In the Sky Tonight

last SG · 2005-08-23T14:26:28+00:00

Spotting the Summer Triangle Wednesday, May 17, 2006 Looking East-Northeast in Late Evening In the east-northeast in late evening, you'll find a famous...

poon cho tang SG

Saturn and Beehive Cluster

Thursday, January 19, 2005

Looking West One-Two Hours Before Sunrise

This chart is set at the same area and time of our January 15th chart. If you turn your gaze towards the westward an hour or two before dawn, you will spot the planet Saturn. We wanted to point out the famous Beehive Cluster now located to the right of Saturn. This star cluster is best seen in a very dark country sky (although it can be glimpsed with binoculars from the suburbs). In a dark sky, it appears as a fuzzy patch to the eye alone. A small telescope shows about 50 stars here, but astronomers know that the Beehive actually contains some 400 stars. The cluster is 15 light-years across, and is located about 500 light-years from Earth.

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Jupiter in early morning southeast

Friday, January 20, 2006

Looking Southeast One Hour Before Sunrise

"When will I be able to see Jupiter through my new telescope?"

The planet Jupiter can be found in early morning skies right now. It is undeniably the brightest object up in the southeast in the early hours before sunrise. And it's no wonder -- it is considered to be the fourth brightest object in the sky after the sun, the moon, and Venus. The next brightest object in this area is the star Spica of the constellation Virgo the Maiden, located to the upper right of Jupiter.

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Venus emerges in morning sky

Saturday, Janaury 21, 2006

Looking East-Southeast at Sunrise

Our sister planet Venus reached its greatest brilliancy in our evening skies last month. Since then, Venus sunk out of view as it reached its "inferior conjunction" on January 13th. Venus has now re-emerged in the east-southeast at sunrise. It will continue to rise earlier each successive morning, and soon itll be high up enough in the sky for early risers to notice the bright morning star.

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Jupiter, Spica near moon tomorrow

Sunday, January 22, 2006

Looking South-Southwest Shortly Before Sunrise

The bright star to the left of the last quarter moon tomorrow morning is actually not a star -- it is the planet Jupiter. If you have a clear sky, you can also catch sight of a smaller object closer and to the right of the moon. This little star is Spica in the constellation Virgo the Maiden. Virgo is associated with Demeter, Greek goddess of the harvest. Demeters daughter was Persephone, who was captured by Pluto, god of the underworld. According to the myths, Pluto allowed Persephone to return to her mother for six months of every year. During the time that Persephone and Demeter are reunited, the world is warm and fruitful. But when Persephone returns to the underworld, Demeter withdraws from the world as well . . . and winter falls on the land.

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Jupiter near the moon Sunday, Monday

Monday, January 23, 2006

Looking South-Southwest Shortly Before Sunrise

This chart shows tomorrows predawn sky. Jupiter will be the brightest object near the crescent moon on both Sunday and Monday mornings. The bright star near Jupiter is Spica in the constellation Virgo. The other bright star up before dawn is Arcturus in the constellation Bootes the Herdsman.

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Flashing Sirius

Monday, January 23, 2006

Looking Southeast In Early Evening

A bright star in the southeast in early evening, twinkling madly and flashing different colors, is sure to be Sirius. Its the brightest star visible from any part of Earth. A couple of months ago, Sirius was below our horizon. Now this star is relatively low in the southeast when night begins. And when we look at objects low in the sky, we see them through a greater thickness of Earths atmosphere than when they are overhead. The flashing colors of Sirius now come 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!

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Lag of the seasons

Wednesday, January 25, 2006

Looking South in the Hour Before Sunrise

Tomorrow, shortly before dawn, you can find the waning crescent moon near the planet Jupiter. Lots of people wonder whether the phases of the moon affect earthly weather, but theres no evidence that they do. Still, theres an astronomical reason why it might be colder outside for you this month than it was last month, even though last month had the December solstice and the least daylight of the year. The reason has nothing to do with the moon and everything to do with the Earth under your feet. Its always coldest some weeks after the shortest day because the land beneath our feet cant change its temperature instantaneously. The whole hemisphere in which we live (both land and oceans) takes some time to lose heat after the time of least daylight. So the coldest weather of the year generally follows the time of least daylight by a month or so. This is called the lag of the seasons.

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Early morning planet crescent

Thursday, January 26, 2006

Looking East-Southeast at Sunrise

You can find our sister planet Venus in the southeast at sunrise tomorrow. The further south you are located on the globe, the better your chances of seeing Venus right now, though all locales would benefit from an unobstructed eastern view of the sky. If you happen to own a telescope or a pair of binoculars, you may be surprised to find that Venus takes the shape of a slim crescent on closer view -- about 6% illuminated.

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How to tell a planet from a star

Thursday, January 26, 2006

Looking East-Southeast in Early Evening

Today's chart shows a view of the east-southeast in early evening, where the famous constellation Orion the Hunter resides with a smattering of bright stars and the planets Saturn and Mars. We get lots of questions about how to tell the difference between stars and planets. We might take a few tips from our ancient astronomers. When they looked into the skies, they noticed that most bright objects in the sky travel in fixed positions with relation to each other, while a few bright objects didn't seem to follow this pattern. They took the "fixed objects" and grouped them into constellations, whose movements were so regular and reliable that these groupings helped them find their way on the ocean, on land, and even helped them predict annual events like floods and harvests. If you were to look at the sky night after night, you'd notice the same thing. Stars will appear in fixed positions; think about how constellations retain their familiar shapes but still move across our sky. Planets, on the other hand, move in much more complex paths with respect to stars -- sometimes even appearing to move backwards in our sky, in an event known as retrograde. So, it'll take a little practice -- and some patience -- but if you can track the movement of objects in the sky for several nights in a row, you will be able to tell which are stars and planets by the movements that they make relative to each other in the sky. Another way of telling planets apart from stars is that stars appear to twinkle in the sky, and planets generally do not.

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Identify Saturn in tonight's sky

Friday, January 27, 2006

Looking East in Early Evening

Here is the view of the eastern sky about one hour after the sun goes down. Tonight there is a bright golden object ascending in the east shortly after the sun sets. This is the famous planet of the rings, Saturn. Today Earth passes between Saturn and the sun. Thus the sun is now opposite Saturn as seen from Earth. Astronomers call this an "opposition" of Saturn. Although Saturn is the faintest of the planets visible to the eye, and although this part of the sky has many bright stars, today's chart will help you spot it. Your best bet is to identify the twin luminary stars Castor and Pollux of the constellation Gemini. Due to the closeness of these two bright stars to each other, they should be fairly easy to spot in the night sky.

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Morning star

Sunday, January 29, 2006

Looking East-Southeast at Sunrise

The planet Venus is always a sight to behold. Even at its dimmest, it easily outshines any other star or planet in the night sky. And sharp-sighted people can see Venus against the early morning light of sunrise in the southeast every morning for the next couple of weeks. As time moves on, and Venus rises earlier each morning, people will soon be wondering about the bright morning star up in the east. But youll know that that star is actually our neighbor planet Venus!

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New moon

Monday, January 30, 2006

Visualization Only - Looking Southeast at About 9 AM

If you don't see this ghostly moon near the sun tomorrow morning, don't worry. The image shows up fairly well on a computer screen -- but it won't show up at all in the real sky -- and you shouldn't ever look toward the sun without a protective filter. Today's chart is purely an illustration of the fact that the moon is new tomorrow. That means it's passing more or less between the Earth and sun as these bodies move in space. Thus, although the moon is near the sun in the sky, you won't see the moon anywhere in it. There are two reasons why. First, the moon's lighted face -- its "day side" -- is turned entirely away from us at this point. Also, the moon is hidden in the sun's glare. As the moon moves eastward in orbit around Earth, it'll edge slowly away from the sun on our sky's dome. When might you next glimpse the moon in the night sky? You might see it in the southwest after sunset tomorrow, but it'll be tough. In a couple of days from now, it'll be easier to see the moon as it'll be higher in the southwest at sunset, and its crescent shape will be a bit plumper.

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Early evening eastern stars

Monday, January 30, 2006

Looking East-Southeast in Early Evening

The bright star Capella in the constellation Auriga the Charioteer can be found shining bright and strong high in the east-southeastern sky in the early hours of evening. It's the sixth brightest star in the sky, and it's located just to the left of an other identifiable object -- the Pleiades, or Seven Sisters -- a misty-looking star cluster in the shape of a tiny dipper. Capella is the most northern of all the bright stars. Tonight, it looks like any ordinary bright star. However, when it appears lower in the horizon, it can appear as a multi-colored shining star. 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. In fact, it would be hard to overlook the current brightly flashing star low in the horizon in this area -- the dogstar Sirius.

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Saturn, Crab leads to Beehive cluster

Wednesday, February 1, 2006

Looking East in Early Evening

Tonight look for the constellation Cancer the Crab in the east in early evening. You will probably notice golden colored Saturn in this area first. Cancer is the faintest of the 12 constellations of the zodiac. You won't see much of this constellation with the eye alone, but some people describe Cancer's shape as resembling the spokes of a wheel. You can aim your binoculars in this direction, just next to Saturn to see one of the sky's hidden treasures. It's a cluster of stars called M44, otherwise known as Praesepe or the Beehive, and it's right in the middle of the Crab. As usual, the darker your night sky, and the farther you are from city lights, the better the view.

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Hare, Dove in south

Thursday, February 2, 2006

Looking South-Southeast in Mid Evening

If you look south-southeast around 8-10 p.m., you'll easily notice a short, straight row of three medium bright stars. These stars represent the Belt of Orion the Hunter. Also, notice the star Sirius nearby. On old sky maps, the mighty Hunter of the ancient myths is seen poised with an upraised club and shield, as though fending off the raging Bull, Taurus. Meanwhile, two meek animals seem to cower at the Hunter's feet. Lepus the Hare was described by Roman stargazers as being "swift," "light-footed," and "eared." Columba the Dove can be found to the south of the Hare. This little constellation is sometimes ignored in books about the sky, probably because it is so far south as seen from the U.S. Richard Hinckley Allen, in his classic book, Star Names: Their Lore and Meaning, wrote that Columba was first seen in constellation drawings in 1603. But, he said, there are hints in early writings that stargazers knew the name Columba, and identified a Dove here, as much as 17 centuries ago.

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Moon, Mars, Queen, Messier objects

Friday, Febraury 3, 2006

Looking West-Southwest in Mid Evening

Tonight look for the waxing crescent moon to be in the west in mid-evening. It is accompanied by several distant celestial objects. Above the moon can be found the red planet Mars, still shining bright despite waning in brilliancy since its close encounter with us last year in October. Above Mars is the conspicuously dipper-shaped pattern of stars known as the Pleiades star cluster also known as M45. You may catch a pattern of stars to the right of the moon that appears to form a W or M -- this is the constellation Cassiopeia the Queen -- and she rules the northwestern sky at this time. Binocular viewing of the area of the sky approximately between the moon and Casssiopeia reveals a hazy object in the sky. This object is known as M32, and it is a small companion galaxy to M31, or the Andromeda Galaxy.

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Moon, Mars, M45 sandwich

Sunday, February 5, 2006

Looking West-Southwest in Mid-Evening

If you look outside in mid-evening, you'll find the now first quarter moon in the west-southwestern sky. Tonight it appears to be sandwiched by two easily recognizable objects in the night sky. Below it, it's flanked by the red planet Mars. Above it is the Pleiades star cluster, or Seven Sisters --an actual cluster in space whose member stars are bound by gravity. The Pleiades appears to the eye as a tiny dipper, wrapped in a veil of mist. Despite the name Seven Sisters, many people see this cluster with the eye alone as six stars. Thus there are legends explaining the whereabouts of the "lost Pleiad." But people have different abilities to see faint stars. It's said that as many as 18 stars may be seen with the eye alone if your sky is exceptionally dark and clear. The cluster lies some 400 light-years away. Most stars in the Pleiades occupy a volume of space about eight light-years across. The misty look to the Pleiades is actually gas floating in space between these stars. Throughout history, and in the lore of many nations, the Pleiades have had their own special mystery. This beautiful sky object has been compared to a swarm of fireflies or bees, to seven maidens, to a flock of doves, and to a hen surrounded by her chicks.

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Galaxy anti-center

Monday, February 6, 2006

Looking Southwest In Mid-Evening

Heres an important chart for gaining astronomical perspective. To orient this chart, look for the waxing gibbous moon in the southwest in mid-evening. Youll see that it is still near the Pleiades and the planet Mars, for more on them, see yesterdays chart. Another bright red object near the moon is Aldebaran of the constellation Taurus the Bull. Now look for El Nath, another, fainter star in Taurus, located at an estimated distance of 131 light-years. El Nath lies nearly in the direction of the anti-center of our Milky Way galaxy. The anti-center is the point on the skys dome opposite the center of the galaxy, and El Nath is three degrees west of this point. You might find this confusing because there are two systems of perspective at work here. One is the perspective that our galaxy, the Milky Way, is a real three-dimensional realm always surrounding us in space. Our sun and solar system are thought to be located about two-thirds of the way from the center of the galaxy, and, in winter, our night sky faces opposite the center. The other perspective at work here is that there is a sphere of stars surrounding Earth, on which distances like three degrees west of this point can be measured. This celestial sphere is imaginary, of course, but convenient. Thus El Nath lies three degrees west of the anti-center of the galaxy . . . that is, three degrees west of the direction on our skys dome opposite the direction to the center of the galaxy. Tomorrow evening this time, the moon will have moved ever-eastward in our skies and will be located directly in this direction.

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Moon near Chariot constellation

Tuesday, February 7, 2006

Looking South-Southwest In Mid-Evening

Heres a close-up look at the constellation Auriga the Charioteer in mid-evening tonight. The moon has moved eastward from the point in yesterdays chart, as it always does. Its brightest star is called Capella. If youre unsure whether youve identified Capella, you can always look nearby for a small acute triangle of stars . . . marked on our chart as Almaaz and Haedus I and II. Capella is sometimes called the Goat Star, and this little triangle is called the Kids. Capella is located at one corner of a large five-sided figure. Capella marks the left shoulder of the Charioteer. Menkalinan, the second-brightest star in Auriga, marks the right shoulder. Also, notice the star Elnath, now covered by the waxing gibbous moon at the southern tip of Auriga. This star used to belong both to Auriga, where it was known as the heel of the Charioteer . . .and to the constellation Taurus, where it represented the tip of the Bulls northern horn. In the last century, though, the International Astronomical Union decreed that this star shall belong only to Taurus! Elnath is also thought to be an outlying member of the Pleiades star cluster, which was marked on yesterdays chart.

poon cho tang SG

Arc to Arcturus

Thursday, February 9, 2006

Looking East-Northeast One Hour Before Dawn

Todays chart has you facing east-northeast in the hour before dawn. The star Vega is about midway up in this area, and the Big Dipper and star Arcturus in the constellation Bootes are overhead. There's an old saying among stargazers: "follow the arc to Arcturus." It means that if you follow the curve of the Big Dipper's handle outward, you'll come to the orange star Arcturus in the constellation Bootes the Herdsman. Unlike nearly all the stars we see in the night sky with the eye alone, Arcturus doesnt travel in the plane of our Milky Way galaxy. Like all out galaxys stars (including our sun), Arcturus orbits the center of the galaxy -- but it does so in a way that causes it to cut almost perpendicularly through the galactic plane. So, although most of the stars we see at night are our longtime traveling companions on our suns journey around the galactic center, Arcturus is a temporary visitor to Earths night sky. It has been visible to us earthlings for only half a million years, and itll pass closest to us several thousand years from now. In half a million years more, Arcturus distance will have become so great that itll have faded from from earthly view.

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