osvjetlio crnu rupu

Composite image

Optical



* NGC 6872 i IC 4.970 su dvije galaksije u procesu kolizije (sudaranja).

* IC 4.970 je mala galaksija na vrhu slike, zahvaljujući Chandra i Spitzer podatataka, prikazana je da sadrži aktivnu Supermasivnu crnu rupu.

* Zagonetka je odakle IC 4.970 crpi gorivo jer promatranja pokazuju nedostatak materijala koji okružuje crnu rupu.

* Novi rezultati pokazuju da je IC 4.970 skinula hladni plin iz NGC 6872 i koristi ga da hrani i uzgaja svoju crnu rupu.


Ova slika podataka sastavljen je od tri različita teleskopa i pokazuje tijek kolizije između dvije galaksije, NGC 6872 i IC 4970. X-ray podatke iz NASA-in Chandra opservatorij X-zraka prikazana je u ljubičasto, dok je Spitzer Space Telescope infracrvenih podataka crvena i optičke podatke iz ESO's VLT je obojena crvena, zelena i plava.

Astronomi misle da Supermasivne crne rupe postoje u središtu većine galaksija. Ne samo da galaksija i crne rupe koegzistiraju, oni su očito nerazmrsivo povezani u njihov razvoj. Da bi bolje razumjeli ovaj simbiozni odnos, znanstvenici su se okrenuli brzorastućim crnim rupama - takozvanim "aktivnim galaktičkim jezgrim" (AGN) - radi proucavanja kakav je uticaj galaktičke okoline na njih.

Najnovijim podacima Chandra i Spitzer pokazuju da IC 4.970, mala galaksija na vrhu slike, sadrži AGN, a to je teška larva plina i prašine. To znači da u svjetlu optičkog teleskope, kao što je VLT, malo se moze vidjeti. Medjutim, X-zrake i infracrvena svjetla mogu prodirati u ovaj veo materijala i otkriti light show, koji se generira zagrijavanjem materijala, prije pada na crnu rupu.

Unatoč magli plina i prašine oko 4.970 IC, Chandra podaci pokazuju da nema dovoljno vrućeg plina u IC 4.970 da bi AGN (crna rupa) rasla. Dakle, odakle dolazi hrana za ovu crnu rupu? Odgovor leži u partnerskoj galaksiji NGC 6.872. Ove dvije galaksije ulaze u proces kolizije (spajanja), i gravitacijska privlacnost IC 4.970 je vjerojatno povukla neki NGC 6.872 duboki rezervoar hladnog plina (istaknuto u Spitzer podacima), te pruža novi dovod goriva za divovsku crnu rupu.

Observation Date December 14 & 16, 2005
Release Date December 10, 2009
http://chandra.harvard.edu/photo/2009/ngc6872/

[stvarno]

Astradamus se bavio prorocanstvima na bazi posmatranja neba.
Tako je predviodio da ce 2013 godna doci do velikih poremecaja jer tada zemlja prolazi kroz centar Mlijecnog puta´.
Kada se pojave 3 mjeseca na nebu tada ce doci do poremecaja i stradanja ljudi. Tada ce civilizacija opet poci da sve stvara od 0. Interesantno je da i kalendar MAJA ide do 2013 godine i tu se zavrsava.

[walkabout]

Astradamus se bavio prorocanstvima na bazi posmatranja neba.
Tako je predviodio da ce 2013 godna doci do velikih poremecaja jer tada zemlja prolazi kroz centar Mlijecnog puta´.
Kada se pojave 3 mjeseca na nebu tada ce doci do poremecaja i stradanja ljudi. Tada ce civilizacija opet poci da sve stvara od 0. Interesantno je da i kalendar MAJA ide do 2013 godine i tu se zavrsava.

znachi da prestanem otplacivat kredit...

[tranquil]

Astradamus se bavio prorocanstvima na bazi posmatranja neba.
Tako je predviodio da ce 2013 godna doci do velikih poremecaja jer tada zemlja prolazi kroz centar Mlijecnog puta´.
Kada se pojave 3 mjeseca na nebu tada ce doci do poremecaja i stradanja ljudi. Tada ce civilizacija opet poci da sve stvara od 0. Interesantno je da i kalendar MAJA ide do 2013 godine i tu se zavrsava.

Jeko Astradamus? Ovo opet nešto, fol, tri tegle ajvara u špajzu, šta li? Pa zašto na ovoj temi, ljudi dragi?

BTW Orionova ruka (ima li neko bolji prevod) je dio galaksije u kojoj se nalazimo. To ti je krak na onoj slici spiralne galaksije. Nema šanse da prođemo kroz centar Mliječnog puta u idućih par stotina miliona godina, sve da se galaksija naopako nasadi. Sve su šanse da ćemo prije toga proletiti kroz središta Andromeda galaksije, al' tek za par milijardi godina. (živi bili pa vidjeli)

[NIN]

Astradamus se bavio prorocanstvima na bazi posmatranja neba.
Tako je predviodio da ce 2013 godna doci do velikih poremecaja jer tada zemlja prolazi kroz centar Mlijecnog puta´.
Kada se pojave 3 mjeseca na nebu tada ce doci do poremecaja i stradanja ljudi. Tada ce civilizacija opet poci da sve stvara od 0. Interesantno je da i kalendar MAJA ide do 2013 godine i tu se zavrsava.

Jeko Astradamus? Ovo opet nešto, fol, tri tegle ajvara u špajzu, šta li? Pa zašto na ovoj temi, ljudi dragi?

BTW Orionova ruka (ima li neko bolji prevod) je dio galaksije u kojoj se nalazimo. To ti je krak na onoj slici spiralne galaksije. Nema šanse da prođemo kroz centar Mliječnog puta u idućih par stotina miliona godina, sve da se galaksija naopako nasadi. Sve su šanse da ćemo prije toga proletiti kroz središta Andromeda galaksije, al' tek za par milijardi godina. (živi bili pa vidjeli)

Ma procitao co'jk negdje u Extri ili Svetu. Cuj Astradamus! Jest nam omladina educirana to je cudo bozije...

Nego, ticano za prijevod - ja ga zove Orionov krak.

[statix]

Ljudi ce i od ovoga napraviti smak svjeta ili 2012 scenario , samo nek' je spekulacija i senzacija...
Mozda najgori scenarijo je solarna oluja, s tim da ce visoko-razvijene zemlje biti znatno vise na gubitku od onih koje manje ovise o tehnologiji.

A evo clanak o poslijedicama takvog scenarija:http://www.bbcfocusmagazine.com/feature ... olar-storm

Ukratko, tesko ce biti predvidjeti oluju, kojoj treba 18-35 sati da dodje do zemlje, i malo vremena za dobru reakciju, ali gasenjem struje na vrijeme moze se spreciti veliki krah tehnologije, jer u suprotnom bi bili par mjeseci biti bez struje, a potpuni oporavak tehnologije bi trajao par decenija, kao i lansiranje novih satelita poput telekomunikacijskih, meteoroloskih, navigacionih itd. U trenutku oluje u najvecoj zivotnoj opasnosti bi bili ljudi u avionima.

Naravno, sve ovo u slucaju velike oluje poput one iz 1859. Ako je prenapuhano, nek' neko ispravi.

[NIN]

Year's Best Mars View



Mars shines brightly over Mount Taftan in southeast Iran.
Photograph by Babak Tafreshi/Dreamview.net, TWAN

Andrew Fazekas
for National Geographic News
Published January 25, 2010

Mars is zooming in for a close approach to Earth this week, offering backyard astronomers their best views of the red planet until 2014.

For the past few months Mars has appeared at night as a ruddy, starlike beacon rising in the east. On January 27 Mars will pass within 61 million miles (98 million kilometers) of Earth—close enough for well-equipped sky-watchers to make out details on the Martian surface. "With a small telescope of about 6 inches (15.2 centimeters), the polar ice caps and other surface features are visible," said Raminder Singh, staff astronomer at the H.R. MacMillan Space Centre in Vancouver, British Columbia.

(Related: "Mars Pole Holds Enough Ice to Flood Planet, Radar Study Shows.")

"Even a pair of binoculars will show it as a disk, as opposed to a star, which looks like a pinpoint of light." And on January 29 Mars will reach opposition, which means it will rise in the east just as the sun sets in the west, making the red planet visible all night long. "When opposition occurs, Mars is on the opposite side [of Earth] from the sun. If viewed from above the solar system, the sun, Earth, and Mars would be in a straight path," Singh said. Adding to the cosmic spectacle, on the night of opposition Mars will appear fairly close to the full moon, and the pair will glide together across the sky.

Mars Easy to See

The exact distance between Mars and Earth changes over time, because the orbits of the planets are not perfect circles, but elongated ellipses. This orbital setup means Mars makes a close pass by Earth roughly every two years. In August 2003 Mars made its closest pass by Earth in 60,000 years, swinging by at a mere 35 million miles (56 million kilometers) away. That event created spectacular views for astronomers but also seems to have spawned the recurring "Mars Spectacular" email hoax. This year's approach won't be a particularly close pass. Still, the "flyby" will highlight how easy it is to spot Mars even with the naked eye, Singh noted.
"It's the third brightest object in the night sky, aside from the moon and the star Sirius," Singh said.

"People should really go outside and look at it, as it's an easy thing to see in the sky."

http://news.nationalgeographic.com/news ... est-earth/

[NIN]

Mars i mjesecava duga iznad Havaja

[arzuhal]

Aman

[NIN]

Kako nas samo nasa percepcija moze prevariti, ma to je za nepovjerovati! Da bi malo razbili tu nasu iluzornu ususkanost i arogantnost evo kako nas svijet izgleda sa udaljenosti od samo 4 milijarde kilometara (kilometri sa astronomskog aspekta su jednostavno neprakticni i neupotrebljivi. Recimo, upotrebljavati ih u astronomiji bi bilo kao kada bi koristili nanometre u izracunavanju geografskih udaljenosti. Naime, svjetlosna godina je jedinica koja se koristi u astronomiji i predodzbe radi, ona iznosi 9,460,800,000,000 kilometara dok je nas svemir, grubo receno, sirok nekih desetine milijardi svjetlosnih godina!).

Pitanje koje se samo namece je da li smo mi uopste bitni za toliko enorman i nama prakticno nezamisliv prostor i ustroj kojeg nazvasmo svemirom, tj. kosmosom? Da li je uopste ispravno zamisljati bilo kakvu znacajnost u svom ovom ogromnom prostoru, znacajnost koju sami sebi neopravdano pridajemo, sto kroz religiju, sto kroz svoju uljuljanu i delirijsku aroganciju?



Taken in 1990 by NASA's Voyager 1 spacecraft, the "pale blue dot" photo shows what our planet looks like from 4 billion miles away. Earth is the klix speck of light indicated by the arrow and enlarged in the upper left-hand corner. The pale streak over Earth is an artifact of sunlight scattering in the camera's optics.


This week marks the 20th anniversary of a photograph. It's a very dramatic photo, even though, at first glance, it's mostly dark and seems to show nothing at all. But if you look closely, you can see a klix speck of light. That speck is the Earth, seen from very, very, very far away. Two decades ago, Candice Hansen-Koharcheck became the first person to ever see that speck, sitting in front of a computer at NASA's Jet Propulsion Lab in California. "I was all alone, actually, that afternoon, in my office," she recalls. Her office was dark. The window shades were drawn. She was searching through a database of images sent home by the Voyager 1 spacecraft, which at the time was nearly 4 billion miles away. "I knew the data was coming back," she says, "and I wanted to see how it had turned out." Finally, she found it. "It was just a little dot, about two pixels big, three pixels big," she says. "So not very large."

But this was the Earth — seen as no human had ever seen it before. What's more, an accidental reflection off the spacecraft made it look as though the klix speck was being lit up by a glowing beam of light. "You know, I still get chills down my back," says Hansen-Koharcheck. "Because here was our planet, bathed in this ray of light, and it just looked incredibly special." And yet, if you weren't searching for it, that special little speck would be almost invisible. The Apollo astronauts had taken photos that showed the Earth as a big blue marble, swirling with clouds and continents. But this picture showed the smallness of Earth in the vastness of space.

A New Perspective On The Planet

The late astronomer Carl Sagan eloquently tried to express how he felt about this photo in his book Pale Blue Dot:

Look again at that dot. That's here. That's home. That's us. On it everyone you love, everyone you know, everyone you ever heard of, every human being who ever was, lived out their lives. The aggregate of our joy and suffering, thousands of confident religions, ideologies, and economic doctrines, every hunter and forager, every hero and coward, every creator and destroyer of civilization, every king and peasant, every young couple in love, every mother and father, hopeful child, inventor and explorer, every teacher of morals, every corrupt politician, every 'superstar,' every 'supreme leader,' every saint and sinner in the history of our species lived there — on a mote of dust suspended in a sunbeam.

Robert Poole, a historian at the University of Cumbria in the United Kingdom who wrote a book on images of Earth from space called Earthrise: How Man First Saw the Earth, says this particular photo shows what an extraterrestrial might see as it approached our solar system.

"This is not our view. We've managed to go out and get the view that somebody else might have, whereas the early Apollo pictures of the blue marble were our own view of Earth," Poole says. "Like most people, I saw it in the newspaper not long after it was taken and kind of intellectually I thought, 'This is amazing!' "



Onboard the Voyager spacecraft is a 12-inch, gold-plated record with greetings in 59 languages, music samples and images.

Photo That Almost Didn't Happen

Pictures like this are still few and far between. They are not exactly easy to take. In fact, we almost didn't get this one. Sagan lobbied for it early in the Voyager 1 mission. But others objected that taking it might fry the spacecraft's camera. That's because the Earth is so close to our extremely bright sun. "There was a reluctance to take any kind of risk when we would point back towards the sun; we didn't want to accidentally damage the cameras in any way," says Hansen-Koharcheck. "Oh, there was a lot of debate as to what its value would be," recalls Edward Stone, who was — and still is — the chief scientist for the Voyager mission. "It was not a scientific image. It was really, I think, an image to sort of declare that here, for the first time we could take such an image, and second of all it provided a new perspective of Earth and its place in our solar neighborhood." But the idea was shelved for years, as Voyager 1 flew through the solar system and did its science, sending images back from Saturn and Jupiter.

In 1989, the mission was winding down — some staff was going to leave. And Sagan made a last-minute request to please, please, take this unique photo before the opportunity disappeared forever. The decision went to the top levels of NASA "because it was going to extend the mission in terms of imaging capability for an additional six months or so and that of course did cost money," explains Stone. "I did get a visit from Carl Sagan. We talked about a lot of things. And somewhere in that conversation he mentioned this idea," recalls the then-head of NASA, retired Vice Adm. Richard Truly. "I thought, heck, with Voyager so far away, if it could turn around and take a picture of the different planets including the Earth, that that would really be cool. And so I was a great advocate of it, although I can't take any credit for it." In 1990, late on Feb. 13 — or on Valentine's Day, in the time zone used by the Voyager 1 team — the spacecraft turned its cameras to Earth.

A Relatively klix Object In The Vastness Of Space

Later, the image was released to the world to great fanfare. But it never really captured the popular imagination like the famous Apollo images. "I think it was hard — it's still hard — to get really your head around the fact that our solar system is so immense, compared to Earth," says Stone. To get the full impact of this photo, Stone says, you really have to see it up on a wall, as part of large panorama that Voyager 1 took of the solar system's distant planets.
NASA's Jet Propulsion Lab used to have just such a display with the full mosaic of photos posted up in an auditorium, says Hansen-Koharcheck. "And to show the whole thing it covered, oh, I don't know, 12 or 14 feet," she says — of mostly empty black space, with just a few pinpricks of light showing the planets. One of them was labeled Earth.
"One of the guys that took care of that display told me one time that he was forever having to replace that picture," says Hansen-Koharcheck, "because people would come up to look at it and they would always touch the Earth."
Voyager 1 is now about three times farther away than it was 20 years ago, says Stone. The spacecraft still routinely phones home, although its cameras no longer take photos. But if it could send back another picture, the little dot that is Earth would look even fainter and even smaller.

http://www.npr.org/templates/story/stor ... c=fb&cc=fp


Ugodno citanje i informisanje!

[arzuhal]

Tačno

[statix]

Ako nas nekad posjeti neka napredna civilizacija, nadam se miroljubiva, sjecat cemo se i zahvaljivati genijalnosti Sagana i njegovoj ideji.

[walkabout]

mali smo, mali...

mali ali zajebani...

[NIN]

Water Found in Apollo Moon Rocks
Proof was right under our noses for decades?



Moist center? Moon rocks, such as this sample seen in an undated photo, contain traces of water, new studies say.
Photograph by Tyrone Turner, National Geographic Stock


John Roach
for National Geographic News
Published March 9, 2010

Recently NASA crashed two spacecraft into the moon and orbiters scanned the lunar surface for telltale light signatures—all to confirm the rocky body isn't bone dry after all. But, it turns out, solid evidence for water on the moon was under our noses the whole time.

klix amounts of water have been found in some of the famous moon rocks brought back to Earth by the Apollo astronauts, scientists announced last Wednesday. (Related: "Apollo 11 at 40: Facts, Myths, Photos, and More.") The water levels detected in Apollo moon rocks and volcanic glasses are in the thousands of parts per million, at most—which explains why analyses of the samples in the late 1960s and early 1970s concluded that the moon was absolutely arid.

"Only in the last decade have instruments become sensitive enough to even analyze water at those kinds of concentrations," said Gary Lofgren, the lunar curator at NASA's Johnson Space Center in Houston, Texas.Lofgen, who wasn't involved with the new research, called it "solid work" worthy of further investigation.

http://news.nationalgeographic.com/news ... oon-rocks/

[NIN]

hmmm...

Orange Dwarf Confirmed to be On Collision Course With Earth

Gliese 710 should arrive sometime within the next 1.5 million years



Our solar system's 'hood may get a bit rougher sometime during the next 1.5 million years. An astronomer has given an 86 percent chance for a neighboring star to smash into the frozen Oort Cloud surrounding the outskirts of the solar system, and may scatter some comets toward Earth, Technology Review reports.

That's not the only close encounter for our sun, according to Vadim Bobylev at the Pulkovo Astronomical Observatory in St. Petersburg, Russia. He combined data from several databases of stars and found at least nine more stars that have already swung past the sun or will do so in the future. The data on Gliese 710, an orange dwarf star, comes from position and velocity measurements of about 100,000 stars in the Hipparcos Catalogue published in 1997. Updates for the Hipparcos data in 2007 allowed Bobylev to calculate the likelihood that Gliese 710 might smash into our solar system.

A hail of comets sweeping toward Earth from that collision could pose a problem, given the relatively pathetic investment in detecting incoming space threats. The loose chunks of ice debris within a comet's gaseous body might also prove more of a nightmare than solid asteroids, and scientists still don't know exactly how to deal with the rockier cousins. If Bobylev's prediction holds and Earth escapes unscathed, it will catch a bit of a breather barring the oddball asteroid, solar storm or human-engineered disaster. That should give enough time to figure out a plan for the inevitable Andromeda galaxy collision in 4.5 billion years.
http://www.popsci.com/science/article/2 ... ward-earth

[mala_truba]

Astradamus se bavio prorocanstvima na bazi posmatranja neba.
Tako je predviodio da ce 2013 godna doci do velikih poremecaja jer tada zemlja prolazi kroz centar Mlijecnog puta´.
Kada se pojave 3 mjeseca na nebu tada ce doci do poremecaja i stradanja ljudi. Tada ce civilizacija opet poci da sve stvara od 0. Interesantno je da i kalendar MAJA ide do 2013 godine i tu se zavrsava.

Jeko Astradamus? Ovo opet nešto, fol, tri tegle ajvara u špajzu, šta li? Pa zašto na ovoj temi, ljudi dragi?

BTW Orionova ruka (ima li neko bolji prevod) je dio galaksije u kojoj se nalazimo. To ti je krak na onoj slici spiralne galaksije. Nema šanse da prođemo kroz centar Mliječnog puta u idućih par stotina miliona godina, sve da se galaksija naopako nasadi. Sve su šanse da ćemo prije toga proletiti kroz središta Andromeda galaksije, al' tek za par milijardi godina. (živi bili pa vidjeli)

Ma nema to veze sa prolaskom Zemlje kroz centar galaksije (to je tako laički)! Mi smo daleko od samog centra i nikad tamo necemo ni stici (prije ce nas nase vlastito Sunce progutati pri svom umiranju)! Ova priča oko majanskog kalendara se odnosi na tzv. 'galakticko poravnanje', kad ce položaj Sunca u decembarskom solsticiju biti u ravni sa ekvatorom galaksije (zamisljena ravan koja dijeli galaksiju na 2 dijela). To se ponavlja svakih 26.000 godina, a upravo 21.decembra 2013. se završava ciklus koji Maje imaju u svom kalendaru.

Po nekim misljenima gravitacijski uticaj crne rupe, koja se nalazi u centru galaksije, je najjači na ekvatoru galaksije, pa bi to moglo uticati na Suncev sistem i eventualne katastrofe...no, niko ne moze znati...mozda ce se to samo desiti i zapoceti novi ciklus, kao sto se smjenjuju godisnja doba...???!!!

[yflorida02]

Za sada Sunce vodi Zemlju. Gde ono, tu i mi

[Zlocin&Kazna]

Tamni tok" nije prazna priča, sugerira nova studija koja ojačava slučaj nepoznate, nevidjenje "strukture" koja vreba na periferiji stvaranja. U 2008. godini naučnici su prijavili otkriće stotina galaktičkih jata koji se kreću u ustom smjeru pri brzini od preko 3,6 miliona kilometara na čas.

Ovo misteriozno kretanje ne može biti objašnjeno trenutnim modelom raspodjele mase u univerzumu. Zbog toga su istraživači načinili kontraverzni prijedlog da su jata pod uticajem gravitacionog uticaja materije koja se nalazi izvan poznatog univerzuma.

Sada, isti tim istarživača je otkrio i da se ovaj "tamni tok" proteže jos dublje u univerzum nego su to ranije izvjestili: najmanje 2.5 milijardi svjetlosnih godina vani u odnosu na Zemlju.

Nakon korištenja podataka skupljanih 2 dodatne godine (od 2008 do 2010), i praćenja duplo više galaktičkih skupina, "jasno vidimo Tok, jasno vidimo da je usmjeren u istom smjeru", kaže vodja studije Alexander Kashlinsky, astrofizičar u NASA-inom "Goddard Space Flight Center" u Marylandu.

"Izgleda kao da je veoma koherentan tok."

Otkrića doprinose scenariju da su ostaci materije bili izbačeni izvan poznatog univerzuma kratko nakon Velikog praska - što zauzvrat daje nagovještaj da je naš univerzum dio nečega mnogo većeg : multiverzuma.

Produženi domet tamnog toka

Kashlinksy i kolege su prvi puta primjetili tamni tok kada su izučavali način na koji gas u galaktičkim jatima interaguje sa kosmičkom mikrotalasnom pozadinskom radijacijom. Smatra se da je ova raspršena svjetlost oslobodjena 380 000 godina nakon Velikog praska i da sada prožima čitav univerzum.


Novi podaci mogu pokazati temperaturne promjene koje nastaju kada se mikrotalasna pozadinska radijacija kreće kroz gasove u galaktičkim jatima. Ovi gasovi raspršuju svjetlost od mikrotalasne radijacije dok ona prolazi kroz jata, na sličan način kao što Zemljina atmosfera može raspršiti svjetlost od zvijezda, čineći da neke zvijezde trepću.

Ali galaktička jata se takodjer kreću u odnosu na pozadinsku radijaciju, pa raspršena svijetlost biva dodatno izobličena usljed Doplerovog efekta. Ovo izobličenje se javlja u vidu temperaturnog pomjeraja u podacima koje prima WMAP (Wilkonson Microwave Anisotropy Probe - svemirska letjelica koja mjeri razlike u temperaturi kosmičke mikrotalasne pozadinske radijacije zaostale od Velikog praska), koje mogu otkriti pravac i smjer glaktičkih jata.

"Vrlo je teško izolirati (temperaturske promjene) za svako individualno jato," kaže Kashlinsky, pa je originalna studija izučavala 700 skupina. Nova studija je bazirana na kolektivnom kretanju oko 1400 galaktičkih jata, i posmatranje tamnog toka sa većim brojem galaktičkih jata daje istraživačima više povjerenja u dobijene rezultate.

Osim toga, tim je testirao korištenu analiičku metodu poređenjem sjajnosti određenih jata sa intenzitetom temperaturnih promjena vidjenih u podacima WMAP-a. Sjajnija jata - ona sa više vrelih gasova - bi trebala imati više uticaja na pozdainsko mikrotalasno zračenje, i to je ono što je nova studija i potvrdila. Kashlinsky pretpostavlja da se tamni tok proteže "skroz preko vidljivog univerzuma", ili oko 47 milijardi svjetlosnih godina, što bi se poklapalo sa idejom da su jata pod uticajem sile vuče od strane materije koja leži izvan horizonta poznatog univerzuma.

Tamni tok, kako kaže Kashlinsky "bi bilo mnogo teže objasniti teoretski kada bi se on protegnuo (2,5 milijardi svjetlosnih godina) i onda samo stao."

(National Geographic)

[statix]

Cassini Captures Calypso



March 27, 2010
This is Calypso, one of Saturn's 60 known moons, as photographed by NASA's Cassini Equinox mission. Measuring only 21 kilometers (or 13 miles) across at its widest point, this potato-shaped Saturnian satellite has a surprisingly smooth surface.

It is thought that Calypso is as cratered as the other moons in the Saturn system, but it is covered in fine dust, filling in the impact craters. As the spacecraft passed within 21,000 kilometers (13,000 miles) on Feb. 13, Cassini's narrow-field camera managed to capture this view with a resolution of only 128 meters (or 420 feet) per pixel, showing just how dust-covered and featureless the moon is.

Calypso is a special moon as it is engaged in a gravitational dance with a larger moon called Tethys, trailing its orbit by 60 degrees. There's another moon called Telesto (slightly larger than Calypso, but equally as dust covered) leading Tethys in its orbit by 60 degrees. Both Calypso and Telesto are known as "Tethys Trojans," two of only four known "Trojan Moons" in the solar system. (The other two trojan moons are called Helene and Polydeuces, leading and trailing the larger moon Dione, also orbiting Saturn.)

So why is Calypso (and Telesto) trapped in this 60 degree trojan orbit? Calypso is sitting in a region of gravitational calm known as a Lagrangian Point (in this case, it's the "L4 point") where the combined gravitational pull of both Saturn and Tethys balance out creating an island of gravitational stability. As the Saturnian system evolved, its many moons gradually growing from dust and smaller rocks sticking together, Calypso found itself being dragged around its orbit by the motion of Tethys' L4 point (like a dog on a gravitational leash).

Before now, only very fuzzy photographs of Calypso have been available (originally shot by Voyager 2 in Aug. 1981 and later by Cassini -- from over 100,000 km away -- in Sept. 2005), so this stunning Calypso portrait is the most detailed ever taken, definitely one for the Cassini hall of fame.