Category: What’s Up

Please note that this is going to be the last edition of the What’s Up series of articles on Universe Today. From here on out, Tammy’s daily skywatching guide will be published in a book called the Night Sky Companion. Tammy is still writing for Universe Today, and will be posting articles about skywatching and events on a regular basis.

Monday, December 24 – Twas the night before Christmas in a sky filled with stars… And low on the horizon are the Yule Moon and Mars! That’s right. It’s the Full Yule Moon, and arriving at the same time Mars reaches opposition. For many viewers, the spectacular pair will rise with Mars less than a degree south of Luna… But a pairing this close means a few lucky observers could be in for an occultation event! Be sure to check IOTA for possible times and locations.

Today in 1968, Apollo 8 became the first manned spacecraft to orbit the Moon. Let’s celebrate that by having a look at the lunar surface. On the eastern limb we see the bright splash ray patterns surrounding ancient Furnerius – yet the rays themselves emanate from much younger crater Furnerius A. All over the surface, we see small points light up and the testament to the Moon’s violent past written in its scarred lines. Take a look now at the western limb… For the sunrise is about to advance around it.

Until this date, no man had seen with his own eyes what lay beyond. Frank Borman, James Lovell and William Anders were to become the first to directly view the “dark side” and the first to witness earthrise over the Moon. As the days ahead bring the terminator around to the eastern limb, let your mind take flight to the distant orb and enjoy its landscape as the shadows take on new angles and old features become new again.

“And from the crew of Apollo 8, we close, with good night, good luck, a Merry Christmas, and God bless all of you, all of you on the good Earth.” (Astronaut Frank Borman)

Tuesday, December 25 – Wishing you all the very best for the Christmas season! Like a present, Sir Isaac Newton was born on this day 1642 – Newton was the British “inventor” of calculus and a huge amount of what we now consider modern classical physics. Even young children are aware of his simple laws of motion and gravity. It wasn’t until the time of Einstein until things changed!

In keeping with the season, tonight’s astronomical object is a celebration of both starlight and asterism. Located 10 degrees east of Betelgeuse (RA 06 41 00.00 Dec +09 53 -0.0), NGC 2264 will be a challenging object thanks to the Moon. Also known as the “Christmas Tree Cluster,” this bright asterism of approximately 20 bright stars and over 100 fainter ones is embroiled in a faint nebula that will be lost to bright skies, leaving only the delightful Christmas tree shape adorned with stars.

The very brightest of these stars, S Monocerotis, is 5th magnitude and will show clearly in the finderscope, and will be seen as a double at magnification. Steady skies will reveal that the “star” at the top of our “tree” is also a visual double. Many of the stars will also appear to have companions, as well as tints of silver as gold. The visual effect of this splendid open cluster is well worth the challenge it presents. Happy Holidays!

Wednesday, December 26 – Is it gone yet? Nope. The Moon will rise a little later this evening, but we’re going to run ahead of it tonight and enjoy some studies in Auriga! Looking roughly like a pentagon in shape, start by identifying the brightest of these stars – Capella. Due south of it is the second brightest star, El Nath. By aiming binoculars at El Nath, go north about one-third the distance between the two and enjoy all the stars!

You will note two very conspicuous clusters of stars in this area, and so did Le Gentil in 1749. Binoculars will reveal the pair in the same field, as will telescopes using lowest power. The dimmest of these is M38, and it will appear vaguely cruciform in shape. At roughly 4200 light-years away, larger aperture will be needed to resolve the 100 or so fainter members. About two and a half degrees to the southeast you will see the much brighter M36. More easily resolved in binoculars and small scopes, this “jewel box” galactic cluster is quite young – and about 100 light-years closer!

Thursday, December 27 – Born today in 1571 was Johannes Kepler – Danish astronomer and assistant to Tycho Brahe. Kepler used Brahe’s copious notes of Mars’ positions to help formulate his three laws of planetary motion. These laws are still in use today.

Is it gone yet? No. The Moon will be along shortly, but we still have time to set our sights about halfway between Theta Aurigae and El Nath. Our study object will be the open cluster M37. Apparently discovered by Messier himself in 1764, this galactic cluster will appear almost nebula-like to binoculars and very small telescopes – but comes to perfect resolution with larger instruments.

At around 4700 light-years away, and spanning a massive 25 light-years, M37 is often billed as the finest of the three Aurigan opens for bigger scopes. Offering beautiful resolvability, this one contains around 150 members down to magnitude 12, and has a total population in excess of 500.

What makes it unique? As you view, you will note the presence of several red giants. For the most part, open clusters are comprised of stars that are all about the same age, but the brightest star in M37 appears orange in color and not blue! So what exactly is going on in here? Apparently some of these big, bright stars have evolved much faster – consuming their fuel at an incredible rate. Other stars in this cluster are still quite young on a cosmic scale, yet they all left the “nursery” at the same time! In theory, this allows us to judge the relative age of open clusters. For example, M36 is around 30 million years old and M38 about 40, but the presence of the red giants in M37 puts its estimated age at 150 million years! Just awesome…

Friday, December 28 – Today we celebrate the birth of Arthur S. Eddington. Born in 1882, Eddington was a British theoretical astrophysicist whose work was fundamental to interpreting and explaining stellar nature. He also coined the phrase “expanding universe” to refer to the mutual recession of the galaxies.

Is it gone yet? Not yet… But before the Moon rises tonight, let’s enjoy the early dark skies and go to our maps west of M36 and M38 to identify AE Aurigae. As an unusual variable, AE is normally around 6th magnitude and resides approximately 1600 light-years distant. The beauty in this region is not particularly the star itself but the faint nebula in which it resides. Known as IC 405, this is an area of mostly dust and very little gas. What makes this view so entertaining is that we are looking at a “runaway” star.

It is believed that AE originated in the M42 region in Orion. Cruising along at a very respectable speed of 130 kilometers per second, AE flew the “stellar nest” some 2.7 million years ago! Although IC 405 is not directly related to AE, there is evidence within the nebula that areas have been cleared of their dust by the rapid northward motion of the star. AE’s hot, blue illumination and high energy photons fuel what little gas is contained within the region, and its light reflects off the surrounding dust as well. Although we cannot “see” with our eyes like a photograph, together this pair makes an outstanding view for the small backyard telescope, and it is known as “The Flaming Star.”

And when the Moon rises? Look for Regulus less than one half degree to its north and Saturn another two degrees further. This could be an occultation of Regulus, so be sure to check IOTA!

Saturday, December 29 – If you’re up before dawn this morning, take the time to step outside and view the simple beauty of the ecliptic plane. To the west, Mars hangs just above the horizon with Saturn not far above it. The Moon dances high overhead and Venus shines just before the rising Sun. In a matter of weeks, Jupiter will return again to the morning skies!

Is it gone yet? Not yet. Since the Moon won’t begin to interfere for quite a while after the skies turn dark, this would be a great opportunity to locate an easy Messier object – M34. If you remember our previous study stars Almach and Algol, you’re halfway there. Draw an imaginary line between them and look with your binoculars or finder scope just a shade north of center.

In binoculars, M34 will show around a dozen fainter stars clustered together, and perhaps a dozen more scattered around the field. Small telescopes at low power will appreciate M34 for its resolvability and the distinctive orange star in the center. Larger aperture scopes will need to stay at lowest power to appreciate the 18 light-year span of this 100 million year old cluster, but take the time to power up and study. You will find many challenging doubles inside!

Sunday, December 30 – Is it gone yet? Not quite! The Moon will be along much later, but not before we’ve had an opportunity to head for another northern gem, M76.

Located in western Perseus just slightly less than one degree north-northwest of Phi, M76 is often referred to as “The Little Dumbbell.” Originally discovered by Messier’s assistant MÈchain in September of 1780, Charles didn’t get around to cataloging it for another six weeks. What a shame it took him so long to view this fine planetary nebula! Its central star is one of the hottest known, but its resemblance to M27 is what makes it so fascinating.

Looking very much like a miniaturization of the much larger M27, M76 is rather faint at magnitude 11, but is quite achievable in scopes of 114mm in aperture or larger. It is small, but its irregular shape makes this planetary nebula a real “class act!”

For our Southern Hemisphere friends, get thee out there and view Eta Carinae! First recorded by Halley in 1677, this nebular variable star left even the great Sir John Herschel at a loss to describe its true beauty and complexities. This “slow nova” is filled with all the wonders that we “northerners” can only dream about…

Monday, December 31 – Today is the birthday of Robert G. Aitken. Born in 1864, Aitken was a prolific American observer who discovered and catalogued more than 3100 double and binary stars. Just look at what a prolific observer YOU have become in just a year!

Is it gone yet? No. The Moon will be around much later tonight, but the year 2007 is just about ended. Try celebrating in a unique and inspiring way! Go observing…

In the hours before midnight, you could take a cosmic journey that spans millions of light-years. In the northern hemisphere, visit with the Andromeda Galaxy again – or the Small and Large Magellanic Clouds if you live in the South. Feast your eyes on vast and wondrous displays of stars like the “Double Cluster” in Perseus, or the “Jewel Box” – the Kappa Crucis star cluster. Rejoice in the birth of new stars by voyaging to M42 – the Orion Nebula… And remember the old by returning to M1 – the Crab Nebula. Take delight in the movements of our own solar system by watching Mars rise, or peeking in on Saturn’s rings as it follows behind. Perhaps the ISS will make a pass over your area tonight, or maybe only a single star will shine through your cloudy sky. It may be something as spectacular as watching a meteor go down in a blaze of glory, or as quiet and contemplative as watching the Moon rise as the year ends.

Now take a moment to look up at the stars and think about all the billions of years that they have been in the making and all the time that it has taken for the light to reach us. Salute! Our observing year has been wonderful together… And I’ll look for you under the stars! I hope you’ll join me again when 2008 begins as “The Night Sky Companion.”

May all your journeys be at light speed!

Monday, December 17 – Tonight there are craters galore to explore: Plato, Aristotle, Eudoxus, Archimedes… But let’s head to the north of Sinus Medii and have a look at a pair we’ve not yet encountered on our lunar travels – Agrippa and Godin. The larger of the two, Agrippa, measures around 46 kilometers in diameter and drops to a depth of 3070 meters. To the south is Godin, which is somewhat smaller at 35 kilometers in diameter, but a bit deeper at 3200 meters. Note how Godin’s interior slopes towards its central peak.

With deep sky studies improbable for the next few days, why don’t we try taking a look at another interesting variable star? RT (star 48) Aurigae is a bright Cepheid that is located roughly halfway between Epsilon Geminorum and Theta Aurigae. This perfect example of a pulsating star follows a precise timetable of 3.728 days and fluxes by close to one magnitude.

Located 1600 light-years away, RT was first discovered in 1905 by T. H. Astbury of the British Astronomical Association. Like all Cepheids, it expands and contracts rhythmically – for reasons science is not completely sure of. Yet, we do know that it takes about 1.5 days for it to expand to its largest and brightest and 2.5 days for it to contract, cool, and dim.

Tuesday, December 18 – Tonight on the south shore of the emerging Mare Nubium, look for ancient craters Pitatus and Hesiodus right on the terminator. During this phase, something wonderful can happen! If you are at the right place at the right time, sunlight will shine briefly through a break in Hesiodus’ wall and cast an incredible ray across the lunar surface! If you don’t catch it, you can still enjoy one of the few concentric craters on the Moon.

Want a challenging double this evening? Then let’s have a look at Theta Aurigae located on the east side of the pentagonal shape of this constellation.

Located about 110 light-years away, 2.7 magnitude Theta is a four star system, whose members range in magnitude from 2.7 to 10.7. Suited even to a small telescope, the brightest member – Theta B – is itself a binary at magnitude 7.2, and was first recorded by Otto Struve in 1871. The pair moves quite slowly, and may take as long as 800 years to orbit each other at their separation of about 110 AU. The furthest member of this system was also noted by Struve as far back as 1852, but it is not a true member – the separation only occurring thanks to Theta’s own proper motion.

While you are there, be sure to note Theta’s unusual color. While it will appear “white,” look closely at the diffraction caused by our own atmosphere which acts much like a prism… You’ll notice a lot more purple and blue around this star than many others of the same spectral type. Why? Theta is a silicon star!

Wednesday, December 19 – While the mighty Copernicus on the terminator will draw the eye like no other crater tonight, it’s time to pick up another study which you may not have logged – Crater Davy. You will find it just west of the large ring of Ptolemaeus on the northeastern edge of Mare Nubium. It will appear as a small, bright ring, with the large crater Davy A on its southern border. Now skip across the grey sands of Nubium further west and let’s take a look at the crater on the peninsula-like feature Guericke. Named for Dutch physicist Otto von Guericke, this 58 kilometer diameter crater has all but eroded away. Look for a break in its eastern wall and notice how lava flow has eradicated the north!

Now, for apparently no good reason, let’s head for Alpha Persei (Mirfak). While there’s nothing particularly interesting about this 570 light-year distant star, what is incredible is the field in which it resides! Take a look at lowest power with a rich field telescope or binoculars and be prepared to be blown away…

This is the Alpha Persei moving group – a fantastic field of main sequence stars that contains a little over 100 members. Even though it will take 90,000 years before any perceptible change is seen in this bright collection, they are happily moving at a pace of about 16 kilometers per second towards Beta Tauri! Enjoy this fine group also known as Melotte 20…

Thursday, December 20 – Tonight is the peak of the Delta Arietid meteor shower. While most showers are best after midnight, this is an early evening shower that must be viewed before the radiant sets. The fall rate is modest – about 12 per hour.

On the lunar surface, we’re going to head to the deep south as we pick up one of the last of our lunar studies – Longomontanus. Named for the Danish Astronomer Christian Longomontanus (an assistant to Tycho Brahe), this wonderland of details stretches around 145 kilometers across the surface. Look for a great collection of interior craters along its northwest interior wall and note how it has eradicated a much older crater which still shows an edge to the east.

Today marks the founding of Mt. Wilson Solar Observatory. It officially opened its doors in 1904. We also celebrate the birth of Walter S. Adams on this date. Born in 1876, Adams was the astronomer at Mt. Wilson who revealed the nature of Sirius B, the first known white dwarf star. Sirius B was first seen by Alvan Clark in 1862 and most recently, the Hubble Space Telescope precisely measured the mass of B for the first time. While Sirius is far too low at an early hour to study its white dwarf, we can have a look at a similar star when we view Omicron 2 Eridani located roughly a handspan west of Rigel. As the southernmost of the Omicron pair, it is sometimes known as 40 Eridani, and you’ll find it to be an interesting multiple star system that’s very worthy of your time.

Discovered by William Herschel in 1783, this 16 light-year distant system is the eighth nearest of the unaided visible stars. Well spaced from the primary, the companion star is also a double for high powers and will reveal a red dwarf discovered by Otto Struve. Now, look closely at the 9th magnitude B star. This is the only white dwarf that can be considered “easy” for the backyard telescope. Its diameter is only about twice the size of Earth and its mass is about that of our Sun. Power up and locate the 11th magnitude companion…for it’s one of the least massive stars known! And this white dwarf may be the smallest stellar object visible in an amateur telescope – it would be like spotting a tennis ball…on the moon!

Friday, December 21 – Ah, yes… Is there any more beautiful crater on the Moon than graceful Gassendi? While we have visited it before, take the time to power up and enjoy its features. Look for rimae which crisscross the shallow floor, and the strong A crater which mars its northern wall. How many of its interior features can you resolve?

While we’re out, let’s have a look at one of the best known double stars in the night – Gamma Arietis (RA 01 53 31.81 Dec +19 17 37.9).

Also known as Mesarthim, this combined magnitude 4 beauty was unintentionally discovered in 1664 by Robert Hooke who was following a comet. While no real change has been spotted in the more than 343 years since that time, there has been a slight difference detected in the components’ radial velocities. Roughly 160 light-years away, you’ll enjoy this almost matched-magnitude pair of white stars – but look carefully: in 1878, S. W. Burnham found a third star nearby that might not be a physical member, but is also a double!

Saturday, December 22 – Up early? Fantastic! In the pre-dawn hours of this morning, I have a treat for you – the Ursid meteor shower! Cruising around the Sun about every thirteen and a half years, Comet 8P/Tuttle sheds a little skin. Although it never passes inside of Earth’s orbit, some six years later we pass through its debris stream. Not so unusual? Then think again, because it takes as much as six centuries before the meteoroid trail is affected enough by Jupiter’s gravitation to deflect the stream into our atmosphere.

With little interference from the Moon while watching this circumpolar meteor shower, the hours before dawn could see activity of up to 12 per hour. By keeping watch on the constellation of Ursa Major, you just might spot one of these slow moving, 600 year old travelers that make their path only halfway between us and Selene!

Today marks Winter Solstice – for the northern hemisphere, the shortest day and the longest night of the year – and the point when the Sun is furthest south. Now is a wonderful time to demonstrate for yourself our own movements by choosing a “solstice marker.” Anything from a fence post to a stick in the ground will suffice! Simply measure the shadow when the Sun reaches the zenith and repeat your experiment in the weeks ahead and watch as the shadow grows shorter…and the days grow longer!

And be sure to look at the Moon tonight as well, for it is at perigee – its closest point to the Earth. While you might hear a tall tale or two about it being brighter than normal since it is also close to Full, judge for yourself! And be sure to look for signs of libration while you’re there…

Sunday, December 23 – While the Moon will command tonight’s skies, we can still have a look at a tremendous star as we head 150 light-years away to Menkar…

Better known as Alpha Ceti, you’ll find this nearly second magnitude giant orange beauty just west of Orion’s “bow” (RA 03 02 16.77 Dec +04 05 23.0). With even a small telescope, you will also see 5th magnitude 93 Ceti in the eyepiece as well! Although they are not a true physical pair (the blue 93 is 350 light-years further away), they make a wonderful color contrast which is well worth your time. Just think… If 93 were as close as Menkar, it would be 250% brighter. But up the magnification and see if you can spot another true double in the field!

Tonight in 1672, astronomer Giovanni Cassini discovered Saturn’s moon Rhea. Although you will have to wait until a little later in the evening to catch the ringed planet, why not try your hand at finding Rhea as well? A well-collimated scope as small as 4.5″ is perfectly capable of seeing Tethys, Rhea and Dione as they orbit very nearly to the edges of the ring system. All it requires is steady skies and a little magnification!

Monday, December 10 – If you are out stargazing until the morning hours, look for the peak of the Monocerid meteor shower. Its fall rate is around one per hour and its radiant point is near Gemini.

Tonight let’s go north for a mid-size scope challenge about two fingerwidths east-northeast of the beautiful double star Gamma Andromedae (RA 02 22 32.90 Dec +43 20 45.8).

The 12th magnitude NGC 891 is a perfect example of a spiral galaxy seen edge-on. To the mid-sized scope, it will appear as a pencil-slim scratch of light, but larger telescopes will be able to make out a fine, dark dust lane upon aversion. Discovered by Caroline Herschel in 1783, NGC 891 contained a magnitude 14 supernova event recorded on August 21, 1986. Often considered a “missed Messier,” you can add this one to your Caldwell list as number 23!

Tuesday, December 11 – On this date in 1863, Annie Jump Cannon was born. She was a United States astronomer who created the modern system for classifying stars by their spectra. Why not celebrate this achievement by coming along with me and viewing some very specific stars that have unusual visual spectral qualities! Let’s grab a star chart, brush up on our Greek letters and start first with Mu Cephei.

Nicknamed the “Garnet Star,” this is perhaps one of the reddest stars visible to the unaided eye. At around 1200 light-years away, this spectral type M2 star will show a delightful blue/purple “flash.” If you still don’t perceive color, try comparing Mu to its bright neighbor Alpha, a spectral type A7, or “white,” star. Perhaps you’d like something a bit more off the beaten path? Then head for S Cephei about halfway between Kappa and Gamma toward the pole. Its intense shade of red makes this magnitude 10 star an incredibly worthwhile hunt.

To see an example of a B spectrum star, look no further than the Pleiades… All the components are blue white. Want to taste an “orange?” Then look again at Aldeberan, or Alpha Tauri, and say hello to a K spectrum star. Now that I have your curiosity aroused, would you like to see what our own Sun would look like? Then choose Alpha Aurigae, better known as Capella, and discover a spectral class G star that’s only 160 times brighter than the one that holds our solar system together! If you’re enjoying the game, then have a look at a star with one of the most unusual spectra of all – Theta Aurigae. Theta is actually a B class, or a blue/white, but instead of having strong lines in the helium, it has an abnormal concentration of silicon, making this incredibly unusual double star seem to glitter like a “black diamond.”

Still no luck in seeing color? Don’t worry. It does take a bit of practice! The cones in our eyes are the color receptors and when we go out in the dark, the color-blind rods take over. By intensifying the starlight with either a telescope or binoculars, we can usually excite the cones in our dark-adapted eyes to pick up on color.

Tonight is also the peak of the Sigma Hydrid meteor stream. Its radiant is near the head of the Serpent and the fall rate is also 12 per hour – but these are fast!

Wednesday, December 12 – Today in 1961, OSCAR-1 was launched. The project started in 1960; the name stands for Orbital Satellite Carrying Amateur Radio. OSCAR-1 operated in orbit for 22 days, transmitting a signal in Morse Code – the simple greeting “Hi.” The success of the mission helped to promote interest in amateur radio which still continues to this day!

Tonight before the Moon interferes with fainter studies, let’s head far north for one of the oldest galactic clusters in our visible sky – NGC 188.

Hovering near Polaris (RA 00 44.5 Dec +85 20) this circumpolar open cluster also goes by other names: Collinder 1 and Melotte 2. Discovered by John Herschel on November 3, 1831, this 8th magnitude collection of faint stars will require a telescope to resolve its 120 members. At one time, it was believed to be as old as 24 billion years, later updated to 12 billion; but it is now considered to be around 5 billion years old. No matter how old it may truly be, it is one of the time-honored great studies and is also number one on the Caldwell list!

Thursday, December 13 – Today in 1920, the first stellar diameter was measured by Francis Pease with an interferometer at Mt. Wilson. His target? Betelgeuse!

Tonight will being be one of the most hauntingly beautiful and most mysterious displays of celestial fireworks all year – the Geminid meteor shower. First noted in 1862 by Robert P. Greg in England, and B. V. Marsh and Prof. Alex C. Twining of the United States in independent studies, the annual appearance of the Geminid stream was weak initially, producing no more than a few per hour, but it has grown in intensity during the last century and a half. By 1877 astronomers realized a new annual shower was occurring with an hourly rate of about 14. At the turn of the century, it had increased to over 20, and by the 1930s up to 70 per hour. Only eight years ago observers recorded an outstanding 110 per hour during a moonless night… And our Moon will soon set!

So why are the Geminids such a mystery? Most meteor showers are historic – documented and recorded for hundred of years – and we know them as being cometary debris. When astronomers first began looking for the Geminids’ parent comet, they found none. It wasn’t until October 11, 1983 that Simon Green and John K. Davies, using data from NASA’s Infrared Astronomical Satellite, detected an orbital object (confirmed the next night by Charles Kowal) that matched the Geminid meteoroid stream. But this was no comet, it was an asteroid.

Originally designated as 1983 TB, but later renamed 3200 Phaethon, this apparently rocky solar system member has a highly elliptical orbit that places it within 0.15 AU of the Sun about every year and half. But asteroids can’t fragment like a comet – or can they? The original hypothesis was that since Phaethon’s orbit passes through the asteroid belt, it may have collided with other asteroids creating rocky debris. This sounded good, but the more we studied the more we realized the meteoroid “path” occurred when Phaethon neared the Sun. So now our asteroid is behaving like a comet, yet it doesn’t develop a tail.

So what exactly is this “thing?” Well, we do know that 3200 Phaethon orbits like a comet, yet has the spectral signature of an asteroid. By studying photographs of the meteor showers, scientists have determined that the meteors are denser than cometary material and not as dense as asteroid fragments. This leads us to believe that Phaethon is probably an extinct comet that has gathered a thick layer of interplanetary dust during its travels, yet retains the ice-like nucleus. Until we are able to take physical samples of this “mystery,” we may never fully understand what Phaethon is, but we can fully appreciate the annual display it produces!

Thanks to the wide path of the stream, folks the world over get an opportunity to enjoy the show. The traditional peak time is tonight as soon as the constellation of Gemini appears around mid-evening. The radiant for the shower is right around bright star Castor, but meteors can originate from many points in the sky. From around 2 am tonight until dawn (when our local sky window is aimed directly into the stream) it’s possible to see about one “shooting star” every 30 seconds.

The most successful of observing nights are ones where you are comfortable, so be sure to use a reclining chair or pad the ground while looking up. Please get away from light sources when possible – it will triple the amount of meteors you see. Enjoy the incredible and mysterious Geminids!

Friday, December 14 – Today was a very busy day in astronomy history. Tycho Brahe was born in 1546. Brahe was a Danish pre-telescopic astronomer who established the first modern observatory in 1582 and gave Kepler his first job in the field. In 1962, Mariner 2 made a flyby of Venus and became the first successful interplanetary probe. As we begin our evening on the Moon, be sure to check with IOTA for a possible occultation event in your area. Neptune is less than a degree away to the north!

On this day in 1972, the last humans (so far) to have walked on the lunar surface returned to Earth. Eugene Cernan left the final bootprint at Taurus-Littrow and called it the “end of the beginning.” As we reach the end of our observing year, let this only be the beginning for you as we look to that distant orb to seek out the Apollo 17 landing area.

You have learned so much over the last 12 months! Even if the terminator has not progressed as far as the illustration shows, you should know the approximate location of Posidonius on the surface and recognize Mare Crisium and the Taurus Mountains to its east as well as the small, grey expanse of Sinus Amoris between them. Littrow is on its western shore, and although it is rather small with a 31 kilometer diameter, Mons Vitruvius will shine like a beacon to the south.

Enjoy your Moon walk!

Saturday, December 15 – Today in 1970, the Soviet spacecraft Venera 7 registered a first as it made a successful soft landing on Venus, and so went into the history books as the first craft to land on another planet. You can catch Venus yourself in the pre-dawn skies!

Tonight, one of the most outstanding features on the lunar surface will be the southern crater Maurolycus. Although we have visited it before, look again! At an overall diameter of 114 kilometers, this double impact crater sinks below the surface to a depth of 4730 meters and displays a wonderful multiple mountain-peaked center. If you have not collected Gemma Frisius for your studies, you will find it just north of this grand crater, looking much like a “paw print” at low power.

Now let’s travel 398 light-years away as we have a look at AR Aurigae – the centermost star in a brilliant collection. It is about one-third the distance from southern Beta to northern Alpha (Capella). AR is an eclipsing binary which consists of two main sequence white dwarf stars. About every 4.1 days, this pair will make a slight magnitude drop. While both are chemically peculiar, neither fills its Roche Lobe – meaning they are not stripping material from each other to cause these unusual abundances. Recent studies have shown the possibility of a third, unseen companion! But even binoculars will see that AR resides in a great field of stars and is worth a little of your time…

Sunday, December 16 – With only nine days left until the holiday, astronomers have recently discovered a unique feature on the lunar surface. While accepted for many years to be a natural feature of selenography, modern photography coupled with today’s high powered telescopes have discovered an area near the lunar North Pole that’s being used as a runway by a man in a red suit piloting an unusual spacecraft. Be sure to spark the imaginations in your young viewers as you show them the Alpine Valley!

Today we celebrate the birthday of Edward Emerson (E. E.) Barnard. Born in 1857, Barnard was an American observational astronomer and an absolute legend. He led a very colorful life in astronomy, and his sharp skills have led to a multitude of discoveries. His life was a very fascinating one: Barnard was often known to simply set the scope on one point in the sky and just watch for new objects as the field moved! Tonight let’s take a look at a bright star that has Barnard’s touch, as we explore Beta Aurigae – Menkalinan.

First identified as a spectroscopic binary by A. Maury in 1890, Beta itself is part of a moving group of stars that includes Sirius, and is an Algol-type variable. While you won’t see changes as dramatic as those of the “Demon Star,” it has a precise drop of 0.09 magnitude every 3.96 days. This system contains almost identical stars which are more than two and a half times the size of our Sun, but they orbit each other at a distance of less than 0.1 AU! While Menkalinan’s 10th magnitude optical companion was first spotted by Sir William Herschel in 1783, only E. E. Barnard noticed the 14th magnitude true tertiary to this incredible multiple system!