Astronomija - opšta tema

[Amos]

The winter is coming!

[אַף אֶחָד]

velika vest sa konferencije u new mexicu je da nam sunce krepava, tačnije odlazi u hibernaciju.global warming pričeri, zaluđeni brojači ugljen dioksida, proizvođači solarnih ploča, i ostali paničari drhte u neverici zbog verovatnog gubitka medijske pažnje i novaca, jer je moguće da nam sledi novo ledeno doba, kad ćemo kod marvina u goste ići pomoću sličuga.http://news.national...-space-science/

Gledam juce naslovnu stranicu B92 i samo sto nisam pao sa stolice. "Sta ce biti sa Suncem?"!?!?! Odgovor iz prve ruke: nista epohalno se nece desiti. Pred svaki novi solarni ciklus postoji malo nezvanicno ali tradicionalno takmicenje u predvidjanju kakva ce biti aktivnost u sledecih 11 godina. Rezultati su uvek neverovatno sareni, neki predvidhjaju jacu, neki slabiju aktivnost. Ono sto im je zajednicko je da se ne kraju svi pokazu manje ili vise pogresnim. Mi danas jos uvek ne poznajemo suncev ciklus dovoljno dobro da bismo mogli da predvidimo sta ce se sledece desiti. Cinjenica je da je ovaj ciklus poceo neuobicajeno dugim minimumom i da je prethodni bio neuobicajeno jak. Ali i jedno i drugo su na nivou uobicajene statisticke varijacije. Na primer, slican dugi minimum imali smo i pocetkom XX veka, pa je za njim usledio normalan ciklus. Sto se klime na Zemlji tice, malo ledeno doba u Evropi i severnoj Americi krajem XVII veka delom korespondira sa smanjenim brojem pega. U popularnim predavanjima cesto pokazujemo slike Averkampa i Brueghela koje pokazuju klizace na zaledjenim holandskim kanalima i kazemo - eto, vidite kako je tada bilo hladno, danas se kanali uopste ne lede. Ali veza izmedju malog ledenog doba i suncevog ciklusa NIJE DOKAZANA. Stavise, ne postoji nijedan dokaz da je istovremeno sa promenom klime u Evropi i s.Americi doslo i do promene klime u drugim delovima sveta. Drugo, i pomalo ironicno, najpoznatija slika Averkampovih klizaca je iz 1608, dakle prakticno 50 godina pre pocetka Maunderovog minimuma i gotovo u isto vreme kada je Galileo uperio svoj teleskop ka Suncu i otkrio pege (kojih je, i to velikih, dakle moralo biti na Suncu). Elem, senzacionalizam ovakvih otkrica treba uzeti sa rezervom. Izmedju ostalog, znam licno i jednog od dizaca prasine u ovom slucaju. Zanimljiv tip, dobar naucnik, ali covek koji je trebalo da bude u penziji pre 15ak godina. I kad je bio u punoj snazi desavalo mu se da objavi radove koji su kasnije bili kasapljeni. Ipak, sve ovo samo pokazuje da moramo vise truda da ulozimo kako bismo razumeli vezu izmedju sunceve aktivnosti i klime. Do tada, molim vas reciklirajte svoje djubre. :)

[Њујоркер]

Pa, danas je veliki dan, velika godisnjica!Neptune completes its first circuit around the Sun since its discoveryThe planet plods along in its huge orbit, slowly completing one revolution approximately every 165 years.By STScl, Baltimore, Maryland — Published: July 12, 2011Today, Neptune has arrived at the same location in space where it was discovered nearly 165 years ago. To commemorate the event, NASA’s Hubble Space Telescope has taken these “anniversary pictures” of the blue-green giant planet.Neptune is the most distant major planet in our solar system. German astronomer Johann Galle discovered the planet September 23, 1846. At the time, the discovery doubled the size of the known solar system. The planet is 2.8 billion miles (4.5 billion kilometers) from the Sun, 30 times farther than Earth. Under the Sun’s weak pull at that distance, Neptune plods along in its huge orbit, slowly completing one revolution approximately every 165 years.These four Hubble images of Neptune were taken with the Wide Field Camera 3 June 25–26, during the planet’s 16-hour rotation. The snapshots were taken at roughly 4-hour intervals, offering a full view of the planet. The images reveal high-altitude clouds in the northern and southern hemispheres. The clouds are composed of methane ice crystals.The giant planet experiences seasons just as Earth does because it is tilted 29°, similar to Earth’s 23° tilt. Instead of lasting a few months, each of Neptune’s seasons continues for about 40 years.The snapshots show that Neptune has more clouds than a few years ago, when most of the clouds were in the southern hemisphere. These Hubble views reveal that the cloud activity is shifting to the northern hemisphere. It is early summer in the southern hemisphere and winter in the northern hemisphere.In the Hubble images, absorption of red light by methane in Neptune’s atmosphere gives the planet its distinctive aqua color. The clouds are tinted pink because they are reflecting near-infrared light.A faint, dark band near the bottom of the southern hemisphere is probably caused by a decrease in the hazes in the atmosphere that scatter blue light. The band was imaged by NASA’s Voyager 2 spacecraft in 1989, and may be tied to circumpolar circulation created by high-velocity winds in that region.The temperature difference between Neptune’s strong internal heat source and its frigid cloud tops, about –260° Fahrenheit (–160° Celsius), might trigger instabilities in the atmosphere that drive large-scale weather changes.Neptune has an intriguing history. It was Uranus that led astronomers to Neptune. Uranus, the seventh planet from the Sun, is Neptune’s inner neighbor. British astronomer Sir William Herschel and his sister Caroline found Uranus in 1781, 55 years before Neptune was spotted. Shortly after the discovery, Herschel noticed that the orbit of Uranus did not match the predictions of Newton’s theory of gravity. Studying Uranus in 1821, French astronomer Alexis Bouvard speculated that another planet was tugging on the giant planet, altering its motion.Twenty years later, Urbain Le Verrier of France and John Couch Adams of England, who were mathematicians and astronomers, independently predicted the location of the mystery planet by measuring how the gravity of a hypothetical unseen object could affect Uranus’s path. Le Verrier sent a note describing his predicted location of the new planet to the German astronomer Johann Gottfried Galle at the Berlin Observatory. Over the course of two nights in 1846, Galle found and identified Neptune as a planet, less than a degree from Le Verrier’s predicted position. The discovery was hailed as a major success for Newton’s theory of gravity and the understanding of the universe.Galle was not the first to see Neptune. In December 1612, while observing Jupiter and its moons with his handmade telescope, astronomer Galileo Galilei recorded Neptune in his notebook, but as a star. More than a month later, in January 1613, he noted that the “star” appeared to have moved relative to other stars. But Galileo never identified Neptune as a planet, and apparently did not follow up those observations, so he failed to be credited with the discovery.Neptune is not visible to the naked eye, but may be seen with binoculars or a small telescope. It can be found in the constellation Aquarius, close to the boundary with Capricorn.Neptune-mass planets orbiting other stars may be common in our Milky Way Galaxy. NASA’s Kepler mission, launched in 2009 to hunt for Earth-size planets, is finding increasingly smaller extrasolar planets, including many the size of Neptune.

[eoten]

Dva perseida za 10 minuta, dobro bi došao neki power out ove noći.

[bigvlada]

[bigvlada]

Komparacija nebeskih tela

[bigvlada]

Billion-pixel camera set to snap Milky Way shotsEuropean Space Agency mission to gather super shots of Milky Way galaxy The European Space Agency says it has completed what it calls the largest digital camera ever built for a space mission - a one billion pixel array camera that will help create a three-dimensional picture of the Milky Way Galaxy.Set to be launched onboard the ESA's galaxy-mapping Gaia mission in 2013, the digital camera was "mosaicked together from 106 separate electronic detectors." ESA says that Gaia's measurements will be so accurate that, if it were on Earth, it could measure the thumbnails of a person on the Moon.More on space: Gigantic changes keep space technology hot According to the ESA, the camera was developed by e2v Technologies of Chelmsford, UK and uses rectangular detectors a little smaller than a credit card, each one measuring 4.7x6 cm but thinner than a human hair. The completed mosaic is arranged in seven rows of charge coupled devices (CCDs). The main array comprises 102 detectors dedicated to star detection. Four others check the image quality of each telescope and the stability of the 106.5º angle between the two telescopes that Gaia uses to obtain stereo views of stars.The 0.5x1.0 m mosaic was assembled at the Toulouse facility of Gaia prime contractor Astrium France. Technicians spent much of May carefully fitting together each CCD package on the support structure, leaving only a 1 mm gap between them.According to ESA, the Gaia satellite will operate at the Earth-Sun L2 Lagrange point, 1.5 million kilometers behind the earth, when looking from the sun. "As the spinning Gaia's two telescopes sweep across the sky, the images of stars in each field of view will move across the focal plane array, divided into four fields variously dedicated to star mapping, position and motion, color and intensity and spectrometry," the space agency stated.Gaia is expected to map a billion stars within the Milky Way Galaxy over the course of its five-year mission, charting brightness and spectral characteristics along with their three-dimensional positions and motions.From the ESA on Gaia's mission:Gaia's transmitter is weak, much less powerful than a standard 100 W light bulb. Even so, this equipment will be able to maintain the transmission of an extremely high data rate (about 5 Mbit/s) across 1.5 million km. ESA's most powerful ground stations, the 35 m-diameter radio dishes in Cebreros, Spain, and New Norcia, Australia, will intercept the faint signal transmitted by Gaia. The numbers foreseen in Gaia's celestial census are breathtaking. Every day it will discover, on average, 10 stars possessing planets, 10 stars exploding in other galaxies, 30 'failed stars' known as brown dwarfs, and numerous distant quasars, which are powered by giant black holes. Estimates suggest that Gaia will detect about 15, 000 planets beyond our Solar System. It will do this by watching for tiny movements in the star's position caused by the minute gravitational pull of the planet on the

[bigvlada]

Mei će se ovome obradovati :)http://www.youtube.com/watch?v=s-cCpCu6NWw&feature=channel_video_titleočekujemo travel blog iz čileanske pustinje :D

[mei]

baš su lepi :). (za sada odgledah video bez zvuka, pošto sam na smeni)

[bigvlada]

Edited October 22, 2011 by bigvlada

[Roger Sanchez]

Imaćemo đe dabežimo!

Astronomers have confirmed the existence of an Earth-like planet in the "habitable zone" around a star not unlike our own.The planet, Kepler 22-b, lies about 600 light-years away and is about 2.4 times the size of Earth, and has a temperature of about 22C.It is the closest confirmed planet yet to one like ours - an "Earth 2.0".

Miraleme, 10€ da izvidiš situaciju! -_-

[fonTelefon]

Primer krajnjeg bezobrazluka NASE nesto sto se klasifikuje kao warm Neptunian proglasavati Earthlike, a nema se ni naznake o sastavu.

[Jolly Roger]

Povodom jubileja supernove 1987AMilan M. Ćirković | 24/02/2012.U ovim satima navršava se tačno 25 godina od kako je do Zemlje stigao signal supernove SN 1987A, prvog takvog fenomena u poslednja četiri veka, i prve supernove vidljive golim okom od kako uopšte postoji nauka u savremenom smislu te reči. U ranim jutarnjim satima 24. februara 1987, kanadski astronom Jan Šelton radio je rutinska posmatranja na opservatoriji Las Kampanas, visoko u čileanskim Andima. Jedan od njegovih asistenata, Oskar Dualde, nakratko je izašao na otvoreno, i dokono pogledao u tamno noćno nebo. Pošto je odlično poznavao raspored sazvežđa, brzo je uočio nešto veoma čudno – na rubu magličaste mrlje svetlosti poznate kao Veliki Magelanov oblak, zapravo obližnje patuljaste galaksije, nalazila se zvezda, ne posebno sjajna – približno istog sjaja (zvezdane veličine, u astronomskim terminima) kao one u Orionovom pojasu. Ono što je bilo neobično je da ona nije bila tamo prethodne noći.

Edited February 24, 2012 by Jolly Roger

[bigvlada]

Cassini detects oxygen around second Saturn moonBY STEPHEN CLARKSPACEFLIGHT NOWPosted: March 4, 2012 Researchers analyzing data from NASA's Cassini spacecraft announced Friday the discovery of a tenuous atmosphere around Saturn's moon Dione, a small, colorless world of ice and rock near the giant planet's famous rings. Cassini captured this image of Dione, backdropped by Saturn and its rings, in October 2005. Credit: NASA/JPL-Caltech/Space Science Institute Cassini's plasma spectrometer instrument detected ions of molecular oxygen during a flyby of Dione in April 2010, and scientists announced their findings in a recent issue of the journal Geophysical Research Letters. Dione's atmosphere is extremely thin, about 5 trillion times less dense than the atmosphere at Earth's surface. Cassini's measurements indicate there is just one oxygen ion for every 0.67 cubic inches, or 2,250 ions per cubic foot. "We now know that Dione, in addition to Saturn's rings and the moon Rhea, is a source of oxygen molecules," said Robert Tokar, a Cassini team member based at Los Alamos National Laboratory, and the lead author of the paper. "This shows that molecular oxygen is actually common in the Saturn system and reinforces that it can come from a process that doesn't involve life." Dione's oxygen could come from solar photons or energetic particles from space bombarding the moon's icy surface, liberating oxygen molecules, according to a NASA press release. Scientists are also looking for other processes that could be a source of Dione's exosphere. One possible origin is geology. Dione is believed to be about two-thirds water ice, with a dense core likely composed of silicate rock, according to NASA. Cassini identified a thin atmosphere around Saturn's moon Rhea in 2010. With a diameter of 698 miles, Dione is slightly smaller than Rhea. Researchers are studying data from a Cassini flyby near Dione in December in which the spacecraft's ion and neutral mass spectrometer collected data on the moon's atmosphere. The new data could discover other molecules in Dione's atmosphere. "Scientists weren't even sure Dione would be big enough to hang on to an exosphere, but this new research shows that Dione is even more interesting than we previously thought," said Amanda Hendrix, Cassini deputy project scientist at NASA's Jet Propulsion Laboratory. "Scientists are now digging through Cassini data on Dione to look at this moon in more detail." Officials suspected Dione may harbor a neutral atmosphere of oxygen when the Hubble Space Telescope detected ozone.http://spaceflightnow.com/news/n1203/04dione/

[Tale]

NASA Mars Orbiter Catches Twister in Action

A towering dust devil, casts a serpentine shadow over the Martian surface in this image acquired by the High Resolution Imaging Science Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orbiter. Image credit: NASA/JPL-Caltech/Univ. of Arizona

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