Night Skies with Mark Brown, VIPP
Mark Brown the charter member of our Volunteers in Peterson Planetarium (VIPP). He has contributed presentations, custom shows, operator training, and photographs to Peterson Planetarium and now Night Skies. In other words, Mark is a very important person to Peterson Planetarium!
April is great time to catch Jupiter shining brilliantly in the evening sky. And for the next few weeks it will be its best and brightest for the year. The solar system’s largest planet reaches opposition at 4:28pm CDT on Friday, April 7. At that time, the sun is located on one side of the Earth and Jupiter is found directly opposite, on the other side of the Earth.
This places Jupiter opposite the sun and on the night-side of the Earth. Hence, the planet rises as the sun sets, is high in the southern sky around midnight (when the sun is directly below us) and sets as the sun rises. But not only do we get to see Jupiter all night long, we also see it at its brightest.
Being the largest planet, Jupiter is always easy to see. It is only rivaled by Venus, which is brighter than Jupiter because it is much closer and its thick atmosphere reflects sunlight very well. But around the time of opposition Jupiter really dazzles. This is because, with both Earth and Jupiter located on the same side of the sun, the two planets are closest together for the year. This year they will be separated by 414 million miles (666 million km).
Gazing at Jupiter through a pair of binoculars will reveal four of its largest moons; Ganymede, Europa, Callisto, and Io. Careful observations will show that these moons change positions as they orbit the giant planet. Jupiter’s own complex atmospheric details can be spied through a small telescope. For those with larger backyard telescopes, watch for the famed Great Red Spot to pop into view as the planet spins on its axis. This cyclonic storm is twice the size of Earth and has been raging for at least three centuries. On Friday evening, look for Jupiter in the East-Southeast sky around 9:00pm. Spica, a bluish-white star will be following close behind as both planet are star climb higher into the evening sky.
On Monday, March 20th, at 6:29 a.m. EDT, the sun will move northward across the celestial equator at a point marking the vernal equinox. This marks the beginning of spring in the northern hemisphere (autumn in the southern hemisphere) where vernal is from the Latin word “spring.” The ecliptic and the celestial equator intersect at only two points, which are exactly opposite each other on the celestial sphere. Each point is called the equinox – also from Latin meaning “equal night”, because when the Sun appears at either of these points, day and night are each of equal length or about 12 hours long at all locations on Earth. During an equinox, the sun rises due east and sets due west. If you could see the stars and constellations, you would see the mid-day Sun passing through the constellation Pisces the Fish. Six months from now (September 22), the northern hemisphere will experience the autumnal equinox (first day of fall) where the Sun will move southward across the celestial equator.
For about the past five months, our “evening star”, bright planet Venus has been a dazzling spectacle in our evening sky. The planet, in its rapid pace around the Sun, is about to catch up and lap planet Earth in its orbit. Since reaching its highest elevation in the evening sky in January, the planet has been gradually descending toward the Sun. Because Venus is now closer to Earth, a telescope will show that Venus’ disk has grown in diameter, but its phase has waned to a very thin crescent shape. Over the next few days, Venus will become more difficult to see and be lost in the Sun’s glare. On March 25th Venus will pass directly between the Earth and Sun, a point called inferior conjunction. By the end of March, you may be able to spy Venus close to the eastern horizon about 45 minutes before sunrise where it will become our “morning star.”
Among the astronomical phenomena visible to the unaided eye, the zodiacal light is perhaps one of the grandest sites to behold in the evening sky. Delicate in every respect, the zodiacal light is a uniform, soft wedge of light that stands above the horizon at the end of twilight. It is typically no brighter than the faintest patch of Milky Way, so you can easily see dim stars through it. The light is so elusive that it’s most brilliant displays are often mistaken for lingering sunset glow or light pollution from a nearby city or town. Although elusive, the zodiacal light is well worth hunting for and springtime is a good time to start looking for it in the evening sky.
The zodiacal light comes from sunlight scattering off trillions of microscopic dust particles orbiting the Sun. The particles come from the tails of comets and from debris knocked off meteorites and asteroid collisions. Like the planets, the dust orbits largely in the plane of the solar system, which is essentially the same as the ecliptic, the plane of Earth’s orbit about the Sun as projected against the background stars. The constellations through which the ecliptic path passes are known cumulatively as the zodiac, and it is from these constellations that the eerie zodiacal light got its name.
From an Earth-bound perspective, the zodiacal light is broadest near the horizon and tapers upward as it extends above the horizon – somewhat appearing as a cone of diffuse light. On dark transparent nights far away from city lights, the zodiacal light may extend anywhere from 30 to 60 degrees above the horizon. Because the glow stretches along the ecliptic, it reaches a higher altitude and is easier to observe during seasons when the ecliptic inclines most steeply to the horizon. Thus, in mid-northern latitudes, the zodiacal light is most prominent in the west after nightfall in spring, and in the east before dawn during autumn.
To see it, drive to a dark site far away from city lights roughly about an hour to hour and a half after sunset. The Sun has to be at least 18 degrees below the horizon or at the end of astronomical twilight when the sky is sufficiently dark and the entire sunset glow has disappeared. A clear unobstructed western horizon will help. Take time for your eyes to adapt to the darkness (usually 20 to 30 minutes) and scan the west-southwest horizon. If skies are clear and transparent, you should notice a wedge of light extending upward from the horizon and appearing to lean toward the south.
Don’t bother with optical aid. Binoculars and telescopes are no help at all because of their constricted fields of view. Your eyes will act as your best equipment as you slowly shift your gaze across the sky. Look for a dim diffuse patch or wedge of light contrasting with the darker sky background. Once you’ve discerned this light and can say it is not from the glow of a distant town then you’ve seen something that even most backyard astronomers have trouble seeing or have yet to discover. It is quite a rewarding experience to see and discover.
In the accompanying images, the zodiacal light is the diffuse bluish (almost hazy) wedge of light in the center of the images. The bright star-like object is the planet Venus. If you look closely, you can see the contrast between the zodiacal light and the background sky with the wedge of light leaning toward the left (south) in the images.
The brightest star in all the night-time sky is Sirius, the Dog Star, in the constellation Canis Major, the Greater Dog of Orion the Hunter. Its brilliance makes it impossible to mistake, but any confusion can be remedied by glancing at Orion’s belt, which points generally down to the left toward Sirius. In early March, the Dog Star is well-placed in the southeast sky after sunset. As evening turns into night, the star and constellation arcs across the southern sky.
The constellation Canis Major, sometimes called the Dog of Orion, makes one of the sky’s most interesting patterns in which it does look somewhat like a dog. Sirius is central in a straight line of three stars. To the left or east is Muliphein, a 4th-magnitude star. The 2nd-magnitude star to the west of Sirius is called Murzim, “The Announcer,” because it rises shortly before Sirius. Murzim forms one of the front legs or hip of the dog. Drawing a line downward from Sirius you will find a small triangle of 2nd-magnitude stars as well. They are called Adhara, Aludra, and Wezen. Adhara and Wezen form the dog’s hind hips while Aludra forms its tail.
On a clear night away from city lights, to the right of a line drawn between Sirius and Wezen, lies a bright open cluster star cluster (M41) which can be seen with the naked eye. No doubt it was the importance of Sirius that caused this cluster to be known in ancient times. It was mentioned by Aristotle in 325 B.C. as one of the sky’s mysterious “cloudy spots.” A pair of binoculars or small telescope will show a rich view of the cluster as it stands out against the backdrop of an unremarkable patch of sky.
Five thousand years ago in ancient Egypt, Sirius was worshiped as the Nile Star or Star of Isis (an ancient Egyptian goddess). Its appearance in the predawn sky each summer heralded the start of the annual flood of the Nile River, whose fertile sediments made the river valley one of civilizations first cradles of agriculture.
In the northern hemisphere, Sirius can be seen rising shortly before the Sun in the hottest part of summer. In the Middle Ages, skywatchers believed that the combined light of the Sun and the Dog Star created the extreme summer heat. The saying or phrase, “Dog days of summer,” is in reference to the hottest weeks of summer.
The name Sirius comes from a Greek word meaning “the trembling one” or “sparkling one.” Its twinkle is so fierce because it is so bright. Because it is often seen low in the sky, its twinkling light is due to the fact that its light must travel through a greater-than-usual thickness of atmosphere. Earth’s atmosphere also causes Sirius to flash many different colors, yet if you saw this star from outer space it would shine purely white.
Sirius may be our sky’s brightest star, but it is no giant in the Milky Way Galaxy. It is an ordinary main-sequence star, about twice the diameter of the Sun. It is bright because it is very close, the nearest of all the naked-eye stars visible from mid-northern latitudes, at about 8.6 light-years away.
Much like Capella and many other stars in our sky, Sirius also has a companion called Sirius B, sometimes called the Pup. Sirius B was the first white dwarf discovered and is still the brightest and nearest white dwarf star to Earth. It was first seen in 1862 by Alvan Graham Clark. Sirius B is a star that is at the end of its life. It has evolved through the main sequence and red-giant state where it will remain as a white dwarf star – the final state in which stars like our Sun will eventually succumb. Sirius B has a mass nearly equal to that of the Sun, but is packed into the volume the size of Earth. A handful of this star’s material would weigh as much as an elephant.
As temperatures begin to moderate this spring, step outside and look for Sirius – the brightest star in all the night time sky. You can’t miss it.
Taurus the Bull
Our trek through the winter sky brings us to a prominent zodiacal constellation called Taurus the Bull. It is easily recognized by a V-shaped grouping of stars and its brightest star, Aldebaran. This is the Hyades, an open star cluster similar to the Pleiades (see the 11/21/2016 entry) but more spread out and therefore less striking. Binoculars reveal dozens more stars just below the limit of naked-eye visibility. Taurus looks remarkably like its namesake, the bull. The “V” forms the head with Aldebaran at the end of the “V” marking the eye of the beast. The bull’s horns extend up and over Orion. To find Taurus, draw an imaginary line westward or to the right through Orion’s three belt stars. This line will lead you to the bright orange star Aldebaran and the bull’s V-shaped head.
Actual Night Sky Image of Orion and Taurus. Image taken byb Mark A. Brown
The Hyades cluster resides about 150 light-years from the Sun. Aldebaran is not part of the cluster, but is actually closer, spanning about half the distance to the Hyades. Aldebaran is the 14th brightest star in the night sky. It is a red giant star, much older and redder than the Sun which has shifted from fusing hydrogen into helium in its core to the fusion of helium to carbon and oxygen. The star is about 40 times as wide as the Sun. If you replaced the Sun with Aldebaran in our solar system, its surface would extend out to about the orbit of Mercury. Because of its relative closeness to Earth, astronomers have been able to accurately measure Aldebaran’s size and rotation rate.
Graphic of size comparison of Aldebaran to the Sun. Image taken from Wikimedia Commons.
The bull’s long horns are marked by the stars Beta (β) and Zeta (ζ) Tauri. Just inside the bull’s horns nearest to Zeta Tauri is one of the most sought after deep sky targets, the Crab Nebula. The Crab Nebula is the remnant of a supernova explosion, an explosion which ripped apart a large star, ejecting much of its matter into space. In the year 1054 AD, Chinese astronomers recorded the brilliant appearance of this “new star” or supernova. The brilliance of this object was six times brighter than the planet Venus and was visible in the daytime sky for nearly three weeks. It eventually faded from view two years later. Through small telescopes, the nebula appears as a faint smudge of light. By comparing photographs taken several years apart, astronomers can determine the expansion rate of the Crab Nebula.
Crab Nebula Mosaic taken by Hubble Space Telescope. Image Credit NASA, ESA, J. Hester, A. Loll (ASU)
The bull appears in many Greek and Roman mythologies. One of the best known stories involves Taurus and Europa, the daughter of the King of Sidon. Jupiter, looking down from Mount Olympus, saw Europa and her companions playing in a field of flowers. To Jupiter, the lovely Europa was irresistible. Encouraged by an arrow in the heart from Cupid’s bow, he was determined to possess her. Using caution so as not to frighten her, Jupiter changed himself into a magnificent bull. So docile was he that Europa was attracted to the bull. He lay down in the field of flowers and coaxed her onto his back. Then immediately he sprang up, dashed to the sea shore and jumped into the Mediterranean Sea. He swam to the island of Crete, a favorite hideout, and then revealed himself as the great god Jupiter. He confessed his love – for no mortal woman could resist and he won her as his bride. (Never mind that he was already married to the Roman goddess Juno).
Watch the Disappearance of a Star!
Aldebaran, the brightest star in Taurus the Bull will be hidden by the first quarter moon on Saturday evening March 4, 2017. Such an event is called an occultation and is defined when one object is hidden by another that passes between it and the observer. This event will be visible for folks living in Hawaii, the contiguous United States, Central America and the western Caribbean.
For Emporians, the Moon will begin to hide or “occult” Aldebaran at approximately 9:45 pm with the star emerging about one-hour later. Go outside a few hours before the occultation and look for the Moon and Aldebaran high in the southern sky. Note the distance between the two objects and watch how the gap between them shrinks before Aldebaran disappears. This is an event you can view with the unaided eye, but a pair of binoculars will help to see exactly when Aldebaran slips behind the Moon. In addition, this event may occur nearly every month up to 2018. Good Luck and Clear Skies!
Aldebaran Occultation. Image Credit: Stellarium Planetarium Software
On those very cold winter days near sunrise or sunset; have you ever noticed what looks like a detached or partial rainbow on either side of the Sun? Most likely, you are witnessing an atmospheric phenomenon called a sundog or mock Sun. The technical term is called parhelia where at times they can be quite colorful or appear as a bright white patch that mimics the Sun.
Such phenomenon is caused by light refracting through tiny ice crystals high in Earth’s atmosphere - usually in cold cirrus or cirrostratus clouds. Reflection occurs when light bounces off the surface of an object, like a mirror. But refraction is the bending of light rays when they pass from one transparent medium to another (i.e. air to water or ice). In the case of a sundog, light rays are bent as they enter the ice crystals which act like a prism and separates sunlight into its individual colors.
Image from Adam Voiland, NASA Earth Observatory.
According to atmospheric optics expert Les Cowley, when water droplets freeze in Earth’s atmosphere, they form flat, platy, six-sided (hexagonal) crystals. As these crystals slowly flutter through Earth’s atmosphere, their large flat crystal faces are oriented parallel to the ground. The crystals act like miniature lenses which refracts light before reaching the observer. Sundogs will often form in pairs spanning 22 degrees on either side of the Sun. When you observe a sundog, the red portion of the rainbow patch is on the inside toward the Sun and blue on the outside.
Mark A. Brown, Moon Halo
Sometimes you might witness a halo around the daytime Sun or even the Moon at night. Halos are also caused by these same platy crystals, but form because the crystal faces are randomly oriented. Light pillars on the other hand are caused by the reflection of artificial lights (street/building lights) or natural light (Sun or Moon) on the tiny ice crystals that hang in the air. Sun and Moon pillars occur in the same way, but usually when the Sun is at or below the horizon. Whether the source of the light pillar is natural or artificial light, the pillar tends to take on the color of the light source.
Rayann Elzein, Light Pillars, www.rez.photography.com
And just in case you were wondering, there appears to be no clear understanding as to why parhelia are called sundogs. A diagram describing the sundog atmospheric phenomenon can be found here: http://www.atoptics.co.uk/halo/dogfm.htm
In the late summer sky, there is a familiar asterism called the Summer Triangle. The vertices of the triangle are marked by three fairly bright stars from three separate constellations; Vega in Lyra the Harp, Altair in Aquila the Eagle and Deneb in Cygnus the Swan. But did you know interesting shapes or letters can also be found by using the stars visible in the wintertime sky? The wintertime sky contains many of the year’s brightest stars, but many people do not know this because they fail to venture outside on cold winter nights. Depending on your patience or imagination, the winter sky also has its own Winter Triangle, as well as the Winter G or Winter Heptagon.
In February, all of the winter constellations are well above the horizon. Let’s first start with spying the Winter Triangle and work our way up in sophistication. One of the easiest constellations to recognize is Orion the Hunter. Orion serves as a guidepost for locating other nearby stars and constellations. For observers in mid-northern latitudes, you’ll find Orion by facing south and looking about halfway up from the horizon. Look for Orion’s unmistakable three belt stars.
To the upper left of Orion’s belt is the orange-red star Betelgeuse. This star marks the shoulder of Orion and is the first point in our triangle. Go back to Orion’s belt and draw a line to the lower left along these three stars. This line will lead you to the brightest star in all the nighttime sky, Sirius, which is in the constellation Canis Major, the greater or large dog. Sirius rests to the lower left of Orion and marks the second point of the triangle. Now that you have found two of the three stars, the third one is a cinch. Now look up and to the left of Sirius for the star Procyon, in the constellation of Canis Minor, the lesser or little dog. Congratulations – that’s it! You have just found the third and final star in the Winter Triangle. Looking closely and tracing a line between each of these stars, Betelgeuse, Sirius, and Procyon, you will see that it very nearly makes an equilateral triangle with one apex of the triangle pointing down toward the horizon.
Now let’s look for the Winter G and Winter Heptagon which are basically one within the same grouping of stars. We’ll again use Orion as our tour guide to get us started. Once you have found Orion’s belt, draw a line up through the stars and to the right. Following this line very nearly leads you to the bright orange star, Aldebaran, in the constellation Taurus the Bull. This is the first star we’ll use to trace out the Winter G and Heptagon. From Aldebaran, extend a line to the north far above Orion to the bright yellow-white star, Capella, in the constellation Auriga the Charioteer. Capella should be easy to find as it resides almost directly above your head. This is the northern most star of our Winter G and Heptagon. While facing Orion, extend a line down from Capella to the southeast. This line should bring you to the stars, Pollux and Castor, in Gemini the Twins. These stars reside fairly close together, but to make sure you’ve found the right stars, you can find them by drawing a line diagonally between the stars Rigel and Betelgeuse in Orion, and extending the line upward and to the left of Orion. Now draw a line between Castor and Pollux.
Are you still with me? We’re almost finished! The next two stars, Procyon and Sirius, should sound familiar because they were part of the Winter Triangle we traced out earlier. By extending a line down and slightly to the right of Castor and Pollux, you will find the star Procyon. Further down and to the right is the star Sirius. This star marks the southern-most point of our “G” or Heptagon. From Sirius you can now draw a line to the upper right (not through Orion’s belt) to the bright blue-white star, Rigel. Rigel marks the lower right knee of Orion. To finish the Heptagon, draw a line upward and slightly to the right and connect to Aldebaran which was our starting point. To complete the Winter G draw a line about one-third of the way up between Rigel and Aldebaran. Instead of continuing on to Aldebaran, hook the line to the left and connect to the star Betelgeuse in Orion’s shoulder. Awesome!
As you can see, star hopping through the stars of Orion and some of the other constellations is relatively easy. Not only will it help you find and learn your way through the sky, but it’s also a fun way to get you out of the house once in a while – even on cold winter nights.
Since October, the planet Venus, the “evening star,” has been moving eastward through the background stars and gaining elevation in the evening sky. On January 12, Venus reached its greatest elevation and furthest point from the Sun as seen in our sky – a point called greatest eastern elongation. Venus is dazzling and will continue to do so throughout the remainder of January and February, setting nearly 4 hours after the Sun.
To the upper left of Venus is the orange-red planet, Mars. Over the past several weeks, the gap between the two planets has gradually decreased. On March 31, the two planets will be approximately five degrees apart and will be joined by a thin crescent moon, forming a small triangle in the sky. Throughout February and March, Venus will decrease in elevation and the distance between the two planets will increase. As Venus rapidly rounds the Sun, it is not only overtaking Earth in its orbit, but also Mars. But at the same time, Earth is also overtaking Mars in its orbit. This is much like race cars traveling on the inside track. The cars on the inside travel faster around the track than those on the outside.
Venus and Mercury, the two inner planets of our solar system, transition through phases much like Earth’s Moon. In a small telescope, Venus will appear like a quarter or “half-moon” phase. As Venus makes its descent toward the horizon in March, its disk size will increase but its phase will shrink into the shape of a crescent. The planet will transition to the morning sky in April, this time reappearing as the predawn “morning star" for spring.
At magnitude -4.4, Venus is the brightest object in the night sky other than the Moon. The planet is so brilliant that it can actually cast shadows. You can demonstrate this by simply traveling into the countryside on a clear, dark, moonless night well away from city lights. Turn and face away from Venus. Hold a white piece of paper out in front of you. Place your other hand about 6-inches above the paper and slowly move it back and forth. The light from Venus coming over your shoulder will project your hand’s ghostly shadow onto the paper. Once you see it you’ll be amazed, but any local light falling on the surface destroys the effect.
Auriga the Charioteer
The crisp skies of winter are home to many bright and beautiful stars. During the early evenings in mid - to late-January, start by looking high in the east-northeast sky for the constellation Auriga the Goatherd or Charioteer. The constellation is a five-sided figure situated in the midst of the winter Milky Way. Its brightest star is Capella and is sometimes called the “Goat Star” representing a mother goat carried by the Charioteer. Capella falls into the same star temperature category as our Sun. Capella is the 6th brightest star in the night sky and shines at an apparent magnitude 0.08 from a distance of about 42 light-years from the Sun. Capella is so far north that it is nearly circumpolar and can be seen at some time during the night from northern latitudes any time of the year.
If you look near Capella, you’ll notice a small asterism in the shape of a triangle. This asterism is called the Kids. Remember – a constellation is a grouping of stars in the night sky seen as an officially recognizable pattern where as an asterism is a smaller pattern of stars within the same constellation or may be composed of stars from more than one constellation.
Auriga is one of the oldest constellations and is associated with a couple of mythologies. The best known story indicates that the constellation honors Erichthonius, King of Athens. Erichthonius was born lame and could not walk. To overcome his handicap, he invented the chariot to help ferry himself from one place to another. Jupiter was so impressed with this invention that he gave its inventor an honored place among the stars. Curiously, the constellation is usually depicted as a goatherd holding two small kids in his arms and an additional goat on one shoulder. The two smaller goats are marked by a small faint isosceles triangle of stars near Capella.
Running through Auriga is a chain of three large star clusters, imbedded in the stream of the Milky Way. Pointing a pair of wide-angle binoculars toward Auriga will reveal all three in the same field of view, appearing as fuzzy patches of light. These three clusters are known as M36, M37, and M38 with each containing between 60 and 150 stars. The “M” in the object number comes from Charles Messier’s catalog. Messier was an 18th-century French astronomer whose primary goal was to discover new comets. In the process of his comet searches, Messier occasionally found objects that appeared comet-like in the small telescopes he used, but which were not comets. They appeared to be permanent parts of the night sky (like the stars), but he was unaware of the true nature of most of them. To avoid confusion in future comet searches, Messier compiled a catalog of these non-cometary objects. Today, we recognize the Messier Catalog to consist of a collection of deep sky objects that all lie far beyond the Solar System.
So take some time this January to bundle up in warm clothes and grab a pair of binoculars for some tantalizing views of these faint fuzzies in Auriga. There are many bright stars, constellations and gems scattered throughout the winter sky awaiting your gaze.
Where will you be on Monday, August 21, 2017? If you’re not sure, now is the time to start thinking about it because the continental United States is about to experience one of nature’s most awesome spectacles – a total eclipse of the Sun! On Monday, August 21 at 11:38am Central Daylight Savings Time, a finger of darkness will sweep down from space and touch the surface of Earth. The Moon will come between Earth and the Sun and begin casting its shadow onto the planet below.
The arrangement necessary for a total solar eclipse is an exact alignment of Earth, Moon, and Sun, with the Moon blotting out the Sun and casting its shadow on Earth. This is a fairly frequent event that occurs almost every year. However, the problem for those who wish to view a total solar eclipse is the small size of the Moon’s shadow. By the time the Moon’s shadow reaches Earth, it is usually less than 150 miles (240 kilometers) wide. One must be within this shadow in order to see darkness during the day which lasts from a few seconds to a maximum of about seven minutes.
On August 21, the limb or edge of the Moon’s disk will make contact with the limb of the Sun. From its contact point at sunrise in the North Pacific Ocean, the lunar shadow will race eastward across the ocean at over 2,000 miles per hour. At around 10:15am Pacific time, the zone of darkness will touch the continental United States. For nearly 2 brief minutes, the west coast of Oregon will come under the fast moving shadow.
For the next 1h 33m, the Moon’s 70-mile wide shadow will traverse across the entire length of the continental United States before leaving the coast of South Carolina and moving on into the Atlantic Ocean. The darkest part of the eclipse will pass through the following states: Oregon, Idaho, Nebraska, Kansas, Missouri, Illinois, Kentucky, Tennessee, North Carolina, Georgia, and South Carolina (tiny portions of Montana and Iowa are also in the path). And yes! The exciting thing is that the darkest part of the Moon’s shadow, the umbra, will clip the extreme northeastern part of Kansas. To see a total eclipse you must be in the umbra of the Moon’s shadow. For much of Kansas, 90% or more of the Sun’s light will be blotted out by the Moon. If you stay in Emporia, only about 96% of the Sun will be eclipsed (a partial eclipse). If you want to be in the direct line of the eclipse (100% coverage), you will need to travel north and east! For those in northeast Kansas where the Moon completely covers the Sun’s disk, they will experience up to 2m 38s of darkness.
Annular Eclipse: Film image through an 8-inch telescope of the Annular Solar
eclipse on May 10, 1994. Imaged from Ft. Wayne, Indiana. This is a similar
view of what observers in Emporia will see on August 21st.
It has been a long wait. The last total eclipse to grace the continental United States was February 26, 1979 but was only a partial eclipse event for Kansas. The last time a total solar eclipse fell on Kansas soil was June 8, 1918. After 2017, the next one for Kansas will not be until August 12, 2045. However, the next total solar eclipse for the continental United States will occur on April 8, 2024. If you see just one total solar eclipse in your life, consider yourself fortunate. But eclipses of the Sun are actually quite common – celestial mechanics dictates that there be at least two solar eclipses somewhere on Earth each year. There can be as many as five in a year, though this is rare. Often times the Moon’s shadow does not fall onto land, but onto Earth’s oceans which is why many people do not see it.
Hybrid Eclipse: Digital image through a 3-inch telescope of the
Hybrid Solar eclipse on November 3, 2013. Imaged from Carlisle, Pennsylvania.
It can be expected that hundreds of thousands of people from across the country and other continents will travel and converge somewhere along the darkest part of the eclipse path. Millions more will elect to stay home on eclipse day, away from the dark central path of the Moon’s shadow, but still within its lighter boundaries. For them, August 21 will bring a partial eclipse of the Sun.
Chances are you’ll be one of those eclipse watchers. Although your day will be less dramatic, it can still be memorable. Even a partial eclipse provides a fascinating example of what happens when celestial bodies align.
For those of us in Emporia, Kansas the partial eclipse will begin at 11:38am local time. For the next 88 minutes, the Moon will appear to take small bites out of the Sun’s disk. At 1:06pm, 96.46% of the Sun will be covered (maximum eclipse) with the Sun appearing as a very thin crescent. At 2:33pm, the eclipse spectacle ends.
Although 96% of the Sun will be covered, looking at the Sun, either during the partial phases or at any other time, can be extremely dangerous. Without any optical aid the retina of an unprotected eye can be burned in as little as 30 seconds. With the extra light-gathering ability of a telescope or binocular, a burn takes only a fraction of a second. Because the retina of the eye has no pain sensation, this injury occurs painlessly, and the visual effect of the burn will not appear until hours after the damage has been done.
I cannot stress this enough…
DO NOT LOOK AT THE SUN!
DO NOT LOOK AT THE SUN!
DO NOT LOOK AT THE SUN!
On March 30th, Peterson Planetarium will host an event “How to safely observe the great American Total Solar Eclipse 2017.” This will be in Science Hall room 72 and all are welcome to attend this free presentation. This event will discuss the types of eclipses and provide details about where and how to safely view the August 21 eclipse. As the date gets closer, I will also be posting additional details and safe methods for viewing the eclipse. So…Please stay tuned!
In addition to rotating on its axis every 24 hours, the Earth revolves around the Sun, meaning that it orbits the Sun in about 365¼ days. As we travel with the Earth around its orbit, we experience the annual cycle of seasons. Furthermore, the seasons are opposite in the northern and southern hemispheres. When the northern hemisphere experiences summer, the southern hemisphere experiences winter.
Earth_Tilt: Image depicting Earth's axial tilt of
approximately 23.5 degrees from perpendicular.
The reason for the seasons in different hemispheres is that the Earth’s axis of rotation is not perpendicular to the plane of Earth’s orbit about the Sun. Instead, Earth is tilted about 23½ degrees away from the perpendicular. The Earth maintains this tilt as it orbits the Sun, with the North Pole pointing toward the north celestial pole. During part of the year in one part of its orbit, the northern hemisphere is tilted or leaning toward the Sun. This is called summer – when days are long (more than 12 hours in sunlight) and nights are short. It is also the time when temperatures are warmer because the noon-time Sun is higher in the sky. The Sun’s energy is concentrated or shines more directly onto a small area during those long days, which heats the ground effectively and makes the days warm. On or about June 21st the Northern Hemisphere experiences the Summer Solstice, but in the Southern Hemisphere it is winter.
The Earth's axis of rotation is inclined 23.5 degrees away from the perpendicular
to the plane of Earth's orbit. The north pole is aimed at the north celestial pole,
near the star Polaris. Earth maintains this orientation as it orbits the Sun. The
amount of solar illumination and the number of daylight hours at any location
on Earth vary in a regular pattern throughout the year which is the origin of the seasons.
Half a year later, the Earth is in the part of its orbit where the situation is now reversed with winter in the Northern Hemisphere which is now tilted away or leaning away from the Sun. During this time of year, the days are short (fewer than 12 hours in sunlight) and the nights are long. The noon-time Sun is low in the sky, so sunlight is less concentrated and strikes the ground’s surface at a grazing angle that causes little heating. This accounts for the colder temperatures in winter. On or about December 21st, the Northern Hemisphere experiences the Winter Solstice while the Southern Hemisphere is enjoying summer. During spring and autumn (Equinoxes), the two hemispheres receive roughly equal amounts of illumination from the Sun, and daytime and nighttime are of equal length everywhere on Earth (about 12 hours).
A common misconception is that the seasons are caused by variations in the distance from the Earth to the Sun. According to this idea, the Earth is closer to the Sun in summer and farther away in winter. But in fact, the Earth’s orbit is very nearly circular, and the Earth-Sun distance varies only about 3% over the course of the year. We are slightly closer to the Sun in January than in July, but this small variation has little influence on the cycle of seasons. When you think about it, if the seasons were really caused by variations in the Earth-Sun distance and not by the tilt of Earth’s axis, then the seasons would be the same in both hemispheres.
Noon_Sun - Winter Solstice: On the day of the Winter Solstice,
the noon-time sun is lowest in the sky where sunlight is less
concentrated and less heating of the ground takes place.
So for those of you who do not like winter or the weather it brings, there is something to look forward to as we approach the Winter Solstice. The Winter Solstice marks the turning point where the nights begin to grow shorter and the days grow longer – darkness decreases and daylight increases and with it will come warmer temperatures.
Geminids to peak near Full Moon -BEST SEEN 12.13-14.2016
Meteor Showers streaking through Gemini and Orion. Photos by Mark A. Brown.
The night of December 13/14 brings with it the peak of this year’s Geminid meteor shower. The bad news is that the Moon will be just shy of Full Moon phase washing the sky with unwanted light much of the night. The good news is that the Geminid shower is one that’s seen from early evening until dawn and naked-eye observers should be able to spot some of the brightest meteors despite the moonlight. Normally an observer from a dark-sky site and no moon interference might see about 60 to 100 meteors per hour. Expect to see a few dozen bright meteors per hour, the majority of them white but many streak yellow and some blue, orange, red, and green ones.
Meteor showers occur when Earth’s orbit crosses the orbit of a comet. Meteors are grains of dust released from a comet as it approaches the Sun. Often the parent comet wears away with time to leave just a stream of dust. The Geminid meteor shower, however, is different. An asteroid, 3200 Phaeton, lies in the same orbit as the Geminids. This discovery, made by a satellite in the 1980s, suggests that some comets may have solid cores lurking beneath a layer of dirty snow. In the Geminid parent comet’s case, when all the snow melted, an asteroid was left, plus many, many more meteoroids all rolling along the same orbit. As such, asteroid 3200 Phaeton may be a “dead comet.”
The Geminid meteor stream orbits the Sun with a period of 1.65 years with tiny meteoroids slamming into Earth’s atmosphere at 22 miles per second. The point where the stream’s orbit intersects Earth’s orbit lies in the constellation Gemini, hence the shower’s name. The meteors zip into Earth’s atmosphere along nearly parallel lines, but from our perspective, they appear to radiate away from the intersection point in Gemini. To get the best view of the shower, face eastward but look about halfway between Gemini and straight overhead. Because December nights are often chilly, if not cold, dress warmly (or lie in a sleeping bag) and bring along some hot coffee, tea, or chocolate in a thermos! If it is cloudy, you may continue to see some meteors after the peak date. It’s always worth one more look.
In addition if it is cloudy or if you do not want to venture outside into the cold, you can tune into Spaceweather Radio and listen to the meteors as they slam into Earth’s atmosphere. The radar “pings” when a meteor passes overhead. The ghostly “ping” is the reflected signal from the trail left behind by the meteor. To “listen” to the meteors you can visit http://spaceweatherradio.com/ Good Luck!
Climbing the eastern sky in mid-evening is a constellation many people recognize – Orion the Hunter. The bright bluish star Rigel marks one knee with orange-red Betelgeuse marking his opposite shoulder. Above Betelgeuse a few dim stars indicate his upraised club. From Bellatrix, other dim stars depict a shield on his other arm. Opposite Rigel is Saiph, the hunter’s other knee.
The constellation Orion is a distinctive grouping rising after sunset.
Below the three belt stars in the sword is the Orion Nebula (M42),
where man stars are forming from collapsing clouds of gas.
M42 is a striking object in binoculars and small telescope.
The Great Orion Nebula, which appears as a small dim glow in a pair of binoculars. The nebula contains four very young, hot stars called the Trapezium which formed from the nebula about 100,000 years ago. Because they are young and very hot, they are heating the nebula so that it glows. Many other stars are also forming deep within the cloud.
The middle "star" in the sword region of Orion contains the
Great Orion Nebula as well as other stars shrouded in gas and dust.
The Orion Nebula (telescope view) glows brilliantly as the middle "star" in Orion's sword.
Also known as M42, the famous nebula is visible with the unaided eye,
but a pair of binoculars or small telescope will reveal much more.
Greek stories of Orion’s life are quite varied. One popular story involves Artemis, who fell in love with Orion. Artemis’s brother, Apollo, disapproved of the couple. One day, he spotted Orion swimming in the ocean and challenged his sister to hit the far away floating target with an arrow. Artemis was a skilled archer who took aim at the target, released the arrow, and struck the target on her first attempt. When Orion’s body washed ashore she was devastated, realizing she had killed her love.
It is also said that Orion met his death as the result of a scorpion’s sting. It was not uncommon for Orion to boast of his talents and conquests. He was especially proud of his hunting abilities and claimed that no animal alive could harm him and threatened to slay every beast upon the earth. The goddess Gaia became angry at Orion’s arrogant threat and decided to teach him a lesson. As such, she placed a scorpion along the path Orion always took on his way to his hunting grounds. Late one night, as Orion hunted in the forest, the scorpion silently waited along the path to ambush the hunter. When Orion passed, the scorpion mortally stung the hunter in the heel - which is why when the constellation Scorpius rises in the east, Orion flees and sets below the horizon in the west.
Graphic artwork of Orion the Hunter from Stellarium free planetarium software.
Three stars in nearly a straight line cross Orion’s middle to form his belt; from bottom up they are Alnitak, Alnilam, and Mintaka. About halfway between Alnitak and Rigel, look for several faint stars of the Hunter’s sword. Greek stories of Orion’s life are quite varied. One popular story involves Artemis, who fell in love with Orion. Artemis’s brother, Apollo, disapproved of the couple. One day, he spotted Orion swimming in the ocean and challenged his sister to hit the far away floating target with an arrow. Artemis was a skilled archer who took aim at the target, released the arrow, and struck the target on her first attempt. When Orion’s body washed ashore she was devastated, realizing she had killed her love.
Look for Orion rising in the east around 7pm local time. By about 8pm, the mighty hunter has cleared the horizon and sits high in the southern sky by midnight.
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Spot the International Space Station
Over the next few nights this week if you step outside on a clear night you’ve got a good chance of seeing the International Space Station (ISS) as it glides across the skies of Emporia (https://www.nasa.gov/mission_pages/station/main/index.html). So whether you’ve seen it dozens of times or never at all, this is your chance to see it.
Since 1998 the International Space Station has been crisscrossing the heavens. It is the largest satellite in space and is crewed with up to six people from various nations. Travelling at over 17,000 miles per hour (5 miles per second), and orbiting about 250 miles (400 kilometers) above Earth, ISS can appear like a very bright, fast-moving star. We see the space station because of a couple of reasons. First, it is very large – about the size of a football field. And second, it is covered by materials that reflect a lot of sunlight. Although the space station does have lights, they are much too dim and far away for us to see them. ISS is often mistaken for a passing aircraft, but if you look closely, you will not see any blinking or flashing navigation lights like an aircraft. For the most part, the reflected light from the ISS will remain bright and steady. The amazing thing is that ISS can be seen with the unaided eye!
pass captured on February 5, 2015 over Carlisle, Pennsylvania.
It takes ISS approximately 90 minutes to complete one orbit of Earth and is usually seen before sunrise or after sunset passing from west to east. The orbital path of the space station frequently changes so it will not be seen every night or will appear in the same part of the sky. Depending on your location, the space station can trek very close to the horizon, directly overhead, or anywhere in between with passes lasting 2 to 4 minutes. But in order to see it, you need to know two things – Will it be clear? And when will it pass over your location?
Between November 28th and December 5th ISS will make a number of evening passes. But the brightest and highest passes will occur on December 1st and 2nd. On December 1st, the space station will rise in the southwest at 6:23pm. At 6:27pm, the station will be high in the northwest sky at an altitude of 74°. Its orbital path will take it to the northeast where it will disappear into Earth’s shadow at 6:28pm.
showing the station passes over Emporia on the evening
of December 1st (above) and December 2nd (below).
On December 2nd the space station will rise above the southwest horizon at 5:32pm and trek across the southern part of the sky. At 5:35pm, ISS will be 54° above the southeast horizon where its orbital path will then take it toward the east-northeast.
Much of this information is freely available from various websites or mobile apps for your tablets and smartphone devices. Websites such as http://spaceweather.com/flybys/ and http://www.heavens-above.com/ are online prediction tools which will provide up to the minute information on space station passes from your location. These websites allow you to pinpoint your location either by using your zip code, city name, or by clicking on a map.
For the tech savvy, you can also find mobile apps for Heavens-Above, NASA’s Spot the Station, ISS Spotter, ISS Locator, and Sky Safari. Make sure you are not paying for the app and that the app automatically updates the satellite tracking database. Some of the more advanced apps will show other visible satellite passes and even provide text or voice alerts prior to visible passes for your location. It is important that you provide yourself with enough time to go outside and get oriented. Try to know in advance where and when you should be looking for the space station because if you’re outside looking down for the app on your phone, you just might miss it. When you do see the space station, be sure to look up, enjoy, and wave – as mentioned earlier, there are six people currently living and working up there.
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The Pleiades, located approximately 430 light years from Earth, is the brightest and most obvious star cluster visible to the unaided eye in late autumn and winter. This small grouping of stars is often mistaken for the Little Dipper because of the arrangement of its six brightest stars. The Pleiades are sometimes referred to as the seven sisters which is a reference to the seven stars visible to people with better than average eyesight. For most people, six stars are plainly visible but some have reported seeing as many as eleven stars when viewed from dark transparent skies away from city lights. There are Greek legends of a “lost Pleiad,” the seventh sister, said to have given up her place among the stars after marrying a mortal.
In late autumn evenings, the Pleiades can be seen rising slightly north of east after sunset. According to mythology, the seven sisters are being pursued by the great hunter Orion which rises after the Pleiades. Orion pursues them across the sky nearly all night in November before setting in the west before sunrise. If you have difficulty finding the cluster, wait until the constellation Orion has sufficiently risen above the eastern horizon. Now find his belt – three stars standing nearly in a straight line above the horizon. An imaginary line drawn westward through the belt points to the bright orange star Aldebaran – the fiery eye of the bull in the constellation Taurus. The V-shape pattern of stars to which Aldebaran appears to belong is called the Hyades. Extending the line just a bit further up or to the west will lead you to the Pleiades marking the shoulder of Taurus the bull.
Photo by Mark Brown; 11-20-2016.
Pointing a pair of binoculars or telescope toward this cluster will reveal dozens of individual stars. Long exposure photographs of the cluster will reveal faint wisps of nebulosity around the cluster – which is left over gas and dust from which the stars were born. The stars were born about 100 million years ago, much younger than our Sun, and many times more luminous.
Close up of the Pleiades as imaged through a 400mm refracting telescope.
Thin wisps of nebulosity is apparent. Photo by Mark Brown, 12-29-2013.
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Polaris – The North Star
The sky's most steadfast star is Polaris, in the constellation Ursa Minor the Little Bear. Also called the North Star or Pole Star, this is without doubt the most famous star in the sky. Many people mistakenly believe it is also the brightest star in the sky. But in fact, it ranks only 49th in brightness. Polaris is important because it is located very near to the north celestial pole, the point at which the entire northern sky appears to rotate. While other stars rise and set throughout the night and appear prominent in various seasons, Polaris stays more or less fixed at a single point in the sky – not only throughout the night, but also the entire year.
Polaris was of great importance to early navigators and explorers. By traveling either northward or southward on Earth’s globe one can take note and watch how the altitude of Polaris shifts accordingly. This star’s height above the northern horizon reflects your latitude. The latitude of Emporia, Kansas is 38.4 degrees. Hence, Polaris resides 38.4 degrees above the northern horizon. The width of the adult human fist held at arm’s length measures about ten degrees. By facing north and using your fist as a measuring tool, you can easily find Polaris’ altitude. When measuring upwards from the northern horizon, Polaris will be approximately equivalent to four clenched fists stacked on top of the other. If you stood precisely at Earth’s North Pole, Polaris would be almost directly overhead or at the zenith.
Polaris is the brightest star in its constellation at magnitude 2.0. For centuries, in the mythologies of many different nations, this star has been a symbol of constancy. Yet even steady Polaris moves a bit in the sky. That’s because it is not located exactly at the pole, but instead a little less than one degree from it. Photographs of the pole taken over several minutes or hours reveal that Polaris moves in its own small circle in our sky. What’s more, Polaris is not always the Pole Star. Because of precession – a 26,000-year cycle – the position of the true north celestial pole continually shifts among the northern stars. Nearly five thousand years ago, for example, the star Thuban in the constellation Draco was considered to be the Pole Star. Polaris will be closest to the exact pole in the year A.D. 2102.
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This month a bright “evening star”, the planet Venus, is visible above the southwestern horizon after sunset. It shines at magnitude -3.9 meaning it is the third brightest object in the sky after the Sun and Moon. Venus is bright for two reasons - its orbital position with respect to Earth and from sunlight reflecting off the poisonous acidic clouds in the planet’s atmosphere. Venus is currently just over 108 million miles from Earth or about 1.17 astronomical units (AU).
It is the second planet from the Sun and travels in its orbit much like Earth, but because Venus is an inner planet and closer to the Sun it travels along its orbit faster than Earth – much like a car traveling on the inside lane of a racetrack. Over the next several months Venus will catch up to Earth reducing the distance between the two planets. As it does, the planet will climb higher in the sky away from the glow of sunset and actually become brighter.
Venus is currently moving eastward along the “path of the planets,” the ecliptic. During November, it travels among the stars of Ophiuchus and Sagittarius. On October 30th, Venus passed the pale-yellow planet Saturn and the orange-red star Antares both of which will disappear into the glow of sunset by late November. Venus itself sets about 1 3/4 hours after the Sun. The Moon will join Venus and Saturn in the evening sky on November 1st and 2nd. Compare bright Venus with the waxing crescent moon when the Moon passes nearby.
Image above for the first week in November and taken from EarthSky.org
Image below is from September 8, 2013, Carlisle, Pennsylvania.
A waxing crescent Moon and Venus loom over the western horizon shortly after sunset.
Did you know Venus has been mistaken for a UFO? Its bright appearance above the horizon or tree tops has prompted curious citizens to call local authorities to report a strange light shimmering in the sky.
Did you know Venus has been the only planet given permission to land at an airport? Air traffic controllers have mistakenly identified Venus as an approaching aircraft causing other aircraft in the area to remain in a holding pattern until “the unidentified plane” could land.
Capturing the Aurora Borealis with a digital camera requires the simplest of equipment. All you need is a camera that has a bulb setting (look for a B on the shutter speed dial), a sturdy tripod, a fairly wide-field lens, and a remote shutter release. A remote shutter release is a way to activate your camera shutter without having to touch the camera. In the earlier days of manual film cameras, it was generally referred to as a cable release. If you have to touch your camera to open and close the camera shutter by pressing and releasing the shutter button, then there is the risk of blurring the image. A camera that has a timer to start and stop the exposure is ideal while some DSLR (Digital Single Lens Reflex) cameras also have the capability to trigger the shutter with a wireless remote.
Use the widest and fastest lens you own. A normal 50mm lens will do, but a wider lens such as a 17 or 24mm lens is much better for capturing the sweeping arc of a bright display or large pillars and curtains over a wide landscape. A fast lens refers to the maximum aperture of the lens or the amount of light that your lens will let in. This is usually designated by an “f-number” or “f-stop” – for example f/2.8. The smaller the f-number, the bigger the maximum aperture is for your lens and the more light that will be collected on the image sensor or film. A lens set at f/2.8 will allow more light into the camera than will a lens set at f/4. You must also have the ability to manually focus your camera lens or to set the focus ring to infinity. In low-light or dark situations, the automatic focus feature on your camera will not work.
Your exposure will depend on the brightness of the aurora, ISO setting, and the overall sky brightness (city, suburb, or dark rural location). The ISO setting of a digital camera determines the sensitivity of the camera’s image sensor and is similar to ISO ratings for film photography. An ISO setting of 800 increases the sensitivity of the image sensor more so than an ISO setting of 400. As such, a high ISO (800 – 1600) setting would be more appropriate for dark or low-light situations.
Faint aurora displays, which can sometimes show beautiful hidden colors, might require an exposure lasting up to 30 seconds with the aperture set at f/2.8 and ISO setting of 800. Brighter aurorae can be imaged in less time and with a lower ISO setting. Depending on the focal length of your lens, longer exposures will also lead to stars trailing in the image.
For the most striking photos, include a familiar horizon such as silhouetted trees, distant houses, hills, fences, or even an old windmill. Including foreground objects adds drama to the image. If possible, a nice touch might also include a recognizable constellation in the frame. To increase your chances of seeing an aurora, it is imperative that you find a dark location away from city lights with an unobstructed horizon. Depending on your latitude, an auroral display might only appear close to the horizon. Any city light, glare, or obstructions will reduce your chances of seeing the aurora.
On October 8th, 2016 a magnetic filament erupted from the Sun propelling a CME in the direction of Earth and was predicted to impact Earth’s magnetic field sometime on October 13th. I was aware that an aurora display might be possible because the CME had impacted Earth’s magnetic field and was sparking aurorae across northern Europe at mid-latitudes. As night approached, I traveled a short distance away from city lights and waited.
Indeed the aurora did make a brief appearance as seen in the accompanying image, Old Windmill and Aurora Borealis (above). I used a Canon 60Da DSLR camera with an ISO setting of 400. My lens choice was a Sigma 17 to 50mm lens at 17mm with the aperture set at f/4. The exposure was 30 seconds. I chose these particular settings because there was a bright waxing gibbous moon. Much of the aurora was drowned out by the moonlight, but as the image shows, the windmill and rural landscape was illuminated by the moonlight. The beauty of using a digital camera is that it provides immediate results without shooting several rolls of film and waiting to have them developed. Sometimes it is difficult to discern whether an aurora is present. Because the image sensor of the camera can capture and hold light, I will often times take an image or two of the sky to pick up on any activity that my eyes may not be able to see.
Even though the autumn season is firmly in place, not all of the summer Milky Way has been lost. A short drive into the countryside away from city lights will reveal an impressive view. The Milky Way, that hazy band of light, climbs up from the southwest horizon, passes a few bright stars, divides in two, and then rejoins high overhead. From there it heads toward the northeast where it flows down to greet the early-rising stars of winter.
Looking high (and nearly directly) overhead after sunset, three bright stars form a large asterism called the Summer Triangle. The Summer Triangle is not a constellation, but a prominent grouping of stars from three separate constellations. The three stars in this triangle are Vega in Lyra the Lyre, Altair in Aquila the Eagle, and Deneb in Cygnus the Swan. Lyra is a small trapezoidal constellation and according to some of the mythological sky-lore represents the Lyre of Orpheus. Cygnus, also called the Northern Cross, is easy to trace. The long neck and body of the swan or staff of the cross follows the path of the Milky Way to the southwest while the arms of the cross or wings stretch out on either side. However, Aquila, somewhat resembling a slender diamond-shape pattern of stars, requires a bit more imagination to see the eagle. Yet, how appropriate is it to find an eagle and a swan apparently flying south in the fall?!
Following the Milky Way to the northeast will lead to a distinct side-ways letter “W” or “M” grouping of stars. This is queen Cassiopeia sitting on her throne. To her left and high in the northern sky is Cepheus her husband, and mythical king of Ethiopia. Cepheus’ stars look very similar to a child’s crude drawing of a house. The house is nearly upside down with the apex of the roof pointing toward the pole star, Polaris.
Below the “W” of Cassiopeia stands Perseus, who in mythology was the slayer of the Gorgon Medusa and rescuer of Andromeda, the daughter of Cepheus and Cassiopeia. Located between the stars of Perseus and Cassiopeia your unaided eye should spy a dim fuzzy spot. However, a pair of binoculars will reveal a striking pair of open star clusters known as the Double Cluster, which is always a treat to see in the autumn sky.
Andromedia Galaxy through the eyes of the telescope. Photo by Mark Brown.
To aid in your search of objects in the night sky, visit Peterson Planetarium and take in one of their night sky programs where you can learn more about “what’s up” in the October sky. Or you can download a free copy of the current night sky at http://www.skymaps.com/downloads.html
During the course of the past week, the moon has gradually changed its appearance in the night sky by growing and brightening in phase, a sequence known as waxing. On Saturday, October 15th at 11:24pm CDT, the moon will reach its full phase when the moon’s orbit takes it around to a point when the moon, earth and sun line up. It is in this alignment when the sun’s light fully illuminates the earth-facing side or full phase of the moon. In this alignment moon rise occurs very near to the same time as sunset. A full moon rising above the horizon can be an awesome sight to behold. But as viewed through a pair of binoculars or telescope, the full moon is the worst time to observe the moon. The harsh sunlight falling upon the moon washes out many of the details in the craters and other surface features. A first quarter moon will reveal more detail because of the contrast between the light and dark portions of the moon.
Finally, October’s full moon is known as the Hunter’s Full Moon. As Native Americans prepared for the cold months ahead they often looked toward October’s full moon to gather meat for winter. After the fields had been harvested in late September or early October, deer and fox would venture into the fields in search of fallen grains. As such, hunters could easily spot their prey by the light of the full moon. Regardless of whether the moon is full, at first quarter, waxing or waning, you do not need an excuse to look up at the moon. When looking at the moon, the beauty is simply in the eye of the beholder, so enjoy it.
The Moon will take center stage for stargazers around the world on Saturday, October 8, 2016 during International Observe the Moon Night (InOMN). InOMN is an annual worldwide public engagement program that encourages observation, appreciation, and understanding of Earth’s closest neighbor - the Moon, and its connection to NASA planetary science and exploration.
From Emporia, Kansas, the Moon will be high in the southern sky after sunset with planet Mars positioned to the lower right. A pair of binoculars or small telescope turned toward the Moon will reveal numerous craters and the dark lunar seas called maria. The lunar maria are large, dark, basaltic plains which formed by ancient volcanic eruptions.