Starry Night College Textbook - Horry-Georgetown Instructions

To resolve the error when submitting an assignment in Starry Night College Textbook, we have new instructions to login at https://learn.simcur.com. Before following these instructions, ensure that you have the new login password sent earlier by email. Please contact your instructor if you do not have it.

Update: Video walkthrough is available here: https://youtu.be/Tyr7PX4oOhU

Please follow the personalized instructions below to login to Starry Night moving forward.

Step 1.  Sign Into Starry Night

  • Go to https://learn.simcur.com

  • Click on “Sign In”.

  • Sign Into Starry Night using your school email (ends with @hgtc.edu).
    Note: if you don’t see the window below, select “Sign Out of All Accounts” and try again.

  • Click “Continue”.

Step 2. Choose a System

  • In the “Choose a System” window, select the “Canvas” option, NOT Brightspace. If you select Brightspace, you will not be able to submit your assignments.

Step 3. Login in with your student email and new password.

  • A new window pops up.

  • Enter your student email and the custom password that was emailed to you earlier.

  • Click “Login” and then “Authorize” in the new window that opens.

  • You are now logged in.

Notes:

  1. Your previous assignments up to Feb 6. will not be visible.  However, your instructor has your grades already for all assignments before this date.

  2. You can still sign in to Brightspace to view previous assignments by selecting the “Brightspace” option in the Choose a System window. However, after Feb 6 you should select the Canvas option to do and submit your work.


Twenty Great Fuzzies: Brilliant Treasures Lie Buried Within The Constellations

Introduction

Brilliant treasures lie buried within the constellations. Collected here for your delight: twenty "objects"; favorites of many amateur astronomers. Among these twenty "fuzzy" targets are star clusters, nebulae, and galaxies. They make  a rewarding starting point for the exploration of the deep sky.

Of course, comets are fuzzies too. Fuzzy, but fickle. Sometimes their orbits (and therefore their return dates) are known. Sometimes not. And you never know in advance just how good—or how disappointing—the cometary show will be. So here, we've chosen to profile only those objects that will always be there for you.

Most are visible to the naked eye or with binoculars under a clear, moonless night. This list is just a hint of what's out there. Celestial riches abound, hidden out there among—and beyond—the stars.

The Eta Carinae Nebula

Eta Carinae (pronounced "ATE-ah ca-RYE-nee") is the largest and most splendid diffuse nebula in the sky, surpassing even the famous Orion Nebula (M42) in size and glory. Only its position far south of the celestial equator prevents this nebula from being a household name. You can't see it from much of the Northern Hemisphere.

Eta Carinae is a colossal star-forming region of hot gas, heated by ultraviolet rays from its hot young stars. It covers a full two degrees of sky (four times the width of the full moon).

Eta Carinae is obvious to the naked eye as a bright, elongated glow, but that only hints at its telescopic grandeur. With binoculars it appears large and bright. Its nebulosity seems split in two by a V-shaped dark lane of dust, called the Keyhole Nebula.

The field of view in most binoculars is just stunning, with Eta Carinae embedded in the star-studded Milky Way. A telescope will reveal many bright wisps, dark lanes, and subtle details that will keep the most ardent observer busy for years. And don't neglect the two open clusters—NGC 3532 and NGC 3114—that flank the Eta Carinae Nebula. 

The star at the center of the nebula has a unique story to tell. Eta Carinae is one of the most massive stars known, 100 times the mass of our sun. It emits four million times as much light as our friendly local star, making it the brightest object in the sky when viewed through an infrared detector. Eta Carinae is a highly unstable star which fluctuates greatly in brightness. It will undoubtedly explode as a supernova soon.

On the cosmic time scale, "soon" means anytime in the next few hundred thousand years. But it could happen in your lifetime. It could happen tonight! Today the star is at the edge of naked eye visibility, but an outburst in the mid-18th century temporarily made Eta Carinae the second brightest star in the night sky, trailing only Sirius—and not by very much! This outburst ejected gas that now surrounds the central star and is known as the Homunculus Nebula, itself a great "fuzzy" for southern sky watchers with telescopes.

The Great Orion Nebula

The Great Orion Nebula (M42) is visible to the naked eye as a fuzzy patch in the middle of Orion's sword. It's called the "great" one because there are other nebulae in Orion.

What astronomers call the Orion Nebula is just the central part of a larger cloud that stretches across several hundred light years. Four bright stars in a parallogram near the nebula's center form the so-called Trapezium. They're the spotlights that let us see this celestial show. These hot young stars heat up the surrounding gas clouds, causing the nebula to emit light.

The Orion Nebula is full of hot, bright blue stars. It's an area of active star formation. The Hubble Space Telescope has found protoplanetary disks of gas and dust around some of these stars. These disks are about twice the size of our solar system, and may eventually condense to form exoplanets or binary stars. 

M42 is a veritable catalog of different object types, including multiple stars, reflection nebulae, and emission nebulae. Try to view the Great Orion Nebula whenever you can, with whatever you've got: telescope, binoculars, or your eyes. The wealth of detail visible in this nebula is outstanding. The intricate wisps, shapes, and the contrast between brighter and darker regions will never cease to amaze you.

The Andromeda Galaxy

The Andromeda Galaxy is one of the most magnificent objects in the night sky and undoubtedly the most famous galaxy outside our own Milky Way.

Persistent staring with your naked eyes will reveal it as a surprisingly large hazy patch. Andromeda covers as much of the sky as five full moons put together!

Binoculars will show Andromeda in its entirety along with two of Andromeda's companion galaxies, M32 and M110. Careful observation of the nuclear region with a telescope will reveal faint dust lanes.

M31 was once thought to be a nebula inside our galaxy, but in 1923, astronomer Edwin Hubble showed that it was outside the Milky Way.

And it wasn't the only one! Andromeda opened our eyes to the true scale of the cosmos. M31 is now about 2.9 million light-years away. It is over 150,000 light-years across and has a mass 1.2 trillion times that of our sun.

And it's headed this way! Andromeda will collide with our own galaxy, perhaps five billion years from now. It's larger than the Milky Way too, and will devour us. Or, at least, merge with us.

Andromeda's done that before. The Hubble Space Telescope has shown that the Andromeda Galaxy has a double nucleus, indicating that it probably cannibalized another large galaxy.

Omega Centauri

Omega Centauri is the finest globular cluster in the night sky. First discovered by Edmond Halley (better known for predicting the return of the comet that still bears his name) in 1677, Omega Centauri is a blazing ball containing over one million stars in an area larger than the full moon. Even the Hercules Cluster (M13) pales in comparison to Omega Centauri.

Omega Centauri is visible to the naked eye, but is truly delightful with binoculars. Step up to a telescope and you'll be simply amazed at the number of bright stars you can resolve. Use low magnification to see the cluster in its entirety and then zoom in for a closer look. 

Omega Centauri's bulk is equal to five-million solar masses. That's ten times the mass of most globular clusters, and as much as some small galaxies.

The stars in Omega Centauri did not all form at the same time, indicating that it may be the nuclear remnant of a small galaxy that merged with the Milky Way sometime in the distant past.

The Great Hercules Cluster

The Great Hercules Cluster (M13) is one of the sky's most precious jewels and among the best globular clusters in the Northern Hemisphere. Visible to the naked eye under dark skies, M13 looks like a fuzzy ball of light in binoculars. A moderate-sized telescope and high magnification shows a blazing ball of stars with many individual members resolved.

The Great Hercules Cluster contains about 400,000 stars, spread across 140 light-years of space. The star density near the cluster's center is extremely high, with stars separated by only a few astronomical units.

M13 was originally discovered by Edmond Halley. Because it compacts a lot of stars in a small area, M13 was selected as a target for one of the first radio messages broadcast to extraterrestrials from the Arecibo Observatory in Puerto Rico. But don't stay on hold waiting for them to pick up the call. If alien civilizations exist in the Great Hercules Cluster, we won't receive their reply for at least 50,000 years; M13 is 25,000 light-years from Earth.

The Large Magellanic Cloud

The Large Magellanic Cloud (LMC) is one of the closest galaxies to our own Milky Way. It's only 180,000 light years away, and closer than its companion galaxy, the Small Magellanic Cloud. 

But don't expect the LMC to have that classic spiral galaxy shape. Because of the gravitational attraction of the Milky Way—which is ten times larger—the Large Magellanic Cloud has an irregular shape and no central core. 

The LMC spans several degrees in the southern sky and can be easily seen with the unaided eye by observers south of the equator. But it was unknown to Europeans until the voyage of Portuguese explorer Ferdinand Magellan in 1519.

It appears as a huge and diffuse cloud in the sky and contains a treasure trove of celestial objects. Amongst its many interesting sights are nebulae, globular and open clusters, planetary nebulae, dust clouds, and a giant region of hydrogen gas. 

In 1987, supernova 1987A exploded in the LMC, the nearest supernova in 400 years. The most prominent object in the LMC is the Tarantula Nebula, a large diffuse nebula. Sweep through this region with binoculars and rich field—or wide angle—telescopes to take it all in. But don't forget to zoom in afterwards and take some closer looks.

The Pleiades

The Pleiades is the most famous of all open star clusters, containing around 500 members set against a black velvet sky. This young first magnitude open cluster is easily visible to the unaided eye and resembles a smaller version of the Big Dipper. At least six hot blue stars are readily visible and keen-eyed observers can see more.

It's a large diameter object; fully two degrees or four full moon-widths. So M45 is best seen with binoculars. A faint veil of nebulosity surrounds the brightest Pleiades members, with the most easily observable patch being the Merope Nebula (IC 349), which surrounds the star Merope. These reflection nebulae are not remnants of the gas cloud where the Pleiades was born, but a chance cloud of dust that the cluster is passing through. 

In some ancient cultures, ceremonies to honor the dead were held on the day when the Pleiades reached its highest point in the sky at midnight (this is around Halloween). Ancient Aztecs believed the Pleiades would be overhead at midnight the day the world ended.

NGC 6231

NGC 6231 is one of the prettiest premium open clusters in the sky. It shines at magnitude 2.6 and spans an area half that of the moon.

It's easy to mistake it for a comet. You can imagine the stars Zeta 1 Scorpii and Zeta 2 Scorpii forming the comet's nucleus and NGC 6231, Collinder 316, and Trumpler 24 to the north forming the tail. 

This very young open cluster (about three million years old) contains lots of young hot giants and supergiants. It also contains two extremely rare Wolf-Rayet stars, which are very hot, massive stars rapidly bubbling off their bulk and converting it to super-hurricane-force stellar winds.

The Double Cluster

The famous Double Cluster in Perseus is one the night sky's finest jewels. NGC 869 and 884 are a pair of bright and large open clusters embedded in the faint glow of the Milky Way. 

This double cluster is visible without optical aid, but binoculars are required to separate the two clusters, which are half a degree apart. A rich-field telescope gives the best view of the Double Cluster, with many stars of differing brightness visible. 

NGC 869 is more tightly packed than NGC 884. Both clusters are about 7,000 light-years away and are part of the Perseus arm, one of the spiral arms of our Milky Way. The two clusters are actually a few hundred light-years apart.

The Small Magellanic Cloud

The Small Magellanic Cloud (SMC) is an irregular galaxy orbiting the Milky Way. Your eye will see it as a hazy patch of light in the sky about three degrees across. But you have to be pretty far south in the Northern Hemisphere or south of the equator to see it. 

Because of its low surface brightness, it might not be visible in the light-polluted skies of cities. It is best viewed with binoculars and telescopes under low magnification. 

Portuguese explorer Ferdinand Magellan was the first European to note the galaxy, during his attempted circumnavigation of the globe in 1519. Magellan promptly adopted the SMC as a navigational aid. 

The SMC is 200,000 light-years away, slightly more distant than its neighbor, the Large Magellanic Cloud. It is a small galaxy, with an estimated mass of two billion suns. Gravitational interactions with the Large Magellanic Cloud and the Milky Way have distorted its shape.

The Ring Nebula

M57 is called the Ring Nebula and it's obvious why. Astronomers estimate that the shell of this planetary nebulawas blown off about 20,000 years ago.

The different colors of the shell visible in photographs represent different elements. Helium gas emits blue light, oxygen emits green light, and carbon emits red light. The apparently empty region between the shell and the central star is actually filled with gas. This area only appears as a void because it is so hot that the gas emits most of its energy as ultraviolet rays instead of visible light.

M57 is tiny but bright when viewed from the Earth. Because its brightness is spread over a small area, it is best viewed under high magnification. The 14th magnitude central star (a white dwarf) is difficult to identify without a fairly big telescope.

The Bode’s and Cigar Galaxies

M81 and M82 are perhaps the most famous pair of galaxies in the sky. Both can be seen in the same low magnification field of view and both are spiral galaxies. However, M81 is viewed nearly face-on, while M82 is edge-on.

M81 is one of the brightest galaxies in the Messier catalog and can be seen with most binoculars. Long exposure photographs display two prominent spiral arms, which may also be observed with larger telescopes. M81 and M82 are separated by only 150,000 light-years.

This could have been the scene of a colossal cosmic collision. It's astounding to realize that what you're actually seeing is the result of a very near miss. Tens of millions of years ago, the larger (and ten times as massive) M81 passed close by its smaller neighbor. As a result of the rising star tides during that encounter, M82 now glows with the fireworks of starburst formation.

The Whirlpool Galaxy

The Whirlpool Galaxy might just be the most impressive galaxy for amateur astronomers. It is easy to locate with binoculars and it lies just over three degrees northwest of Alkaid, the star at the end of the Big Dipper's handle.

The Whirlpool is a face-on galaxy, making its spiral structure easy to observe. A telescope, dark skies, and moderate power will begin to reveal the spiral arms.

M51 has a bright central core but no stars can be resolved. The core likely contains a supermassive black hole. Of special interest is the bridge of nebulosity that connects M51 to its companion galaxy, NGC 5195. The gravitational pull of NGC 5195 is touching off a volley of new star-formation in the Whirlpool Galaxy.

The Lagoon Nebula

The Lagoon Nebula (M8) is a magnificent object easily seen by the naked eye as a large hazy patch in the sky. The Lagoon is a bright emission nebula with an embedded open cluster. The cluster of young stars is heating the nebula's gas and causing it to emit light.

With binoculars you'll see the dark lane that divides the nebula's brighter regions and gives this object its name. A small telescope begins to reveal this nebula's intricate folds and dark regions amidst brighter areas.

Dark Bok globules in the nebula mark dense clouds of gas and dust. These are sites of star birth. The Trifid Nebula lies close to M8 and both nebulae can be seen in the same binocular field of view.

The Beehive Cluster

The Beehive Cluster was first described by Galileo, but it has been known as long as humans have watched the skies. It is easily visible to the unaided eye as a faint round patch of luminosity. Your binoculars will reveal a cosmic swarm of bees, buzzing with gravitational energy. Many of these stars are close enough to attract each other and the cluster contains many double stars.

The Beehive occupies 1.2 degrees of sky and is set against a region of low star density, making it stand out even more. The cluster contains several hundred stars and may share a common origin with the Hyades Cluster.

The Crab Nebula

The Crab Nebula is the remnant of a star that exploded as a supernova in 1054 A.D. The supernova was visible in the daytime for 23 days, shining four-times brighter than Venus. The supernova was visible to the naked eye in the night sky for almost two years before fading out. What we see today is the gaseous material ejected by the exploding star. This material is moving outward from the nebula's center at 1,800 kilometers (1,080 miles) per second. At the nebula's core is an extremely dense neutron star or pulsar, which rotates 30 times per second. 

Astronomer Charles Messier observed the Crab Nebula in 1758 while searching for Comet Halley. This was the inspiration for Messier to develop a list of all celestial objects that might be mistaken for comets—the Messier catalog. The Crab Nebula is the only supernova remnant in the Messier catalog. 

The Crab Nebula can be a disappointing object for stargazers. Look for a dim, elongated glow in a small telescope or good binoculars. A network of fine filaments can be glimpsed with a large telescope under dark skies and averted vision. Discern the classic "S" shape of the nebula's central region. The central pulsar is, of course, tiny and is not visible.

The Rosette Nebula

The Rosette Nebula is a vast cloud of dust and gas spanning more than the width of two full moons. Open cluster NGC 2244 formed inside the Rosette Nebula. The hottest young stars in NGC 2244 excite the surrounding gas clouds, causing the nebula to emit light.

The Rosette Nebula is about 130 light-years in diameter and 5,500 light-years distant.

A Galactic Glutton

A huge jet of hot ionized gas (plasma) extends out from the nucleus, but it is only visible through the largest amateur telescopes. Despite its huge size, M87 resembles an unresolved globular cluster. It's like a titanic puffball and offers little in the way of details in small telescopes. A tiny 11th magnitude elliptical galaxy, NGC 4478 can be observed close to M87.

The Eagle Nebula

The Eagle Nebula is the subject of the most famous Hubble Space Telescope photo, the "pillars of creation" image that shows columns of cool hydrogen gas and dust protruding from a molecular cloud. New stars are being formed within these clouds. 

A young, hot cluster of stars lights up this emission nebula in the Sagittarius spiral arm of the Milky Way, which is a treasure trove for amateur astronomers. Many nights can be spent with the naked eye and binoculars scanning this area.

The "Big Chicken," as it's sometimes called among amateur astronomers, is visible as a hazy patch under dark skies with the unaided eye. The view through binoculars can be breathtaking with M16, M17, M18, and M24 framed in the same field of view against the background glow of the Milky Way.

M16 itself is an open cluster surrounded by a haze of nebulosity. Although not as spectacular as in photographs, this is nonetheless a tantalizing object best seen with binoculars and with low power in telescopes.

The Triangulum Galaxy

A possible satellite of the Andromeda Galaxy, the Triangulum Galaxy is quite small, with a mass one-seventh that of the Milky Way.

In a truly dark and transparent sky, one may be able to get a glimpse of this galaxy, making it one of the most distant objects visible to the naked eye, at 2.9 million light-years.

Binoculars show that M33 has an oval glow while a telescope will begin to reveal subtle details.

Keep Digging!

These twenty great fuzzy targets are just the barest beginning!

Congratulations, you're now an astronomically wealthy individual!


If you'd like to follow along with NASA's New Horizons Mission to Pluto and the Kuiper Belt, please download our FREE Pluto Safari app for iOS and Android.  It is available for mobile devices. Simulate the July 14, 2015 flyby of Pluto, get regular mission news updates, and learn the history of Pluto. 

What You Need To Know About The New Horizons Mission To Pluto In 10 Infographics

The New Horizons mission team has released some very cool infographics that illustrate the amazing journey to Pluto and the science we will do at this new frontier.

If you'd like to follow along with NASA's New Horizons Mission to Pluto and the Kuiper Belt, please download our FREE Pluto Safari app for iOS and Android.  It is available for mobile devices. Simulate the July 14, 2015 flyby of Pluto, get regular mission news updates, and learn the history of Pluto.

Simulation Curriculum is the leader in space science curriculum solutions and the makers of Starry Night, SkySafari and Pluto Safari. Follow the mission to Pluto with us on Twitter @SkySafariAstro, Facebook and Instagram

Night Sky Tour: The Summer Sky

Summer is upon us and observing the summer Milky Way is one of the simple joys for night sky enthusiasts. Find out what other sights await you on a clear summer night.

The Summer Triangle

The Summer Triangle dominates the summer sky. It crosses the hazy band of the Milky Way, which is split into two near the star Deneb by a large dust cloud called the Cygnus Rift.

The Summer Triangle.

The points of the triangle are three of the brightest stars in the summer sky, each the brightest star in its own constellation. The brightest is Vega, in Lyra; second is Altair, in Aquila; and third is Deneb, in Cygnus. Even city-dwellers with glowing, light-polluted skies can find the Summer Triangle.

Using the Big Dipper as the guide to the other stars and constellations, imagine a line extending 75 degrees of sky from the two bowl stars closest to the handle, to a point in the middle of the Summer Triangle. Stretch out your arm out at full length and measure about three spread hands from little finger to thumb. Each hand covers about 25 degrees of sky.

The Harp of the Gods

Vega is the brightest star in the triangle and is almost directly overhead in the summer. Contrary to what you might have seen in the movie Contact, no signs of an extraterrestrial civilization have been detected around this hot star—at least not yet.

Lyra, the Harp.

The name Vega comes from the Arabic word meaning swooping eagle or vulture. Vega is the luminary of Lyra, the Harp, a small but prominent constellation that is home to the Ring Nebula and the star Epsilon Lyrae. In mythology, Orpheus led Eurydice back from the underworld by charming the guards of the underworld with the music of his harp.

M57, the Ring Nebula.

The Ring Nebula is a luminous shell of gas that was ejected from an old star. It resembles a smoke ring or doughnut. Epsilon Lyrae appears to the naked eye as a double star, but through a small telescope you can see that the two individual stars are themselves double! Epsilon Lyrae is popularly known as the "double double."

Vega is a hydrogen-burning dwarf star, 54 times as luminous and 1.5 times as massive as the sun. It's relatively close to us, 25 light-years away.

The Eagle of Zeus

Once you have found Vega, look down to the south-southeast and you will see Altair in the constellation Aquila (the Eagle).

Aquila, the Eagle.

Altair spins at an amazing 750,000 kilometers (470,000 miles) per hour. This rotation has stretched Altair into an egg shape, wider than it is tall.

Altair is one of our nearest neighbors, 16 light-years away.

The Northern Cross

The most prominent constellation that forms part of the Summer Triangle is Cygnus. The main stars in Cygnus create a pattern in the sky known as the Northern Cross, with Deneb at the top. 

Cygnus, the Swan.

Cygnus is in an area of the Milky Way that contains many objects easily seen with an amateur telescope, including a beautiful red and blue double star at the base of the cross, Albireo.

The Strong Man of the Heavens

Imagine drawing a line from Phecda, the star on the bottom of the bowl of the Big Dipper closest to the handle, and continuing through Mizar, the star at the bend of the handle. It will pass by the constellation Hercules. Using Mizar as your starting point, stretch your arm out at full length and measure about two spread hands from little finger to thumb.

Hercules, the Hero.

Hercules is an ancient and faint constellation devoid of bright stars, such as those forming the Summer Triangle. Four of its main stars form a trapezoidal asterism called "the Keystone." On one side of the Keystone is a beautiful globular cluster—a stellar ball containing several hundred thousand stars. 

The Hercules Cluster (M13).

The Hercules cluster—also named Messier 13 or simply M13—is one of the sky's most beautiful sights and the finest globular cluster in the Northern Hemisphere. It is visible with the unaided eye by observers far removed from a city's glow. In binoculars, M13 looks like a fuzzy star; it's one of the more spectacular objects in the sky when seen through a telescope.

Edmond Halley, better known for predicting the return of the comet that still bears his name, discovered the Hercules Cluster.

M13 was selected as a target for one of the first radio messages broadcast to extraterrestrials from the Arecibo Observatory in Puerto Rico. If alien civilizations exist in the Great Hercules Cluster, we won't receive their reply for 50,000 years, because M13 is 25,000 light-years from Earth.

The Summer Milky Way

Summer nights offer the best time to explore our own Milky Way, a ribbon of pale light, formed by the combined light of billions of stars, that in summer stretches across the entire sky from northeast to southwest.

The Summer MilkyWay.

As summer comes on, the view gets exciting. We are treated to glowing clouds of dust, dark rifts, and star clusters as we look at our galaxy edge-on. Think of it as a flattened pancake of stars, seen on its edge.

The Milky Way is one of the most remarkable naked-eye sights in good dark skies far removed from the bright glows of civilization. You should be able to see the Cygnus Rift, a dark lane in the Milky Way between the constellations Cygnus and Scutum. The Cygnus Rift is not a hole in the Milky Way but rather a cloud of dust that obscures the view of distant stars.

Scanning with binoculars unveils the misty band of the Milky Way and reveals a sparkling river of thousands of stars. The most interesting regions stretch from the Summer Triangle toward the south-southeastern horizon.


If you'd like to follow along with NASA's New Horizons Mission to Pluto and the Kuiper Belt, please download our FREE Pluto Safari app for iOS and Android.  It is available for mobile devices. Simulate the July 14, 2015 flyby of Pluto, get regular mission news updates, and learn the history of Pluto.

Simulation Curriculum is the leader in space science curriculum solutions and the makers of Starry Night, SkySafari and Pluto Safari. Follow the mission to Pluto with us on Twitter @SkySafariAstro, Facebook and Instagram

Night Sky Tour: The Spring Sky

The spring is a wonderful time to observe. Learn what to look for in the spring night sky tour.

Your Celestial Guidepost

The Big Dipper is a great starting point to learn your way around the night sky; in spring it's conveniently overhead. The Big Dipper itself is not an official constellation but part of a larger constellation called Ursa Major (the Great Bear). Ancient cultures saw the Big Dipper's star pattern as a bear with a long tail. 

The orientation of the Big Dipper from mid-northern latitudes one hour after sunset.

The name originates from the dipper-shaped pattern formed by the seven main stars of the constellation, although observers with keen vision will see that Mizar, the second star from the end of the dipper's handle is, in fact, a double-star. Binoculars make it easier to split the pair.

The stars of the Big Dipper serve as a handy guide to other stars and constellations. The two stars that form the front part of the dipper's bowl point straight to Polaris, the North Star, and because Polaris marks the location of the celestial north pole, the other stars in the sky seem to turn counterclockwise around it. Find Polaris and you know which way is north!

The Little Dipper and Polaris as seen from mid-northern latitudes one hour after sunset.

Polaris itself marks the end of the handle of another dipper—the Little Dipper in Ursa Minor (the Little Bear). Wrapping around Polaris is the constellation Draco. The stars that form this constellation are associated with dragons in the mythologies of many different cultures. 

Earth's north pole has wandered over the millennia and so has pointed to different stars in different eras. Right now it points to Polaris, but one of Draco's stars, Thuban, was the North Star when the pyramids were built.

Arc to Arcturus...

The handle of the Big Dipper points to two of spring's brightest stars—Arcturus and Spica.

The Little Dipper and the star Arcturus as seen from mid-northern latitudes one hour after sunset.

Arcturus is the Alpha (meaning the brightest) star of the constellation Bootes (the Herdsman). Follow the arc of the handle of the Big Dipper until you come to a bright orange star. This is Arcturus, forming the point of a pattern of stars resembling a kite. 

Arcturus is a giant star, twice as massive and 215 times as bright as the sun. It takes 37 years for the light of Arcturus to reach us, so when we gaze at it, we're seeing the star as it looked 37 years ago.

Ancient astromers had measured the position of Arcturus for nearly 2,000 years, which gave Edmond Halley enough data, in 1718, to discover that it was slowly moving against the background stars of its constellation. Before this discovery of proper motion, the stars were thought to be permanently fixed in the sky. Today we know that all stars move, but Arcturus moves much faster than most—about the width of the full moon every 800 years.

...and Speed on to Spica

If you keep following the arc of the handle of the Big Dipper past Arcturus, you'll encounter another bright star, Spica. Keep them straight by remembering this phrase: "Arc to Arcturus and speed on to Spica."

Polaris to Arcturus and on to Spica as seen from mid-northern latitudes one hour after sunset.

Spica resides in the constellation Virgo (the Virgin), a large zodiacal constellation that over time has represented almost every major female deity.

The Prominent Constellation of Spring

The most prominent constellation in the cool evenings of spring is Leo (the Lion).

Leo as seen from mid-northern latitudes one hour after sunset.

To find Polaris, you used the front of the bowl. To find Leo, you need to draw a line through the stars at the back of the bowl—away from Polaris. Stretch out your arm to its full length and measure about three fist-widths from Phecda—the star at the bottom of the bowl. This should put you at a point within the constellation of Leo.

Leo is a constellation of the Zodiac whose main stars have been included in many different mythologies. Stars depicting the mane and head of Leo form a pattern of stars resembling a sickle or a backward question-mark.The brightest star in Leo is Regulus, marking the end of the handle of the sickle or the dot in the question-mark. Regulus, Arcturus, and Spica are the three brightest stars of spring.

The Leonids meteor shower radiates from this constellation around mid-November.

A Beehive of Stars

To the side of Leo is the fainter constellation of Cancer (the Crab).

The Beehive Cluster in Cancer as seen from mid-northern latitudes one hour after sunset.

M44, the Beehive Cluster.

Inside the boundaries of Cancer is a group of stars neatly tucked together into a beehive shape. The Beehive Cluster (also known as Messier 44) was first described by Galileo, but it has been known since antiquity. 

The beehive is easily visible to the unaided eye as a faint round patch of light. Through binoculars, it resembles a swarm of bees.


If you'd like to follow along with NASA's New Horizons Mission to Pluto and the Kuiper Belt, please download our FREE Pluto Safari app.  It is available for iOS and Android mobile devices. Simulate the July 14, 2015 flyby of Pluto, get regular mission news updates, and learn the history of Pluto.

Simulation Curriculum is the leader in space science curriculum solutions and the makers of Starry Night, SkySafari and Pluto Safari. Follow the mission to Pluto with us on Twitter @SkySafariAstro, Facebook and Instagram

First Night Out Series: How The Stars Got Their Names

Humans have been naming the stars for millennia. The brightest stars were named long ago by people who immortalized their folklore in the heavens, and many of their names are still used today.

Centuries later, formal and systematic naming systems were developed when more extensive lists of stars were compiled.

The following sections describe in more detail how the stars received their names over the years.

Common Names

You might have heard of some of the more popular stars, such as Sirius, Betelgeuse, and Polaris. These names sound foreign, and they are—their origins are mostly Arabic translations of Latin descriptions.

Common names. Credit: Starry Night software.

But to add to the confusion, scribes in the Middle Ages reproduced astronomical manuscripts by hand—a method that introduced errors, especially when copying words they did not know. Over time, the process of making copies of copies made it harder to decipher the original meaning of some words. 

The common names for the brightest stars in the sky date back to ancient myths. Stars were often named after heroes, animals, or components of the constellations they helped form. The folklore of the stars offers a tantalizing glimpse into the associations ancient peoples established with the stars.

In all, about 900 stars have common names primarily of Arabic, Greek, or Latin origin. A few star names are relatively modern, however, invented as recently as the 20th century.

A few examples of common names are Sirius (Greek for scorching), Thuban (corrupted Arabic for serpent's head), and Betelgeuse, (a copying error from yad al-jauza, meaning the hand of al-Jauza, the "Central One").

The Bayer System

Johann Bayer was a German lawyer and uranographer. He was born in Rain, Lower Bavaria, in 1572. 

Johann Bayer was a German lawyer and uranographer. He was born in Rain, Lower Bavaria, in 1572. 

Common names are handy for identifying the brightest stars in the sky, but astronomers needed a system for naming all the stars in the sky, including even the faintest ones.

The Bayer system is the first of two naming systems that incorporate constellation names into the identification of stars. It names the brightest stars by assigning a Greek letter (Alpha, Beta, Gamma, Delta, and so on) in an approximate order of decreasing brightness, along with the Latin possessive name of the constellation in which the star resides.

Bayer Names. Credit: Starry Night software.

In this system, Sirius, which is in the constellation Canis Major, is known as Alpha Canis Majoris. Betelgeuse, which resides in the constellation Orion, is known as Alpha Orionis.

The ordering of stars by brightness in the Bayer system is only approximate. As an example, Rigel's name according to the Bayer system is Beta Orionis, suggesting it's the star in Orion just dimmer than Betelgeuse—but it's actually brighter. Brightness fluctuations in Betelgeuse make it brighter than Rigel at times, such as when the system was first introduced in 1603.

The Flamsteed System

John Flamsteed was an English astronomer and the first Astronomer Royal. He catalogued over 3,000 stars.

John Flamsteed was an English astronomer and the first Astronomer Royal. He catalogued over 3,000 stars.

The second system that uses the constellations in which the stars reside is the Flamsteed system.

The Bayer system was useful for naming the stars—certainly better than using common names—but it had problems. The first was that of fluctuating brightness, as in the case of Betelgeuse and Rigel. The second problem was that there are only so many letters in the Greek alphabet.

Unlike the Bayer system, the Flamsteed system can be used to name an unlimited number of stars. In this system, we still use the Latin possessive name of a star's constellation, but this time the stars are distinguished not by their brightness, but also by their proximity to the western edge of their constellations.

Flamsteed Names. Credit: Starry Night software.

The star closest to the western edge is assigned the number 1; the second-closest star to the western edge is number 2, and so on.

For example, the star Sirius is called Alpha Canis Majoris in the Bayer system and 9 Canis Majoris in the Flamsteed system, meaning that it is the ninth-closest star to the western edge of the constellation Canis Major.

Catalog Names

The faintest of stars are known only by their identifiers in specialized catalogs. These catalogs can contain billions of stars, from the brightest to the very faintest, which can be seen only with powerful telescopes and long exposures.

Catalog Names. Credit: Starry Night software.

For example, Sirius is bright enough to have a poetic common name, descriptive Bayer and Flamsteed names, and the label HIP32349 in the Hipparcos catalog.

Naming Your Own Star

You may have read that you can buy a star, or invest in real estate on the moon or Mars.

Some companies provide this service to raise funds for science or a charity but others do it only to line their own pockets. Please do your research and be aware that although these companies charge you a fee for an official-looking certificate, these services have no formal validity at all. The scientific community only recognizes naming conventions based on the regulations of the International Astronomical Union (IAU). 

Remember that the beauty of the night sky is not for sale, and it is free for everyone to enjoy.


If you'd like to follow along with NASA's New Horizons Mission to Pluto and the Kuiper Belt, please download our FREE Pluto Safari app.  It is available for iOS and Android mobile devices. Simulate the July 14, 2015 flyby of Pluto, get regular mission news updates, and learn the history of Pluto.

Simulation Curriculum is the leader in space science curriculum solutions and the makers of Starry Night, SkySafari and Pluto Safari. Follow the mission to Pluto with us on Twitter @SkySafariAstro, Facebook and Instagram

The Ten Brightest Stars In The Sky

From our corner of the galaxy, these stars are the most brilliant signposts in the heavens and can be enjoyed even from the light-polluted hearts of major cities.

Sirius

All stars shine but none do it like Sirius, the brightest star in the night sky. Aptly named, Sirius comes from the Greek word Seirius, meaning, "searing" or "scorching." Blazing at magnitude -1.42, it's twice as bright as any star in our sky besides the Sun.

Sirius resides in the constellation Canis Major, the Big Dog, and is commonly called the Dog Star. In ancient Greece the dawn rising of Sirius marked the hottest part of summer—the season's "dog days."

Sirius no longer marks the hottest part of summer, because it now rises later in the year. This happens because the Earth has been wobbling slowly around its axis in a 25,800-year cycle. This wobble—called precession—is caused by the gravitational attraction of the Moon on Earth's equatorial bulge, and it gradually changes the locations of stars on the celestial sphere

The best time to see Sirius is probably in winter (for northern-hemisphere observers), because it rises fairly early in the evening. To find the Dog Star, use the constellation Orion as a guide. Follow the three belt stars 20 degrees southeast to the brightest star in the sky. Your fist at arm's length covers about 10 degrees of sky, so it's about two fist-widths down.

Sirius, the red giant star Betelgeuse, and Procyon in Canis Minor form a popular asterism known as the Winter Triangle.

Sirius is 23 times as luminous as the Sun, and about twice the mass and diameter. At a mere 8.5 light-years away from Earth, Sirius seems so bright in part because it's the fifth-closest star to the Sun.

The brilliance of Sirius illuminates not only our night skies, but also our understanding. While observing it in 1718, Edmond Halley (of comet fame) discovered that stars move in relation to one another—a principle now known as proper motion. 

This Hubble Space Telescope image shows Sirius A, the brightest star in our nighttime sky, along with its faint, tiny stellar companion, Sirius B.

In 1844, the German astronomer Friedrich Bessel observed that Sirius had a wobble, as if it were being tugged by a companion star. And in 1862, Alvan Clark solved this mystery (while testing his new 18.5-inch lens, the largest refracting telescope in the world at that time). Clark discovered that Sirius was not one star but two.

This proved to be the first discovery in what became a whole class of stars: the compact stellar remnant or white dwarf. These are stars that, once depleting all their hydrogen, collapse to a very dense core. Astronomers have calculated that Sirius's companion—dubbed Sirius B—contains the mass of the Sun in a package as small as the Earth. 

Sixteen milliliters of matter from Sirius B (that is, about one cubic inch of the stuff) would weigh 2000 kilograms on Earth.

At magnitude 8.5, it is one four-hundredth as luminous as the Sun. The brighter and larger companion is now known as Sirius A.

Canopus

Canopus resides in the constellation Carina, the Keel. Carina is one of three modern-day constellations that once formed the ancient constellation of Argo Navis, named for the ship Jason and the Argonauts sailed in to search for the Golden Fleece. Two other constellations form the sail (Vela) and the stern (Puppis). 

In modern odysseys, spacecraft like Voyager 2 used the light from Canopus to orient themselves in the sea of space.

Canopus is a true powerhouse. Its brilliance is due more to its great luminosity than its proximity. This number two on our list of stars has 14,800 times the intrinsic luminosity of the Sun! But at 316 light-years away, it's more than 37 times as far from us as the number one star, Sirius.

With a magnitude of minus-0.72, Canopus is easy to find in the night sky, though it is only visible at latitudes south of 37 degrees north. 

To catch a glimpse of it from middle-latitude or southern locations in the United States, look for a bright star low on the southern horizon during the winter months. Canopus is 36 degrees below the brightest star in the sky, Sirius. The further south you are, the better your view will be.

Canopus is a yellow-white F super giant—a star with a temperature from 5,500 to 7,800 degrees Celsius (10,000 to 14,000 degrees Fahrenheit)—that has stopped hydrogen fusion and is now converting its core helium into carbon. This process has led to its current size, 65 times that of the Sun. If we were to replace our Sun with Canopus, it would nearly envelop Mercury. 

Canopus will eventually become one of the largest white dwarfs in the galaxy and might just be massive enough to fuse its carbon, turning into a rare neon-oxygen white dwarf. These are rare because most white dwarfs have carbon-oxygen cores, but a massive star like Canopus can begin to burn its carbon into neon and oxygen as it evolves into a small, dense, and cooler object.

Canopus lost its place in the celestial hierarchy for a short time in the 1800s when the star Eta Carinae underwent a massive outburst, surpassing Canopus in brightness and briefly becoming the second-brightest star in the sky. And Eta Carinae may yet outdo even Sirius, the brightest. It is fated to become a supernova, perhaps very soon in cosmic time-terms: within a few hundred thousand years.

Alpha Centauri

Alpha Centauri (or Rigel Kentaurus, as it is also known) is actually a system of three stars gravitationally bound together. The two main stars are Alpha Centauri A and Alpha Centauri B. The tiniest star in the system is Alpha Centauri C, a red dwarf. 

The Alpha Centauri system is a special one. At an average distance from us of 4.3 light-years, these stars are our nearest known stellar neighbors. 

A comparison of the sizes and colors of the stars in the Alpha Centauri system with the Sun. 

Centauri A and B are remarkably Sun-like, with Centauri A a near twin of the Sun (both are yellow G stars). In comparison to the Sun, Alpha Centauri A is 1.5 times as luminous and shines at magnitude -0.01 while Alpha Centauri B is half as luminous and shines at magnitude 1.3.

Alpha Centauri C is one seven-thousandth as bright and shines at eleventh magnitude. 

Of the three stars, the smallest is the closest to the Sun, 4.22 light-years away. Because of its proximity, it is known as Proxima Centauri.

When night falls and the skies are clear in summer, the Alpha Centauri system shines at a magnitude of minus-0.27, low in the southern sky. You can find it at the foot of the Centaur in the constellation Centaurus. 

Because of its position in the sky, the Alpha Centauri system is not easily visible in much of the northern hemisphere. An observer must be at latitudes south of 28 degrees north (or roughly from Naples, Florida and locations further south) to see the closest stellar system to us. 

The two brighter components of the system make a wonderful double star to observe in a small telescope.

Naked-eye Alpha Centauri appears so bright because it is so close. This also means that it has a large proper motion—the drifting of stars relative to each other due to their actual movements in space. In another 4,000 years, Alpha Centauri will have moved near enough to Beta Centauri for the two to form an apparent double star.

Arcturus

Arcturus is the brightest star in the northern celestial hemisphere. (The first three stars on this list are actually in the southern celestial sphere, though seasonally they are visible from the northern hemisphere of Earth).

Known as the Bear Watcher, Arcturus follows Ursa Major, the Great Bear, around the north celestial pole. The name itself derives from the Greek word arktos, meaning bear.

Arcturus is an orange giant, twice as massive and 215 times as bright as the Sun. It takes 37 years for the light of Arcturus to reach us, so when we gaze upon it, we are seeing the star as it looked 37 years ago. It glows at magnitude -0.04 in our night sky.

variable star, Arcturus is in the last stages of life. 

During its internal struggle between gravity and pressure, Arcturus has swelled to 25 times the Sun's diameter. 

Eventually the outer envelope of Arcturus will peel away as a planetary nebula, similar to the famed Ring Nebula (M57) in Lyra. The star left behind will be a white dwarf.

Arcturus is the alpha (meaning brightest) star of the springtime constellation Bootes, the Herdsman. You can find it by using the Big Dipper as your celestial guidepost. Follow the arc of the handle until you come to a bright orange star. This is Arcturus, forming the point of a pattern of stars resembling a kite. 

In the spring, if you keep following the arc, you'll encounter another bright star, Spica. (Keep it straight by remembering the phrase: "Arc to Arcturus, speed on to Spica.")

In the 1930s, astronomers were busy measuring the distance to nearby stars and determined—incorrectly, it turned out—that Arcturus was 40 light-years from Earth. During the 1933 World's Fair in Chicago, the light from Arcturus was collected with new photocell technology and used to activate a series of switches. Light believed to have originated at the time of the previous Chicago World's Fair 40 years earlier was used to illuminate and officially open the fair in 1933.

The science of astronomy progresses, and we now know that Arcturus is only 37 light-years away.

Vega

The name Vega comes from the Arabic word for "swooping eagle" or "vulture." Vega is the luminary of Lyra, the Harp, a small but prominent constellation that is home to the Ring Nebula (M57) and the star Epsilon Lyrae. 

The ring is a luminous shell of gas resembling a smoke ring or a doughnut that was ejected from an old star. Epsilon Lyrae appears to the naked eye as a double star, but through a small telescope you can see that each of the two individual stars is itself a double! Epsilon Lyrae is popularly known as the "double double."

Vega is a hydrogen-burning dwarf star, 54 times as luminous and 1.5 times as massive as the Sun. At 25 light-years away, it is relatively close to us, shining with a magnitude of 0.03 in the night sky. 

In 1984, a disk of cool gas surrounding Vega was discovered—the first of its kind—extending 70 AU from the star, roughly the distance from our Sun to the edge of the Kuiper Belt. This discovery's important because a similar disk is theorized to have played an integral role in planet development within our own solar system. 

Astronomers also found a "hole" in the Vega disk, indicating the possibility that planets might have already coalesced and formed around the star. This led the astronomer and author Carl Sagan to choose Vega as the source of advanced alien radio transmissions in Contact, his first science-fiction novel. (In real life, no such transmissions have ever been detected.)

Together with the bright stars Altair and Deneb, Vega forms the popular Summer Triangle asterism that announces the beginning of summer in the northern hemisphere. The asterism crosses the hazy band of the Milky Way, which is split in two near Deneb by a large dust cloud called the Cygnus Rift. 

This area of the sky is ideal for sweeping with binoculars of any size in dark-sky conditions.

Vega was the first star to be photographed, on the night of July 16, 1850, by the photographer J.A. Whipple. With the daguerreotype camera used at the time, he made an exposure of 100 seconds using a 15-inch refractor telescope at Harvard University. Fainter stars (those of second magnitude and dimmer) would not have registered at all using the technology of the time.

Vega used to be the North Star, but 12,000 years of Earth's precession has altered its place in the celestial sphere. In another 14,000 years, Vega will be the North Star again.

Capella

Capella is the primary star in the constellation Auriga (the Charioteer), and the brightest star near to the north celestial pole. 

Capella is actually a fascinating star system of four stars: two similar class-G yellow-giant stars and a pair of much fainter red-dwarf stars. The brighter yellow giant, known as Aa, is 80 times as luminous and nearly three times as massive as the Sun. The fainter yellow giant, known as Ab, is 50 times as luminous as the Sun and two-and-a-half times as massive. The combined luminosity of the two stars is the equivalent of about 130 Suns.

The Capella system is 42 light-years away, its light reaching us with a magnitude of 0.08. 

It is highest in the winter months and circumpolar (meaning it never sets) at latitudes higher than 44 degrees north (or roughly north of Toronto, Canada).

To locate it, follow the two top stars that form the pan of the Big Dipper across the sky. Capella is the brighter star in the irregular pentagon formed by the stars in the constellation Auriga.

South of Capella is a small triangle of stars known as the Kids. One of the most ancient legends had Auriga as a goat herder and patron of shepherds. The brilliant golden yellow Capella was known as the "She-Goat Star." The nearby triangle of fainter stars represents her three kids.

Both yellow giants are dying, and will eventually become a pair of white-dwarf stars.

Rigel

On the western heel of Orion, the Hunter, rests brilliant Rigel. In myth, Rigel marks the spot where Scorpio, the Scorpion, stung Orion after a brief but fierce battle. Its Arabic name means the Foot.

Rigel is a multiple-star system. The brighter component, Rigel A, is a blue supergiant that shines a remarkable 40,000 times stronger than the Sun! Although it's 775 light-years distant, its light shines bright in our evening skies, at magnitude 0.12.

Rigel resides in the most impressive of the winter constellations, mighty Orion. After the Big Dipper, it's the most-recognized and easiest-to-identify constellation. It helps that the shape made by Orion's stars closely matches the shape of a human hunter: three bright stars are lined up together to form a belt, the other four stars surrounding the belt compose shoulders and legs.

Telescope observers should be able to resolve Rigel's companion, a fairly bright seventh-magnitude star. But the jewel in Orion is the Great Orion Nebula (M42), a vast stellar nursery where new stars are still being born. It can be found six moon-widths south of the belt stars.

A heavy star of 17 solar masses, Rigel is likely to go out with a supernova-sized bang one day. Or it might become a rare oxygen-neon white dwarf.

Procyon

Procyon resides in the small constellation of Canis Minor, the Little Dog. The constellation symbolizes the smaller of Orion's two hunting dogs (the other is, of course, Canis Major). 

The word procyon is Greek for "before the dog," for in the northern hemisphere, Procyon announces the rise of Sirius, the Dog Star.

Procyon is a yellow-white, main-sequence star, twice the size and seven times as luminous as the Sun. Like Alpha Centauri, it appears so bright because at 11.4 light-years, it is relatively close.

Procyon is an example of a main sequence subgiant star, one that is starting to die as it converts its remaining core hydrogen into helium. Procyon is currently twice the diameter of the Sun, one of the largest stars within 20 light-years.

Canis Major can be found fairly easily east of Orion during northern-hemisphere winter. Procyon, along with Sirius and Betelgeuse, form the Winter Triangle asterism.

Procyon is orbited by a white-dwarf companion detected visually in 1896 by John M. Schaeberle. The fainter companion's existence was first noted in 1840, however, by Arthur von Auswers, who observed irregularities in Procyon's proper motion that were best explained by a massive and dim companion. 

At just one-third the size of Earth, the companion dubbed Procyon B has the equivalent of 60 percent of the Sun's mass. The brighter component is now known as Procyon A.

Achernar

Achernar is derived from the Arabic phrase meaning "the end of the river," an appropriate name for a star that marks the southernmost flow of the constellation Eridanus, the River.

Achernar is the hottest star on this list. Its temperature has been measured to be between 13,000 and 19,000 degrees Celsius (24,700 and 33,700 Fahrenheit). Its luminosity ranges from 2,900 to 5,400 times that of the Sun. Shining at magnitude 0.45, its light takes 144 years to reach your eye. 

Achernar is more or less tied with Betelgeuse (number ten on this list) for brightness. However, Achernar is generally listed as the ninth-brightest star in the sky because Betelgeuse is a variable whose magnitude can drop to less than 1.2, as was the case in 1927 and 1941.

For northern-hemisphere observers, Achernar rises in the southeast during the winter months and is visible only from latitudes south of 32 degrees north; those further north only see a portion of the constellation. 

(For Star Trek fans, the constellation of Eridanus is also home to Epsilon Eridanus, the star around which Mr. Spock's imaginary home planet of Vulcan supposedly revolves!)

Achernar is a massive class-B star containing up to eight solar masses. It is currently burning its hydrogen into helium and will eventually evolve into a white dwarf star.

Betelgeuse

Don't let Betelgeuse's ranking as the tenth-brightest star in the sky fool you. Its distance—430 light-years—hides the true scale of this supergiant. With a whopping luminosity of 55,000 suns, Betelgeuse still shines bright in our skies at a magnitude of 0.5.

Betelgeuse (pronounced "beetle juice" by most astronomers) derives its name from an Arabic phrase meaning "the armpit of the central one." 

Image from ESO's Very Large Telescope showing the stellar disk.

The star marks the eastern shoulder of mighty Orion, the Hunter. Another name for Betelgeuse is Alpha Orionis, indicating that it's the brightest star in the winter constellation of Orion. But Rigel (Beta Orionis) is actually brighter. This misclassification probably happened because Betelgeuse is a variable star (a star that changes brightness over time) and it might have been brighter than Rigel when Johannes Bayer originally categorized it. 

Betelgeuse is an M1 red supergiant, 650 times the diameter and about 15 times the mass of the Sun. If Betelgeuse were to replace the Sun, all the planets out to the orbit of Mars would be engulfed! 

Observe Betelgeuse and you are witnessing a star approaching the end of its long life. Its huge mass suggests that it might fuse elements all the way to iron. If so, it will blow up as a supernova that would be as bright as a crescent moon, as seen from Earth. A dense neutron starwould be left behind. The other possibility is that it might evolve into a rare neon-oxygen dwarf. 

Betelgeuse was the first star to have its surface directly imaged, a feat accomplished in 1996 with the Hubble Space Telescope.

Perhaps a much more advanced orbiting telescope will be watching someday when Betelgeuse goes supernova, an event which will certainly make it the brightest star in Earth's skies—if only for a few months.


If you'd like to follow along with NASA's New Horizons Mission to Pluto and the Kuiper Belt, please download our FREE Pluto Safari app.  It is available for iOS and Android mobile devices. Simulate the July 14, 2015 flyby of Pluto, get regular mission news updates, and learn the history of Pluto.

Simulation Curriculum is the leader in space science curriculum solutions and the makers of Starry Night, SkySafari and Pluto Safari. Follow the mission to Pluto with us on Twitter @SkySafariAstro, Facebook and Instagram

First Night Out Series: Measuring Brightness In The Sky

In 120 B.C. Hipparchus, a Greek astronomer, ranked the brightness of stars in the sky on a scale of one to six. He classified the brightest stars he could see as first magnitude and ranked the rest down to the faintest at sixth magnitude.

Astronomers still use this scale to measure the brightness of celestial objects, although it has since been modernized.

The Magnitude Scale

The magnitude scale is logarithmic, so a difference of one point in magnitude is equal to a difference in brightness of about 2.5 times.

The magnitude of stars in the Big Dipper and Little Dipper asterisms.  Credit: Starry Night software.

A magnitude-one star is about 2.5 time brighter than a magnitude-two star, and a hundred times brighter than a magnitude-five star.

The lower the magnitude, the brighter the object.

The brighter planets and stars have negative magnitudes. The sun, the brightest object in the sky, has a magnitude of -26, followed by a full moon at magnitude -12.6.

Objects with a magnitude of six or less can be seen without optical aid under ideal observing conditions away from all artificial light.

Where Do Objects Fit in the Scale?

The table below is a list of well-known celestial objects and roughly where they fall on the magnitude scale—some objects, such as Venus, vary in brightness. The magnitude values have been rounded.

Object Mag
   
Sun -26
Full Moon -12.6
Crescent Moon -6
Venus (the brightest planet) -4
Jupiter -2
Sirius (the brightest star in the sky) -1
Vega (the brightest star in the Summer Triangle) 0
Saturn +1
Polaris (the North Star) and the Stars of the Big Dipper +2
The Andromeda Galaxy +4
Uranus and the Faintest Stars Visible with the Naked Eye +6
Objects You Need Binoculars to See +7 and greater

A Few Handy Terms

Here are a few handy terms to keep in mind when reading about the appearance of celestial objects.

Luminosity

Luminosity is the intrinsic brightness of a star—compared to the sun—as it would appear if you were there in orbit around it, rather than viewing it from Earth. The sun's luminosity is 1. Sirius has a luminosity of 23 and Betelgeuse has a luminosity of 55,000.

Brightness

Brightness is the light given off by a celestial object as seen from Earth. Brightness depends on luminosity and the distance from the object. 

Magnitude

Magnitude is a logarithmic brightness scale. Magnitude-one objects are 2.512 times brighter than magnitude-two objects, which are 2.512 times brighter than magnitude-three objects, and so on. The difference between magnitude one and magnitude five is one hundred times. The higher the magnitude, the fainter the object. The lower the magnitude, the brighter the object. The brightest stars have negative magnitudes.


If you'd like to follow along with NASA's New Horizons Mission to Pluto and the Kuiper Belt, please download our FREE Pluto Safari app.  It is available for iOS and Android mobile devices. Simulate the July 14, 2015 flyby of Pluto, get regular mission news updates, and learn the history of Pluto.

Simulation Curriculum is the leader in space science curriculum solutions and the makers of Starry Night, SkySafari and Pluto Safari. Follow the mission to Pluto with us on Twitter @SkySafariAstro, Facebook and Instagram

First Night Out Series: Measuring Distances In The Sky

Measuring the distance from one star to another in the sky is easy when you master using your hands to measure the degrees between objects. 

Hold your hand at arm's length:

  • The width of your little finger is about one degree—enough to cover the moon and sun, both of which are each half a degree across.
  • The width of the first three fingers side-by-side spans about five degrees.
  • A closed fist is about ten degrees.
  • If you spread out your fingers, the distance from the tip of your first finger to the tip of your little finger is 15 degrees.
  • If you spread out your fingers, the distance from little finger to thumb covers about 25 degrees of sky.

Measuring degrees with your hands.

With a bit of practice, this hand system is endlessly useful when measuring your way around the sky.

Calibrating with the Big Dipper

Everyone's hands are slightly different, so you might want to practice and calibrate your own hand measurements using the Big Dipper.

Big Dipper Distances.

Here are the rough distances from Dubhe to several other prominent Big Dipper stars:

Dubhe to Merak 5 degrees
Dubhe to Megrez 10 degrees
Dubhe to Alioth 15 degrees
Dubhe to Mizar 20 degrees
Dubhe to Alkaid 25 degrees

If you'd like to follow along with NASA's New Horizons Mission to Pluto and the Kuiper Belt, please download our FREE Pluto Safari app.  It is available for iOS and Android mobile devices. Simulate the July 14, 2015 flyby of Pluto, get regular mission news updates, and learn the history of Pluto.

Simulation Curriculum is the leader in space science curriculum solutions and the makers of Starry Night, SkySafari and Pluto Safari. Follow the mission to Pluto with us on Twitter @SkySafariAstro, Facebook and Instagram

First Night Out Series: Finding Your Way Around The Sky

The Big Dipper is a great starting point for learning the night sky. Being circumpolar, it never completely sets or dips below the horizon—it's visible in the night sky year-round!

The Big Dipper itself is not a constellation, but it resides in one called Ursa Major, the Great Bear, the third largest of the 88 constellations. The name originates from the dipper-shaped pattern formed by the seven main stars in the constellation.

To locate the Big Dipper, face north and look for the seven bright stars that dominate the sky in this direction—they should be easy to find. Depending on the time of year, the pattern formed by these stars appears in a difference orientation, but the shape is always the same:

  • In autumn, the dipper appears to be sitting flat.
  • In spring, the dipper is upside-down, spilling its contents.
  • In summer, it sits upright on its bowl.
  • In winter, it sits up on its handle.
The Big Dipper through the seasons.

The Big Dipper through the seasons.

The stars of the Big Dipper are a handy guide to other stars, constellations, and other thought-provoking objects that may be too faint to spot with the naked eye. Using well-known spots in the sky to find fainter ones is known as star hopping—think of it as an astronomical treasure hunt! And one of the easiest and coolest place to start is with the two end stars that form the front of the dipper's bowl—they point straight to Polaris, the North Star.

All the other stars in the sky seem to turn counterclockwise around Polaris. Polaris itself marks the end of the handle of another pattern, the Little Dipper in Ursa Minor, the Little Bear. If you find Polaris, you know which way is north. 

Following the arc of the handle of the Big Dipper points to two of spring's brightest stars—Arcturus and Spica. With a bit of practice, it's surprisingly easy to imagine lines and arcs from star to star and hop from constellations you know to those you're still learning.

The Big Dipper points the way.

The trick to successfully learning the night sky is to use easily recognizable star patterns to find the more difficult ones—just like we used the Big Dipper's stars to find Polaris.

Don't try to learn the entire sky on your first night out. Begin by learning the major constellations and then search out the more obscure patterns as the need and challenge arise.

Like riding a bicycle, once you know a constellation, it's hard to forget it.


If you'd like to follow along with NASA's New Horizons Mission to Pluto and the Kuiper Belt, please download our FREE Pluto Safari app.  It is available for iOS and Android mobile devices. Simulate the July 14, 2015 flyby of Pluto, get regular mission news updates, and learn the history of Pluto.

Simulation Curriculum is the leader in space science curriculum solutions and the makers of Starry Night, SkySafari and Pluto Safari. Follow the mission to Pluto with us on Twitter @SkySafariAstro, Facebook and Instagram

Astronomy Concept Diagrams

Explain difficult astronomical concepts with clear, concise diagrams from Starry Night Education. Click on each image to view a larger version.  Feel free to use in your classroom or outreach activities.


If you'd like to follow along with NASA's New Horizons Mission to Pluto and the Kuiper Belt, please download our FREE Pluto Safari app.  It is available for iOS and Android mobile devices. Simulate the July 14, 2015 flyby of Pluto, get regular mission news updates, and learn the history of Pluto.

Simulation Curriculum is the leader in space science curriculum solutions and the makers of Starry Night, SkySafari and Pluto Safari. Follow the mission to Pluto with us on Twitter @SkySafariAstro, Facebook and Instagram

Astronomical Audio Pronunciation Guide

Some astronomical monikers truly do seem alien, and ensuring correct pronunciation can be hazardous for even the most advanced educator. Starry Night Education is here to help with our Audio Pronunciation Guide for the top 500 most commonly mispronounced astronomical objects, from Acamar through Zubeneschamali.

Choose your category:
asteroids
constellations
planets
meteors
stars

     
Click the name to hear the correct pronunciation.

Asteroids

 
 
Name
Pronunciation
 
ANN-FRANK
 
a-PAW-fis
 
a-STREE-a
 
BACK-us
 
BRAIL
 
SEER-eez
 
e-JEER-ee-a
 
EER-os
 
ewe-NOM-ee-a
 
FLOOR-a
 
for-TUNE-a
 
HEE-bee
 
hy-GEE-a
 
eye-REE-nee
 
EYE-ris
 
JEW-noe
 
ka-LYE-o-pee
 
lew-TEE-sha
 
ma-SALL-ee-a
 
mel-POM-e-nee
 
MEE-tis
 
PAL-as
 
par-THEN-o-pee
 
SYE-kee
 
SIL-vee-a
 
the-LYE-a
 
THEE-tis
 
VES-ta

Constellations

 
 
Name
 
Pronunciation
 
an-DROM-eh-da
 
ANT-lee-uh
 
APE-us
 
ack-KWAIR-ee-us
 
ack-WILL-lah
 
AY-rah
 
AIR-ease
 
or-EYE-gah
 
bow-OH-tease
 
SEE-lum
 
ca-MEL-oh-PAR-dal-iss
 
KAN-surr
 
KAN-es veh-NAT-ih-see
 
KANE-es MAY-jer
 
KANE-es MY-ner
 
CAP-rih-CORN-us
 
car-EE-na
 
KASS-ee-oh-PEE-ah
 
sen-TOR-us
 
SEE-fee-us
 
SEE-tus
 
kah-ME-lee-un
 
SIR-sin-us
 
ko-LUM-ba
 
CO-ma bare-uh-NYE-sees
 
coe-ROW--nah ow-STRAHL-iss
 
coe-ROW--nah BOR-ee-AL-iss
 
CORE-vuss
 
CRAY-ter
 
Kruks
 
SIG-nus
 
del-FYE-nus
 
doh-RAY-doh
 
DRAY-ko
 
eh-KWOO-lee-us
 
eh-RID-uh-nuss
 
FOR-naks
 
GEM-in-eye
 
GROOS
 
HER-kyou-leez
 
hor-uh-LOW-gee-um
 
HY-druh
 
HY-drus
 
IN-dus
 
la-SIR-ta
 
LEE-oh
 
LEE-oh MY-ner
 
LEE-puss
 
LEE-bra
 
LOUP-us
 
links
 
LIE-rah
 
MEN-sa
 
MY-krow-SKOH-pee-em
 
mon-OSS-er-us
 
MUSS-ka
 
NOR-ma
 
OCK-tens
 
Oaf-ih-YOU-kus
 
oh-RYE-un
 
PAY-vo
 
PEG-uh-suss
 
PURR-see-us
 
FEE-nix
 
PICK-tor
 
PIE-sees
 
PIE-sees oss-TREE-nus
 
PUP-iss
 
PICK-sis
 
reh-TICK-yuh-lum
 
suh-JIT-uh
 
sa-jih-TARE-ee-us
 
SKOR-pee-uss
 
SKULP-tor
 
SCOOT-um
 
SIR-pens CAP-ut
 
SIR-pens KAW-dah
 
SEX-tens
 
TOR-us
 
tell-es-SCOPE-ee-um
 
tri-ANG-yuh-lum
 
tri-ANG-yuh-lum aus-TRAY-lee
 
too-KAY-nah
 
URR-sah MAY-jer
 
URR-sah MY-ner
 
VEE-la
 
VER-go
 
VO-lans
 
vul-PECK-yoo-la

Planets & Moons

 
 
Name
Pronunciation
 
ah-DRAHS-tee-ah
 
et-NEE
 
ah-mal-THEE-ah
 
a-NAN-kee
 
AIR-ee-el
 
AT-lus
 
aw-TON-oe-ee
 
be-LIN-dah
 
bee-AHNK-uh
 
KAL-e-ban
 
ka-LIRR-o-ee
 
ka-LIS-toe
 
ka-LIP-soe
 
KAR-mee
 
kal-DEE-nee
 
CARE-en
 
core-DEAL-ya
 
KRESS-e-da
 
DYE-mos
 
DES-de-MOAN-a
 
de-SPEEN-a
 
dye-ON-ee
 
URTH
 
EE-lahr-ah
 
en-SELL-ah-dus
 
EPP-e-ME-thee-us
 
err-IN-o-mee
 
EE-ris
 
ewe-AN-thee
 
ewe-POUR-ee-e
 
you-ROE-pah
 
ewe-RID-o-mee
 
GAB-ree-ell
 
GAL-aTEA-a
 
GAN-eh-meed
 
har-PAL-e-kee
 
he-LEAN
 
her-MIP-ee
 
HIM-ah-lee-ah
 
hye-PER-ee-on
 
ee-AHP-eh-tus
Io
 
EYE-oh
 
EYE-o-KAS-tee
 
eye-SON-oe-ee
 
JAY-nus
 
JEW-lee-ette
 
JEW-pi-ter
 
KAY-lee
 
KAL-e-kee
 
la-RISS-a
 
LEE-dah
 
lis-ih-THEE-ah
 
MARZ
 
MEG-a-KLYE-tee
 
MIRK-you-ree
 
MEE-tis
 
MYE-mus
 
mi-RAN-dah
 
moon
 
NYE-ad
 
NEP-toon
 
NAIR-ee-id
 
OH-ba-ron
 
oh-FEEL-ya
 
or-THOE-see-e
Pan
 
PAN
 
pan-DOOR-ah
 
pa-SIF-ah-ee
 
PAS-e-thee
 
FOE-bos
 
FEE-bee
 
PLOO-toe
 
POR-sha
 
prak-SID-e-kee
 
pro-MEE-thee-us
 
PRO-per-oe
 
PRO-tee-us
 
PUCK
 
KWA-oh-ar
 
REE-a
 
ROS-a-lind
 
SA-turn
 
SET-e-bus
 
se-NO-pee
 
SPON-dee
 
ste-FAA-noe
Sun
 
sun
 
SICK-o-RACKS
 
tay-IJ-e-tee
 
tah-LES-toe
 
TEE-this
 
tha-LASS-a
 
THEE-bee
 
the-MISS-toe
 
Thy-OE-nee
 
TYE-tun
 
tye-TAIN-ee-ah
 
TRING-kew-loe
 
TRY-ton
 
UM-bree-el
 
YOU-rah-nus
 
VEE-nus

Meteor Showers

 
 
Name
Pronunciation
 
AY-tah AK-wa-rids
 
GEM-e-nids
 
LEE-o-nids
 
LYE-rids
 
north TOR-ids
 
o-RYE-o-nids
 
PUR-see-ids
 
kwa-DRAN-tids
 
south DEL-tah AK-wa-rids
 
south TOR-ids

Stars

 
 
Name
Pronunciation
 
AH-kuh-mar
 
AK-er-nar
 
A--krucks
 
ACK-you-benz
 
ad-HAR-a
 
al-KAP-rah
 
all-NAYR
 
all-NEE-yaht
 
all-soo-HAIL
 
al-BAL-dah
 
al-BEE-ri-oh
 
al-CHIH-ba
 
AL-kor
 
all-SYE--o-nee
 
al-DEB-ah ran
 
al-DER-a-min
 
al-da_FER-a
 
All-firk
 
all-JED-ee
 
al-JEN-nib
 
al-GEE-bah
 
al-GEEB-bah
 
AL-gall
 
ALL-gor-ab
 
al-HAY-nah
 
AL-lee-oth
 
AL-kade
 
al-ka-LOOR-ops
 
ALL-maaz
 
ALL-mahk
 
all-NAH-zul
 
ALL-nil-ahm
 
ALL-nit-ahk
 
AL-fard
 
al-FECK-ah, JEM-a
 
AL-fer-rats
 
all-RAH-kiss
 
all-RESH-ah
 
all-SHAIN
 
AL-tair
 
ALL-tays
 
al-TARF
 
al-TERF
 
 
al-UDE-rah
 
a-LOOL-ah ow-STRAH-liss
 
a-LOOLah bor-ee-AH-liss
 
ALL-zirr
 
UNG-ka
 
ANG-kah
 
an-TAIR-ease
 
arc-TOUR-russ
 
AR-kub
 
AR-kub
 
AR-kub PREE-or
 
AHR-neb
 
ah-SELL-a
 
ah-SELL-us ow-STRALICE
 
ah-SELL-us bore-ee-AL-is
 
ah-SELL-us
 
ah-SELL-us
 
ah-SELL-us
 
ass-mid-ISS-kee
 
ass-pid-ISS-kee
 
AH-tik
 
AT-las
 
AH-tree-a
 
 
AV-i-or
 
AH-za
 
ba-HAHM
 
BARN-ards star
 
BUT-en KYE-tos
 
BYED
 
BEL-la-trix
 
BET-el-jooz
 
boh-TAYN
 
can-OH-pus
 
kah-PELL-ah
 
KAF
 
CASS-ter
 
SEB-all-rye
 
ke-LAY-no
 
CHAH-ra
 
KERT-ahn,
 
core-ca-ROLE-ee
 
COOR-sah
 
DAH-bee
 
DEN-ebb
 
DEN-ebb al-JEE-dee
 
DEN-ebb
 
DEN-ebb
 
DEN-ebb KAY-tos
 
de-NEB-oh-la
 
DYE-a-dem
 
JOOB-a
 
DOOB-huh
 
ED-a-sick
 
e-LEK-tra
 
EL-noth
 
EL-ta-nin
 
EEN-if
 
er-RYE
 
e-RAHK-is (mu Draconis)
 
FO-mal-oh
 
fur-ROOD
 
GAK-kruks
 
JAW-sahr
 
JEEN-ah
 
GIRR-tahb
 
go-MAY-sah
 
GRAH-fi-us
 
GROOM-bridge
 
"
 
GROO-mi-um
 
HAH-dahr
 
HAM-al
Han
 
HAN
 
 
 
HEE-dus
 
HEE-dus
 
HOH-mahm
 
EYE-zar
 
JAB-bah
 
KAFF-al-JID-mah
 
KOWSS ow-STRAH-liss
 
KOWSS bor-ee-AH-liss
 
KOWSS me-RID-i-an-AL-is
 
KYED
 
kit-AL-fa
 
KOE-cab
 
core-ne-FOR-uss
 
 
KOOR-hah
 
la su-PURR-ba
 
la-KA-ya
 
la-KA-ya
 
la-LAHND
 
LAY-soth
 
MAH-ya
 
MAR-fick
 
MAR-kab
 
MAH-tahr
 
meb-SOO-tah
 
meg-REZ
 
MAY-sah
 
mek-BOO-dah
 
men-KAH-li-nan
 
men-KAHR
 
men-KENT
 
men-KIB
 
MER-ak
 
MER-o-pee
 
mess-AHR-tim
 
mee--a-PLASS-id-uss
 
mim-OH-sah, BAY-cruks
 
MIN-kar
 
MIN-ta-ka
 
MEE-ra
 
MIRR-ahk
 
MERE-fak
 
MERE-zam
 
MYE-zahr
 
MOOL-if-ayn
 
MOO-frid
 
MUSS-id-a
 
nar-AL-safe
 
NOWSS
 
nah-SHE-rah
 
NECK-ahr
 
nih-HALL
 
NOH-dus
 
NUN-kee
 
noo-SAH-kahn
 
Oaf-ih-YOU-kus
 
FEYE-et
 
FEK-da
 
ferk-AHD
 
PLAY-o-nee
 
poe-LAIR-is
 
POL-lucks
 
pour-EE-mah
 
PRO-see-on
 
PRO-puss, TAY-zhaht PRYE-or
 
RAH-sa-luss
 
rah-sell-GAYTH-ee
 
RAHS-al-haig
 
RAHS-al-MOTH-al-ah
 
REG-you-luss
 
RYE-jel
 
RYE-jel ken-TAW-russ
 
ROH-ta-nev
 
ROOK-baht
 
ROOK-baht
 
SAH-bik
 
sah-DUCK-be-ah
 
sah-dul-BAH-ree
 
sah-dul-MEL-ik
 
sah-dul-su-OOD
 
SADE-der
 
SAFE
 
SAHR-goss
 
SAHR-in
 
SHEE-at
 
SHED-er
 
SEG-in
 
seg-EEN-us
 
SHOWL-a
 
SHEL-ee-yak
 
SHARE-ah-tan
 
SEER-ee-us
 
SKAHT
 
SPEE-ka
 
STER-o-pee
 
swah-LOH-sin
 
soo-HALE-al-MOO-liff
 
SOOL-a-faht
 
SIRM-a
 
TAH-lith-a
 
THA-ni-ya ow-STRAH-liss
 
THA-ni-ya bor-ee-AH-liss
 
TAHR-ah-zed
 
TAY-get-a
 
teg-MEEN-e
 
TAY-zhaht pos-TER-i-o
 
THOO-bahn
 
tra-PEEZ-i-um
 
tra-PEEZ-i-um
 
tra-PEEZ-i-um
 
tra-PEEZ-i-um
 
uh-NOO-kul-lye
 
VEY-ga
 
vin-de-mee-AY-tricks
 
wah-SAHT
 
WUZ-un
Wei
 
 
WEZ-en
 
YED pos-TER-i-or
 
YED PRYE-or
 
zah-NYE-a
 
ZAW-rahk
 
zah-vee-JAH-vah
 
ZOSS-mah
 
zoo-BEN-el-AK-rab
 
zoo-BEN-el-je-NEW-bee
 
zoo-BEN-esh-ah-MAL-ee

If you'd like to follow along with NASA's New Horizons Mission to Pluto and the Kuiper Belt, please download our FREE Pluto Safari app.  It is available for iOS and Android mobile devices. Simulate the July 14, 2015 flyby of Pluto, get regular mission news updates, and learn the history of Pluto.

Simulation Curriculum is the leader in space science curriculum solutions and the makers of Starry Night, SkySafari and Pluto Safari. Follow the mission to Pluto with us on Twitter @SkySafariAstro, Facebook and Instagram

Saturn Through the Ages

On May 23rd, Saturn will reach opposition — the closest it will be to Earth in 2015.

Saturn, the original Load of the Rings.

Saturn can be viewed in the morning sky until May 23, when it moves into the evening sky. From November to the end of the year it will be behind the Sun.

Looking south-east on May 23, 2015 at 11:00 p.m. from mid-northern latitudes.

The rings are now widely open, making them easy to see in any telescope magnifying more than about 30x. Saturn’s largest moon Titan is readily visible in a small telescope, and several more moons may be seen in larger telescopes. At opposition, the planet’s equatorial angular diameter will be 19 arc seconds, its rings being 42 arc seconds across.

As you peer through your eyepiece and ponder the ringed planet with the benefit of our modern understanding of science, consider how perplexing Saturn must have been to ancient people whose instruments and grasp of nature were at their infancy.

Eyepiece view (10 arc minutes) of Saturn on May 23, 2015.  The planet’s equatorial angular diameter will be 19 arc seconds, its rings being 42 arc seconds across.

In our feature article below, “Saturn Through the Ages” — a departure from our usual technical take on the universe — we will be returning to times past to explore a piece of the puzzle that highlights our search for knowledge and meaning.

Saturn Through the Ages  

Throughout human history, we have looked to the light of the heavens to illuminate our role on Earth. Next time you are star gazing, consider all of the people throughout time and across the world who have reflected upon the same celestial bodies, conducting their nightly dance across our sky.

Our study of the celestial sphere has brought us understanding of physical and mathematical principles, models for society and perhaps fundamentally, a comforting sense of order. It is the human imagination however, and our quest to find a meaning behind this order, that led us to create a screenplay of the night sky. For millennia we have told our own tale through the guise of a heavenly cast of characters. Because celestial mythology is common throughout many cultures, these stories reveal our discoveries of the human condition.

In the upcoming month, many of us will be gazing at the planet Saturn in the northeastern sky. Perhaps due to a planet’s slow trek through our heavens, the stories we've told about Saturn often involve the passage of time and inevitable fate. We've expressed through Saturn both our appreciation for life and our fear of time's cruel and inescapable quality.

In ancient Mesopotamia, they prayed to Saturn as the Lord of Death, appealing to him thus:

“O Lord Saturn
whose name is august
whose power is widespread
whose spirit is sublime
O Lord Saturn
the cold, the dry, the dark, the harmful…
crafty sire who knowest all wiles
who are deceitful, sage and understanding
who causest prosperity and ruin
happy or unhappy is he whom thou makest such.”

In ancient Rome, Saturn was an agricultural god, a harvest deity. Controlling our fate through the success of our crop, he was celebrated in times of bounty and appealed to when times were hard. The Golden Age of Saturn, an ideal era of equality and abundance, was memorialized during the mid-winter festival of Saturnalia. A time of feasts and gifts from which we can trace rituals of modern day Christmas. During the celebration, a man chosen to represent the god was attentively fêted, only to be sacrificed on the final day of the festival. Try as we have to sway him however, we are all equally powerless before the forces personified by Saturn. 

In Hindu mythology, Saturn appears as the god Sani, holder of the secrets of fate. One could predict the future through use of a Saturn diagram, which represents the planet’s path through our skies. This god is so malevolent that a single glance from the evil-eyed deity burned off the head of the infant Ganesa, god of good fortune and prosperity. Associated with childhood disease, Sani demonstrates that not even a god’s luck can stand against the inevitability that Saturn represents.

Though we may wish it otherwise, nothing in our human existence remains static; nothing escapes the passage of time. Falcon-headed Horus, Saturnine god of the ancient Egyptians, succeeded his father Osiris when he was dethroned, marking the beginning of a new regime. As all change implies death of the old, we tell our tales of Saturn to reconcile ourselves to the necessity of welcoming the new. 

Cronos, Saturn-god of ancient Greece, whose name may originally have referred to his universal governance (from the verb kreno), became known as Father Time. Cronos not only overthrew and replaced his father, but consumed each of his own children at birth, much as time itself consumes all that it creates. Demonstrating the universality of this principle, Cronos himself was ultimately dethroned by his offspring, making way for a new era.

Through our creation of Saturn mythology, we attempt to explain our relationship to fate, time and death. Our ability to perceive these issues is fundamental to our very humanity. When next gazing at Saturn in the night sky, perhaps you will see not only a wonder of the cosmos, but also the history of humanity’s struggle to find meaning therein.


If you'd like to follow along with NASA's New Horizons Mission to Pluto and the Kuiper Belt, please download our FREE Pluto Safari app.  It is available for iOS and Android mobile devices. Simulate the July 14, 2015 flyby of Pluto, get regular mission news updates, and learn the history of Pluto.

Simulation Curriculum is the leader in space science curriculum solutions and the makers of Starry Night, SkySafari and Pluto Safari. Follow the mission to Pluto with us on Twitter @SkySafariAstro, Facebook and Instagram

Sky Events For May 2015

Moon Phases

Full Moon

Sunday, May 3, 11:42 p.m. EDT

The Full Moon of May is known as the Milk Moon,” “Flower Moon,”  or Corn Planting Moon.It rises around sunset and sets around sunrise; this is the only night in the month when the Moon is in the sky all night long. The rest of the month, the Moon spends at least some time in the daytime sky.

Last Quarter Moon

Monday, May 11, 6:36 a.m. EDT

The Last Quarter Moon rises around 2 a.m. and sets around 1 p.m. It is most easily seen just after sunrise in the southern sky.

New Moon

Sunday, May 18, 12:13 a.m. EDT

The Moon is not visible on the date of New Moon because it is too close to the Sun, but can be seen low in the East as a narrow crescent a morning or two before, just before sunrise. It is visible low in the West an evening or two after New Moon.

First Quarter Moon

Monday, May 25, 1:19 p.m. EDT

The First Quarter Moon rises around 1 p.m. and sets around 2:15 a.m. It dominates the evening sky.

Observing Highlights

Mercury at greatest elongation

Thursday, May 7, evening twilight

This is the best evening apparition of Mercury this year for observers in the northern hemisphere. Use Venus to help you locate it. Mercury is most easily located by sweeping with binoculars, but once youve located it, you should be able to see it with your unaided eyes

Uranus and the Moon

Friday, May 15, dawn

The Moon will pass just south of the Uranus just before sunrise.

Double shadow transit on Jupiter

Wednesday, May 20, 8:068:35 p.m. EDT

The shadows of Io and Ganymede will be on opposite limbs of Jupiter, while the moons Io and Callisto will be central on the disk.

Saturn at opposition

Friday, May 22, 10 p.m. EDT

Saturn will be in opposition to the Sun.

Note how most of Saturns moons are in the same plane as the rings, except for Iapetus, whose orbit is tilted 8.3 degrees. At opposition, Iapetus is close to maximum elongation towards the west, while Tycho is close to maximum elongation towards the east.

Double shadow transit on Jupiter

Wednesday, May 27, 10:01 p.m.12:18 a.m. EDT

The shadow of Io chases the shadow of Ganymede across the face of Jupiter, catching up with it and passing it at 11:48 p.m. EDT. The Great Red Spot will also cross Jupiters disk during this period.

Planets

 Mercury is well placed for northern hemisphere observers in the evening twilight sky for the first three weeks of May.

Venus shines high in the western sky after sunset.

Mars moves from Aries to Taurus on May 3, too close to the Sun to be visible.

Jupiter is well placed in the evening sky all month.

Saturn is just north of Scorpius’ “claws.At opposition on May 22, it is visible all night.

Uranus rises just before the Sun in Pisces.

Neptune is in the eastern morning sky in the constellation Aquarius.


If you'd like to follow along with NASA's New Horizons Mission to Pluto and the Kuiper Belt, please download our FREE Pluto Safari app.  It is available for iOS and Android mobile devices. Simulate the July 14, 2015 flyby of Pluto, get regular mission news updates, and learn the history of Pluto.

Simulation Curriculum is the leader in space science curriculum solutions and the makers of Starry Night, SkySafari and Pluto Safari. Follow the mission to Pluto with us on Twitter @SkySafariAstro, Facebook and Instagram