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  • An artist's concept shows a supernova, with energy from the exploding star slamming into a ring of gas ejected from the star long before the explosion itself. Several bright stars visible in the night sky will someday end their lives in such titanic explosions, perhaps endangering life on any planets within a few dozen light-years. None of the stars is close enough to endanger Earth, however. [Alexandra Angelich/NRAO/AUI/NSF] Text ©2014 The University of Texas at Austin McDonald ObservatoryFor more skywatching tips, astronomy news, and much more, read StarDate magazine.      Related StoriesMoon and the Scorpion - EnclosureMoon and the ScorpionSupernova Factory - Enclosure 

  • Several ticking time bombs are in view as darkness falls this evening. The list includes most of the bright stars of Orion, which is low in the west: orange Betelgeuse, the three stars of Orion’s Belt below it, and Rigel below the belt. And over in the southeast there’s Spica, the brightest star of Virgo. Each of these stars — and several others that are visible to the unaided eye — is destined to explode as a supernova — a blast that can outshine billions of normal stars. A supernova is bad news for any nearby planet. The explosion can strip away a planet’s protective ozone layer and bombard its surface with X-rays, gamma rays, ultraviolet radiation, and other nasty stuff. In fact, some studies have suggested that nearby supernovae could be responsible for mass extinctions distant past. Most studies put the “danger zone” at anything within a few dozen light-years of the supernova. Betelgeuse and the others are all hundreds of light-years away, though, so they shouldn’t be a problem. The greatest threat to life may come from other types of stars. When these stars explode, they channel jets of particles and radiation into space from their poles. These jets are like massive particle-beam weapons, exterminating any life within tens of thousands of light-years, and perhaps a good bit farther. No known stars in this class are aiming their poles toward Earth, so we appear to be safe from these megablasts.   Script by Damond Benningfield, Copyright 2014 For more skywatching tips, astronomy news, and much more, read StarDate magazine.      Related StoriesMoon and the Scorpion - EnclosureMoon and the ScorpionGlowing Civilizations? 

  • The Space Age was on display at the 1964 World's Fair in New York, which opened 50 years ago. Visitors could see a movie about Moon (top left), a Mercury capsule (bottom left), a Titan rocket and Gemini spacecraft (top right), and concepts about lunar bases (bottom right), among many other space-themed attractions. At center, the grand symbol of the fair was the Unisphere, a stainless steel sphere encircled by rings representing the orbits of early spacecraft. The fair ran for two years, drawing more than 50 million visitors. Text ©2014 The University of Texas at Austin McDonald ObservatoryFor more skywatching tips, astronomy news, and much more, read StarDate magazine.      Related StoriesLunar Eclipse - EnclosureLunar EclipseBlackout! - Enclosure 

  • NEWSREEL: Everyone is counting the days until the opening of the great New York World’s Fair — an exposition symbolized by the Unisphere, that dominates the grounds. The 1964 World’s Fair in Queens, New York, was all about the future. It opened 50 years ago today, offering visitors a chance to see TV phones, a computer that could read handwriting, and a futuristic new sports car: the Ford Mustang. Mostly, though, the fair was about the Space Age. Fountains and courtyards were named for the astronauts, the planets, and the universe, and many pavilions offered space exhibits. The transportation and travel pavilion was crowned by an 80-foot dome that was an accurate map of the lunar surface. And inside, visitors saw “Beyond the Moon,” a Cinerama movie projected on the dome itself. A rocket park displayed a real Mercury capsule and replicas of the Apollo Moon ship, probes to Mars and Venus, and the rockets to get them there. The fair’s centerpiece was the Unisphere, a 350-ton open-framework globe made of stainless steel. Three rings around the globe represented the orbits of early spacecraft. Most of the structures from the fair are gone. But the Unisphere was refurbished 20 years ago. Of course, it was then promptly smashed in “Men in Black” by a flying saucer disguised as an observation tower — one more relic of the early Space Age at the World’s Fair. NEWSREEL: The New York World’s Fair of 1964 promises something for everyone. See you at the fair!   Script by Damond Benningfield, Copyright 2014 For more skywatching tips, astronomy news, and much more, read StarDate magazine.      Related StoriesChanging Skies - EnclosureChanging SkiesBear’s Lodge - Enclosure 

  • It’s lonely out here in the galactic suburbs. The closest neighbors are light-years away — distances that are truly astounding. The distance to the Sun’s nearest stellar neighbor, Proxima Centauri, is almost 29 million times the Sun’s diameter. At that same scale, if you live in a house that’s 50 feet wide, your nearest neighbor would be more than a quarter-of-a-million miles away — farther than the Moon. That’s a pretty typical gap between star systems in this part of the galaxy — although not necessarily between individual stars. While the Sun is alone, many other stars have close companions. Proxima Centauri, for example, belongs to a system of three stars. The space between the stars isn’t completely empty. It contains wisps of hydrogen and helium gas, plus a tiny smattering of heavier elements. On average, there’s about one atom of gas for every cubic centimeter of space. There’s a lot more stuff packed together in the giant clouds known as nebulae. If they have enough gas and dust, they can give birth to new stars. Even so, by earthly standards a nebula still qualifies as a hard vacuum. The stars are all following their own orbits around the center of the galaxy, so over time, the distances between them varies. In 10,000 years, for example, Proxima Centauri will no longer be our closest neighbor. Instead, it’ll be Barnard’s Star, at just 3.8 light-years — about half a light-year closer than Proxima Centauri is today.   Script by Damond Benningfield, Copyright 2014 For more skywatching tips, astronomy news, and much more, read StarDate magazine.      Related StoriesBear’s Lodge - EnclosureBear’s LodgeMoon and Saturn - Enclosure 

  • The mild nights of spring are generally a good time for skywatching. Only one thing is missing: a great meteor shower. The really good showers are clustered in fall and winter, with the Perseids of August sometimes joining the list. Although the season doesn’t offer a great shower, a pretty good one is at its peak tomorrow night: the Lyrids. Under a dark sky, you might see up to a couple of dozen meteors per hour between midnight and dawn. The number of meteors increases closer to dawn, as your part of Earth turns into the meteor stream. Unfortunately, by then the last-quarter Moon will be in the sky, so its light will compete with the fainter meteors. One good thing about meteors, though, is that you don’t have to wait for a shower to see them. A shower occurs when Earth passes through a stream of small bits of rock shed by a comet or asteroid, which happens a few times a year. But other bits of rocky debris are scattered throughout the solar system. So on any dark night you can see several meteors zipping across the sky. And unlike the meteors in a shower, which all appear to “rain” into the sky from the same general point in space, these “random” meteors can come from any direction and blaze across any part of the sky. So if you have a chance, look for the Lyrid meteor shower in the wee hours of Tuesday morning. If not, then take advantage of just about any clear, dark night to look for meteors flashing across the heavens.   Script by Damond Benningfield, Copyright 2014 For more skywatching tips, astronomy news, and much more, read StarDate magazine.      Related StoriesBear’s Lodge - EnclosureChanging Skies - EnclosureBear’s Lodge 

  • If Gallup took a poll to find the best-known star pattern in the night sky, the odds are the winner would be the Big Dipper. Perhaps surprisingly, though, the dipper isn’t a constellation. Instead, it’s an asterism — a star picture that may be a part of a constellation, or that may not be related to any constellation at all. The stars of the dipper, for example, are part of Ursa Major, the great bear — they represent the bear’s body and tail. But the bear incorporates many other stars besides the dipper — and a dipper has little to do with a bear. But in some cultures, there’s a link between bears and the seven stars of the Big Dipper. A Kiowa story, for example, says that eight children — seven sisters and a brother — were playing at the edge of the Black Hills one day. The boy was suddenly struck by powerful magic. He was transformed into a bear and began to chase his frightened sisters. A tree called to them, and when they climbed into its branches it grew to an enormous size. The angry bear scratched and clawed at the tree, gouging deep grooves in its bark. But the sisters were borne safely into the sky, where they became the stars of the Big Dipper. The petrified stump of that mighty tree is known as the Bear’s Lodge — the Kiowa name for a stump-like mountain in Wyoming that’s also known as Devil’s Tower. Each night, the sisters look down upon it — from the safety of that most popular of star pictures, the Big Dipper.   Script by Damond Benningfield, Copyright 2014 For more skywatching tips, astronomy news, and much more, read StarDate magazine.      Related StoriesBright and Fast - EnclosureBright and FastChanging Skies 

  • Most of the world’s major observatories stand on remote mountaintops, far from the pesky glow of city lights. So as twilight fades away this evening, their skies will be speckled with an amazing richness of twinkling stars. And their telescopes have a clear shot at even more amazing sights — from stellar nurseries and the remains of dead stars to the feeble glow of distant galaxies. By shortly after midnight, though, those skies will look a good bit murkier — thanks to the Moon. Sunlight is illuminating more than 80 percent of the lunar hemisphere that faces our way, so the Moon shines brightly. Molecules of air scatter the moonlight, filling the sky with a faint glow — a weaker version of daylight. During the daytime, the air molecules scatter sunlight — especially bluer wavelengths, which is what makes the sky look blue. But the Sun is about 800,000 times brighter than the Moon is tonight, so the effect is much more dramatic — the stars are completely obliterated from view. Even so, there’s enough moonlight to cause astronomers to change their viewing tactics. Since they can’t see faint stars and galaxies when there’s a bright Moon in the sky, they instead look at brighter objects, which still shine through. And they must carefully calibrate their observations to subtract the effects of the moonlight. Still, there’s plenty for the casual skywatcher to see, as bright stars and planets shine through the Moon’s hazy veil.   Script by Damond Benningfield, Copyright 2014 For more skywatching tips, astronomy news, and much more, read StarDate magazine.      Related StoriesNorth Galactic Pole - EnclosureNorth Galactic PoleMoon in the Middle - Enclosure 

  • Thousands of galaxies of all sizes, shapes, and distances congregate in this newly released Hubble Space Telescope image. Some of the small, red galaxies are perhaps 10 billion light-years away or farther, while some of the larger ones are much closer. The image includes a prominent gravitational lens (bright white ring to the lower left of center), in which the gravity of two large galaxies is bending and magnifying the light of a distant quasar. The image was compiled over 14 hours of observations in both optical and infrared wavelengths. [NASA/ESA] Text ©2014 The University of Texas at Austin McDonald ObservatoryFor more skywatching tips, astronomy news, and much more, read StarDate magazine.      Related StoriesNorth Galactic Pole - EnclosureNorth Galactic PoleRunaway Stars - Enclosure 

  • The heart of the scorpion is doomed. Sometime within the next million years or so, the star Antares is likely to blow itself apart as a supernova. Only its tiny, dead core will remain — a neutron star. That same fate awaits several other bright stars in Scorpius, including one that’s quite close to the Moon tonight. Acrab is to the right of the Moon as they climb into view after midnight, at the end of a short line of three stars that represents the scorpion’s head. Acrab is actually a stellar sextuplet. It consists of two tight pairs of stars, each of which has a distant companion. The two triplets are then bound to each other as well, giving Acrab six stars in all. Two of those stars appear to be at least 10 times as massive as the Sun. That’s above the weight limit that determines which stars will explode as supernovae. So within a few million years, the cores of each of these stars probably will collapse, and their outer layers will blast into space. For a few weeks, each explosion will shine as brightly as billions of normal stars. After that, the stars will fade from sight. For now, though, Acrab remains in good view. Look for it just to the right of the Moon after midnight. Much brighter Antares, the orange star that marks the scorpion’s heart, stands below them. And an even brighter pinpoint of light — the golden planet Saturn — is farther to their upper right. The whole tableau is low in the southwest at first light.   Script by Damond Benningfield, Copyright 2014 For more skywatching tips, astronomy news, and much more, read StarDate magazine.      Related StoriesSupernova Factory - EnclosureSupernova FactoryOutbursts - Enclosure 

  • The Moon and the planet Saturn stage quite a performance tonight. They rise in late evening, with bright golden Saturn quite close to the upper left of the Moon. They remain close as they arc low across the south during the wee hours of the morning, with Saturn moving to the right of the Moon at first light. Saturn has quite a collection of moons of its own. More than 50 have been confirmed, with several more on the list of possibilities. Some of these moons are fascinating worlds in their own right. Titan, the largest of them, has a dense, cold atmosphere made of hydrocarbons. Lakes of liquid methane and ethane dot its surface, and an ocean of liquid water may lie far below Titan’s icy crust. Liquid water also lies beneath the crust of Enceladus, which is near the outer edge of Saturn’s rings. But some of its water escapes into space through powerful geysers near the moon’s south pole. The water freezes, adding fresh ice to one of the rings. These moons probably formed along with Saturn itself. But many of the planet’s moons may be asteroids that were captured when they flew close to Saturn. Such a capture would have been easier early in Saturn’s life, when it was likely encircled by gas and dust left over from its formation. Friction with this material slowed the asteroids, allowing them to enter orbit — adding to Saturn’s impressive entourage of moons. We’ll talk about the Moon and more bright companions tomorrow.   Script by Damond Benningfield, Copyright 2014 For more skywatching tips, astronomy news, and much more, read StarDate magazine.      Related StoriesMoon and Saturn - EnclosureEmptiness - EnclosureSpace Fair 

  • A bright streak at the bottom of Saturn's rings may be caused by a small, icy moon that is growing as it captures more ice particles from the rings. The scientists who discovered this possible moon, nicknamed "Peggy," say it could be migrating out from the rings, scattering ring particles in its path. The Cassini spacecraft snapped this image on April 15 at a distance of about 775,000 miles (1.2 million km). [NASA/JPL/SSI] Text ©2014 The University of Texas at Austin McDonald ObservatoryFor more skywatching tips, astronomy news, and much more, read StarDate magazine.      Related StoriesEmptiness - EnclosureSpace FairEmptiness 

  • The star patterns that form pretty pictures in the night sky are all temporary. Over time, their shapes will change, erasing the old pictures and creating new ones. It’s not something that’s visible in a human lifetime — or, with a few exceptions, in a hundred lifetimes. One of those exceptions is Arcturus, one of the brightest stars in the night sky. The yellow-orange star is in the east as the sky gets good and dark, well to the upper left of the Moon. Don’t confuse it with the brighter orange light that’s above the Moon — the planet Mars. One reason Arcturus shines so brightly is that it’s a close neighbor — just 37 light-years away. In fact, it’s about as close right now as it ever will be. Arcturus is racing across the sky at about 270,000 miles per hour relative to our own solar system — roughly the distance from Earth to the Moon. That’s faster than any of the other especially bright stars in the night sky. As a result of that motion, Arcturus will fade from view in a hurry — astronomically speaking. A million years from now it’ll be lost from view. In the meantime, its motion will drastically alter the pictures of a couple of constellations. Today, Arcturus is the leading light of Bootes, the herdsman. But 50,000 years from now it’ll have moved one constellation over, and will be shining near the bright star that lines up between the Moon and Mars tonight — Spica, the leading light of Virgo.   Script by Damond Benningfield, Copyright 2014 For more skywatching tips, astronomy news, and much more, read StarDate magazine.      Related StoriesBear’s Lodge - EnclosureBear’s LodgeBright and Fast - Enclosure 

  • Tonight is one of the best skywatching nights of the year. The planet Mars blazes through the night like a brilliant orange beacon, with the bright star Spica nearby. But what really elevates the night is a total lunar eclipse, which takes place just a few degrees away from Mars. The eclipse occurs as the Moon passes through Earth’s long shadow. The Moon’s orbit is tilted a little, so most months the Moon passes outside the shadow. This month, though, the geometry is just right, creating a total eclipse. The Moon first touches the dark inner shadow at 12:58 a.m. Central Daylight Time. Over the following hour, the shadow will appear to take a bigger and bigger “bite” out of the lunar disk. The Moon will be fully immersed by 2:06, and will remain totally eclipsed for almost an hour and 20 minutes. Sunlight filtering through Earth’s atmosphere usually gives the eclipsed Moon a dark orange or red color, although your ability to see it depends on your viewing conditions and your color sensitivity. The Moon will exit the shadow, bringing the partial eclipse to an end, a little more than an hour later. And to add to the night sky’s entertainment, the star Spica huddles quite close to the Moon. At their closest, they’ll be separated by just a degree or so — the width of your finger held at arm’s length. Spica will look a bit pale next to the uneclipsed Moon, but should be especially beautiful as the eclipse unfolds.   Script by Damond Benningfield, Copyright 2014 For more skywatching tips, astronomy news, and much more, read StarDate magazine.      Related StoriesMore Lunar Eclipse - EnclosureChanging Skies - EnclosureChanging Skies 

  • If the Moon’s orbit around Earth were aligned just a little differently, human history might have played out a little differently, too. That’s because eclipses of the Sun and Moon have played pivotal roles in some historical events. Lunar eclipses occur when the Moon passes through Earth’s shadow, while solar eclipses occur when the Moon crosses in front of the Sun, blocking it from view. But the Moon’s orbit is tilted with respect to Earth’s orbit around the Sun. So most months, the Moon, Sun, and Earth don’t line up properly to cause an eclipse. The geometry is right only a few times per year, so any given location on Earth sees a total lunar eclipse every year or so, and a total solar eclipse every few decades. Because eclipses are rare, they were hard to predict — and that made them scary. In 413 BC, for example, the army of Athens suffered a major defeat when it delayed retreating after a lunar eclipse. And two millennia later, Christopher Columbus and his men avoided starvation when Columbus accurately predicted another eclipse, causing hostile natives in the New World to bring them food. If the Moon’s orbit were perfectly aligned with the Sun, though, then eclipses would be so common that they would have attracted far less concern — perhaps changing the course of history. An eclipse will darken the Moon tomorrow night. A nearby star and planet will help make it an unforgettable experience — which we’ll talk about tomorrow.   Script by Damond Benningfield, Copyright 2014 For more skywatching tips, astronomy news, and much more, read StarDate magazine.      Related StoriesLunar Eclipse - EnclosureMore Lunar Eclipse - EnclosureMore Lunar Eclipse 

  • Our home galaxy, the Milky Way, is shaped like a giant pancake. On dark nights, away from city lights, you can see the outline of that disk as the hazy band of light known as the Milky Way. Tonight, with the help of a bright star, you can gaze straight up and out of the disk — deep into intergalactic space. One of the two points where we look perpendicular to the Milky Way's starry disk is called the north galactic pole. It has nothing to do with the North Star, which is above Earth's north pole, marking the north celestial pole. Unfortunately, no bright star marks the galactic pole, which is in the faint constellation Coma Berenices. But you can still find the galactic pole’s rough position thanks to the bright orange star Arcturus. Arcturus is the fourth-brightest star in the night sky. Look for it in the east as night falls. If you need help finding it, just look for the Big Dipper. Follow the curve of the dipper’s handle away from the bowl, and you’ll “arc to Arcturus.” Now, to find the north galactic pole, look just a little to the west of Arcturus. There, you’ll be gazing nearly straight out of the Milky Way’s disk of stars, into a universe of galaxies. In fact, the two best-known galaxy clusters — the Virgo cluster and the Coma cluster — lie quite close to the galactic pole, so this part of the sky often attracts astronomers who study galaxies beyond our own. Tomorrow: getting ready for a lunar eclipse.   Script by Ken Croswell, Copyright 2014 For more skywatching tips, astronomy news, and much more, read StarDate magazine.      Related StoriesChanging Skies - EnclosureChanging SkiesNorth Galactic Pole - Enclosure 

  • A total lunar eclipse will grace skies across the United States several hours before dawn on Tuesday, April 15, according to the editors of StarDate magazine. read more       

  • Like young birds that are leaving their nests for good, a few stars are taking wing from their galactic nest. They’re moving so fast that they’ll eventually escape from the Milky Way and head into the vastness of intergalactic space. They’re known as “hypervelocity” stars. They’re moving more than a million miles per hour faster than the other stars in the galaxy. And they seem to come in two varieties. One consists of hot, heavy stars that were kicked out of the galaxy’s core. The other consists of stars that are similar to the Sun residing away from the core. The first group was discovered almost a decade ago. These stars originally had stellar companions. These systems passed close to the supermassive black hole at the galaxy’s heart. A gravitational dance resulted in one of the stars being captured by the black hole, with the other getting a kick powerful enough to propel it out of the galaxy. The second group was discovered just last year. A team of astronomers looked at a survey of hundreds of thousands of stars. The study revealed about 20 stars moving fast enough to escape the galaxy. Unlike the other group, though, these stars appeared to come from the galaxy’s disk, well outside the core. All of the stars are similar to the Sun. There’s no obvious way for these stars to get a strong enough kick to leave the galaxy behind. That leaves the astronomers with a mystery to solve — the mystery of the runaway stars.   Script by Damond Benningfield, Copyright 2014 For more skywatching tips, astronomy news, and much more, read StarDate magazine.      Related StoriesRunaway Stars - EnclosureMoon and Saturn - EnclosureMoon and Saturn 

  • Powerful winds and radiation from a pulsar (bright dot at center of green and purple cones) heat and erode a companion star in this artist's concept. Over time, this process may completely evaporate the companion. The pulsar spins rapidly, emitting beams of energy (the colored cones) that can be seen from Earth as pulses of energy. [NASA/GSFC/Cruz deWilde] Text ©2014 The University of Texas at Austin McDonald ObservatoryFor more skywatching tips, astronomy news, and much more, read StarDate magazine.      Related StoriesBlack Widow Pulsars - EnclosureBlack Widow PulsarsMoon and Saturn 

  • Black widows lurk among the stars. They slowly destroy their companions, ingesting part and sweeping away the remains. These nasty-sounding objects are pulsars — the spinning corpses of once-mighty stars that blasted themselves apart. All that’s left is their crushed cores, known as neutron stars. Some neutron stars spin, emitting beams of energy that sweep across the cosmos like a lighthouse. From Earth, we see such a beam as on-and-off pulses — hence the name “pulsar.” Some pulsars have companions — “normal” stars like the Sun, or perhaps the “failed” stars known as brown dwarfs. Radiation from the pulsar heats the companion, causing it to puff up and lose its grip on the hot gas at its surface. Some of the gas is pulled in by the pulsar, causing it to spin faster — up to hundreds of times per second. But pulling material off the surface of its companion is only half of the story of a black widow. In some cases, the pulsar’s radiation also erodes the surface of its companion like a blowtorch, with gas streaming away from the pulsar. Over time, the combination of accretion — pulling material into the pulsar — and erosion — blasting stuff away from the pulsar — can completely destroy the companion. So far, astronomers have caught only a handful of black widows in the process of destroying their companions. But they suspect that many more have already finished the deed — dead stars that have devoured their mates.   Script by Damond Benningfield, Copyright 2014 For more skywatching tips, astronomy news, and much more, read StarDate magazine.      Related StoriesBlack Widow Pulsars - EnclosureDoomed MateMoon and Saturn 

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