From Webcam to Planetcam: Planetary Imaging on the Cheap

Photo by Author

It’s a question we get often.

“What sort of gear did you use to capture that?” folks ask, imagining that I’m using a setup that required a second mortgage to pay for.

People are often surprised at the fact that I’m simply using a converted off-the-shelf webcam modified to fit into the eyepiece-holder of a telescope, along with freeware programs to control the camera, stack,and clean up images. And while there are multi-thousand dollar rigs available commercially that yield images that would have been the envy of professional observatories even a decade ago, you may just find that you have the gear lying around to start doing planetary and lunar photography tonight.

OK, I’ll admit: you do need a laptop and telescope, (things that we typically have “laying around” our house!) but these are the two priciest items on the list to get started. Living the vagabond life of a veteran, a teacher, and a freelance science writer assures that our preferred cameras for conversion are always in the double-digit dollar range.

Converted "Planetcam" installed on the 'scope.
Our first converted “Planetcam” installed on the ‘scope.

But converted webcam imaging is not new. We first read about the underground movement over a decade ago. Back in the day, amateur astrophotographers were hacking their Phillips Vesta and ToUcam Pro webcams with stunning results. Celestron, Meade and Orion later caught up to the times and released their own commercial versions for planetary imaging some years later.

A few freeware installations and the modification of a Logitech 3000 that I bought on rebate for 50$ later, and I was soon imaging planets that same night.

Photo by author
Modified webcams, old (right) and new (left).

Just about any webcam will yield decent results, though the discontinued Phillips ToUcam Pro webcams are still the heavily sought after Holy Grail of webcam astrophotography. The modification simply consists of removing the camera lens (don’t do this with any camera that you don’t want to gut and void the warranty) and attaching a standard 1 ¼” eyepiece barrel in its place using cement glue.

For camera control, I use a program called K3CCDTools. This was freeware once upon a time, now the program costs $50 to install. I still find it well worth using, though I’ve been turned on to some equally useful programs out there that are still free. (more on that in a bit).

K3CCDTools will process your images from start to finish, but I find that Registax is great for post-image processing. Plus, you don’t want to waste valuable scope time processing images: I do the maximum number of video captures in the field, and then tinker with them later on cloudy nights.

Screen cap
A screen capture of K3CCD tools during a daytime alignment test. Note the focusing dialog (FFT) box to the right.

Stacking video captures enables you to “grab” those brief moments of fine atmospheric seeing. Many astrophotographers will manually select the best frames from thousands one by one, but I’ll have to admit we’re often impatient and find the selection algorithm on Registax does an acceptable job of selecting the top 10% of images in a flash.

And like Photoshop, a college course could be taught around Registax. Don’t be intimidated, but do feel free to experiment! After stacking and optimizing, we find the true power in making the images “pop” often lies in the final step, known as wavelet processing.  A round of sharpening and  contrast boosting in Photoshop can also go a long way, just remember that the goal is to apply the minimum to get the job done, rather than looking unnatural and over-processed.

Photos by author
A photo mosaic of the historic Mars opposition of 2003.

At the eyepiece, the first target hurdle is object acquisition. A standard webcam can go after bright targets such as the Moon, the Sun (with the proper filter) planets, and bright double stars. We’ve even nabbed the International Space Station with our rig using a low-tech but effective tracking method. Your field of view, however, will typically be very narrow; my webcam coupled to a Celestron C8” Schmidt-Cassegrain typically yields a field of view about 10’ on a side. You’ll want to center the object in the eyepiece at the highest power possible, then plop the camera in place.

The next battle is centering and focusing the object on the screen. An out-of-focus planet scatters light: tweaking the focus back and forth sometimes reveals the silvery “doughnut” of the planet lurking just out of view.

From there, you’ll want the object in as razor sharp a focus as possible. K3CCDTools has a great feature for this known as a Fine Focusing Tool (FFT). Some observers also using focusing masks, which can also be easily built — remember, were being cheapskates! — out of cardboard. Be sure those reflector mirrors are properly collimated as well.

Photos by author
Objects shot over the years (clockwise from the upper left): the close double star Porrima, Saturn, the International Space Station, and Venus.

Don’t be surprised if the planet initially looks over-saturated. You’ll want to access the manual controls of via the camera software to take the brightness, contrast and color saturation down to acceptable levels. I typically shoot at about 15 frames a second. Fun Fact: the “shutter speed” of the dark adapted “Mark 1 human eyeball” is generally quoted around 1/20th of a second, slower than you’d think!

Note: all those thousands of frames of video go somewhere… be sure to occasionally clean them off your hard-drive, as it will swiftly fill up!

When you image makes a big difference as well. The best time to shoot an object is when it transits the local north-south meridian and is at its highest point above the horizon. The reason for this is that you’re looking through the thinnest possible cross-section of the often turbulent atmosphere.

Universe Today reader Scott Chapman of Montpelier, Virginia also recently shared with us his exploits in planetary webcam imaging and his technique:

Credit-Scott Chapman
A webcam image of the Mare Crisium region on the Moon. Credit-Scott Chapman

“Recently, while looking for an affordable basic telescope, to see if I really had any interest in astronomy, searches and reviews led me to purchase a 70mm refractor. The last thing on my mind was that I could expect to take any pictures of what I might see.

Previously, I had assumed that the only way to take even basic pictures of sky objects was with equipment that was way out of my price range. Imagine my surprise to learn that I could use a simple webcam that I already had sitting around!”

Like many of us mere mortal budget astrophotographers, Scott’s goal was great images at low cost. He also shared with us the programs he uses;

SharpCap2: For capturing .avi video files from the webcam connected to the telescope.

VirtualDub: For shortening the .avi video.

PIPP: For optimization of stacked images.

AutoStakkert2: Selects and stacks the best frames into a single .tiff file using a simple 3-step process. Scott notes that its “MUCH easier for a beginner to use than Registax!”

-Registax6: The latest version of the software mentioned above.

JPEGView: For final cropping and file conversion. (I sometimes also use ye ole Paint for this).

Even after a decade of planetary imaging, some of these were new to us as well, a testament to just how far the technique has continued to evolve. Astrophotography and astronomy are lifelong pursuits, and we continue to learn new things every day.

The current camera I’m shooting with is a Logitech c270 that I call my “Wal-Mart 20$ Blue Light Special.” (Yes, I know that’s Kmart!) Lots of discussion forums exist out there as well, including the QuickCam and Unconventional Imaging Astronomy Group (QCUIAG) on Yahoo!

Some observers have even taken to gutting and modifying their webcams entirely, adding in cooling fans, more sensitive chips, longer exposure times and more.

All great topics for a future post. Let us know of your trials and triumphs in webcam planetary photography!

-Watch Dave Dickinson pit his 20$ webcam against multi-thousand dollar rigs weekly in the Virtual Star Party.

-Be sure to send those webcam pics in to Universe Today!

 

NEOWISE Spots Mars-Crossing Comet

NASA's NEOWISE Mission takes aim at Comet A1 Siding Spring on January 16th, 2014 when the comet was 571 million kilometres distant. Credit: NASA/JPL-Caltech

One of the big ticket astronomical events of 2014 will be the close passage of Comet C/2013 A1 Siding Spring past the planet Mars in October 2014. Discovered just over a year ago from the Australian-based Siding Spring Observatory, this comet generated a surge of excitement in the astronomical community when it was discovered that it was going to pass very close to the planet Mars in late 2014.

Now, a fleet of spacecraft are poised to study the comet in unprecedented detail. Some of the first space-based observations of the comet have been conducted by NASA’s Hubble Space Telescope and the recently reactivated NEOWISE mission. And although the comet may not look like much yet in the infrared eyes of NEOWISE, its estimated 4 kilometre in diameter nucleus is already active and shedding about 100 kilograms of dust per second.

And although an impact has been since ruled out, it’s that dust that may present a hazard for Mars orbiting spacecraft, as well as a unique scientific observing opportunity.

“Our plans for using spacecraft at Mars to observe Comet A1 Siding Spring will be coordinated with plans for how the orbiters will duck and cover, if we need to do so that,” said NASA/JPL Mars Exploration Program chief scientist Rich Zurek.

The 2014 passage of Comet A1 Siding Spring through the inner solar system. Credit: NASA/JPL-Caltech
The 2014 passage of Comet A1 Siding Spring through the inner solar system. Credit: NASA/JPL-Caltech

Comet A1 Siding Spring is projected to pass within just 138,000 kilometres of Mars on October 19th, 2014. This is one-third the Earth-Moon distance, and 10 times closer than the closest recorded passage of a comet by the Earth, which was Comet D/1770 Lexell in the late 18th century. The comet will also miss the Martian moons of Phobos and Deimos, which have the closest orbits of any moons in the solar system at just 5,989 and 20,063 kilometres above the surface of Mars, respectively.

Assets in orbit around the Red Planet are also slated to observe the close approach and passage of Comet A1 Siding Spring, as well as any extraterrestrial meteor shower that its dust may generate.

“We could learn about the nucleus – its shape, its rotation, whether some areas on its surface are darker than others,” Zurek said in a recent NASA/JPL press release.

The rovers Curiosity and Opportunity are currently active on the surface of Mars. Above in orbit, we’ve got the European Space Agency’s Mars Express, and NASA’s Mars Odyssey and the Mars Reconnaissance Orbiter (MRO).  These will be joined by India’s Mars Orbiter Mission and NASA’s Mars Atmosphere and Volatile Evolution (MAVEN) spacecraft just weeks prior to the comet’s passage.

“A third aspect for investigation could be what effect the infalling particles have on the upper atmosphere of Mars,” Zurek said. “They might heat it and expand it, not unlike the effect of a global dust storm.”

Just last year, Mars based spacecraft caught sight of the ill-fated sungrazer Comet C/2012 S1 ISON as it passed Mars. But that dim passage yielded a scant pixel-sized view in the eyes of MRO’s HiRISE camera; Comet A1 Siding Spring will pass 80 times closer than Comet ISON and could yield a view of its nucleus dozens of pixels across.

Though the tenuous Martian atmosphere will shield to surface rovers from any micro-meteoroid impacts, they may also be witness to a surreptitious meteor shower from the debris shed by the comet, a first seen from the surface of another world.

But engineers will also be assessing the potential hazards that said particles may posed to spacecraft orbiting Mars as well.

“It’s way too early for us to know how much of a threat Siding Spring will be to our orbiters,” said JPL’s Mars Exploration Program chief engineer Soren Madsen recently. “It could go either way. It could be a huge deal or it could be nothing – or anything in between.”

In a worst case scenario, Mars orbiting spacecraft would be shuttered and oriented to “shelter in place” as the dust from the comet passes. There’s precedent for this in Earth orbit, as precious assets such as the Hubble Space Telescope were closed for business during the Leonid meteor storm of 1998.

“How active will Siding Spring be in April and May? We’ll be watching that,” Madsen continued. “But if the red alarm starts sounding in May, it would be too late to start planning how to respond. That’s why we’re doing what we’re doing right now.”

Comet A1 Siding Spring was the first comet discovered in 2013 at 7.2 Astronomical Units (AUs) distant. From our Earth based perspective, the comet will reach opposition on August 25th at 0.96 AU from the Earth, and approach 7’ from Mars on October 19th in the constellation Ophiuchus in evening skies. The comet reaches perihelion just 4 days later, and is slated to be a binocular comet around that time shining at magnitude +8.

The comet nucleus itself is moving in a retrograde orbit relative to Mars. Particles from A1 Siding Spring will slam into the atmosphere of Mars — and any spacecraft that happens to be in their way — at a velocity of 56 kilometres per second. For context, the recent January Quadrantids have a more sedate atmospheric impact velocity of 41 kilometres a second.

The unfolding 2014 drama of “Mars versus the Comet” will definitely be worth keeping an eye on… more to come!

How to See Planet Mercury at its Best in 2014

Looking west on January 31st 30 minutes after sunset. (Created using Stellarium).

 There’s an often told anecdote that astronomer Nicolaus Copernicus never spied Mercury. And while this tale is almost certainly apocryphal, it does speak to just how elusive the innermost planet of our solar system really is.

Never seen Mercury for yourself? This final week of January offers a good time to try, as Mercury reaches greatest elongation east of the Sun on Friday, January 31st.

This will offer northern hemisphere viewers one on the best chances to spot the fleeting world low to the west immediately after local sunset. And although we get on average six apparitions of Mercury per year – three each in the dawn and dusk – all apparitions aren’t created equal.

The approximate moment of greatest elongation occurs on January 31st at 10:00 UT / 5:00 AM EST, when Mercury is 18.4 degrees east of the Sun. This is only 0.5 degrees shy of the smallest elongation for Mercury that can occur, as the planet reaches perihelion just three days later on February 3rd at 0.3075 Astronomical Units (AUs) from the Sun. The last time this was surpassed was the evening elongation of February 16th, 2013th, and the next time it’ll be topped is October 16th, 2015 at just 18.1 degrees from the Sun.

Path of Mercury from January 27th to February 12th. (Created using Starry Night).
Path of Mercury from January 27th to February 12th as seen from latitude 30 degrees north. (Created using Starry Night Education Software).

And though this elongation is closer than usual, this also works in the Mercury-spotter’s favor. At greatest elongation, Mercury will present a 50% illuminated 7 arc second disk, readily apparent in a small telescope. But a also means that Mercury will appear almost a full magnitude brighter than it does when it reaches greatest elongation near aphelion, as it last did on March 31st of last year, and will do again on March 14th of this year.

Mercury will shine at magnitude -0.4 low towards the west into this coming weekend. We managed to pick up Mercury with binoculars on January 16th and have since managed to start tracking the planet unaided since January 18th.

Mercury also has another factor going for it, in terms of the angle of the evening ecliptic. Following ahead of the Sun, Mercury occupies a space that the Sun will trace up its apparent path along the ecliptic as it begins its long slow crawl northward towards the Vernal Equinox on March 20th. This means that Mercury is almost perpendicular above the western horizon at dusk and is currently getting a maximum boost above the atmospheric murk.

Mercury also gets joined by a razor thin waxing crescent Moon just over 24 hours past New sliding by it on the evening of Friday, January 31st. Look for the Moon five degrees to the right of Mercury on the 31st. The Moon will be a much easier catch on the February 1st when its 10 degrees above Mercury. And can you spy the +1 magnitude star Fomalhaut in the constellation Piscis Austrinus just 20 degrees to the south of Mercury?

Stellarium
The orientation of the Moon and Mercury on the evening of February 1st. Credit: Stellarium.

And speaking of the Moon, this week’s New Moon is the second of the month, a feat that repeats in March 2014 and leaves the month of February “New Moon-less…” such an occurrence in either instance is informally known as a Black Moon.

Orbiting the Sun once every 88 days, Mercury completes about 4.15 circuits of the Sun for every Earth year. From our Earthbound vantage point, however, Mercury seems to only orbit the Sun 3.15 times a year. Thus 6 elongations (3 in the dusk and 3 in the dawn) will occur every year, through 7 can occur, as last happened in 2011 and will occur again next year in 2015.

August 15th, 2012.
Mercury (to the lower left) and the Moon on August 15th, 2012. (Photo by author).

After this weekend, Mercury will resume its plunge towards the horizon through early February. Mercury will begin retrograde (westward) apparent motion against the starry background on February 6th before resuming direct (eastward motion) on February 27th. And although astrologers may  find that “Mercury in retrograde” is a convenient “blame magnet,” they’re also falling prey to a logical fallacy known as retrofitting, as Mercury spends a longer fraction of time than any other planet “in retrograde” at about 20%!

From there, Mercury heads towards inferior conjunction between the Earth and the Sun on Saturday, February 15th, passing just 3.7 degrees north of the solar disk. You can catch Mercury entering into the field of view of the Solar Heliospheric Observatory’s (SOHO) LASCO C3 camera from February 12th to February 18th.

And although Mercury misses this time, we’re not that far away from the next transit of Mercury across the face of the Sun on May 9th, 2016.

Up for more? An even tougher challenge is to attempt to spot Mercury… in the daytime. We’ve noted this possibility before as Mercury reaches maximum elongation from the Sun while still in the negative magnitude range. Of course, you want to physically block the Sun out of view, and don’t even try sweeping the sky near the Sun visually with binoculars or a telescope! You’ll need a clear, blue sky for maximum contrast and a polarizing filter may help in your quest… but this should be possible under exceptional conditions.

Good luck, and be sure to send those Mercury pics in to Universe Today!

An Incredible Time-lapse of Venus Passing Through Inferior Conjunction

Image credit: Shahrin

Some of the most amazing celestial sights are hidden from our view in the daytime sky. Or are they? We recently challenged readers to try and follow the planet Venus through inferior conjunction as it passed between the Earth and the Sun on January 11th. Unlike the previous pass on June 6th, 2012 when Venus made its last transit of the Sun for the 21st century, the 2014 solar conjunction offered an outstanding chance to trace Venus’s path just five degrees from the Sun from the dusk and into the dawn sky.

Expert astrophotographers Shahrin Ahmad based in Sri Damansara, Malaysia and Paul Stewart observing from New Zealand took up that daily challenge as Venus neared the limb of the Sun, with amazing results. Now, Shahrin has also produced an amazing time-lapse sequence of Venus passing through inferior conjunction.

You can actually see the illuminated “horns” of Venus as they thin, extend, and rotate around the limb as the planet passes the Sun.

And it’s what’s more incredible is that the capture was completed in the daytime. But such a feat isn’t for the unskilled. Shahrin told Universe Today of the special safety precautions he had to take to acquire Venus so close to the Sun:

“Since Venus was getting closer each day towards conjunction, I found it far too dangerous to find visually, either using the main telescope or the finderscope.”

Instead, Shahrin relies on computerized software named Cartes du Ciel to drive his Skywatcher EQ6 mount and pinpoint Venus in the daytime sky.

“The sky in Kuala Lumpur is never clear from here, thus it rarely appears dark blue, making it almost impossible to spot Venus visually, especially when it is less than 10 degrees from the Sun.”

Shahrin elaborated further on his special solar safety precautions:

“I always start with all covers in place and the solar filter on the main telescope. I will slew the telescope to the Sun, make some slight repositioning adjustments, and then synchronize the telescope to the new position. After ensuring the Sun is visible and centered on the computer screen, I slew to Venus. Once the mount has stopped in position, I remove the solar filter and replace it with a makeshift cardboard extender mounted on the existing dew-shield. This ensures that any direct sunlight is totally blocked from entering the optics.”

Shahrin notes that 90% of the time, Venus with appear on the computer screen after aligning. Otherwise, a brief spiral search of the field will slide it into view.

Shahrin observes from his ShahGazer Observatory, a roll-off-roof observatory just outside of Kuala Lumpur. He used the Skywatcher 120ED refractor pictured for the captures, with a 2x Barlow lens to achieve a focal length of 1800mm. Shahrin’s main camera is a QHY CCD IMG132e, and the rig is mounted on a Skywatcher EQ6.

Credit: Shahrin Ahmad.
A closeup of Sharin’s barlow and camera rig. Credit: Shahrin Ahmad.

“The experience of being able to track Venus approaching inferior conjunction over the Sun afterwards is exhilarating,” Shahrin told Universe Today. “It felt like watching and waiting for a total eclipse of the Sun, but in slow motion!”

Shahrin also counts himself lucky to have had a string of clear days leading up to and after inferior conjunction.

Shahrin’s capture of Venus 5 degrees from the Sun just 8 hours before inferior conjunction may also be a record. That’s a closer apparent separation than our visual sighting of Venus 7 hours and 45 minutes after inferior conjunction on January 16th 1998 as seen from North Pole Alaska, when the planet passed 5.5 degrees from the limb of the Sun.

“I’ve also noticed that in some of the photos, we can see a slight ‘glint’ of sunshine on part of Venus’ atmosphere,” Shahrin noted to Universe Today. “(This sighting) was actually confirmed by the RASC Edmonton Centre in Canada via their Twitter feed.”

An amazing capture, indeed. Venus is now back in the realm of visibility for us mere mortal backyard observers low in the dawn sky, shining at a brilliant magnitude -4.3. Expect it to vault up in a hurry for northern hemisphere observers as the favorable angle of the ecliptic will give it a boost in the dawn. Venus is also headed towards a spectacular 0.2 degree conjunction with Jupiter this summer on August 18th: expect UFO sightings to rise correspondingly.  The Indian Army even briefly mistook the pair for Chinese spy drones early last year.

The waning crescent Moon approaches Venus on the morning of January 28th, 2014. Created using Stellarium.
The waning crescent Moon approaches Venus on the morning of January 28th, 2014. Created using Stellarium.

Venus will spend most of 2014 in the dawn sky and is headed for superior conjunction on October 25th, 2014. Venus spent a similar span in the dawn for the majority 2006, and will do so again in 2022. It’s all part of the 8-year cycle of Venus, a span over which apparitions of the planet roughly repeat. And the next shot we’ll have at inferior conjunction?  That’ll be on August 15th, 2015 for favoring the southern hemisphere and March 25th, 2017 once again favoring the northern, when the planet very nearly passes as far from the Sun as it can appear at inferior conjunction at 8 degrees.

Congrats to Shahrin on his amazing capture!

-Follow the stargazing adventures of Sharin Ahmad on Google+ and as @shahgazer on Twitter

-Got pictures of Venus? Send ‘em in to Universe Today.

 

The Moon Occults Saturn in the Dawn this Weekend

Saturn and the waning crescent Moon rising to the SE at about 4 AM local on January 25th, 2014. Created using Stellarium

 Mark your calendars: the first in a series of interesting occultations of Saturn by the Moon for 2014 starts this weekend.

The year 2014 features 11 occultations of the planet Saturn by the Moon, and there are 23 total for 2014 of every planet except Neptune and Jupiter.

An occultation occurs when one foreground celestial object completely obscures another. Technically, a total solar eclipse is an occultation of the Sun by the Moon, although it’s never referred to as such. The term finds modern usage mainly for the blocking of stars and planets by the Moon. Very occasionally, an asteroid or planet can occult a distant star as well.

And yes, the modern astronomical term “occultation” traces its hoary roots back to the days when astronomy was intertwined with the pseudoscience of astrology.  To this day, the term still makes some folks wonder if astronomers are secretly casting horoscopes. Trust us, you’re still on a solid astronomical footing to use the term “occultation.”

Unfortunately, the January 25th occultation of Saturn by the Moon will only grace part of Antarctica, southern Argentina and Chile, and the Falkland Islands post-sunrise. The rest of us still will see a very photogenic pass of Saturn near the waning crescent Moon on the morning of Saturday, January 25th. The Moon will pass just about a degree — two times its apparent width — south of Saturn for northern hemisphere observers.

The footprint for the January 25th occultation of Saturn by the Moon. dashed lines indicate where the events occurs in the daytime sky. (Created using Occult 4.0.11 software)
The footprint for the January 25th occultation of Saturn by the Moon. dashed lines indicate where the events occurs in the daytime sky. (Created using Occult 4.0.11 software)

Both the Moon and Saturn will reside in the astronomical constellation of Libra this weekend during closest passage. The pair will rise around 2 AM local. After their brief tryst, the Moon will head towards New on January 30th while Saturn will continue to rise successively earlier as its heads towards opposition and the start of evening Saturn observing season on May 10th, 2014.

January 2014 is also notable for having two New Moons, an occurrence informally known as a Black Moon. This occurs again this year in March, and February 2014 is devoid of a New Moon. February is the only month that can be “missing a Moon phase” as it’s the only one shorter the synodic period of 29.5 days, in which the Moon returns to like phase.

Saturn as imaged by the author in 2012.
Saturn as imaged by the author in 2012.

In the telescope, Saturn will present a +0.8 magnitude disk 16” across (38” with rings from tip-to-tip). Saturn’s rings are tipped open to our line of sight by about 22 degrees in 2014, and are widening towards a maximum of 27 degrees in 2016 through 2017. If you have an equatorial telescope with tracking capability, it may be possible this weekend to follow Saturn up into the daytime sky. Though Saturn isn’t quite bright enough to see in the daytime unaided, it might just be possible to spy using binoculars on the 25th using the nearby crescent Moon as a guide.  Saturn is a tough daytime target to be sure, but it’s not impossible to acquire with a little skill and patience.

The current cycle of occultations of Saturn began on December 1st, 2013 and ends on November 22nd, 2014. The cycle will move progressively northward through the year.

The Moon and Saturn put on a repeat performance over almost the same exact location (this time in darkness) on April 17th, 2014, and the best event in the cycle for North America will be the August 31st daytime occultation of Saturn by the waxing crescent Moon.

Now for the wow factor of what you’re seeing. On Saturday morning, the Moon is just over 371,000 kilometres distant, or a little over a light second away. Saturn is over four thousand times more remote at just over 10.1 astronomical units (AUs) distant, which works out to 1.5 billion kilometres, or over 83 light minutes away.  And although the Moon is over a 112 times larger in apparent diameter than Saturn as seen from the Earth, the globe of Saturn is actually over 34 times bigger.

Saturn and the Moon crossing the local meridian shortly after sunset on January 25th. Created using Starry Night Education Software.
Saturn and the Moon crossing the local meridian shortly after sunset on January 25th. Created using Starry Night Education Software.

And though we’ve been to the Moon lots since the dawn of the Space Age, only two spacecraft (Voyagers 1 and 2) have made brief flybys of the ringed world, and only one – Cassini – has orbited it. Note that China’s Chang’e-3 lander and rover are about to experience their second sunset this weekend as well from the lunar surface since landing on the Moon last month.

And although lots of planets get occulted by the Moon in 2014, no stars brighter than +1st magnitude lie in its path. In fact, the next cycle of bright star occultations by the Moon doesn’t resume until the Moon meets Aldebaran in January 29th, 2015.

There are, however, over a 100 lesser events involving the Moon occulting naked eye stars worldwide in 2014. Two such events occur this week as well, when the 48% illuminated Moon occults the +4.5th magnitude star Lambda Virginis for west-central South America on the morning of January 24th, and the occultation of the +2.8th magnitude star Alpha Librae  (Zubenelgenubi) for central Asia on January 25th.

Don’t miss these celestial events, and be sure to send those pics in to Universe Today… there’s something for everyone happening in the sky this week worldwide!

A “MiniMoon” Seen Around the World

A 99% illuminated Moon within 24 hours of Full. Image Credit: Stephen Rahn.

So, did last night’s Full Wolf Moon seem a bit tinier than usual? It was no illusion, as avid readers of Universe Today know. As we wrote earlier this week, last night’s Full Moon was the most distant for 2014, occurring just a little under three hours after apogee.

The Full Moon, a "Moon Dog" halo, and a rare parhelic (or do you say Palunic?) arc as seen from North Slope Borough County, Alaska. Credit-Jason Ahrns.
The Full Moon, a “Moon Dog” halo, and a rare parhelic (or do you say Palunic?) arc as seen from North Slope Borough County, Alaska. Credit-Jason Ahrns.

Sure, the Moon reaches apogee every lunation, at a distance nearly as far.  In fact, the Moon at apogee can be as far as 406,700 kilometres distant, and last night’s apogee, at 406,536 kilometres, is only the second farthest for 2014. The most distant apogee for 2014 falls on July 28th at 3:28 Universal Time (UT) at just 32 kilometres farther away from our fair planet at 406,568 kilometres distant.

A 20 image composite shot using a Canon 60Da camera and a a 10" Newtonian telescope. Credit-Stephen Rahn.
A 20 image composite shot using a Canon 60Da camera and a a 10″ Newtonian telescope. Credit-Stephen Rahn.

What made last night’s MiniMoon special was its close proximity in time to the instant of Full phase. The July 2014 apogee, for example, will occur just a day and four hours from New phase.

The 2014 MiniMoon rising behind clouds from Hudson, Florida. Photo by author.
The 2014 MiniMoon rising behind clouds from Hudson, Florida. Photo by author.

Of course, it isn’t the Moon that’s doing the shrinking, though you’d be surprised the stuff we’ve seen around ye ole Web even on reputable news sites over the past week. The variation of the apparent size of the Full Moon does make for an interesting study in perception. The Moon varies in size from apogee to perigee from about 29.3’ across to 34.1’. This is variation amounts to 14% in apparent diameter.

The Full MiniMoon, clouds, and Jupiter. Credit- Shaun Reynolds, Bungay UK.
The Full MiniMoon, clouds, and Jupiter. Credit– Shaun Reynolds (@shaunreylec), Bungay UK.

Here’s an interesting challenge that you can do for a one year period, requiring just a working set of eyes: observe the Full Moon for 12 successive lunations. Can you judge which one was the “SuperMoon” and which one was the “MiniMoon” without prior knowledge?

A "MiniMoon Nebula..." The Full Moon illuminating foreground clouds. The HDR visualization of the Moon was added for context. Taken with a tripod mounted Nikon P90 Bridge camera. Credit: Giuseppe Petricca of Sulmona, Abruzzo, Italy.
A “MiniMoon Nebula…” The Full Moon illuminating foreground clouds. The HDR visualization of the Moon was added for context. Taken with a tripod mounted Nikon P90 Bridge camera. Credit: Giuseppe Petricca of Sulmona, Abruzzo, Italy.

And as you can see, we also got plenty of pictures here at Universe Today from readers of the Mini-Moon from worldwide.

The MiniMoon shot using a mobile phone held up to the eyepeice of a telescope. Credit-Andrew Millarkie (@Millarkie)
The MiniMoon shot using a mobile phone held up to the eyepiece of a telescope. Credit-Andrew Millarkie (@Millarkie) Glasgow, Scotland.

The rare occurrence of an “Extreme-MiniMoon” — or do you say “Ultra?” — also sparked a lively discussion about the motion of the Moon, how rare this event is, and when it was last and will next be surpassed. A fun online tool to play with is Fourmilab’s Lunar Apogee and Perigee Calculator. Keep in mind, the motion of the Moon is complex, and accuracy for most planetarium programs tends to subside a bit as you look back or forward in time. The distances used in Fourmilab’s calculations are also geocentric, accounting for the center-to-center distance of the Earth-Moon system.

The MiniMoon versus streetlights as seen from Nueva Casarapa, Venezulua. Credit: Jose Mauricio Rozada (@jmrozada)
The MiniMoon versus streetlights as seen from Nueva Casarapa, Venezuela. Credit: Jose Mauricio Rozada (@jmrozada)

Suffice to say, this year’s Full MiniMoon was the most distant for several decades before 2014 or after.

Anthony Cook of the Griffith Observatory notes that JPL’s Horizons web interface gives a max distance for the Moon of 406,533 kilometres at 1:35 UT earlier today, 3 hours and 19 minutes prior to Full.

The Full MiniMoon glimpsed between clouds as seen from central Illinois. Credit-Matt Comerford, (@kb9uwu)
The Full MiniMoon glimpsed between clouds as seen from central Illinois. Credit-Matt Comerford, (@kb9uwu)

The next closest spread of apogee versus perigee occurs on November 18th, 1994 at 1 hour and 51 minutes apart, and 2014’s Mini-Moon won’t be surpassed in this regard until May 13th, 2052. Looking at the distances for the Moon on these dates using Starry Night, however, we get an slightly closer occurrence of 406,345 kilometres for 1994 and 406,246 kilometres for 2052.

The Full MiniMoon rising behind a stand of trees. Credit- Sculptor Lil.
The Full MiniMoon rising behind a stand of trees. Credit– Sculptor Lil.

And to top it off, the 1994 Mini-Moon was during a partial penumbral eclipse as well… we’ll leave that as a homework assignment for the astute readers of Universe Today to calculate how often THAT occurs. It should be fairly frequent over the span of a century, as the Moon has to be at Full phase for a total lunar eclipse to occur.

The MiniMoon as captured by Manish Agarwal from Rajasthan, India.
The MiniMoon as captured by Manish Agarwal (@iManishAgarwal) from Rajasthan, India.

Looking over a larger span of time, @blobrana notes on Twitter that closer occurrences of apogee versus Full Moon with the same approximate circumstances as 2014 also occurred on October 29th 817 AD (with a 1 hour and 38 minute difference) and won’t occur again until December 20th, 2154. If research can prove or disprove that these events were even more distant, then the 2014 Extreme MiniMoon was a millennial rarity indeed…

Perhaps this won’t be the last we’ve heard on the subject!

John Dobson, Inventor of the Popular Dobsonian Telescope, Dead at 98

John Dobson, amateur astronomer and astronomy popularizer, died Jan. 14 at 98 in Burbank, Calif. Credit: Wikipedia

The cosmos lost a good soul Wednesday. John Dobson, famous as the creator of the simple, low-cost Dobsonian telescope, passed away on Jan. 15, 2014. His obituary appeared on the website of the Sidewalk Astronomers:

“It is with heavy hearts that we must report the passing of John Dobson. He died peacefully this morning, Wednesday, January 15th, in Burbank, California. He was 98 years old. He leaves behind a son, numerous close friends, and fans and admirers worldwide.

On March 8th, in honor of John, this year’s ISAN (International Sidewalk Astronomy Night) will be dedicated to his memory. Amateur astronomers around the globe can join in and celebrate John’s life and continue to carry the torch that he lit back in 1968 when he co-founded the San Francisco Sidewalk Astronomers.”

John Dobson tugs on his ear during a lecture as guest speaker during Northwoods Starfest near Eau Claire, Wis. U.S. in August 2000. Credit: Bob King
John Dobson tugs on his ear to make a point during a lecture as guest speaker during Northwoods Starfest near Eau Claire, Wis. U.S. in August 2000. Credit: Bob King

Dobson was born in Beijing, China but moved with his parents to San Francisco in 1927. After spending 23 years in a monastery, some of which time was spent sneaking out to build telescopes and observe the night sky, he left to co-found the San Francisco Sidewalk Astronomers in 1968, a group dedicated to showing people on the street the wonders of the night sky using large (for the time) telescopes.

Dobson’s interest in astronomy started in the early 1950s when he built a small telescope using spare parts found in a junk store. He wanted to see for himself what the universe looked like. By 1956, John got a hold of a 12-inch slab of porthole glass and ground it into a mirror following instructions from Allyn J. Thompson’s classic book Making Your Own Telescope. His first look at the last quarter turned him into an astro-evangelist:

“It looks like you’re coming in for a landing,” he wrote in his own telescope making book many years later. From that moment on Dobson felt “that everybody who lives in this world has to see that.”

The writer with his 10-inch Dobsonian reflecting telescope. The scope comes in two pieces like John Dobson's original design - a cardboard tube with the optics that sits in a cradle. See photo below to see how a "Dob" works. Credit: Bob King
The writer with his 10-inch Dobsonian reflecting telescope. The scope breaks down into two pieces like John Dobson’s original design – a cardboard tube with the optics and a cradle. See photo below to see how a “Dob” works. Credit: Bob King

Toting beat-up, monster telescopes everywhere from downtown San Francisco and to national parks across the country, Dobson made good on his promise. He lectured widely on astronomy and cosmology, rejecting the Big Bang Theory for his own Recycling Steady State Theory.

Agree or not with his cosmology, Dobson shook up the amateur telescope making universe with an innovative telescope design based on simplicity. Most telescopes of his day were small refracting telescopes or small to modest-sized reflectors with metal tubes and heavy equatorial mounts. Neither was exactly user-friendly nor offered much light gathering ability.

The mount is a simple altitude-azimuth or "alt-az" design. The scope moves up and down (altitude) against teflon pegs (right) and turns through in a circle (azimuth) on teflon pads against a laminate surface on the base. Credit: Bob King
The mount is a simple altitude-azimuth or “alt-az” design. The scope moves up and down (altitude) against teflon pegs (right) and turns through in a circle (azimuth) on teflon pads against a laminate surface on the base. Credit: Bob King

John used simple materials like porthole glass, cardboard tubes and wooden altitude-azimuth (alt-az) mounts to build incredibly easy to use large telescopes. However primitive, his instruments delivered bright and satisfying images of all the cool, faint stuff in the sky to the average Joe and Jane. Each telescopes had its own name: Little Bertha, Delphinium, Stellatrope, Little One (an 18-incher).While alt-az mounts were nothing new, Dobson combined cheap materials, large mirrors and a simpler approach to mountings that made his telescope style unique. Too unique for some.


Get to know John Dobson a little better in this video titled “Have Telescopes, Will Travel”

In the summer of 1969 Dobson pitched his simple ideas to Sky and Telescope magazine. Then-editor Charles Federer wrote back a polite rejection, stating that Dobson’s techniques weren’t up to standards and “could hardly lead to satisfactory instruments in the kind most amateurs want in these large sizes.”

How wrong this early assessment would turn out to be! His ideas became widely adopted starting in the early 1980s, when Coulter Optical began manufacturing 13.1-inch and 17.5-inch large reflecting telescopes with inexpensive mirrors and simple alt-azimuth mounts that soon were called “Dobsonian” because they were based on John’s original designs.

John Dobson's book on how to build your own telescope featured a unique cover made of plywood, a favorite material for building Dobsonian mounts. Credit: Bob King
John Dobson’s book on how to build your own telescope featured a unique cover made of plywood, a favorite material for building Dobsonian mounts. Credit: Bob King

These days, Dobsonian reflecting telescopes have gone viral. There are how-to books on how to build everything from simple to sophisticated Dobsonsians , including Dobson’s own unique plywood-bound How and Why to Make a User-Friendly Sidewalk Telescope. Don’t want to build one yourself? Most telescope outlets sell several lines of Dobsonians. Heck, my 10-inch and 15-inch reflectors, the most used of my instruments, originate from John’s genius.

When someone asks me to recommend a telescope, I always say “Get a Dobsonian!” They’re extremely portable, very stable, quick to set up and take down and the least expensive per inch of aperture of any scope out there.

John Dobson's signature in his book on telescope making. Credit: Bob King
John Dobson’s signature in his book on telescope making. Click image for more on Dobson’s life and writings. Credit: Bob King

Dobson wanted everyone to share in the universe’s bounty, the better to appreciate our lives and our world. The next clear night tilt your head back, gaze up at the stars and imagine John up there smiling. What an incredible view he must have.

An Amazing Capture of Jupiter and its Moons

Astrophotographer Michael Phillips with the gear used to capture the Jupiter rotation animation. Credit-Michael Phillips

It’s always a thrill to watch the action at Jupiter, as its moons pass in front of and behind the gas giant planet. We wrote recently about this month’s opposition of Jove on January 5th, marking the start of the Jupiter evening viewing season for 2014. 

Astrophotographer Michael A. Philips also recently undertook a challenging series of sequences of Jupiter and its moons Io and Ganymede, with stunning results. You can see the motion of Jupiter’s rotation, the Great Red Spot and even a bit of cloud swirl as Io disappears behind Jupiter and Ganymede begins to transit in front and cast a shadow back onto the Jovian cloud tops.

Concerning the capture, Michael wrote on his blog:

“This night was a lucky night. I had not looked at the weather forecast enough to know if it would be good or not. Cold temps aside, I decided earlier in the day to set up and go out with the 14” f/4.5 scope named Akule. As an added bonus, Mitchell Duke tipped me off to a transit of the Jovian moon, Ganymede.”

Note that Jupiter and its moons are currently casting their shadows nearly straight back from our perspective. Expect that to change, however, in the coming months,as Jupiter heads towards eastern dusk quadrature on April 1st and we see the action from a sideways angle. Watch the video in full screen mode and you’ll note that Mike captured some detail on the surface of Ganymede as well! Generally, at the eyepiece, the moons of Jupiter disappear entirely due to low contrast against the bulk of the planet, with only the black dot of the shadow seen… this video capture gives the ingress of Ganymede at the start of the transit a great 3-D appearance.

Webcam imaging of planets has really taken off in the past decade, with backyard astronomers now routinely capturing images that far surpass professional and textbook images from just a decade prior. Great images can be taken using nothing more than a telescope, a laptop, free image stacking software such as Registax, and a webcam converted to fit into an eyepiece holder… you may find that you’ve got the gear sitting around to image Jupiter, tonight.

Mr. Phillips rig, however, is a little more advanced. He notes in the description of the video that he’s using a Flea3 camera from PointGrey Research with a 5x Barlow lens yielding a 9200mm focal length. He’s also shooting at 120 frames per second, and taking successive red, green and blue images for 30 seconds. Finally, a derotation of Jupiter – yes, it really rotates that quickly, even in a short sequence – is accomplished using a sophisticated program named WINJupos.

Video stacking gives processors the ability to “freeze” and nab the best moments of seeing from thousands of frames. Some imagers hand select frames one by one, though many programs, such as Registax, use algorithms to nab the best frames from a preselected percentage of the total shot.

Local seeing conditions also play a key role in image capturing.

“I moved far away from the house as possible, and I think that helped some,” Michael noted. “I also started cooling the spit out of the mirror, aggressively. Even when cooled for a few hours in the winter, the heat in the Pyrex mirror comes back. I think there’s a small heat engine inside the beast!”

For best results, imagers tend to go after planets when they’re at their highest in the sky, and viewed through the least amount of turbulent atmosphere. This is when a planet is transiting the local north to south meridian, and when it’s at opposition, which Jupiter is this month. At opposition, a planet transits at local midnight. The same goes for the best opportunities for visual observing as well.

Shadow transits of Jupiter’s moons are also just plain fun to watch. In an often unchanging universe, they offer a chance to see something unfolding in real time. Jupiter has the fastest rotation of any planet at 9.9 hours, and the large Galilean moons of Io, Europa, Ganymede and Callisto are tidally locked in their rotation, keeping one hemisphere permanently turned towards Jupiter like the Moon does orbiting the Earth. The inner three moons also keep a 1:2:4 orbital resonance, assuring you’ll never see more than three of the four Galilean moons transiting from your line of sight at once. You can see two of the inner three moons, plus Callisto in transit, but never all four at the same time! A triple transit last occurred on October 12th, 2013, and will next occur for observers in eastern Europe and Africa this year on June 3rd.

We’re also currently in the midst of a series of shadow transits for the outermost Galilean moon Callisto, which end in July 2016. Can you identify the different moons by the size and hue of shadows they cast? Sky & Telescope publishes a great table for the ingress and egress of Jupiter’s moons. You can also check them out using the freeware program Stellarium.

The double shadow transit of February 6th as seen at 11:22 UT. Created by the author using Starry Night Education software.
The double shadow transit of February 6th as seen at 11:22 UT. Created by the author using Starry Night Education software.

Can’t wait that long? A double shadow transit involving Europa and Callisto occurs in just a few weeks for western North America from 10:20 UT-12:44UT on the morning of February 6th, a chance for another stunning animation sequence…

Congrats to Michael Phillips on a great capture!

A Possible Meteor Shower from Comet ISON?

Credit-Stellarium

Hey, remember Comet C/2012 S1 ISON? Who can forget the roller-coaster ride that the touted “Comet of the Century” took us on last year. Well, ISON could have one more trick up its cosmic sleeve –although it’s a big maybe — in the form of a meteor shower or (more likely) a brief uptick in meteor activity this week.

In case you skipped 2012 and 2013, or you’re a time traveler who missed their temporal mark, we’ll fill you in on the story thus far.

Comet ISON was discovered by Artyom Novichonok and Vitali Nevski on September 21st, 2012 as part of the ongoing International Scientific Optical Network (ISON) survey. Shortly after its discovery, researchers knew they had spotted something special: a sungrazing comet already active at over 6.4 Astronomical Units (A.U.s) from the Sun. The Internet then did what it does best, and promptly ran with the story. There were no shortage of Comet ISON conspiracy theories for science writers to combat in 2013. It’s still amusing to this day to see predictions for comet ISON post-perihelion echo through calendars, almanacs and magazines compiled and sent to press before its demise.

ISON back in the day. Credit-Efrain Morales Rivera, Jaicoa Observatory Aguadilla, Puerto Rico
ISON back in the day. Credit-Efrain Morales Rivera, Jaicoa Observatory Aguadilla, Puerto Rico

The frenzy for all things ISON reached a crescendo on U.S. Thanksgiving Day November 28th 2013, as ISON passed just 1.1 million kilometres from the surface of the Sun. Unfortunately, what emerged was a sputtering ember of the comet formerly known as ISON, which faded from view just as it was slated to reenter the dawn sky.

Hey, we were crestfallen as well… we had our semi-secret dark sky site pre-selected for ISON imaging post-perihelion and everything. Despite heroic searches by ground and space-based assets, we’ve yet to see any compelling recoveries of Comet ISON post-perihelion.

This week, however, Comet ISON may put on its last hurrah, in the form of a minor meteor shower. We have to say from the outset that we’re highly skeptical that an “ISON-id meteor outburst” will grace the skies. Known annual showers are fickle enough, and it’s nearly impossible to predict just what might happen during a meteor shower with no past track record.

But you won’t see anything if you don’t try. If anything is set to occur, the night of January 15th into the 16th might just be the time to watch. This is because the Earth will cross the orbital plane of ISON’s path right around 9:00 PM EST/2:00 UT. Last year, ISON passed within 3.3 million kilometres of the Earth’s orbit on its inbound leg. Earlier last year, ISON was estimated to have been generating a prodigious amount of dust, at a rate of about 51,000 kilograms per minute. Any would-be fragments of ISON outbound would’ve passed closest to the Earth at 64 million kilometres distant on the day after Christmas last year. Veteran sky observer Bob King wrote about the prospects for catching ISON one last time during this month back in December 2013.

Credit: NASA/JPL Solar System Dynamics Small Body Database Browser.
A simulation showing Earth crossing the plane of Comet ISON’s orbit early on January 16th. Credit: NASA/JPL Solar System Dynamics Small Body Database Browser.

Another idea out there that is even more unlikely is the proposal that dust from Comet ISON may generate an uptick in noctilucent cloud activity. And already, a brief search of the internet sees local news reports attempting to tie every meteor observed to ISON this week, though no conclusive link to any observed fireball has been made.

The radiant to watch for any possible “ISON-ids” sits near the +3.5 magnitude star Eta Leonis in the sickle of Leo. Robert Lundsford of the American Meteor Society notes in a recent posting that any ISON-related meteors would pass through our atmosphere at a moderate 51 kilometres a second, with a visible duration of less than one second.

Note that meteor activity has another strike against it, as the Moon reaches Full on the same night. In fact, the Full Moon of Wednesday January 15th sits in the constellation Gemini,just 32 degrees away from the suspect radiant!

Another caveat is in order for any remaining dooms-dayers: no substantial fragments of ISON are (or ever were) inbound and headed towards our fair planet. Yes, we’re seeing rumblings to this effect in the pseudoscience netherworlds of ye ole Internet, along with ideas that ISON secretly survived, NASA “hid” ISON, ISON cloaked like a Romulan Bird of Prey, you name it. Just dust grains, folks… a good show perhaps, but nothing more.

As near as we can tell, talk of a possible meteor shower generated from Comet ISON goes all the way back to a NASA Science News article online from April 2013. Radio observers of meteor showers should be alert for a possible surge in activity this week as well, and it may be the case that more radio “pings” will be noted than visual activity what with the light-polluting Full Moon in the sky. The radiant for any would-be “ISON-ids” transits highest in the sky for northern hemisphere observers at around 2 AM local.

But despite what it has going against it, we’d be thrilled if ISON put on one last show anyhow. It’s always worth watching for meteor activity and noting the magnitude and from whence the meteor came to perhaps note the pedigree as to the shower it might belong to.

The next annual dependable meteor shower won’t be until the night of April 21st to the 22nd, when the Spring Lyrids are once again active. And this year may just offer a special treat on May 24th, when researchers have predicted that the Earth may encounter debris streams laid down by Comet 209P LINEAR way back in 1803 and 1924… Camelopardalids, anyone? Now, that’s an exotic name for a meteor shower that we’d love to see trending!

-Catch sight of any “ISON-ids?” we’d love to see ‘em… be sure to post said pics at Universe Today’s Flickr pool.

 

 

See the Smallest Full Moon of 2014: It’s the “Return of the Mini-Moon”

Last month's rising "Mini-Moon" of 2013. (Photo by Author)

 Last month, (and last year) we wrote about the visually smallest Full Moon of 2013. Now, in a followup  act, our natural satellite gives  us an even more dramatic lesson in celestial mechanics with an encore performance just one lunation later with the smallest Full Moon of 2014.

We’ve noted the advent of the yearly Mini-Moon, a bizzaro twin to the often over-hyped “SuperMoon,” or Proxigean Full Moon. Occurring approximately six months apart, you can always expect lunar apogee to roughly coincide with the instant of a Full Moon about half a year after it coincides with perigee. In fact, the familiar synodic period that it takes the Moon to return to like phase (such as Full back to Full) of 29.5 days has a lesser known relative known as the anomalistic month, which is the period of time it takes the Moon to return to perigee at 27.55 days.

But the circumstances for “Mini-Moon 2014” are exceptional. The first Full Moon of the year occurs on the night of January 15th at 11:52 PM EST/4:52 Universal Time (on January 16th). This is just 2 hours and 59 minutes after the Moon reaches apogee at 406,536 kilometres distant at 8:53 PM EST/1:53 UT. This isn’t the farthest apogee that occurs in 2014, but it’s close: the Moon is just 32 kilometres more distant on July 28th, 2014. Apogee can vary from 404,000 to 406,700 kilometres, and this month’s apogee falls just 164 kilometres short of the maximum value.

As you can see, this year’s Mini-Moon falls extremely close to apogee… in fact, you have to go all the way back to the Full Moon of November 18th, 1994 to find a closer occurrence, and this year’s won’t be topped until May 13th, 2052! The Moon will appear only 29’ 23” in size on Wednesday night at moonrise, very close to its minimum possible value of 29’ 18”. This is also almost 5 arc minutes smaller than the largest “Super-Moon” possible.

Cool factoid: you actually move closer to the Moon as it rises, until it transits your local meridian and you begin moving away from it, all due to the Earth’s rotation. You can thus gain and lose a maximum of one Earth radii distance from the Moon in the span one night.

We also just passed the most northern Moon of 2014, as it reached a declination of 19 degrees 24’ north this morning at 8:00 UT/3:00 AM EST. This is a far cry from the maximum that can occur, at just over 28 degrees north. This is because we’re headed towards a “shallow year” as the Moon’s motion bottoms out relative to the ecliptic in 2015 and once again begins to widen out in its 18+ year cycle to its maximum in 2024-25.

The position of the Moon Monday night on January 13th in Orion. Credit: Stellarium
The position of the Moon Monday night on January 13th in Orion. Credit: Stellarium

This week’s Moon also visits some interesting celestial targets as well. The waxing gibbous Moon sits just 5.1 degrees south of the open cluster M35 tonight. Notice something odd about the Moon’s position Monday night? That’s because it is passing through Orion the Hunter, one of the six non-zodiacal constellations that it can be found in. Can you name the other five? Hint: one was the “13th sign of the zodiac that created a non-traversy a few years back.

On Tuesday evening, the Moon passes six degrees from the planet Jupiter. This presents a fine time to try and spot the planet in the daytime to the Moon’s upper left, just a few hours prior to sunset.

The Moon will also occult the +3.6 magnitude star Lambda Geminorum on January 15th for observers in northwestern North America. In fact, viewers along a line crossing central British Columbia will witness a spectacular graze along the lunar limb as the star winks out behind lunar mountains and pops into view as it shines through lunar valleys along the edge of the Moon. This can make for an amazing video capture, we’re just throwing that out there…

The occultation footprint for Lambda Geminorum for January 15th. (Created using Occult 4.01 software)
The occultation footprint for Lambda Geminorum for January 15th. (Created using Occult 4.10.11 software)

In addition to being this year’s Mini-Moon, the January Full Moon is also known as the Wolf Moon in the tradition of the Algonquin Native Americans, as January was a time of the mid-winter season when starving wolf packs would howl through the long cold night. The January Full Moon is also sometimes referred to as “The Moon after Yule,” marking the first Full Moon after Christmas.

And just when is the next Super Moon, you might ask? Well, 2014 has three Full Moons occurring within 24 hours of perigee starting on July 15th and finishing up on September 8th. But the most notable is on August 10th, when the Moon passes perigee just 27 minutes from Full. Expect it to be preceded by the usual lunacy that surrounds each annual “Super Moon” as we once again bravely battle the forces of woo and describe just exactly what a perigee Full Moon isn’t capable of. Yes, we still prefer the quixotic term “Proxigean Moon,” but there you go.

Also, be sure to wave a China’s Chang’e-3 lander and rover in the Bay of Rainbows (Sinus Iridum) as you check out this week’s Full Moon, as it just experienced its first lunar sunrise this past week.

Be sure to send those Mini-Moon pics and more in to Universe Today, and let’s get this week’s #MiniMoon trending on Twitter!