In the Sky Tonight
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Two bright morning "stars"
Monday, November 28, 2005
Looking East-Southeast One Hour Before Dawn
Today, we look at two objects lighting up our predawn skies. If you look towards the east-southeast about an hour before sunrise tomorrow, you may be able to make out a very slim waning crescent moon. To the lower left of the skinny moon, you may notice a bright "star" closer to the horizon. This object is no star -- it is the giant planet Jupiter. To the upper right of the moon is another bright object. This one actually is a star -- it's Spica, the brightest star in the constellation Virgo the Maiden. -
Flashing Herdsman star
Tuesday, November 29, 2005
Looking East-Southeast One Hour Before Dawn
TodayÂ’s chart is set at the same time and place as yesterdayÂ’s. Notice that the ever-slimming waning crescent moon has now moved below Jupiter in its position in the sky. Higher in the sky, and to the east of the moon, you may notice an orange-ish star, flashing brightly. This star is Arcturus in the constellation Bootes the Herdsman. It flashes so because itÂ’s relatively low in the horizon and youÂ’re seeing it through a greater thickness of atmosphere than when itÂ’s high overhead. The atmosphere refracts or splits the starsÂ’ light to cause the colorful flashing that you see. Arcturus is a giant star with an estimated distance of 37 light-years. It's special because it's not moving with the general stream of stars, in the flat disk of the Milky Way galaxy. Instead, Arcturus is cutting perpendicularly through the galaxy's disk at a tremendous rate of speed . . . some 150 kilometers per second. -
Flashing star in northeast
Tuesday, November 29, 2005
Looking North-Northeast Shortly After Sunset
The bright star Capella in the constellation Auriga the Charioteer can be found shining bright and strong low in the northeastern sky shortly after sunset. It's the sixth brightest star in the sky, and now it's located to the north of another identifiable object -- the red planet Mars, which is up in the east at sunset. Although the red planet is much brighter than it, Capella will still draw the attention of skywatchers with its apparent flashing of red and green colors in the sky. Its colorful appearance when seen low in the sky isn't unusual. Any bright star can appear to flash different colors when near the horizon -- because then you're looking at the star through a greater thickness of Earth's atmosphere than when the same star is overhead. Also, you sometimes glimpse a bright star through polluted air, or even just haze or clouds low in the sky. These factors, too, can distort the light of stars and planets seen near the horizon. -
Hunter easily visible at nightfall
Wednesday, November 30, 2005
Looking East-Southeast in Mid-Evening
Orion the Hunter. Orion contains a very noticeable pattern of three medium-bright stars in a short straight row -- Alnitak, Alnilam, and Mintaka -- the stars which represent Orion's Belt. Orion is in the east-southeast by mid evening at this time of year. The stars in Orion aren't the same distance from Earth. Most stars in constellations aren't physically bound to each other in any way. In the case of Orion, the brightest stars in the constellation lie at similar distances, hundreds of light-years away. Rigel is an estimated 773 light-years away, Betelgeuse 522 light-years, Saiph 815 light-years and Bellatrix 243 light-years. And itÂ’s no coincidence -- when we look toward Orion, we're looking toward the outer edge of the galaxy . . . but into the very arm of the galaxy in which our sun resides (or near which our sun resides -- astronomers aren't sure). So these bright stars in Orion just happen to be giant stars in that nearby spiral arm of our Milky Way galaxy. -
“Star hop” courtesy of the Hunter
Thursday, December 1, 2005
Looking East-Southeast in Mid-Evening
Today's chart is a wider look at the region of the sky we showed you yesterday -- the east-southeastern sky around 9 p.m. Here you'll find two prominent constellations -- Orion the Hunter and Taurus the Bull. Once you find Orion, you can use it to "star hop" to other nearby stars in other constellations. For example, if you draw an imaginary line through Orion's Belt, you'll see that it points in one direction to the reddish star Aldebaran, which lies in a V-shaped pattern of stars representing the Face of the Bull in the constellation Taurus. Aldebaran is located some 65 light-years away. It represents the fiery red eye of the Bull. But don't stop there. -
“Star hop” to Dog Star
Friday, December 2, 2005
Looking Southeast In Late Evening
The constellation Orion is in the east-southeast by mid evening at this time of year. TodayÂ’s chart shows Orion over the southeast in late evening. Once you find Orion, you can use it to "star hop" to other nearby stars in other constellations. For example, in yesterdayÂ’s chart, we showed how you could locate the star Aldebaran by drawing a line through OrionÂ’s Belt. The same line drawn through Orion's Belt points in the other direction to Sirius, the sky's brightest star. In skylore, Sirius is called the Dog Star. It bears that name because it belongs to the constellation Canis Major the Greater Dog. And that's how you come to know the constellations. You use what you've already learned to "build" outward to find new patterns. -
Crescent sister planet
Saturday, December 3, 2005
Looking Southwest Shortly After Sunset
Here is a view of the planet Venus and a very young waxing crescent moon in the southwest shortly after sunset. A skywatcher from Leonardtown, MD wrote, “On Thanksgiving evening we saw what appeared to be a partial eclipse of Venus. What was causing the eclipse?” Venus is one of two worlds in our solar system that orbit the sun inside Earth’s orbit. And so Venus, like the other inner planet Mercury, shows phases like a tiny moon. Every night for the next month or so, you’ll find Venus in the west after sunset. If you could view it through a telescope tonight, you’d find it approximately 32% illuminated. It’s not that it’s eclipsed -- Venus’ lighted half or dayside is facing mostly away from us. Astronomers call this a “crescent” phase. This may seem confusing, as Venus is quite bright in our skies, but has less than half of its “dayside” facing us. This is because although it is in “crescent” phase, and its dayside is currently waning, the planet itself is very close to us, and so appears large in our sky. It’s illumination will continue to decrease until mid January of next year, when it flies between the Earth and the sun in its inferior conjunction. -
Venus near crescent moon tonight
Sunday, December 4, 2005
Looking South-Southwest Shortly After Sunset
TodayÂ’s chart is just like yesterdayÂ’s chart, except that itÂ’s one day later and the waxing crescent moon has moved in its orbit around Earth -- and so itÂ’s closer to the planet Venus. Venus is going to get brighter in the coming month. Since the beginning of October, Venus has begun getting noticeably brighter and higher in the sky for us all -- especially for those of us in the northern hemisphere. Our sister planet reached its greatest eastern elongation, or its greatest angular separation from the sun for itÂ’s evening appearance, on November 3rd. Improving visibility of the planet will continue to delight watchers until December 9th, when Venus will attain its greatest brilliancy in its cycle. -
North Star prominent in predawn sky
Tuesday, December 6, 2005
Looking North-Northeast One - Two Hours Before Sunrise
Today we will show where skywatchers can find Polaris, also known as the North Star, in their skies. Polaris can actually be seen at any time of night. At this time of year, the easiest time to look for it is before dawn -- then you can use the Big Dipper as a guide. The two outer stars in the bowl of the Big Dipper, called Dubhe and Merak, always point to Polaris. There is another neat trick to finding Polaris. Your latitude gives you its height above the northern horizon. In other words, from the latitude of the southern U.S. -- say about 30 degrees N. latitude -- the pole star is 30 degrees above the northern horizon. From a latitude of 40 degrees N., it is 40 degrees up -- and so on. -
Big Dipper vs. Little Dipper
Wednesday, December 7, 2005
Looking North-Northeast One - Two Hours Before Sunrise
“How can I tell apart the Big Dipper from the Little Dipper?” We’re showing you the Big and Little Dippers as they appear before dawn now in today’s chart. The Big Dipper, in the constellation Ursa Major is always easier to find, because it really does look like a dipper. The Little Dipper is much harder to find, because it isn’t shaped like a dipper at all and is generally fainter than the Big Dipper. If you have a dark enough sky, you can find the Little Dipper by using the Big Dipper as a guide, the same way as in yesterday’s chart. Let your eyes gaze north-northeastward in the hour or so before dawn. The Big Dipper should be fairly easy to spot as a large, dipper-shaped star pattern. Its two outermost stars, Dubhe and Merak, are often called “The Pointers” because they point toward Polaris, the North Star. Polaris marks the end of the handle of the Little Dipper in the constellation Ursa Minor. The Little Dipper is faint, but you should be able to see Polaris, along with Kochab and Pherkad, the two outer stars in the Little Dipper’s bowl. -
"Lonely One" near moon tonight
Wednesday, December 7, 2005
Looking Due South Shortly After Sunset
There's the zodiacal constellation Pisces -- and then there's the "other" Piscis -- Piscis Austrinus, the Southern Fish. The moon has been sweeping near its brightest star Fomalhaut on the dome of our sky for the past couple of nights. Look for the pair in the south shortly after sunset tonight. Fomalhaut is sometimes called "The Lonely One" or "The Solitary One" because it's the only bright star in its region of this sky. -
Little Dipper or Seven Sisters?
Thursday, December 8, 2005
Looking East A couple of Hours After Sunset
"I am looking towards the east, and I see stars in the shape of a dipper pattern. Is this the Little Dipper?"
No, it isn't. The Little Dipper is always in the north -- never in the east. Both the Big and Little Dippers are not easily seen during the evening hours at this time of year. We suspect you're seeing a different star pattern... one that many people mistake for the Little Dipper -- the Pleiades, sometimes called the Seven Sisters. It's very easy to recognize as a dipper-shaped pattern in the night sky. This tiny dipper appears to be wrapped in a veil of mist. It's been near the bright red planet Mars these last couple of months. When you see these stars, you might want to recall that they are siblings of sorts. Most stars that make patterns on our sky's dome aren't really related to each other, but the Pleiades stars are related. They were born from a single cloud of gas and dust in space and still move together through the galaxy. -
Venus reaches greatest brilliancy
Friday, December 9, 2005
Looking West-Southwest Shortly After Sunset
Around now, many people will look in the west after sunset, and be dazzled at the sight of a large bright object in the western twilight sky. It's quite amazing. ItÂ’s the planet Venus, which reaches greatest brilliancy during the night tonight. You can use todayÂ’s chart to identify a famous pattern of stars sweeping wide over the western horizon -- the Summer Triangle. -
Pleiades' "half sister" cluster
Saturday, December 10, 2005
Looking East-Southeast at Nightfall
Tonight, look for the Hyades star cluster -- not just a pattern on our sky's dome -- but an actual, gravitationally bound cluster of stars in space. You can find it in the eastern horizon, south of the bright red planet Mars, now high in the southeast at nightfall. To the eye, the Hyades appears to be shaped like the letter V (you'd see many more stars if you looked through binoculars or a telescope). On the sky's dome, this V represents the face of Taurus the Bull. In the lore of the sky, the Hyades are half-sisters to another cluster of stars, also in the constellation Taurus -- the Pleiades star cluster. For more about the Pleiades, see our chart for December 8th. Notice the reddish star Aldebaran, which appears to be a part of the V-shaped Hyades cluster. Aldebaran, one of the brightest stars in our sky, represents the Bull's fiery red eye. But at about 60 light-years away, Aldebaran is only about half the distance to the Hyades star cluster in space, and so not a true part of the Hyades cluster. -
Eastern sky at dusk
Monday, December 12, 2005
Looking East A Couple of Hours After Sunset
Here is a view of the eastern sky about one to two hours after sunset. The nearly full waxing gibbous moon will be to the lower left of the red planet Mars, still marvelously bright in our skies. The tiny dipper-shaped Pleiades star cluster can be found to the lower left of the moon. Below the Pleiades, your eye may catch a bright red object above the eastern horizon. This star -- Aldebaran of the constellation Taurus the Bull -- is easy to tell apart from Mars as it is the smaller bright red object closer to the horizon. Towards the northeast, you might catch a lone bright object flashing appropriately festive red and green colors. This is the star Capella of the constellation Auriga the Charioteer, and its flashing ability is tied to its current location near our horizon. -
'Fuzzy' patch on Hunter
Tuesday, December 13, 2005
Looking East-Southeast at Nightfall
Orion is perhaps the most prominent constellation at this time of year. Here it is in the east-southeast around 8-9 P.M. Later at night, you'll see Orion arcing across the southern sky. The Belt of Orion consists of three medium-bright stars in a short, straight row (Alnitak, Alnilam and Mintaka) cinching the "waist" of the Hunter. The Sword of Orion hangs from the Belt as a curved line of stars. About midway down the Sword, as you gaze with your binoculars (or even with your eye if your sky is dark enough), you'll notice that one "star" appears fuzzier than the others. Telescopes show a vast cloud in space! This is the famous Orion Nebula. It's part of a vast cloud in space, a stellar "nursery," a place where new stars are being born. When you use a telescope to look at this region, you can see four bright stars within the nebula, called the Trapezium, whose light reveals they are only a few million years old -- practically babies in star-time! -
Full moon blocks Geminid peak
Looking East-Southeast at Late Evening/Midnight
Thursday, December 14, 2005
Tonight marks the peak of the yearly Geminid meteor shower, usually a spectacular shower (up to 80 meteors an hour) that often times can be as rich before midnight as after. Unfortunately, a nearly full moon will block all but the brightest meteors from view tonight and tomorrow night. The radiant, or point in the sky from which the meteors seem to radiate from for the Geminids is, of course, the constellation Gemini the Twins. You don't need to know the location of the radiant point for a meteor shower in order to view it -- it's quite the opposite! If you can visually trace any meteor backwards in the sky, then you can be sure that you have found the radiant point. -
Northernmost full moon
Thursday, December 15, 2005
Full Moon Will Be Visible All Night
This is a view of tonight’s full moon, which is high in the east at mid-evening -- but it will be visible all night. It can be seen against a blanket of bright stars -- most notably the dogstars Sirius and Procyon, as well as Capella of the constellation Auriga, Aldebaran of the constellation Taurus, and the stars of the constellation Orion. The December full moon is known as the “Cold Full Moon” or the “Full Long Nights Moon.” Both names are appropriate for obvious reasons -- it’s typically cold in December, and the winter nights are longer. The full December moon is also known for typically being the full moon that takes the most northern path in our sky for the year. And tonight’s full moon is extra special -- it takes an even higher path than usual. The moon is now entering into a cycle that repeats itself about every 18.6 years -- a lunar standstill cycle. This cycle is similar to the solar solstice, and involves the moon traveling its northernmost or southernmost path in our skies. And because of this cycle, tonight’s full moon will be the northernmost one in our skies until the year 2023! -
Betelgeuse near moon in southeast
Friday, December 16, 2005
Looking East-Southeast at Late Evening
TodayÂ’s chart continues tracking the moon in its path across our evening skies. In the east-southeast around late evening, you will see the bright flashing star Sirius near the southeastern horizon. The star Betelgeuse -- one of the biggest stars known though it looks like any ordinary bright star -- can be found to the south of the waning gibbous moon. Betelgeuse is much bigger than Sirius, which appears larger in our sky because it is definitely much closer to us. You see different estimates for the distance of Betelgeuse from Earth. The indispensable Observers Handbook lists its distance as 522 light-years . . . while astronomer James Kaler says that Betelgeuse is most likely 425 light-years away. Distance is important because it figures into estimates of the size of this star. Just taking into consideration the smaller estimate of a 425 light-year distance, the measured angular diameter of Betelgeuse suggests a radius 630 times that of our sun! -
Flashing star low in southeast
Saturday, December 17, 2005
Looking East-Southeast at Late Evening
TodayÂ’s chart is set in the same time and direction as yesterdayÂ’s. You can find the two bright dogstars, Procyon and Sirius to the south of the moon, close to the southeastern horizon. TonightÂ’s focus is on the brighter dogstar Sirius in the constellation Canis Major. ItÂ’s the brightest star visible from any part of Earth. It doesnÂ’t shine as brightly as the planets Venus or Mars now, but it does outshine every star in the night sky. When Sirius is located high above the horizon, it twinkles less and flashes fewer colors. But as the seasons progress, and Earth moves around the sun, our vantage point on Sirius shifts. Now this star is relatively low in the southeast in late evening. When we look at objects low in the sky, we see them through a greater thickness of EarthÂ’s atmosphere than when they are overhead. And so flashing colors of green and red can be seen emanating from Sirius. This apparent flashing comes from the refraction (or splitting) of starlight as it travels through Earth's atmosphere. All the stars have their light split in this way by our atmosphere. But the colors are more noticeable with Sirius, because it's such a bright star! -
Jupiter in southeast before dawn
Tuesday, December 20, 2005
Looking Southeast One Hour Before Sunrise
Jupiter is the second-brightest planet visible in EarthÂ’s sky, after Venus. Right now, Venus is long gone below the western horizon by the time Jupiter ascends in the east-southeast about three hours before dawn. And after Jupiter rises it lives up to its reputation for being bright! It dominates the predawn sky, outshining everything else up there with the exception of the moon. If you would like to catch Jupiter, try looking for the planet an hour before dawn, when youÂ’ll find it in the southeastern sky, along with the stars Spica to the upper right and Arcturus shining to its upper left. By April of next year, Jupiter will be appearing at a more convenient time of night. Earth will pass between Jupiter and the sun on May 4, 2006. -
Winter vs. summer sky
Tuesday, December 20, 2005
Looking East-southeast in Late Evening
"Why do stars seem so much brighter in winter than in summer?"
In winter, as in summer, we can see edgewise into the disk of our Milky Way galaxy (marked in translucent blue on today's chart). However, in contrast to late summer (when we face the galaxy's center), on winter evenings we're looking toward the outskirts of the galaxy. The winter stars are so bright because many of them -- for example, Betelgeuse, Rigel, Mintaka, Alnitak, Alnilam -- are really giants in the spiral arm of the Milky Way galaxy in which our sun resides. Another difference between winter and summer skies is that there's a "hazy" quality to the summer sky due to the center of the galaxy being farther away than the nearest outer edge. The "haze" is really the combined light of billions of stars in the direction toward the Milky Way's core. The winter sky, in contrast, looks darker and sharper. Winter stars shine with a diamond clarity because on winter evenings there are fewer stars (and less gas and dust) between us and the vast space beyond. -
Solstice sunset and company
Wednesday, December 21, 2005
Looking West-Southwest At Sunset
The December solstice takes place today at 1:35 p.m. Eastern Standard Time in the U.S. Today's chart shows the solstice sunset. The sun is now setting at its farthest south along the western horizon. ThereÂ’s only one instant each year when the sun reaches the December solstice. ItÂ’s the same instant for all of us. . . when the sun reaches its southernmost point in our sky. The planet Venus is so big and bright in the southwest at sunset that it is possible you may spot her even before the sun has completely sunk below the horizon. To spot the star Altair of the constellation Aquila the Eagle, however, you will have to be patient and wait for evening twilight to dissipate. -
Just a question, can all these be seen in Singapore? I have only seen satellites (not moon), but not the planets and stars. Even under good conditions, dark night, no clouds and no moon, I still don't see stars.
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nope, too much light pollution, unless in secluded places away from city lights like pulau tekong n lim chu kang