EXTRA.9

08 Dec 1995 - 14 Feb 1998

Messages - zvezde

zvezde.107 nenad,
Otkriveno je malo zvezdano jato koje će ili proći izuzetno blizu nas ili je to već učinilo izazivajući meteorsku kišu koja je mogla biti uzročnik nastanka života na zemlji. Ako se ispostavi da nam se zvezde približavaju, ona najbliža će za "samo" milion godina postati najbliža (samo 1 svetlosnu godinu) i gotovo najsjajnija zvezda na nebu, magnitude 0,6. Close-Call Star Using newly released data from the European Space Agency's Hipparcos satellite, a team of astronomers led by Joan Garcia-Sanchez (JPL) has found a small handful stars that did or will pass within 10 light-years of Earth. The closest future approacher will be Gliese 710, now a 10th-magnitude red dwarf 63 light-years away in Ophiuchus. About a million years from now this star will be only about a light-year from the Sun and will shine at a brilliant magnitude 0.6. At that distance it may actually pass through the outer Oort Cloud, sending a deadly shower of comets our way. Statistically, over time other stars should have come as close or closer, and the resulting infalls of distant comets may have triggered some of the mass extinctions that have plagued life on our planet.
zvezde.108 nenad,
Veliki tamni objekat otkriven je iza Neptuna... King of the Kuiper Belt A sizable body discovered last October in the Kuiper Belt beyond Neptune has a unique orbit with links to the distant Oort Cloud of comets. Designated 1996 TL66, this object is currently some 5 billion kilometers (35 astronomical units) from the Sun. Assuming it has a dark surface, the new find is rather large and could be up to 500 km across. Discoverers Jane Luu (Harvard University) and her colleagues calculate that 1996 TL66 is now close to the perihelion of a much more eccentric orbit, one with a semimajor axis of 84 a.u. and a period of nearly 800 years. No other known object bridges the void between the Kuiper Belt and the far more distant Oort Cloud. Whatever its origin, 1996 TL66 undoubtedly represents the first of many such discoveries. Luu's group estimates that thousands more bodies of comparable size and distance await discovery within 30░ of the ecliptic plane.
zvezde.109 johnnya, -> #108, nenad
>> Veliki tamni objekat otkriven je iza Neptuna... Počelo-je-počelo... :)))
zvezde.110 nenad,
Mesec nije jedini Zemljin satelit! A ako nas nešto bude zakačilo to će biti ovo. ;) Ispostavilo se da se jedan asteroid otkriven pre 10 godina kreće po putanji koja je u direktnoj zavisnosti od putanje i položaja Zemlje. Svakih 385 godina on je čas bliži čas dalji Suncu od Zemlje - i to zbog njenog uticaja. U tekstu je dato objašnjenje šta se tu dešava i kako sve to lepo funkcioniše, ali ja nešto nisam siguran. ;) Companion Asteroid Two interesting asteroids are in the news this week. One of them is unnamed but designated 3753. Discovered in 1986, this 5-kilometer-wide body has an inclined and eccentric path that crosses the orbits of both the Earth and Venus. Simulations by Paul Wiegert (York University) and two colleagues show that 3753 circles the Sun in what's termed a horseshoe orbit with respect to Earth. It works like this: the asteroid circles the Sun in just a bit under 1 year. Over time this slight mismatch allows it to overtake Earth, every 385 years to be exact. But as it comes nearby the Earth's gravity adds a little energy, expanding the asteroid's orbit. Suddenly circling the Sun in just over 1 year, the asteroid never quite catches Earth and moves away. Then, 385 years later, Earth catches up, this time robs 3753 of a little energy, and drops it into a smaller, faster orbit. This asteroid appears to be a companion of sorts, under Earth's control. The only other known example of such horseshoe orbits involve Janus and Epimetheus, two small satellites of Saturn located just beyond that planet's ring system. Sometime within the next 100 million years, however, asteroid 3753 will escape its captivity, either crashing onto one of the inner planets or being flung away onto a totally new path.
zvezde.111 nenad,
Izgleda da "mala planeta" (asteroid) Dionis ima svoj satelit! Astronomi se nadaju da će otkriti nešto više tokom jula kada je on u okultaciji pošto će sledeća prilika biti tek kroz 13 godina. Doubled Dionysus? The second newsy asteroid is 3671 Dionysus, an Earth-crosser in a 3.25-year orbit. When astronomers Stefano Mottola and Gerhard Hahn (German Aerospace Research, Berlin) observed its rotational light curve earlier this month, they noticed that every 1.15 days the asteroid's brightness would suddenly drop by 0.08 magnitude. But the asteroid itself is known to rotate every 2.7 hours. So they've concluded that Dionysus probably has a satellite, and we're looking right along its orbital plane. If they're right, every 28 hours this little moon either passes in front of or behind the main asteroid. Mottola and Hahn point out that Dionysus will come within about 17 million km of Earth in early July, when it will brighten to 15th magnitude. Astronomers around the world are trying to learn more in the coming weeks, as the asteroid won't be near us again for 13 years.
zvezde.112 zormi, -> #110, nenad
* Mesec nije jedini Zemljin satelit! A ako nas nešto bude zakačilo * to će biti ovo. ;) Taj asteriod ima "inklinisanu" orbitu i nema šanse da se sudari sa Zemljom.
zvezde.113 vdjole, -> #103, nenad
> Po svemu sudeći ipak je dokazano postojanje malih (veličine kuće ;) > ledenih kometa koje konstantno padaju na Zemlju praveći rupe u > jonosferi. > Frank believes the interlopers have a mass of 20 to 40 > tons and consist of almost pure ice. > The comets strike at rates of five to 30 per > minute. Da nije ovde negde ipak neki lapsus sa redovima veličine za neki od podataka. Objekti "veličine kuće" sastavljeni od leda a koji padaju svakih nekoliko sekundi bi verovatno odavno bili primećeni radarima onih službi što se brinu o lokacijama raznoraznog đubreta u orbiti (koliko znam led dobro reflektuje takve radio talase). Sigurno bi bili vidljivi i golim okom- uostalom i svaki satelit pristojnije veličine se pod povoljnim uslovima vidi golim okom. Pošto taj hipotetički led sigurno ne bi bio baš čist već bi sadržao i prašinu i slično, verovatno bi pri padu svakog ovakvog objekta nastao i prilično impresivan vatromet. Mrzi me da računam, ali verovatno bi sa takvom učestanosti i veličinom objekata sudar sa onolikim satelitima i drugim kosmičkim letelicama što se vrte unaokolo bio sasvim realna mogućnost.
zvezde.114 nenad,
Veliki problemi za orbitalnu stanicu Mir i dalje traju... The Russian space station Mir's problems could be just beginning after an unmanned cargo craft crashed into a crucial module, wiping out half the station's power, space experts said. "It's a complicated situation and it's going to take a lot of work to recover," Jerry Linenger, Mir's previous NASA resident, told a news conference Wednesday. The Progress cargo craft, which went out of control during a docking exercise Wednesday, ploughed into the station's Spektr module, causing a loss of air pressure and wrecking a solar panel. The power from the module's four electricity-generating solar panels was cut off when the crew shut the hatch to seal off the damaged, leaking compartment. Batteries used to power the station during the orbital night were also lost. The power loss is likely to have a snowball effect on other Mir systems and will make life difficult for the three-man crew, which includes British born NASA astronaut Michael Foale. They have already closed down some life-support systems to conserve energy. "It will be a darkened ship," Linenger said. "(They will have to be) very careful before switching anything on." The power loss could lead to rising carbon dioxide levels in the breathing air, so the crew will have to avoid exerting themselves, he added. Exercise, crucial for space travellers to ward off the delibitating effects of weightlessness, would have to be suspended. "The power is the main concern because you depend on that to keep your life support systems going and for the whole operation of the station," Linenger said. It may be possible for spacewalking astronauts to reroute electrical cables from the crippled module's solar panels to regain some of the station's lost power, said Frank Culbertson, who heads NASA's joint program with the Mir space station. "The Russians have a very good record in trouble-shooting problems in orbit," Philip Clark, editor of Jane's Space Directory, said. "In 1985, they brought the Salyut 7 station back from the dead." Just abandoning the Mir space station would not be an easy option, Clark said. The 130-140 tonne complex is too large for a safe reentry that would dump the space station into an ocean. Abandoned in space, Mir would probably fall to earth in four to five years. Its orbit takes it across most of the world's populated areas, in a band roughly south of London and north of Cape Horn at the tip of Argentina. Russian space officials have admitted they do not know what to do with the station when its useful life ends. The U.S. space shuttle might be able to help safely dispose of Mir before parts of it end up on the White House lawn, said Clark. "There will be incentive for NASA to help once they realise it could rain debris on Pennsylvania Avenue," he said. Russia's Salyut 7 space station, a fifth of the size of Mir, rained debris on South America when it reentered in 1991, but there were no reports of damage or injuries. Russia had hoped to operate the station until the planned international space station begins operations in early 1999.
zvezde.115 nenad, -> #113, vdjole
> Da nije ovde negde ipak neki lapsus sa redovima veličine za neki od > podataka. Zaista ne znam, vesti preuzimam iz proverenih izvora tako da ne bi trebalo da su u pitanju naklapanja već rezultati nekakvih (kakvih-takvih) naučnih istraživanja. > Objekti "veličine kuće" sastavljeni od leda a koji padaju > svakih nekoliko sekundi bi verovatno odavno bili primećeni radarima > onih službi što se brinu o lokacijama raznoraznog đubreta u orbiti > (koliko znam led dobro reflektuje takve radio talase). Hm... Za led zaista ne znam kako reaguje na radio talase, ali da se njegova interakcija sa vazduhom ipak ne dešava malo previsoko za radare? Ja se sećam nekih zvaničnih podataka i statistika o količini materije koja svakog minuta/dana padne na zemlju, možda se ovde samo radi i preciznijem određivanju sastava te materije? > Sigurno bi > bili vidljivi i golim okom- uostalom i svaki satelit pristojnije > veličine se pod povoljnim uslovima vidi golim okom. Ako van grada gledaš u noćno nebo uglavnom ne prođe 5-10 minuta između "zvezda padalica" koje se vide gore. To su, naravno, meteori, a možda je se baš radi o ovim ledenim? U svim tim meteoritima što dosegnu zemlju je, svakako, vodu najteže otkriti jer ako nešto i stugne do zemlje, ona sigurno ispari.
zvezde.116 nenad,
Najveća do sada zabeležena vulkanska erupcija... na Jupiterovom mesecu Io. :) Pele's Plume A newly released image from the Hubble Space Telescope shows the Jovian moon Io spouting off as never before. Last July HST captured a major eruption of Pele, one of Io's most powerful volcanoes. A sulfur-driven plume of gas and dust extended 400 kilometers into space, even higher than when seen during Voyager 1's flyby in 1979. For the plume to attain so great a height, John Spencer (Lowell Observatory) calculates that the material had to be escaping at nearly 1 km per second. Pele's spoutings are so big in part due to Io's low gravity and lack of a dense atmosphere, and in part because they are simply more energetic than volcanic eruptions here on Earth.
zvezde.117 nenad,
Prvi nalazi koji bi mogli da potvrde Ajnštajnovu pretpostavku da crne rupe "rotiraju". A New Spin on Black Holes In the June 20th issue of Astrophysical Journal Letters, Shuang Nan Zhang (NASA/Marshall) and others report that two black holes they've been studying with spacecraft are spinning 100,000 times per second. They deduced this by accurately determining the closest stable orbit to a given black hole, which depends on the latter's spin rate. Zhang notes that this knowledge will be enormously helpful in determining how much angular momentum a black hole has "swallowed" during its lifetime. The observations also confirm Einstein's prediction that black holes do spin.
zvezde.118 pdeze,
Pozdrav! Citajuci relativno novu knjigu Arthur C. Clarke-a: The Hammer of God (1993), nais'o sam na poglavlje u kojem se radi o Jupiterovim Trojancima, asteroidima koji se nalaze na Jupiterovoj orbiti 60 stepeni ispred i iza njega i koji se nalaze u nekom ekvilibrijumu sila Sunca i Jupitera... E sad, ja o tome (pre ovog) nisam cuo nista, pa ne mogu razluciti da li je to nauka ili fantastika (odlican ovaj Klark ;)) Pa ako Trojanci postoje, interesuju me koje su tu sve sile prisutne (osim gravitacije) koje 'drze' te asteroide u istom mestu. P.S. Naslov knjige sam napisao na engleskom posto nemam pojma kako je kod nas prevedeno
zvezde.119 petarg, -> #118, pdeze
>Trojanci Ekvilibrijum je ravnoteza. Trojanci postoje, i evo njihovog opisa iz knjige 'University Astronomy', koju s napisali Pasachoff i Kunter. JG trojan.txt
zvezde.120 nenad, -> #118, pdeze
> Pa ako Trojanci postoje, interesuju me koje su tu sve sile > prisutne (osim gravitacije) koje 'drze' te asteroide u > istom mestu. Trojanci postoje i jesu asteroidi (male planete), ali njihovo kretanje nije u direktnoj vezi sa Jupiterom. Jedina veza i interesantna stvar su njihove povremene okultacije sa njim.
zvezde.122 vdjole, -> #120, nenad
>Trojanci postoje i jesu asteroidi (male planete), ali njihovo > kretanje nije u direktnoj vezi sa Jupiterom. Jedina veza i > interesantna stvar su njihove povremene okultacije sa njim. Pa ako su u Lagranževim tačkama, kao što kaže u onom fajlu uz prethodnu poruku, onda valjda JESU u (gravitacionoj) vezi sa celinom Jupiter-Sunce. A ako slede/prethode Jupiter za 60 stepeni po orbiti oko Sunca, kako onda može on da ih zakloni?
zvezde.123 vdjole, -> #118, pdeze
> Pa ako Trojanci postoje, interesuju me U fajlu uz poruku 7.119 je lepo objašnjeno. Možda bi neko kome je to struka mogao malo opširnije da napiše nešto o Lagranževim tačkama- to je jedan od kurioziteta zakona nebeske mehanike i zasniva se na gravitacionim silama i položaju centra masa. Koliko je meni poznato, sistem od dva tela ima 5 Lagranževih tačaka - mesta koje predstavljaju stabilnu lokaciju za neki treći objekat. Često se opisuju na sistamu Zemlja-Mesec: Prva tačka je između Zemlje i Meseca, što bi se (malo neprecizno) reklo, tamo gde su njihova gravitaciona privlačenja jednaka (ako ste čitali "Put oko Meseca" Žila Verna kada ste bili mali...). Druga tačka je na pravoj koja prolazi kroz Zemlju i Mesec, ali IZA Meseca (tj. stalno na suprotnoj strani Meseca od Zemlje). Treća tačka je na istoj pravoj, ali stalno sa suprotne strane Zemlje u odnosu na Mesec. Četvrta i peta tačka se nalaze "levo i desno" od sistema Zemlja-Mesec (kao što su Trojanci "levo i desno" od sistema Sunce-Jupiter) i interesantno je da stabilne lokacije nisu u samim tačkama nego na nekim "pasuljoidnim" putanjama opisanim oko tih tačaka. Elem, ovo napisah koliko se sećam nečega što sam mnogo davno čitao, pa ako neko može to lepo da objasni...
zvezde.124 nenad, -> #122, vdjole
> A ako slede/prethode Jupiter za 60 stepeni > po orbiti oko Sunca, kako onda može on da ih zakloni? Onda sam ja nešto pomešao, tj. njih sam pomešao sa nekim drugim asteroridima. :)
zvezde.125 rdejan,
MARS IN ITS FIRST FULL WEEK, PATHFINDER DELIVERS CUTE NICKNAMES, MONSTER PANS AND AN EXTRATERRESTRIAL CRASH BY LEON JAROFF Barnacle Bill. Yogi. Casper. Scooby Doo. Flat Top, Boo-Boo. The Couch. Souffle. After billions of years of anonymity, a motley collection of rocks on the Martian flood plain called Ares Vallis at last had names of their own. And back on Earth last week, the Pathfinder scientists who had playfully nicknamed the rocks were enjoying, as one of them phrased it, "a rock festival," reveling in the torrent of data being yielded by the rock stars and their surroundings. Indeed, after only a week on the surface of Mars, Pathfinder had conducted dozens of worthy science experiments, had begun to challenge at least one long-held perception about the red planet and had transmitted more than 1,700 photos of the landscape, many of which were incorporated into a "monster pan," a spectacular 360[degrees], three-dimensional, horizon-to-horizon mosaic image that, when viewed through 3-D glasses, is almost as good as being there. The mission had also achieved a historic first on Mars: a motor-vehicle accident. The undisputed star of the week, however, surpassing even the rocks, was the 25-lb. Sojourner, which Rob Manning, Pathfinder's flight-systems chief engineer, dubbed "The Little Rover That Could." Having inched its way down the steeply inclined lander ramp, the six-wheeled Sojourner crept gingerly onto the Martian surface early last week and, in its first official scientific experiment, shoved the nose of its X-ray spectrometer into the dust at the foot of the lander. After bombarding the reddish dirt with helium nuclei and analyzing the resulting patterns of radiation, the spectrometer revealed that the soil was rich in iron and virtually identical to that examined at other sites 21 years earlier by the Viking landers. This suggested to scientists that Martian topsoil is widely distributed by the planet's frequent global dust storms. Why the reddish hue? "The surface of Mars is rusting," explains Jim Bell, a Cornell University scientist. Sojourner next turned toward Barnacle Bill, a 10-in.-high rock lying within arm's length of the lander, and closed in to sniff out its mineral content. Displaying a picture of the rover at the rock, the ever buoyant project scientist Matthew Golombek joked, "Here we have proof that Sojourner sort of nestled up and kissed Barnacle Bill." The high-tech buss, profferred by the rover's X-ray spectrometer, produced an unexpected finding: the rock was apparently loaded with silicon or silicon dioxide, commonly known as quartz. What surprised many scientists was that the data appeared to liken Barnacle Bill to andesites, which are volcanic rocks usually found on Earth in the Andes Mountains and other areas of explosive volcanism. Andesites are typically formed by the repeated melting, solidifying and remelting that occurs during the tectonic-plate processes that shape and reshape terrestrial continents. Yet Mars seems to have very few volcanoes and shows no signs of tectonic plates, which suggested to some scientists that the planet wasn't internally active long enough to form andesites. Then what process could have created Barnacle Bill? "How that happens in the absence of plate tectonics is not well understood," admits Robert Strom, a University of Arizona planetary scientist. To NASA Goddard scientist Jim Garvin, the finding suggests that a geology significantly more complex than scientists had expected was at work on Mars. "It's not the easiest rock to make," he says, "and that alone is very exciting." Sojourner also managed to obtain a "fingerprint" of the other chemicals in Barnacle Bill. The fingerprint turned out to be virtually identical to those of the 12 meteorites found on Earth that are believed to have Martian origins. "So," concluded University of Tennessee scientist Hap McSween after the visit to Barnacle Bill, "now we can say that we have analyzed 13 Martian rocks." Moving on, Sojourner headed toward a nearby, bear-shaped rock named Yogi, stopping on the way to test the consistency of the soil by using five of its wheels for traction and one to dig into the dirt. Sojourner's cameras showed that the rover's shove had displaced what seemed to be a thin layer of crust over the soil. "We used the rover as sort of a bulldozer," explained Golombek. Then, demonstrating a technique that any driver maneuvering into a tight parking spot would envy, Sojourner energetically swiveled its wheels back and forth and "crabbed" sideways into a position near Yogi. The next day, however, when the rover moved toward the rock to perform X-ray spectroscopy, says project scientist Justin Maki, "it got a little too enthusiastic." What really happened is that Sojourner's controllers at NASA's Jet Propulsion Laboratory failed to take into account a small outcropping at the base of the rock. Pushed ever so slightly upward, the rover gently bumped into the rock and began trying to climb it. As one of the rover wheels began rolling up the side of Yogi, sensors aboard Sojourner detected a tilt and shut down the little vehicle, leaving it hung up, in effect, on the rock. A low groan swept across the operations room at the J.P.L., and pictures transmitted by the lander soon afterward showed Sojourner askew, leaning against Yogi and seemingly helpless. But a quick check of the rover's systems confirmed that it was in good health, and controllers had little doubt that they could restart Sojourner, back it off the rock and try a better approach. No such luck. On Sol 6, NASA's designation for Pathfinder's sixth day on Mars, they transmitted the appropriate instructions to the lander, which was to relay them to Sojourner. But the Pathfinder team had inexplicably failed to awaken the lander, which is shut down every Martian night, and the message was not received. "One miscalculation cost us the whole evening," sighed J.P.L. deputy project manager Brian Muirhead. As a result, Sojourner remained incapacitated and unable to operate the next day. That led a rover team member to crack, "On the seventh day, it decided to rest." NASA has ambitious plans for Sojourner this week. It wants the rover to investigate Scooby Doo and Casper, two rocks that look intriguingly white in lander photos and just might contain hints of ancient Martian life. How so? To scientists, the duo's whitish hues suggest that they may be sedimentary rocks. "That would be awesome," says Ken Edgett, an Arizona State University geologist, "because sedimentary rock is the kind of thing that forms under water. And when you have water that sits around for a long time and sediments pour into it, the possibility of preserving fossils goes up." Pathfinder's lander too should have a busy week. It is scheduled to shoot pictures of the Martian sunrise and sunset, the moons Deimos and Phobos and other features of the landscape. Still, J.P.L. engineer Randii Wessen has some concerns. "We're living on borrowed time," he says. Sojourner has a 100% chance of surviving for seven days, he explains, "because that's what we designed it for. But after that, maybe it's got a 90% chance for eight days or 75% for two weeks." While the rover's electronics are protected in a warm box, the Martian temperatures, swinging wildly from 8[degrees]F to 130[degrees]F, may degrade the batteries. "We'll have to see how well they hold charges," says Wessen. Another threat, both to the lander--which is designed to survive for 30 days--and to the rover is Martian dust, which could coat the solar panels, affecting their ability to provide recharging current. Yet at week's end the lander batteries were recharging smartly, and Pathfinder mission manager Richard Cook seemed unconcerned about Sojourner's fast-expiring design life. "I think at this point we're all expecting it to live for a long time," he said. "It has proved to be very capable." And Cook was proved right. On the morning of Sol 8, Sojourner awoke, received its instructions and, after one more brief glitch, backed off Yogi, approached again and began eagerly sniffing out the rock's chemistry. Back at J.P.L., the exuberant Pathfinder team was predicting that Sojourner might live for weeks--and even months. Indeed, the little rover just could. --Reported by Dan Cray/Pasadena and Dick Thompson/Washington PS. Nije za online ;) Pozdrav, Dejan
zvezde.126 nenad,
Jednim od najznačajnih dostignuća u astronomiji ove godine smatra se povezivanje emisija gama zračenja sa vidljivim događajima. To do sada nije uspevalo, povremene emisije su detektovane a da se ništa nije znalo o njima, njihovom poreklu i prirodi. Međutim, možda ipak i dalje ne znamo mnogo - nijedna od propratnih pojava se nije desila _tačno_ na mestu gde su detektovani gama zraci. Something is outhere... ;) Another GRB Counterpart? One of the most significant developments in astronomy this year has been the association of visible objects with gamma-ray bursters. For three decades frustrated astronomers have observed random flashes of high-energy radiation from all over the sky with hardly any clues as to their origin. Typical events last only seconds or minutes, and they never repeat. No matter how hard they tried, researchers couldn't find anything visible at the positions of any of the thousands of gamma-ray bursts observed over the years. Success finally came when an orbiting X-ray telescope and several ground-based optical giants spotted counterparts to a gamma-ray burst on February 28th, then another on May 8th. Now a third optical counterpart appears to have been detected, this time following an intense event picked up last month by NASA's Compton Gamma Ray Observatory and several other satellites. The burst erupted in Cetus on June 16th and was over in less than 3Ż minutes. Four hours later, after the burst's position was nailed down to within a few arcminutes, NASA's Rossi X-ray Timing Explorer examined the area and detected an X-ray afterglow. Within a few days Japan's Advanced Satellite for Cosmology and Astrophysics found several variable X-ray sources in the vicinity, and the Keck II 10-meter telescope revealed a visible-light object fading from view. Curiously, none of these sources exactly match each other's position, and none lie squarely at the coordinates of the original gamma-ray burst. So perhaps none of these variables has anything to do with the burst after all! As astronomer A. Udalski (Warsaw University) put it on IAU Circular 6690, "Apparently the background of variable objects is high, and it may contribute significantly to false afterglow detections."
zvezde.127 nenad,
Evo prilike da zaradite 500 dolara - otkrijte asteroid čija se orbita ukršta sa Zemljinom. ;) Prvih 10 koji to urade dobijaju nagradu, a jedan asteroid je već otkriven. Benson Prize: 1 Down, 9 to Go Speaking of asteroids, three weeks ago James Benson of Space Development Corporation announced that he would award $500 to the first 10 amateur astronomers who discover minor planets whose orbits cross Earth's. And already we have a winner! Roy Tucker of Tucson, Arizona, picked up a fast-moving object in a sequence of CCD images made on the evenings of June 28th and 29th with his Celestron 14-inch telescope. Follow-up observations made over the next few nights by astronomers worldwide confirmed the 18th-magnitude blip to be a previously unknown minor planet. Designated 1997 MW1, it orbits the Sun every 0.91 year in an elongated path that brings it inside the orbits of the Earth and Venus. It is thus an Aten-type asteroid, only the 25th such object known. The Benson Prize was established to encourage amateurs to help locate the hundreds of Earth-crossers believed to inhabit the inner solar system. Space Development Corporation hopes to mine these asteroids for natural resources.
zvezde.128 castrvm,
Koga zanima moze upravo da pogleda zamracenje meseca .
zvezde.130 vstan,
- novo - windows/misc/*.* ================ skymap.exe 1877k ű Skymap 3.1.11: odlican astronomski program (Win95/NT)
zvezde.131 supers,
Na adresi http://ni.ac.yu/Prez/gid/izdanja/sunce/start.htm nalazi se kompletna Web verzija knjige Kako posmatrati Sunce Zorana Tanasijevića. Ova publikacija je vodič za teleskopsko i vizuelno posmatranje Sunca, fotografisanje i obradu podataka. Prezentacija obiluje slikama, od kojih su dobar deo animirani gifovi. Brižljivo je optimizovana da se može lako gledati i na 14400bps. Ima i malo JavaScripta, CP1250, best viewed with Netscape. Imao sam čast da učestvujem u izradi prezentacije :)
zvezde.132 stameni,
Na jugozapadnom delu neba se negde od 17:00 do 18:30 može videti jedan prilično sjajan objekat, koji je najverovatnije neka planeta, jer ne treperi i nije potpuno beo. Prema Skyglobeu, u to vreme se tamo nalaze Venera i Mars, ugaono jako blizu, pa je teško odrediti šta je to zapravo. Uz to, vidi se samo jedno telo. Ako neko ima efemeride za ovu godinu, ne bilo mu teško da pogleda da li u ovo kalendarsko doba manju magnitudu (odnosno magnitudu "više u minus") ima Mars ili Venera, da vidimo šta bi to moglo da bude. Inače, još od leta se na jugu uveče može videti Jupiter -- sada malo zapadnije.
zvezde.133 zormi, -> #132, stameni
* Na jugozapadnom delu neba se negde od 17:00 do 18:30 može * videti jedan prilično sjajan objekat, koji je najverovatnije neka * planeta, jer ne treperi i nije potpuno beo. Prema Skyglobeu, u to * vreme se tamo nalaze Venera i Mars, ugaono jako blizu Venera najverovatnije. Mars je crvenkast i mnogo manje sjajan.
zvezde.134 nbjvsb, -> #133, zormi
>> * Na jugozapadnom delu neba se negde od 17:00 do 18:30 moze >> * videti jedan prilicno sjajan objekat, koji je najverovatnije neka >> * planeta, jer ne treperi i nije potpuno beo. Prema Skyglobeu, u to >> * vreme se tamo nalaze Venera i Mars, ugaono jako blizu >> >> Venera najverovatnije. Mars je crvenkast i mnogo manje sjajan. Venera je, 100%. Akcenat na 'prilicno sjajan objekat'. Mars je, vizuelno, reda velicine sjajnije zvezde, pa ga je ponekad tesko prepoznati (ukoliko ne poznajes nebo dovoljno dobro), narocito ako je nisko nad horizontom kada treperi zbog zagadjenja, isparenja, i slicnih stvarcica iz atmosfere, dok je Venera prilicno raspoznatljiva (najsjajniji objekat na nebu posle Sunca i Meseca).
zvezde.135 nenad,
Novootkrivena najveća zvezda u našoj galaksiji. Do sada nije bila otkrivena jer se nalazi iza gustog oblaka prašine. Dvesta puta teža od sunca i zrači 10 miliona puta veću energiju. Ali, neće još dugo... Most Luminous Star There's apparently a new stellar heavyweight champion in the galaxy. It lies 25,000 light-years away in Sagittarius and is hidden from view by dense clouds of dust. The star was first spotted in infrared observations several years ago, but in 1995 astronomer Don Figer suggested that the star also created the surrounding cloud of glowing gas, which has been dubbed the Pistol Nebula. Figer has followed up with observations using the Hubble Space Telescope's recently installed Near-Infrared Camera and Multi-Object Spectrometer. The star -- which apparently emits 10 million times as much energy as the Sun -- may be only 1 to 3 million years old, and it will live for only another 1 to 3 million years before exploding in a supernova. While it initially may have been some 200 times the mass of the Sun, it is actively throwing off tremendous amounts of matter and so is not that massive now. The UCLA researcher and his team presented Hubble's view of the region this week, clearly showing material that Figer estimates was ejected 4,000 and 6,000 years ago.
zvezde.136 nenad,
Sve planete Sučevog sistema sem Plutona biće moguće videti istovremeno na nebu krajem novembra i početkom decembra. To se naravno mora desiti uveče ili ujutru (ovoga puta uveče), što znači da se mora posmatrati van grada. Tu negde će biti i mesec, detaljnije u tekstu koji sledi i slici uz poruku... Planet Parade If you get an early start in the evening, you can make a sweep of nearly all of the solar system's major planets. Venus through Neptune are well up as the sky darkens with evening twilight, while Mercury is gradually climbing above the southwestern horizon, approaching its greatest elongation from the Sun at the end of November. Starting from Mercury and heading east, you'll find Mars, Venus, Neptune, Uranus, Jupiter, and Saturn. Only 13th-magnitude Pluto is largely out of reach, as it is quite low above the west-southwest horizon. v971201.jpg
zvezde.137 nmaricic,
Voleo bih da konstruisem teleskop, pa ako neko ima korisnih saveta neka mi se javi. Nebojsa ű Maricic
zvezde.138 vdjole, -> #137, nmaricic
>Voleo bih da konstruisem teleskop, Vrlo široko navedena želja. Koliki, kakav, pošto?
zvezde.139 nmaricic, -> #138, vdjole
Kakav teleskop? Za posmatranje Meseca, Saturnovih prstena, pruga na Jupiteru...  Posedujem uputstvo za konstrukciju Njutnovog alt-azimutnog reflektorskog teleskopa 120/90, ali ono mi nije od velike pomoci. ┐╗ Uzgred, da li Astronomsko drustvo Rudjer Boskovic ima EMail?
zvezde.140 naumov, -> #139, nmaricic
ima
zvezde.141 pifat, -> #139, nmaricic
>>┐╗Uzgred, da li Astronomsko drustvo Rudjer Boskovic ima EMail? astrorbo@eunet.yu Prezentacija je na //solair.eunet.yu/~astrorbo
zvezde.142 pdeze,
Pozdrav! Nedavno sam poceo da se bavim posmatranjem promenljivih zvezda, posto sam se tek sad dokopao durbina sa precnikom od 8cm (4 godine mi je trebalo da objasnim direktoru gimnazije da sam ja nevidjeni potencijal za astronomiju ;) Trazim amatere, koji se aktivno bave promenljivima radi razmenjivanja iskustava i rezultata, tek da udjem u fazon. Oskar
zvezde.145 sherloc,
Zeleo bih da kupim teleskop, ali ne znam gde to ima da se kupi, pa ako neko zna bio bih zahvalan na informaciji. Citao sam ranije poruke, i primetio da se uglavnom govori da nema nigde ovde da se kupi, vec samo u inostranstvu, ali reko ko zna mozda se desilo nesto novo... Toliko.
zvezde.147 pdeze,
Pozdrav! Surfujem ja tako webom i naidjem na strava programcic na sajtu NASA-e. Toliko je dobar da nisam mogao odoleti da ga ne posaljem. LM, radi se o sajtu sa java appletom, koji prikazuje trenutni polozaj nekih satelita na orbiti projektovano na kartu sveta !!! To ukljucuje Mir, Hubble Space Telescope, UARS, COBE i GRO. Za ove nisam siguran, al' znam sta je Mir i HST ;) U zip su ubaceni svi fajlovi sa sajta koji su potrebni za applet (neke klase i tako to). A sta se tice kopirajta (dragi moderatori), sve je legalno (pitao sam). DL, pa recite kako vam se svidja! Ako vas interesuje skinuo sam jos i neki JPass, koji izracunava za nekih tridesetak satelita kada ce moci da se vide na nasem nebu, sa sve ucrtanim pravcem prolaska na zvezdano nebo !!! Sve ovo mozete naci i ovde: http://liftoff.msfc.nasa.gov/RealTime/Jtrack/Spacecraft.html jtracj.zip
zvezde.148 pvlada, -> #147, pdeze
> Ako vas interesuje skinuo sam jos i neki JPass, koji izracunava za Naravno, interesuje ;) Pozdrav Vlada
zvezde.149 pdeze, -> #148, pvlada
>> Ako vas interesuje skinuo sam jos i neki JPass, koji izracunava za > > Naravno, interesuje ;) Sorry, zakasnio si. Ostao sam bez modema od 14400, pa sad koristim jedan na 2400 :(((, tako da ne mogu poslati taj fajl. U svakom slucaju za one sa nalogom za inet, stvar (JPass) se nalazi na adresi: http://liftoff.msfc.nasa.gov/RealTime/JPass/JPass.html CU, Oskar