Category: Skywatching

Greetings, fellow SkyWatchers! Ah, yes… Full Moon. Are you ready to howl? If you didn’t get a chance to watch the galiean moons do their dance last weekend, then be sure to catch the awesome video you’ll find inside! In the meantime, keep your ears alert for the rise of tonight’s “Full Corn Moon” and check out the Omicron gems. As the skies get darker, the Herschel challenges warm up – so dust off your optics and I’ll see you in the backyard…

Friday, September 4, 2009 – It’s a Full Moon tonight. Many cultures refer to this one in particular as the ‘‘Corn Moon,’’ because at this time of year most corn crops are ready for harvest. Tonight let’s harvest some bright lunar features as we trace the ray system of Tycho in the lunar south. Look for the bright points of Kepler and Aristarchus in the northwest quadrant. In the east, dazzling crater Proclus will light up the western shore of Mare Crisium. Just north of central, look for the two bright rings of Manlius and Menelaus.

Although the Moon will dominate tonight’s sky, we can still take a very unusual and beautiful journey to a bright and very colorful pair of stars known as Omicron 1 Cygni. Easily located about halfway between Alpha (Deneb) and Delta on the western side (RA 20 13 28 Dec +46 46 40), this is a pure delight in binoculars or any size telescope.

The striking gold color of 3.7-magnitude Omi 1 A is easily highlighted against the blue of its same-field companion, 5th magnitude Omi 1 B. Although this wide pairing is only an optical one, the K-type giant (A) is indeed a double star—an eclipsing variable about 150 times larger than or own Sun—and is surrounded by a gaseous corona more than double the size of the star itself. If you are using a scope, you can easily spot its blue tinted, 7th magnitude companion star about one-third the distance between the two giants. Although our true pair is some 2 billion kilometers apart, they are oriented nearly edge-on from our point of view, allowing the smaller star to be totally eclipsed during each revolution. This total eclipse lasts for 63 days and happens about every 10.4 years, but don’t stay up too late. . . We still have years to wait!

Saturday, September 5, 2009 – Tonight before the Moon commands the sky, let’s start with the brightest star in Vulpecula—Alpha. Although it is not a true binary star, it is quite attractive in the telescope, and an easy split for binoculars. Alpha itself is a 4.4-magnitude red giant, which makes a nice color contrast with the unrelated yellow field star that is 2 magnitudes dimmer.

Now head around a half degree northwest of Alpha (RA 20 19 29 Dec –70 51 36) for open cluster NGC 6800. Also known as Herschel VIII.21, this cluster is suitable for even smaller scopes but requires aperture to resolve completely. Discovered by Sir William in this month (10th) in 1784, you’ll like this ring-like arrangement of stars!

Now drop 2.7 degrees southwest of Alpha (RA 19 23 12 Dec +22 08 00) for yet another open cluster, NGC 6793. Discovered by Herschel in 1789 and logged as catalog object VIII.81, you’ll find a few more bright stars here. The challenge in this cluster is not so much being able to see it in a smaller telescope—but being able to discern a cluster from a star field! Try using the photo to help you distinguish it from the rest…

Sunday, September 6, 2009 – Today we celebrate many births. In 1891, it’s Yrjo Vaisala who produced telescope optics and discovered asteroids. In 1830, John Henry Dallmeyer, who was a master at making telescopes and eyepieces, was born. Last, in 1811, was James Melville Gilliss who founded the United States Naval Observatory.

Tonight we’ll return again to Vulpecula, but with a different goal in mind. What we’re after requires dark skies yet can be seen in either binoculars or a small telescope. Once you’ve found Alpha, begin about two finger-widths southeast, and right on the galactic equator you’ll find NGC 6823 (RA 19 43 10 Dec +23 17 54.). The first thing you will note is a fairly large, somewhat concentrated magnitude 7 open cluster.

Resolved in larger telescopes, the viewer may note these stars are the hot, blue-white variety. For good reason. NGC 6823 only formed about 2 billion years ago. Although it is some 6,000 light-years away and occupies around 50 light-years of space, it’s sharing the field with something more—a very large emission/reflection nebula, NGC 6820 (RA 19 42 27 Dec +23 05 14).

In the outer reaches of star cluster NGC 6823, new stars are being formed in masses of gas and dust as hot radiation is shed from the brightest of the stellar members of this pair. Fueled by emission, NGC 6820 isn’t always an easy visual object; it is faint and covers almost four times as much area as NGC 6823. But trace the edges very carefully, since the borders are much more illuminated than the central cluster region. Take the time to really observe this one! The processes going on here are very much like those in the ‘‘Trapezium’’ area of the Orion nebula. Be sure to mark your siting in your observing notes. NGC 6823 is Herschel VII.18 and NGC 6820 is also known as Marth 401!

Did you catch last week’s awesome Jupiter events? If not – then enjoy this great footage taken by the one and only Joe Brimacombe. (Not only is Dr. Joe cool… but he’s also one of the best observers I know!)

Perhaps you need another little nudge to get you out and observing, huh? Then here’s a list of Jupiter activities over the weekend:

Friday

• 00:58 UT, Io begins transit of Jupiter.
• 01:28 UT, Io’s shadow begins to cross Jupiter.
• 03:16 UT, Io ends transit of Jupiter.
• 03:48 UT, Io’s shadow leaves Jupiter’s disk.
• 22:10 UT, Io enters occultation behind Jupiter.

Saturday

• 01:00 UT, Io exits eclipse by Jupiter’s shadow.
• 02:36 UT, Europa exits eclipse by Jupiter’s shadow.
• 19:24 UT, Io begins transit of Jupiter.
• 19:58 UT, Io’s shadow begins to cross Jupiter.
• 21:42 UT, Io ends transit of Jupiter.

Sunday

• 16:36 UT, Io enters occultation behind Jupiter.
• 17:06 UT, Europa begins transit of Jupiter.
• 18:14 UT, Europa’s shadow begins to cross Jupiter.
• 18:20 UT, Ganymede enters occultation behind Jupiter.
• 19:28 UT, Io exits eclipse by Jupiter’s shadow.

Now get out there and observe!!

This week’s awesome images are (in order of appearance): Full Moon (credit—NASA), Omicron 1 Cygni, NGC 6800, NGC 6793, NGCs 6823 (central) and 6820 (credit—Palomar Observatory, courtesy of Caltech) and Jupiter footage courtesy of Joe Brimacombe. We thank you so much!

Greetings, fellow SkyWatchers! “100 Hours of Astronomy” is now underway – and doesn’t it just figure that most of us are enjoying clouds and rain? Apparently Murphy’s Law (with it’s many variations of names) works everywhere on Earth! But, keep up the good spirits. My own bags are packed and I’m ready to head towards the observatory for the next 3 days of non-stop astronomy programming and here’s some features coming up this weekend I thought you might enjoy sharing as well. Are you ready? Then come on along and let’s have a great time…

Friday, April 3, 2009 – This date marks the 40th anniversary of the launch of the first lunar orbiter, Luna 10. That makes another good reason to view the Moon tonight! Follow the southward descent of large crater rings Ptolemaeus, Alphonsus, and Arzachel to a smaller, bright one southwest named Thebit. We’re going to have a look at Hell.

Just west of Thebit and its prominent Acrater to the northwest, you will see the Rupes Recta (Straight Wall) appearing as a thin, white line. Continue south until you see large, eroded crater Deslandres. On its western shore is a bright ring that marks the boundary of Hell. Although this might seem like an unusual name for a crater, it was named for an astronomer—and clergyman!

While you’re out tonight, be on watch for the Kappa Serpentid meteor shower. Its radiant will be near the ‘‘Northern Crown’’—the constellation known as Corona Borealis. The fall rate is small with an average of 4 or 5 per hour, but this is a great time to just enjoy a Spring evening and share your knowlege with others!

Saturday, April 4, 2009 – Today we celebrate the 1809 birth on this date of astronomer Benjamin Peirce. Peirce was a professor of astronomy and mathematics for nearly 40 years and contributed greatly to the discovery of Neptune.

On the lunar surface, crater Copernicus becomes visible to even the most modest of optical aids. Small binoculars will see Copernicus as a bright ring about mid-way along the lunar dividing line of light and dark called the terminator. Telescopes will reveal its 97-kilometer (60-mile) expanse and 120-meter (395-foot) central peak to perfection. Copernicus holds a special appeal; it’s the aftermath of a huge meteoric impact! At 3,800 meters deep, its walls are 22 kilometers thick. Over the next few days, the impact ray system extending from this tremendous crater will become wonderfully apparent.

Tonight use Copernicus as a guide and look north-northwest to survey the Carpathian Mountains . The Carpathians ring the southern edge of Mare Imbrium, beginning well east of the terminator. But let’s look on the dark side. Extending some 40 kilometers beyond into the Moon’s own shadow, you can continue to see bright peaks, some reaching 2,000 meters high! Tomorrow, when this area is fully revealed, you will see the Carpathians begin to disappear into the lava flow forming them.

Continuing onward to Plato—on the northern shore of Mare Imbrium—and look for the singular peak of Pico. Between Plato and Mons Pico, you will find the many scattered peaks of the Teneriffe Mountains. It is possible that these are the remnants of much taller summits of a once precipitous range. Now the peaks rise less than 2,000 meters above the surface. Time to power up!West of the Teneriffes, and very near the terminator, you will see a narrow line of mountains, very similar in size to the Alpine Valley. Known as the Straight Range, some of its peaks reach as high as 2,000 meters. Although this doesn’t sound particularly impressive, that’s over twice as tall as the Vosges Mountains in west-central Europe and comparable to the Appalachian Mountains of the eastern United States!

“Sun” Day, April 5, 2009 – Today let’s take a look at Vincenzo Viviani. Born on this date in 1622, Viviani was a mathematician. At age 17, he became the student, secretary, and assistant to Galileo, serving him until the Master died in 1642. Viviani published his own books on mathematical and scientific subjects and edited the first edition of Galileo’s collected works. He was an ardent supporter of Galileo and worked tirelessly to reinstate his mentor’s good name. What a great addition to talk about during the International Year of Astronomy!

Tonight let’s continue our lunar mountain-climbing expedition and revisit the ‘‘big picture’’ on the lunar surface. All of Mare Imbrium is bathed in sunlight tonight, and we can see its complete shape. Appearing as a featureless ellipse bordered by mountain ranges, let’s identify them all.

Starting at Plato and moving east to south to west you will find the Alps, the Caucasus, the Apennine, and the Carpathian Mountains. Look at the form closely. Doesn’t it look like it’s possible that an enormous impact created the entire area? Compare it to the younger Sinus Iridum, which is ringed by the Juras Mountains. The latter region may have also been formed by a much later and very similar massive impact event.

Are you in the mood for a double star? Then let’s head west and away from the Moon. Begin your search right after skydark with El Nath. From Beta Aurigae, shift about two finger-widths eastnortheast to identify very dim 26 Aurigae . At low power, look for an 8th magnitude companion due west of the 5.5 magnitude primary. The brighter star should give a warm yellow appearance, while the fainter will appear slightly bluer. This pair shares space with a third member (magnitude 11.5), some three times further out than the closer, brighter secondary. Thanks to lunacy, small instruments will have difficulty distinguishing the C star in such bright skies.

For now? I hope you have clear skies to enjoy the “100 Hours of Astronomy” weekend… and remember to ask for the Moon – but keep on reaching for the stars!

This week’s awesome images – in order of appearance – are credited to these wonderful friends and photographers: Craters Deslandres, Hell and Walter (credit—Alan Chu), Crater Copernicus (credit—Greg Konkel), Vincenzo Viviani (historical image) and Lunar image (credit—Greg Konkel). We thank you so much!

Greetings, fellow SkyWatchers! Ah, yes… the Moon is back in force and that will make for a rather quiet astronomy weekend – or will it? Why let a little reflected sunlight spoil the fun when we can take a look at just how important that studying sunlight really is, or just who drew the line at its studies?! How about taking a look for some very cool lunar craters and some very hot stars? More? Then waltz around the rings of Saturn and challenge yourself to a new star grouping. When ever you’re ready, I’ll see you in the back yard…

Friday, March 6, 2009 – If you see sunshine today, then celebrate the 1787 birth on this date of Joseph Fraunhofer—a trailblazer in modern astronomy. His field? Spectroscopy. Fraunhofer developed scientific instruments and specialized in the area of applied optics. While designing the achromatic objective lens for a telescope, he saw the spectrum of sunlight as it passed through a thin slit and the dark emission lines. Fraunhofer recognized that they could be used as wavelength standards, so he began measuring, labeling the most prominent with the letters still used today. His skill in optics, mathematics, and physics led Fraunhofer to design and build the very first diffraction grating.

You’ve probably seen these little rainbows hundreds of times in your life without even realizing what they are. Would you like to create your own grating? Take a piece of ordinary clear cellophane (a bit of clean food wrapping is fine) and scratch it lightly a few times in one direction only with a piece of sandpaper. Hold it adjacent to a bright light source and tilt it until you see hundreds of hair-fine lines of color. Yes, it’s crude. . . but it works! Did Fraunhofer’s telescope designs also succeed? Of course! His achromatic objective lens is still used in modern telescopes.

Tonight the lunar crater for named for Fraunhofer is visible, but so overlighted it will be difficult to see. Honor the man of lines by looking for another ‘‘line’’ on the Moon. If conditions are right, you’ll notice a thin black line cutting across the scenery not too far
from Arzachel. Crater Thebit and bright Thebit A will guide you. The line is the shadow of an impressive lunar fault called Rupes Recta, or the ‘‘Straight Wall.’’ During lunar sunrise, we can only see the shadow on the floor of Mare Nubium, but during third quarter, the escarpment is lit in brilliant white!

When you’re done, let’s take a look at Alpha Leonis, one of the closest bright stars to the ecliptic and known as far back as medieval times. Some cultures referred to it as the ‘‘fallen angel,’’ ‘‘the heart of the lion,’’ and the ‘‘yellow emperor.’’ We know it more commonly by its Latin name—Regulus. It’s not terribly massive, only about 3.5 times larger than our own Sun and just a few hundred million years old. But unlike Sol, 77.5-light-year-distant Regulus rotates to the extreme, revolving on its axis in less than 16 hours. Because of this rapid spin, its photosphere stretches, giving the star an oblate profile. As a victim of gravity darkening, Regulus’ poles are far hotter than its equator and 500% brighter. If it rotated any faster, centripetal force would pull it apart! But the ‘‘Little King’’ isn’t alone in space; it has two other members in its local court – a gravitationally bound 0.006-light-year-distant binary system. The brighter of the binary companions can be spotted in binoculars, but it will require a telescope to see the fainter third star another 15 billion kilometers away. The pair happily live out their lives orbiting each other about every 2 millennia, and around Regulus itself every 130,000 years.

Saturday, March 7, 2009 – Today we celebrate two notable births. The year 1837 is Henry Draper’s, first to photograph the stellar spectrum; and 1792 is the year Sir William Herschel’s only child—John—was born. John Herschel began his astronomical career in 1816 when he built his first telescope. His path led him to eventual British knighthood for furthering his father’s work, and to South Africa to complete his father’s survey by cataloging the stars, nebulae, and other objects of the southern skies. In his own words;

‘‘He that on such quest would go must know not fear or failing.’’

John returned to England in 1838, published his work, fathered 12 children, named the moons of Saturn and Uranus, and expanded the field of photography. He was a prodigious author, and you’ll even find examples of his handiwork in the Encyclopedia Britannica!

Tonight honor the great J. Herschel by identifying the lunar crater named for him in the lunar northern hemisphere. Once you have located J. Herschel, power up. Caught on this oblique crater’s edge is the deep pit of Horrebow—and a nice double strike. Compare the 156-kilometer diameter interior of J. Herschel to the smoothness of bordering Mare Frigoris. The difference in textures is astonishing! If the view holds steady, look for the larger C crater inside the walls, and a very distinct, drifted look to the crater rims. If John Herschel were alive tonight to share the eyepiece with you on his birthday, he would have said:

‘‘In circumstances where the uninformed and unenquiring eye perceives neither novelty nor beauty, the scientist and natural philosopher walks in the midst of wonder.’’

With such bright sky, it’s going to be difficult to practice much astronomy—or is it? There are always some very cool things to do if you just know where to look! Let’s head for the eighth brightest star in the sky—Procyon.

Often called ‘‘the one who proceeds the Dog,’’ Procyon also represents a dog, the beloved pet of Helen of Troy. If you haven’t noticed, Alpha Canis Minoris is also the eastern member of what is sometimes called the ‘‘Winter Triangle,’’ appearing above the horizon before the Dog Star, Alpha Canis Majoris. At 0 magnitude, it’s in fair competition with the other trio members: dazzling Sirius and mighty Betelgeuse. At a little more than 11 light-years away, it is also one of the closest stars to our Solar System.

Now just stop and look at this beautiful star. Arabic tales describe Procyon and Sirius as two sisters, who along with their brother—Canopus—tried to cross the sky when they came to the Great Sky River. When they both entered the Milky Way and tried to swim across, only Sirius was strong enough to make it and now stands on the southern bank of that river of stars. Left alone to the north as her siblings moved on, Procyon is often referred to in mythology as ‘‘she who weeps.’’ Not surprisingly, astrology also associates Procyon with watery catastrophes!

Sunday, March 8, 2009 – On this date in 1618, Johann Kepler formulated his Third Law of Planetary Motion. Too bad he couldn’t stick around until 1804 to meet Alvan Clark, the ‘‘father’’ of the refractor who was born on this day. Clark refracting telescopes and optics graced the great observatories of the world.

Tonight we’ll turn our own telescopes toward Saturn. For a small telescope at low power, a first glimpse of Saturn is far from the grand image often portrayed of the ringed planet. Instead of beautiful, Hubble-like images, the viewer is greeted with something that looks more like a sesame seed on a black saucer than a fascinating distant world. But don’t give up! No matter what telescope size you use, the image is more dependent on seeing conditions (such as the steadiness of the atmosphere and transparency) rather than aperture.

Even at low power, watching Saturn’s moons orbit over a period of days is very rewarding. And even a very small telescope will reveal Saturn’s ring structure. As optic size increases, so do details on successive nights. Look for such wonders as the wide dark band known as the Cassini division and the dark shadow of the planet’s orb against the rings. Sharp-eyed observers often spy the ‘‘Encke gap’’—the thin, minor ring around the outside. Subtle shadings and the ring shadows on Saturn’s yellowish globe await! Try sketching while observing, even if you throw it away later. When sketching, the eye and the mind coordinate to pick up on finer details than seen by just observing alone. Be sure to take plenty of time! When the one pure moment of seeing and stability combine, even the smallest of telescopes will reward you with a view you’ll never forget.

When you’re done, return to last night’s study star, Procyon, for another treat – a very pleasing little group of stars about a fist-width southeast (RA 08 25 39 Dec 02 54 23). The primary star’s name is C Hydrae, and although the group isn’t truly gravitationally bound, they’re a real delight to binoculars and telescopes of all sizes with their mixed magnitude similar spectral types!

Until next week? Ask for the Moon, but keep on reaching for the stars!

This week’s awesome images are: Joseph Fraunhofer (historical image), Area of Rupes Recta (credit—Roger Warner), Regulus – (Credit: Peter Wienerroither, PWs fotografisches Doppelstern Projekt / PWs Photographic Doublestar Project), John Herschel (historical image), Crater J. Herschel (Credit—Wes Higgins), Procyon (credit – UC Berkeley Department of Astronomy), Saturn (credit—Wes Higgins) and C Hydrae (credit—Palomar Observatory, courtesy of Caltech). Thank you so much!

Greetings, fellow SkyWatchers! For some parts of the world, baby? It’s cold outside… But those -23C temperatures haven’t kept some of us from chasing Comet C/2007 N3 Lulin and just knowing a few bright stars and having a pair of binoculars is all it takes for you to spot it, too! Or maybe you’d just like to spot the ISS? If skies are clear, why not spot the Moon and where SMART-1 did some imaging? Better yet, how about spotting a bright star to learn about – or a fantastic lunar impact crater? If you’re ready to see some “spots”, then grab your observing equipment and meet me outside…

Friday, February 6, 2009 – This date marks the 1991 fiery return of the Soviet space station Salyut 7. Launched in 1982, electrical and maneuvering problems plagued the mission, but cosmonauts were able to stay on board for as long as 8 months before returning. Abandoned in 1986, equipment and supplies were transferred to the orbiting Mir. If you’d like to spot a space station like the ISS, check Heavens Above on how to get information for your area.

Return to the Moon tonight and explore the outstanding ring of crater Gassendi on the north shore of Mare Humorum. It’s over 3.6 billion years old, and about the size of the state of Arkansas! Roughly 110 kilometers in diameter and 2,010 meters deep, this ancient crater contains a central triple mountain peak and forms one of the most ‘‘perfect circles’’ on the Moon. Lava flows have eroded Gassendi’s south wall, and its floor is covered with ridges and rilles. Look for small crater Gassendi A on the northern rim. The northwestern section of the crater wall is slightly higher, saving it from the lava that formed Mare Humorum. Look carefully at the lower southern rim to find the gap where lava spilled over the walls. It’s only 200 meters above the surface, while other areas rise as much as 2,500 meters. The fact that some parts of the rim escaped the lava is what makes this an interesting area for science!

On January 13, 2006, the Advanced Moon Imaging Experiment (AMIE) on board ESA’s SMART-1 spacecraft imaged Gassendi from about 1,220 kilometers above the surface. Previous spectroscopic studies had shown that the central peaks might have experienced their own volcanic period – earlier than the event that filled the lower floors. These ancient highland rocks may one day give us significant insight into the thermal history of the Mare Humorum impact basin and the processes that formed Gassendi. Enjoy this ancient beauty!

Saturday, February 7, 2009 – On this date in 1889, the Astronomical Society of the Pacific was born. In 1926 celebrated cosmonaut Konstantin Feoktistov, who flew Voskhod 1 and helped design Salyut and Mir, was born. Yet most noteworthy today is the 1824 birth of amateur astronomer William Huggins. By age 30, he’d built his own private observatory and through his studies made important contributions to astronomy. According to scientists Kirchoff and Bunsen, the chemical composition of minerals could be determined from their spectral signatures. The inquisitive Huggins began comparing mineral samples to the spectra of celestial objects. Although his experimental methods were crude by today’s standards, his calculations were perfect. Huggins proved the spectrum of the Orion Nebula was like that of a pure gaseous emission, while the spectrum of the Andromeda Nebula was similar to that of starlight—and this long before confirmation of its galactic nature! Huggins was also the first amateur to measure the radial velocities of stars from their spectral shifts. Although most people assume only professional scientists can make such measurements, many of today’s amateurs (unpaid, but not unskilled!) have measured spectra.

Tonight let’s look at a star whose radial velocity has been studied both professionally and personally – Kappa Orionis (RA 05 47 45 Dec -09 40 10). Named Saiph, it’s the often-overlooked eastern ‘‘foot’’ of Orion. According to spectral analysis, this 722 light-year distant blue supergiant is moving away from us at 21 kilometers per second.

Roughly the same type, size, and distance as Rigel, it looks far fainter. But why? Oddly enough, Saiph has an extremely high temperature, burning more than 1,500 K hotter. Near the point where helium fusion replaces hydrogen fusion, the majority of its variable light output is in the ultraviolet band. And as Huggins once said: ‘‘It is remarkable that the elements diffused through the host of stars are some of the most closely connected with the living organisms of our globe.’’

Sunday, February 8, 2009 – On this date in 2001, the Sayh al Uhaymir 094 Mars Meteorite was discovered. Some space-born debris from Martian impact craters is eventually captured by Earth’s gravity. The surviving meteorites can be identified by their mineral composition, as well as from tiny gas deposits matching Viking lander samples of Mars’s atmosphere.

Tonight, aim your optics toward the Moon and study an impact crater large enough to have blasted lunar material back to Earth. Its name is Tycho… Take one glance at the lunar Southern Hemisphere, and you can’t miss the dazzling display of 85-kilometer-wide Tycho, and its brilliant splash ray pattern. Perhaps 100 million years ago a comet, an asteroid, or a large meteorite impacted the Moon, flinging debris far and wide. One of Tycho’s ejecta paths (rays) crosses the Apollo 17 landing site almost 2,000 kilometers away, where it caused a landslide, revealing deeper materials. Shining like a beacon in Tycho’s center is a mountain peak originating from below the surface crust. The crater floor is lumpy and the rim broken by the force of the impact.

Could a collision like Tycho’s create Earth-bound meteoroids? Indeed, you may have walked on one unaware! The first confirmed lunar meteorite was found in 1979 in Antarctica, but it was many years before its true identity was known. Confirmation required comparison of its chemical composition to that of Apollo lunar samples. To date, only around 40 confirmed lunar meteorites are known, but as many as one in every thousand may have originated from our nearest neighbor. Noble gas measurements show some of these materials may have left the lunar surface up to 20 million years ago, but most are around 100,000 years old. They might resemble terrestrial rocks, but ones with their chemical composition are found only on the Moon. Have a look at Tycho and imagine the power that sculpted this mighty crater!

For those who don’t mind getting up early, be sure to keep your eye on the mighty Comet C/2007 N3 Lulin! If you have trouble reading star charts – don’t worry. It’s a whole lot easier to find in binoculars than you might think. All you need to do is just know how to identify a few bright stars! If you live in the northern hemisphere, about an hour (even two if you have a clear skyline) go out and identify Scorpius rising to the southeast – or Virgo high in the south, if you prefer. (For other locations, simply follow the ecliptic plane.) Between the two constellations you’ll see bright optical double star Alpha Librae – Zubenelgenubi. You’ll know if you have the right star because it will appear as two close stars in your binoculars. As of the morning of February 6th, Comet Lulin appeared in the 2 o’clock position with Zubenelgenubi in the field and it’s slowly headed towards Spica – Alpha Virginis. Remember as each successive day passes to start at Zubenelgenubi (it’s about a hand span east-southeast of Spica) and move the binoculars slowly towards Spica until you spot it. It will appear as a small, faint fuzzy in 5X30 binoculars and elongated in 16X60s. Even with telescopes as small as 114mm in aperture, it’s easy to make out that signature tail! Don’t wait too long to capture it, though… Because it won’t be long until the Moon is going to interfere and make this 7th magnitude comet far more difficult to spot.

Until next week? Ask for the Moon, but keep on reaching for the stars! You could just catch a comet…

This week’s awesome images are: Salyut (historical image-NASA), Gassendi (credit-Wes Higgins), William Huggins (historical image), Kappa Orionis: Saiph (credit-Palomar Observatory, courtesy of Caltech), Mars meteorite (historical image), Tycho (credit-Roger Warner) and Comet Lulin (credit-Joe Brimacombe). Thank you for sharing!

Greetings, fellow SkyWatchers! The Moon is back again, but what a terrific target for winter studies. Why not get out your binoculars and telescopes as we take a look at strange and unusual places like the Serpent Sea, the Marsh of Sleep and the Lakes of Time, Death and Dreams? If you haven’t wished upon a star lately, then there’s a serious reason to take a look at Sirius this weekend! Step outside in the dark with me where we’ll explore a little history, a little mystery, and just plain have us some fun…

Friday, January 30, 2009 – Tonight’s early evening Moon is high enough to warrant study. During the last lunar cycle, we reviewed maria large enough to be seen unaided, but many more can be revealed telescopically. Magnify the Crisium region and let’s look around. Along the eastern side near the lunar limb is Mare Marginis, whose position between the nearside and farside will never allow us to see more than a thin gray line. Thanks to the lunar orbiters, we know it has an irregular border and shallow lava fill, which lead scientists to believe Marginus wasn’t created from an impact. Located southeast is Mare Undarum , the ‘‘Sea of Waves.’’ This highly elevated part of the Crisium basin is about the size of Massachusetts, and it probably filled with lava around the time of the Imbrium impact. Northeast, and separated by a mountain range, is Mare Anguis, or the ‘‘Serpent Sea.’’ This Vermont-sized area of lunar landscape formed differently and may be home to a vast number of lava tubes.

Now look to Crisium’s northwest for a new feature, Lacus Bonitatis , or the ‘‘Lake of Goodness.’’ With features similar to those of maria, this small, irregularly shaped area has as much ‘‘coastline’’ as the Black Sea! Further south is Palus Somni, the ‘‘Marsh of Sleep.’’ This curious feature is an upland area. Relatively flat—but very uneven—its high albedo (surface reflectivity) makes it a rewarding study. Last on tonight’s tour is Sinus Concordiae , the ‘‘Bay of Harmony.’’ Essentially part of the maria that spawned it, this inlet leads toward higher ground. Concordiae’s small bay is roughly the size of Pedro Bank in Jamaica. Like its earthly counterpart, it may have mountain peaks that are just barely covered – but by lava flow, not seawater. Be sure to list your evening’s observations in your lunar notes. We’ll return in the months ahead here for more!

‘‘Everything has a natural explanation. The moon is not a god, but a great rock.’’ — Anaxagoras (475 BC)

Saturday, January 31, 2009 – What a busy date in astronomy history! In 1958 the United States. launched its first satellite – Explorer 1 – which discovered the bands of radiation now referred to as the Van Allen Belts . In 1961 the Mercury-Redstone 2 launched, carrying Ham the chimpanzee to fame. Cabin pressure failed during the suborbital flight, but inside his pressure suit, Ham remained safe and performed his tasks with a reaction time only a half second slower than on the ground, proving primates could function in space! (And a few years later, astronauts started drinking and shooting at each other, proving that humans could function like primates.) Ham lived for another 17 years, and the celebrated chimp gave many performances – even guest starring in movies!

Luna 9 was launched in 1962 and 72 hours after its launch became the first craft to successfully touch down on the Moon and broadcast television from Oceanus Procellarum . Even Apollo 14 was Luna-bound today in 1971! Alvan Graham Clark , Jr, made history at the eyepiece on this date in 1862. While watching Sirius and testing an 18″ refractor his family built, Clark uncovered the intense star’s faint companion – Sirius B. Friedrich Bessel had proposed its existence back in 1844, but this was the first visual confirmation.

Try your own hand at the ‘‘Scorching One.’’ Alpha Canis Majoris has an amazing magnitude of -1.42. Next to Alpha Centauri , 8.7 light-year distant Sirius is the closest visual star, but it’s not standing still. Part of the Ursa Major moving stream, Sirius has changed position by one and half times the apparent width of the Moon in just 2,000 years! Telescopically, this main-sequence gem is dazzling white, tinged with blue and diffracts a rainbow of colors. For many of us, beautiful iridescence is all we’ll ever see, but a small telescope (114-150mm) under perfectly steady skies will reveal the secretive companion. In 20 years it will reach maximum separation of 11.500, so keep watching to Sirius’ southeast when you observe – perhaps you’ll spot B!

Sunday, February 1, 2009 – On this day we celebrate the 1905 birth of Lloyd Berkner, the first person to measure Earth’s ionosphere. His work with radar led to an understanding of radio wave propagation. He also served as administrator at Green Bank National Radio Astronomy Observatory. For his achievements in space science, NASA awarded Berkner the Distinguished Public Service Medal.

The broad crescent Moon dominates the early evening sky. Tonight we’ll explore new features as we start in the lunar north with Mare Humboldtianum spanning 350 kilometers, this inconspicuous multi-ringed feature depends on libration for best views.

Further south along the limb is Lacus Spei (the Lake of Hope), a diminutive feature so small it could be crossed at walking speed in 10 hours! West of Humboldtianum and Spei is a pair of lighter areas devoid of features— Lacus Temporis (the Lake of Time). These two small overlapping basins were filled by the same lava flow, thus forming this small mare. How long to walk across Temporis? Twice as much ‘‘Time’’ as ‘‘Hope’’!

Relocate Mare Frigoris (the Cold Sea) and look south along the terminator for Lacus Mortis (the Lake of Death) and its counterpart Lacus Somniorum (the Lake of Dreams). Is there a connection here? You betcha! These two basin areas were filled from a basaltic flow, which might have united them, but a small mountain range kept them apart.

‘‘There is something haunting in the light of the Moon; it has all the dispassionateness of a disembodied soul, and something of its inconceivable mystery.’’ –Joseph Conrad

By the way, we believe Werner Heisenberg died on this day in 1976, but no one is certain.

Until next week? Ask for the Moon… But keep on reaching for the stars!

This week’s awesome images are: The Crisium Region (credit—Greg Konkel), Ham
the Chimpanzee (credit—NASA), Sirius (credit—John Chumack), Lloyd Berkner (public image) and Hope, Time, Death, and Dreams (credit—Greg Konkel). We thank you so much for sharing your splendid talents with us!