Catch ‘The Great American Occultation’ of Aldebaran Saturday Night

The Moon nearing Aldebaran on February 5th, 2017. Image credit and copyright: Chris Lyons.
The Moon nearing Aldebaran on February 5th, 2017. Image credit and copyright: Chris Lyons.

Ever watch the Moon cover up a star? There’s a great chance to see just such an event this coming weekend, when the waxing gibbous Moon occults (passes in front of)  the bright star Aldebaran for much of North America on Saturday night, March 4th.

Shining at magnitude +0.85, Aldebaran is the brightest star that lies along the Moon’s path in the current epoch, and is one of four +1st magnitude stars that the Moon can occult. The other three are Regulus, Antares and Spica. This is the 29th in a series of 49 occultations of Aldebaran worldwide spanning from January 29th, 2015 to September 3rd, 2018, meaning Aldebaran hides behind the Moon once every lunation as it crosses through the constellation Taurus and the Hyades open star cluster in 2017. Like eclipses belonging to the same saros cycle, successive occultations of bright stars shift westward by about 120 degrees westward longitude and slowly drift to the north. Europe saw last month’s occultation of Aldebaran, and Asia is up next month on April 1st.

The occultation footprint for Saturday night’s event. Credit: Occult 4.2 software.

All of the contiguous ‘lower 48 states’ except northern New England see Saturday night’s occultation, and under dark skies, to boot. It’s a close miss for Canada. Mexico, central America and the Caribbean will also witness the event under dark skies. Hawaii will see the event under daytime skies. We can attest that this is indeed possible using binocs or a telescope, as we caught Aldebaran near the daytime Moon during last month’s event.

Occultations give us a chance to see a split second magic act, in a Universe that often unfolds over eons and epochs. The motion you’re seeing is mostly that of the Moon, and to a lesser extent, that of the Earth as the star abruptly ‘winks out’.

Observers in northern tier states might witness an additional spectacle, as Aldebaran grazes the northern limb of the Moon. This can make for an unforgettable sight, as the star successively winks in at out from behind lunar peaks and valleys. The graze line for Saturday night follows the U.S./Canadian border from Washington state, Idaho and Montana, then transects North Dakota, Minnesota just below Duluth and northern Wisconsin, Michigan and New York and Connecticut. Brad Timerson over at the international Occultation Timing Association has a good page set up for the circumstances for the grazing event, and the IOTA has a page detailing ingress (start) and egress times for the event for specific cities.

The northern limit grazeline for Saturday night’s occultation. Credit: USAF/Wikimedia Commons/Dave Dickinson

You’ll be able to see the occultation of Aldebaran with the unaided eye, no telescope over binocular needed, though it will be fun to follow along with optics as well. The ingress along the leading dark limb of the Moon is always more dramatic, while reemergence on the bright limb is a more subtle affair.

The path of the occultation for select cities. Credit: Stellarium.

A simple video aimed afocally through a telescope eyepiece can easily capture the event. We like to run WWV radio on AM shortwave in the background while video recording so as to get a good time hack of the event on audio. Finally, set up early, watch those battery levels in the frigid March night, and be sure to balance out your exposure times to capture both Aldebaran and the dazzling limb of the Moon.

Can you see it? The Moon paired with Aldebaran on February 5th. Image credit and copyright: Lucca Ruggiero.

Anyone Live-casting the event? It’ll be a tough one low to the horizon here in central Florida, but a livestream would certainly be possible for folks westward with Aldebaran and the Moon high in the sky. Let us know of any planned webcasts, and we’ll promote accordingly.

The Moon also occults several other bright stars this week, leading up to an occultation of Regulus on March 10th favoring the southern Atlantic. Read all about occultations, eclipses, comets and more in our free e-book, 101 Astronomical Events for 2017 from Universe Today.

Don’t miss Saturday night’s stunning occultation, and let us know of your tales of astronomical tribulation and triumph.

-Send those astro-images in to Universe Today’s Flickr forum, and you might just see ’em featured here in a future article.

Join the Eclipse MegaMovie 2017 Chronicling the August Total Solar Eclipse

Eclipse Diamond Ring
The November 2012 total solar eclipse as seen from Australia. Image credit and copyright: Alan Dyer.
Eclipse Diamond Ring
The November 2012 total solar eclipse as seen from Australia. The Eclipse Megamovie project hopes to capture a similar extended view. Image credit and copyright: Alan Dyer/Amazing Sky Photography.

Ready for the “Great American Eclipse?” We’re now less than six months out from the long-anticipated total solar eclipse spanning the contiguous United States from coast-to-coast. And while folks are scrambling to make last minute plans to stand in the path of totality on Monday, August 21st 2017, a unique project named the Eclipse Megamovie 2017 seeks seeks to document the view across the entire path.

The Project: Sponsored by Google’s Making & Science Initiative and led by Scott McIntosh from the National Center for Atmospheric Research’s High Altitude Observatory and Hugh Hudson from the University of California at Berkeley, the Eclipse Megamovie Project seeks to recruit 1,500 observers stationed across the eclipse path from Oregon to South Carolina. Although individual observers will only experience a maximum totality length of 2 minutes and 40 seconds, the complete span of the Eclipse Megamovie will last 90 minutes, compiled using observer images from coast-to-coast.

Mega movie
Getting ready for the Eclipse Megamovie project. Credit: Eclipse Megamovie Project.

“The movie is a tool for scientific exploration,” Hudson said in a recent University of California at Berkeley press release. “We’ll be collecting this level of data for the first time, from millions of observers, and it will be a valuable archive. But we don’t know what we’ll see or what we’ll learn about the interactions between the chromosphere and the corona.”

One portion of the project will have trained volunteers image the Sun from along the eclipse path using DSLRs, while another portion of the project will feature smartphone users imaging totality using a forthcoming Eclipse Megamovie app for a full length lower resolution movie.

Bikers and Baily’s Beads

The only total solar eclipse for 2017, totality for this eclipse occurs along a 114 kilometer-wide path touching on 12 states. Millions live within an easy day drive of the eclipse path, so expect lots of general public interest leading up to eclipse day. August is RV and camping season, so expect camplots to fill up quickly as well. The eclipse also occurs just over a week after the annual Biker’s Rally in Sturgis, South Dakota, affording motorcyclists a chance to stand in the shadow of the Moon en route to the annual pilgrimage.

Great American Eclipse
The path of the August 21st, 2017 eclipse across the United States. Credit: Michael Zeiler/Eclipse-Maps.

The last total solar eclipse to cross one of the 50 United States graced Hawaii on July 11th, 1991, and the last time the umbra of the Moon touched down over the lower 48 states was on February 26th, 1979 across the United States northwest. But you have to go all the way back over almost a century ago to June 8th, 1918 to find an eclipse featuring totality which exclusively spanned the United States from sea to shining sea.

Observers have chased after the umbra seeking to extend fleeting totality before. Eclipse chasers documented the January 24th, 1925 eclipse from aloft aboard a dirigible over New York City. On June 30th, 1973, a supersonic Concorde flight chased the umbra of the Moon across northern Africa, extending totality out to 74 minutes.

The team was also on hand to perform a dry run test of the Megamovie Project at this past weekend’s annular eclipse which crossed South America, the Southern Atlantic and Africa and reports that the field test of the promised project app by Mark Bender worked admirably, and the Eclipse Megamovie App should be available to the general public soon.

Baily's Beads
A mosaic of the 2016 total solar eclipse, depicting the evolution of Baily’s Beads before and after totality. Image credit and copyright: Steed Joy.

What sort of science can such a project offer? What is left to learn from a total solar eclipse after centuries of scientific study? Well, some of the most accurate measurements of the solar diameter and the size and shape of the Sun have been made during solar eclipses. A long movie may also reveal streamers and development of the solar corona, the ethereal pearly white glowing outer atmosphere surrounding the Sun. About half as bright as a Full Moon, we only get a brief glimpse of the corona during totality. Also, the Eclipse Megamovie will get another shot at the project in April 2024, when another eclipse crosses the United States from Texas to Maine.

The Eclipse Megamovie is taking volunteers now. The gear setup required is simple, and you might have what’s needed to image the eclipse laying around already.

DSLR
Got a tripod-mounted, zoom lens equipped DSLR? Photo by author.

You’ll need a DSLR camera with a sturdy tripod, a zoom or fixed lens of 300mm focal length or better, and an ability to nail down your GPS location and the time to the nearest second. Once the volunteers are selected, training will be provided to include GPS and time stamping images, flat-fielding and more.

Phone apps will readily supply the GPS part. For time, I’d go with with WWV Radio, which broadcasts a continuous audio time hack out of Fort Collins, Colorado. This is in Universal Time, and has an accuracy of better than a second better than online time sources, which occasionally lag due to spurious web connections.

Keep in mind, you’ll be photographing the eclipsed Sun during very brief moments of totality. You’ll need to have approved solar glasses and filters in place during all partial phases leading up to and immediately after the eclipse. The Eclipse Megamovie project also hopes to catch sight of the Bailey’s Beads phenomenon as final streamers of sunlight pour through the lunar valleys, giving the illusion known as the Diamond Ring effect.

TSE2017
An animation of the August 21st, 2017 total solar eclipse. A.T. Sinclair/NASA/GSFC

And us? We’ll be casting our hubris at the Universe and catch the eclipse from Columbia, South Carolina. We’re heeding the advice of veteran eclipse chasers, and simply enjoying our first eclipse, and imaging our second, though we may sneak in a few shots for the Eclipse Megamovie project. Universe Today publisher Fraser Cain and astronomer and AstronomyCast host Pamela Gay will lead a group watching from southern Illinois, and we’ve also heard from many other observers from around the world who’ll be visiting the U.S. the August… where will you be?

And we’ve already got a spot picked out for 2024, as the next total solar eclipse crosses Aroostook County and our hometown of Mapleton, Maine… hey, you can never start planning too early, right?

Get set for an eclipse for the ages, and be sure to contribute to the Eclipse Megamovie Project.

-Read about all eclipses, comets, occultations and more for the year in our guide to 101 Astronomical Events for 2017, free from Universe Today.

-Eclipse… science fiction? Check out our original eclipse-fueled sci-fi tales Exeligmos, Shadowfall, the Syzygy Gambit, Peak Season and more.

Ring of Fire: Catch the Only Annular Solar Eclipse of 2017 This Sunday

annular eclipse
The May 2012 annular eclipse. Image credit and copyright: Kevin Baird.
annular eclipse
The May 2012 annular solar eclipse. Image credit and copyright: Kevin Baird.

‘Tis the season… eclipse season that is, as a spectacular “ring of fire” annular solar eclipse marks the end of the first of two eclipse cycles for 2017. And although the annular path for this eclipse passes through some sparsely populated parts of the southern hemisphere, we just might get some amazing live views, courtesy of modern technology and some intrepid observers willing to adventurously trek after the shadow of the Moon.

Unlike many of the uncertainties in life, eclipses are sure to happen, a certainty ordained by orbital mechanics. Well, okay, the Vogons could always blow the Moon to smithereens this fine Thursday afternoon… but otherwise, we’re in for a true celestial show.

Eclipse circumstances: Prospects and prognostications.

The eclipse begins far out in the South Pacific at sunrise, and the path of annularity makes first landfall along the southern coast of Chile at 13:31 Universal Time (UT). The eclipse antumbra then races eastward over Argentina at 2.5 kilometers per second, as the “ring of fire” heads out over the South Atlantic where it reaches “maximum annularity” of just 44 seconds 900 kilometers southeast of Brazil. Finally, the 30 kilometer wide path touches down over Angola, nicks Zambia and ends at sunset over a southern track along the Democratic Republic of the Congo. The eclipse is partial across southern portion of South America, the Falkland Islands a swath of Antarctica and southwestern Africa.

2017 Annular Eclipse
The aspects of the February 26th, 2017 annular eclipse. Credit: F.Espenak/NASA/GSFC

Here are the partial prospects for select cities:

City – Maximum obscuration – Time

La Paz, Bolivia – 5% – 13:37 UT

Buenos Aires – 67% – 13:53 UT

The Falkland Islands – 71% – 13:56 UT

Palmer Station, Antarctica – 31% – 14:01 UT

Cape Town, South Africa – 41% – 15:59 UT

Luanda, Angola – 83% – 16:32 UT

eclipse animation
An animation of Sunday’s eclipse. Credit: NASA/GSFC/A.T. Sinclair

Annular vs. Total

Sunday’s eclipse is the first of two solar eclipses for 2017, and the only annular eclipse for the year. We get an annular eclipse when the Moon is near apogee (which occurred eight days ago on February 18th) and the Earth is near perihelion (which occurred last month on January 4th). At this time, the apparent size of the Moon is too small to cover the Sun as seen from the Earth, resulting instead in a brilliant annulus or “ring of fire” in the sky. Likewise, we refer to the shadow trace of this ring across the Earth as an antumbra, instead of the familiar umbra of a total solar eclipse.

Strange as it may seem, annular eclipses are slightly more common than total solar eclipses in our current epoch, and will become increasingly more so as the Moon slowly recedes from the Earth.

annular eclipse
The alignment needed for an annular eclipse. Credit: The National Observatory of Japan.

Observing and Eclipse Safety

Unlike a total solar eclipse, safety precautions must be taken during all phases of an annular solar eclipse. We witnessed the 1994 annular eclipse from the shores of Lake Erie, and can attest that 1% of the Sun is still pretty darn bright. Use only telescope and camera filters or glasses designed specifically for solar observing, even during the annular phase. Venus should also be a splendid sight for those observing near sunset from Africa, as the Cytherian world shines at -4.3 magnitude 34 degrees east of the Sun. Viewers in southwestern African nations will also be treated to a setting Sun during the eclipse, affording the chance to include the spectacle in shots along with foreground objects on the local horizon if skies are clear.

Sun Venus Annular
The eclipse versus Venus as seen from the path through Angola. Credit: Stellarium.

Clouded out? Live on the wrong part of the planet? There are actually several options to watch the eclipse live:

the venerable SLOOH plans to webcast the eclipse.

Time and Date will provide a webcast starting at 12:05 UT from Angola:

Watch this space: we’ll be dropping in more live webcasts of the eclipse as they turn up.

Update: VTR Chile may provide a live broadcast come eclipse time.

Plan on doing an ad hoc webcast of Sunday’s eclipse from anywhere along the annular or partial track? Let us know!

Sunspot activity is currently at a lull, and the Earthward face of Sol may well be blank come eclipse day. At an eclipse magnitude of 99.22%, this eclipse juuuusst misses being a hybrid/total. It’s also possible to catch the brief flashes of Bailey’s Beads along the edge of the antumbral graze line.

Tales of the Saros

This eclipse is member 29 of 71 for saros cycle 140, stretching all the way back to April 16th, 1512 and running out to June 1st, 2774. If you caught the February 16th, 1999 annular eclipse from the Australian Outback, then you witnessed the last eclipse in saros 140. Stick around until March 9th, 2035 and you can then complete an exeligmos or triple saros cycle, joining an elite club of eclipse-chasing adventurers, indeed.

Eclipses occur in pairs or sometimes triplets, when the nodes where the Moon’s orbit intersect the position of the Sun and the Earth’s shadow along the ecliptic plane. These nodes move due to orbital precession of the Moon’s path around the Earth. If the Moon weren’t inclined relative to the ecliptic, we’d see a lunar and solar eclipse every synodic month. The February 11th penumbral eclipse ushered in the current eclipse season, which ends with this weekend’s annular eclipse.

penumbral
The penumbral eclipse from earlier this month, ushering in eclipse season 1 of 2 for 2017. Credit and Copyright: Rob Sparks.

ISS and Views from Space (-ace -ace) Prospects

There is an ISS transit over SW Africa at around 15:45 UT, offering a chance to catch a transit of the station across the partially eclipsed Sun. Sun observing spacecraft in low Earth orbit including Hinode and Proba-2 also usually get good views of the eclipse.

New Moon sightings: And for the rest of the world, the hunt will be on to recover the slim waxing crescent Moon post-eclipse on the evening of Monday, February 27th. This lunation, first sighting opportunity without optical assistance favors southeast Asia.

Then, its on to eclipse season number two, featuring a partial lunar eclipse on August 7th, and then the big ticket event: the total eclipse of the Sun spanning the contiguous United States from coast to coast. Umbraphiles have been planning for this one and its brief 160 seconds maximum of totality for well over a decade now, no lie. Where will YOU be?

-Send those eclipse pics in to Universe Today Flickr.

-Read more about eclipses, occultations, comets and more for the year in our free e-book: 101 Astronomical Events for 2017.

-Eclipse science fiction? Read our original sci-fi tales Exeligmos, The Syzygy Gambit, Peak Season and more.

Watch the Moon Make a Pass at Earth’s Shadow, Then Kiss Regulus This Valentine’s Weekend

Regulus Occultion
The Moon occults Regulus of January 15th, 2017. Image credit and copyright: Lucca Ruggiero
Regulus Occultion
The Moon occults Regulus of January 15th, 2017. Image credit and copyright: Lucca Ruggiero

In the southern hemisphere this weekend in the ‘Land of Oz?’ Are you missing out on the passage of Comet 45/P Honda-Mrkos-Pajdušáková, and the penumbral lunar eclipse? Fear not, there’s an astronomical event designed just for you, as the Moon occults (passes in front of) the bright star Regulus on the evening of Saturday, January 11th.

The entire event is custom made for the continent of Australia and New Zealand, occurring under dark skies. Now for the bad news: the waning gibbous Moon will be less than 14 hours past Full during the event, meaning that the ingress (disappearance) of Regulus will occur along its bright leading limb and egress (reappearance) will occur on the dark limb. We prefer occultations during waxing phase, as the star winks out on the dark limb and seems to slowly fade back in on the bright limb.

The footprint for the February 11th occultation of Regulus by the Moon. Image credit: Occult 4.2 software

The International Occultation Timing Association has a complete list of precise ingress/egress times for cities located across the continent. An especially interesting region to catch the event lies along the northern graze line across the sparsely populated Cape York peninsula, just north of Cairns.

The northern grazeline for the February 11th occultation of Regulus by the Moon. Graphic by author.

The Moon occults Aldebaran and then Regulus six days later during every lunation in 2017. This is occultation number three in a cycle of 19 running from December 18, 2016 to April 24, 2018. The Moon occults Regulus 214 times in the 21st century, and Regulus is currently the closest bright star to the ecliptic plane, just 27′ away.

We’ve also got a very special event just under 14 hours prior, as a penumbral lunar eclipse occurs, visible on all continents… except Australia. Mid-eclipse occurs at 00:45 Universal Time (UT, Saturday morning on February 11th), or 7:45 PM Eastern Standard Time (EST) on the evening of Friday, February 10th, when observers may note a dusky shading on the northern limb of the Moon as the Moon just misses passing through the dark edge of the Earth’s inner umbral shadow. Regulus will sit less than seven degrees off of the lunar limb at mid-eclipse Friday night.

How often does an eclipsed Moon occult a bright star? Well, stick around until over four centuries from now on February 22nd, 2445, and observers based around the Indian Ocean region can watch just such an event, as the eclipsed Moon also occults Regulus. Let’s see, I should have my consciousness downloaded into my second android body by then…

A graphic study of the simultaneous lunar eclipse and occultation of Regulus in 2445. Credit: NASA/GSFC/Fred Espenak/Occult 4.2/Stellarium.

We’ll be streaming the Friday night eclipse live from Astroguyz HQ here in Spring Hill, Florida starting at 7:30 PM EST/00:30 UT, wifi-willing. Astronomer Gianluca Masi of the Virtual Telescope Project will also carry the eclipse live starting at 22:15 UT on the night of Friday, February 10th.

This eclipse also marks the start of eclipse season one of two, which climaxes with an annular eclipse crossing southern Africa and South America on February 26th. The second and final eclipse season of 2017 starts with a partial lunar eclipse on August 7th, which sets us up for the Great American Eclipse crossing the United States from coast to coast on August 21st, 2017.

A lunar occultation of Regulus also provides a shot at a unique scientific opportunity. Spectroscopic measurements suggest that the primary main sequence star possesses a small white dwarf companion, a partner which has never been directly observed. This unseen white dwarf may – depending on the unknown orientation of its orbit – make a brief appearance during ingress or egress for a fleeting split second, when the dark limb of the Moon has covered dazzling Regulus. High speed video might just nab a double step occlusion, as the white dwarf companion is probably about 10,000 times fainter than Regulus at magnitude +11 at the very brightest. Regulus is located 79 light years distant.

Our best results for capturing an occultation of a star or planet by the Moon have always been with a video camera aimed straight through our 8” Schmidt-Cassegrain telescope. The trick is always to keep the star visible in the frame near the brilliant Full Moon. Cropping the Moon out of the field as much as possible can help somewhat. Set up early, to work the bugs out of focusing, alignment, etc. We also run WWV radio in the background for an audible time hack on the video.

The January 15th, 2017 occultation of Regulus by the Moon. Image credit and copyright: Lucca Ruggiero.

The best occultation of Regulus by the Moon for North America in 2017 occurs on October 15th, when the Moon is at waning crescent phase. Unfortunately, the occultation of Regulus by asteroid 163 Erigone back in 2014 was clouded out, though the planet Venus occults the star on October 1st, 2044. Let’s see, by then I’ll be…

Comets and eclipses and occultations, oh my. It’s a busy weekend for observational astronomy, for sure. Consider it an early Valentine’s Day weekend gift from the Universe.

Webcasting the eclipse or the occultation this weekend? Let us know, and send those images of either event to Universe Today’s Flickr forum.

Read about eclipses, occultations and more tales of astronomy in our yearly guide 101 Astronomical Events For 2017, free from Universe Today.

Watch Comet 45P Honda-Mrkos-Pajdušáková Fly Past Earth This Week

A recent image of Comet 45P from February 4th. Image credit and copyright: Hisayoshi Kato.
A recent image of Comet 45P from February 4th. Image credit and copyright: Hisayoshi Kato.

Hankering for some cometary action? An interplanetary interloper pays us a visit this weekend, sliding swiftly through the pre-dawn northern hemisphere sky.

If you’ve never caught sight of periodic comet 45/P Honda-Mrkos-Pajdušáková, this week is a good time to try. Currently shining at magnitude +6.5, the comet makes a close 0.08 AU (7.4 million miles or 12.3 million kilometers) pass near the Earth on Saturday, February 11, at 14:44 Universal Time (UT) or 9:44 AM Eastern Standard Time. This is the closest passage of the comet for the remainder of this century, and with the Moon also reaching Full this weekend, the time to track down this comet is now.

The path of Comet 45/P through Monday, February 13th. Credit: Starry Night Edu.

We wrote about the first act for this comet last December, and Bob King also wrote up a preview last month. The comet passed perihelion 0.53 AU (49.3 million miles/ 82.1 million kilometers) from the Sun on New Year’s Eve 2016, reemerging into the dawn sky. It’s now on a swift sprint through the constellation Ophiuchus, and will cross Hercules at closest approach and into Corona Borealis and Boötes in just one week. At its closest, it’ll be moving at a whooping 23 arc minutes per hour, about three-quarters the diameter of a Full Moon!

The position of Comet 45/P as seen from latitude 30 degrees north at 4 AM. Credit: Stellarium.

At closest approach, the comet may just top naked eye brightness under dark skies at +6 magnitude.

Independently discovered by three observers worldwide in late 1948, Comet 45/P Honda-Mrkos-Pajdušáková orbits the Sun once every 5.25 years. The cumbersome name is often abbreviated as “Comet 45P HMP” or sometimes simply “Comet 45P.” The comet actually passed close enough back in 2011 for Arecibo radar to ping it, one of the very few comets to do so.

Not all apparitions of a given comet are equal, and most passages of Comet 45P were and will be uneventful. Dr. P. Clay Sharrod of the Arkansas Sky Observatory recently wrote a great account of the 1974 passage of Comet 45P, hearkening back to the same year when we were all awaiting Comet Kohoutek and Comet West was yet to come. This account might also hint at what could be in store for comet hunters this weekend.

A sketch of Comet 45P from December 10th, 1974. Image credit and copyright: Dr P. Clay Sherrod.

We managed to nab Comet 45P for the first time this AM from central Florida, though its still a tough catch. Shining at magnitude +7.5, we wouldn’t have otherwise noticed it as we swept along with our trusty Canon 15×45 image-stabilized binocs. Star-hopping finally brought us to the comet, a little fuzzy ‘star’ that stubbornly refused to snap into focus.

Comet 45P from early January, post-perihelion. Image credit and copyright: Sharin Ahmad (@shahgazer).

Unfortunately, the Moon reaches Full on Friday night, entering into the dawn sky this weekend. I’d advise hunting for the comet on every clear morning leading up to this weekend as the comet vaults northward into the pre-dawn sky. Friday night’s subtle penumbral eclipse won’t help much by way of dimming the Moon, though you can always place a house or hill between yourself and the Moon in a bid to block it out and aid in your cometary quest. There’s also a great photo op on February 16, when Comet 45P passes less than three degrees from the globular cluster M3.

As close shaves go, this passage of Comet 45P ranks as the 21st closest recorded passage of a comet near the Earth. The record goes to Comet Lexell, which passed just 0.0151 AU (1.4 million miles, or just under six times the distance to the Moon) past the Earth on July 1st, 1770. At its closest, Lexell had a visible coma spanning more than two degrees, more than four times the diameter of a Full Moon. In recent times, the last close passage of a comet other than 45P was Comet IRAS-Araki-Alcock, which zipped 0.063 AU past the Earth on June 12, 1983.

Ah, those were the days… a depiction of the Great Comet of 1769 as seen from Amsterdam, just one year (!) prior to the passage of Lexell’s Comet. Image in the Public Domain.

The gambler’s fallacy would say we’re due for the next big bright comet, though the universe seems to stubbornly refuse to roll the dice. In addition to 45P, 2017 does host a string of binocular comets, including Comet 2P Encke (March), Comet 41P/Tuttle-Giacobini-Kresák (April), Comet C/2015 ER61 PanSTARRS (May), and Comet C/2015 V2 Johnson (June). These are all explored in detail in our free e-book guide to the year, 101 Astronomical Events for 2017 out from Universe Today.

Stay warm on your comet vigil, and let us know of those observational tales of tribulation and triumph.

Ancient Annular: Dating Joshua’s Eclipse

Annular Eclipse
The May 2012 annular eclipse low to the horizon. Image credit and copyright: Jared Bowens.
Annular Eclipse
The May 2012 annular eclipse low to the horizon. Image credit and copyright: Jared Bowens.

Astronomy turns up in fascinating junctures in history. Besides just the romantic angle, we can actually pin down contextual events in ancient history if we can tie them in with a spectacle witnessed in the heavens. A recent look at the story of ‘Joshua’s eclipse’ is one such possible tale.

Lunar and solar eclipses are especially dramatic events, something that would have really made the ancients stop and take notice. A recent study published in an edition of the Beit Mikra Journal (in Hebrew) by researchers from Ben Gurion University may have pinpointed a keypoint in biblical history: the date of the Battle of Gibeon.

This study first came to our attention via the Yahoo! SEML eclipse message board and a recent Times of Israel article. The article makes mention of NASA eclipse data, which is free for anyone to peruse looking over the five millennium canon of solar and lunar eclipses… hey, it’s what we do for fun.

We did obtain a look at a translation of the abstract from the paper, which ends with the following:

“In the period between 1500-1000 BCE which is the relevant time for the biblical story, there were only three eclipses seen from Jerusalem, one total eclipse and two annular eclipses. We show that the most appropriate one is the annular solar eclipse that occurred on October 30 in 1206 BCE at sunset, an appropriate date for the time of conquest and the early settlement period, at the time of Marneptah’ rule in Egypt.”

The path of the eclipse of October 30th, 1206 BC. Credit: NASA/GSFC/Espenak/Meeus.

Joshua 10:12 reads: “Sun, stand still upon Gibeon; and you, Moon, in the valley of Ayalon.”

According to tradition, Joshua commanded the Sun to stand still long enough to defeat the Canaanite kings. Of course, the Sun and the Moon still move during an eclipse be it lunar or solar, though its mostly our planet that’s doing the moving. Still, the actual biblical term “-dom” is open to interpretation, and the researchers chose the Hebrew “to become dark” instead of the King James translation of “to stand still,” or “stationary”.

If this Bible verse sounds familiar, that’s because it turns up in astronomical history again in medieval Europe, when Church proponents used it as supposed proof of geocentricism.

Mid eclipse
Mid-eclipse over central Israel at sunset on October 30th, 1206 BC. Credit: Stellarium.

It’s tough to predict eclipses in distant time. The rotation of the Earth is not entirely smooth, and the minute change in the length of the day (known as Delta T) accumulates to the point that a leap second must be inserted on occasion to keep observed time in sync with reckoned terrestrial time. Braking action by the Sun and Moon, tectonic activity, and even global warming all cause small changes in the Earth’s rotation that slowly build up over time. This means that it’s tough to predict eclipses more than a few thousand years out, where at best we can only judge which continent they might have or will fall on.

“Not everyone likes the idea of using physics to prove things from the Bible,” said researcher Hezi Yitzhak to the Israeli news site Haaretz. “We do not claim that everything written in the Bible is true or took place… but there is also a grain of historical truth that has archaeological evidence behind it.”

The eclipse in question occurred on October 30th, 1206 BC. This was an annular eclipse, crossing the Atlantic and the Mediterranean and ending over Israel and Jordan at sunset. Researchers pegged this suspect eclipse because of its fit for historical context and visibility. Annularity for the eclipse was 86% obscuration and started at an altitude of nine degrees above the western horizon, and would have still been in progress during its final phases at sunset.

path
The end of the eclipse path over modern day Israel and Jordan. Credit: NASA/GSFC data.

Lots of eclipses turn up in history. A partial lunar eclipse preceded the fall of Constantinople in 1453, seeming to fulfill prophecy. Solar and lunar eclipses made a showing at lots of battles, including the Second Battle of Syracuse on August 28th, 412 BC and during the Zulu War on January 22nd, 1879. A solar eclipse on June 15th, 762 BC mentioned in Assyrian texts pinpoints a crucial time in ancient history, giving us a benchmark for later dates. It’s worth noting that prior to modern times, it seems that battles were the only thing worth writing down…

Still, it’s interesting to imagine the scene as ancient armies clash, only to stop and gaze at the wondrous sight on the horizon: a pair of glowing horns, hanging low in the pre-dusk sky. We caught the 1994 annular eclipse from the Sandusky, Ohio on the shores of Lake Erie and can attest that even a 98% eclipsed Sun is still pretty bright, giving even a clear day a deep steely blue tint. Lower to the horizon though, an annular eclipse is more readily visible to the unaided eye.

You have to be careful when attempting to read ancient texts as astronomical guide books. Great minds, including Kepler and Newton, expended lots of mental juice on attempting to link biblical accounts such as Ezekiel’s Wheel and the Star of Bethlehem with actual astronomical events. We’ll probably never know for sure if a coincidental conjunction graced the sky over the manger in Bethlehem, or if Ezekiel saw the breakup of a brilliant comet, but it’s always fun to imagine and wonder. Then, there’s the inevitable embellishment that accompanies stories that may have been first sparked by meteor showers or sundogs, centuries ago. We don’t, for example, see flaming swords or banners emblazoned with Latin inscriptions across the sky today, though if you can believe medieval accounts, they seemed common back in the day.

And don’t forget: we’ve got our very own history making eclipse (hopefully sans battlefields) this coming August 21st, 2017 crossing the United States from coast-to-coast.

Though far from conclusive, the results of the study concerning Joshua’s eclipse and the battle of Gideon are interesting to consider. Most likely we’ll never truly know what happened that ancient afternoon, unless, of course, we perfect time travel. What other events remain hidden and lost to time, ready for some historical astro-sleuth to uncover them?

-Can’t get enough of eclipses, historical or otherwise? Check out our original eclipse-fueled sci-fi tales Exeligmos, Peak Season and Class Field Trip.

Superbowl Smackdown: Watch the Moon Occult Aldebaran on Sunday

Daytime Aldebaran
Can you see it? Dave Walker accidentally (!) caught Aldebaran near the daytime Moon on October 19th, 2016. Image credit and copyright: Dave Walker
Daytime Aldebaran
Can you see it? Dave Walker accidentally (!) caught Aldebaran near the daytime Moon on October 19th, 2016. Image credit and copyright: Dave Walker

Author’s note: This Superbowl Sunday event and 101 more like it are featured in our latest free e-book, 101 Astronomical Events for 2017, out now from Universe Today.

Sure, this Superbowl Sunday brings with it the promise of sacks, fumbles and tackles… but have you ever seen the Moon run down a star in the end zone? Just such an event, referred to as an occultation, happens this weekend for folks living around the Mediterranean and — just maybe for some sharp-eyed, telescope-owning observers based around the Caribbean region — this coming weekend.

Update: be sure to watch this Sunday’s occultation of Aldebaran by the Moon courtesy of Gianluca Masi and the Virtual Telescope Project live starting at 22:00 UT/5:00 PM EST:

Live starting at 22:00 UT. Credit: The Virtual Telescope Project

We’re talking about Sunday’s occultation of the bright star Aldebaran by the 64% illuminated waxing gibbous Moon. This is the 2nd occultation of Aldebaran by the Moon for 2017 and the 28th of the current ongoing cycle of 49 spanning from January 29th, 2015 to September 3rd, 2018. The Moon actually occults Aldebaran and Regulus once for every lunation in 2017. We won’t have another year featuring the occultations of two +1st magnitude stars (Spica and Antares) again until 2024.

Occultation footprint
The footprint for the February 5th occultation of Aldebaran by the Moon. The broken lines show where the occultation occurs during daytime, and the solid lines denote where the occultation occurs under dark skies. Image credit: occult 4.2.

The event occurs under dark skies for observers based around the Mediterranean and under daytime afternoon skies for folks in central America, the Caribbean, northern South America and the Florida peninsula, including Astroguyz HQ based in Spring Hill, just north of the Tampa Bay area. We’ve managed to spy Aldebaran near the daytime Moon while the Sun was still above the horizon using binocs, and can attest that the +1st magnitude star is indeed visible, if you know exactly where to look for it.

Note that, like solar eclipses belonging to the same saros cycle, occultations of Aldebaran in the ongoing cycle drift north and westward from one to the next, to the tune of about 120 degrees longitude. Though most of North America sits this one out, we do get a front row seat for next lunation’s occultation of Aldebaran on the evening of March 4/5th. The next one is the best bright star occultation of Aldebaran by the Moon for North America in 2017. And be sure to check out the Moon this Sunday evening after the big game, and note Aldebaran hanging just off of its bright limb.

Moon motion
No, the wind is not shaking the ‘scope… Sharin Ahmad chronicled the motion of the Moon past Aldebaran from Kuala Lumpur, Malaysia last month. Image credit and copyright: Shahrin Ahmad (@shahgazer)

The ref will have a close call to make for this one. The northern grazeline in Florida might make this an especially interesting event to watch, though it’ll be challenge, as the occultation occurs in the afternoon under daylight skies. This crosses right along near the cities of Jacksonville and Gainsville. Clear, deep blue high contrast skies are key, and we’ll be watching from Astroguyz HQ north of Tampa Bay during this event.

The northern grazeline across the Florida peninsula for Sunday’s ‘big game’. Credit: Dave Dickinson.

Here are some key times from the occultation zone (noted in Universal Time):

Tampa, Florida

Ingress: 20:08 UT/Moon altitude: 23 degrees

Egress: 20:34 UT/Moon altitude: 29 degrees

Bogota, Columbia

Ingress: 19:34 UT/ Moon Altitude: 49 degrees

Egress: 20:29 UT/ Moon altitude: 31 degrees

The view from Jimena de la Frontera Spain just before the occultation. Credit: Stellarium.

Rome, Italy

Ingress: 20:21 UT/Moon altitude: 37 degrees

Egress: 23:12 UT/ Moon altitude: 28 degrees

Tel Aviv, Israel

Ingress: 22:39 UT/Moon altitude: 16 degrees

Egress: 23:29 UT/Moon altitude: 5 degrees

Casablanca, Morocco

Ingress: 21:49 UT/ Moon altitude: 61 degrees

Egress: 23:07 UT/ Moon altitude: 45 degrees

Note that this occultation spans five continents, a truly worldwide event. The International Occultation Timing Association (IOTA) maintains a page with an extensive list of times for cities worldwide. Note that when the Moon tackles Aldebaran, its also crossing the scrimmage line of the Hyades open cluster, so expect numerous occultations of fainter stars worldwide as well.

Aldebaran is the brightest star along the Moon’s path in our current epoch, along with runner-ups Spica, Regulus and Antares. Though Aldebaran is 1.5 times the mass of our Sun, it’s also 65 light years away, and only appears 20 milliarcseconds (mas) in size, about the equivalent of a 40 meter diameter crater from the distance of the Moon. Still, you might just notice a brief pause as Aldebaran fades then winks out on the dark limb of the Moon, a tiny hitch betraying its diminutive angular size.

And the clockwork gears of that biggest game of all, the Universe, grind on. Don’t miss this first big ticket astronomical event for February 2017, coming to a sky above you. Next up, we’ll watching out for another bright star occultation, two eclipses, and the close passage of a comet near the Earth.

Stay tuned!

A Farewell to Plutoshine

Credit:
Looking back at an overexposed Charon and Plutoshine. Credit: NASA/JPL/New Horizons

Sometimes, its not the eye candy aspect of the image, but what it represents. A recent image of Pluto’s large moon Charon courtesy of New Horizons depicting what could only be termed ‘Plutoshine’ caught our eye. Looking like something from the grainy era of the early Space Age, we see a crescent Charon, hanging against a starry background…

So what, you say? Sure, the historic July 14th , 2015 flyby of New Horizons past Pluto and friends delivered images with much more pop and aesthetic appeal. But look closely, and you’ll see something both alien and familiar, something that no human eye has ever witnessed, yet you can see next week.

We’re talking about the reflected ‘Plutoshine‘ on the dark limb of Charon. This over-exposed image was snapped from over 160,000 kilometers distant by New Horizons’ Ralph/Multispectral imager looking back at Charon, post flyby. For context, that’s just shy of half the distance between the Earth and the Moon. “Bigger than Texas” (Cue Armageddon), Charon is about 1200 kilometers in diameter and 1/8th the mass of Pluto. Together, both form the only true binary (dwarf) planetary pair in the solar system, with the 1/80th Earth-Moon pair coming in at a very distant second.

Earthshine on the Moon. Credit: Dave Dickinson

We see reflected sunlight coming off of a gibbous Pluto which is just out of frame, light that left the Sun 4 hours ago and took less than a second to make the final Pluto-Charon-New Horizons bounce. You can see a similar phenomenon next week, as Earthshine or Ashen Light illuminates the otherwise dark nighttime side of the Earth’s Moon, fresh off of passing New phase this weekend. Snow and cloud cover turned Moonward can have an effect on how bright Earthshine appears. One ongoing study based out of the Big Bear Solar observatory in California named Project Earthshine seeks to characterize long-term climate variations looking at this very phenomenon.

The view on the evening of January 28th looking west at dusk. Credit: Stellarium.

Standing on Pluto, you’d see a 3.5 degree wide Charon, 7 times larger than our own Full Moon. Of course, you’d need to be standing in the right hemisphere, as Pluto and Charon are tidally locked, and keep the same face turned towards each other. It would be a dim view, as the Sun shines at -20 magnitude at 30 AU distant, much brighter than a Full Moon, but still over 600 times fainter than sunny Earth. Dim Plutoshine on the nightside of Charon would, however, be easily visible to the naked eye.

A small 6 cm instrument, Ralph images in the visual to near-infrared range. Ralph compliments New Horizons larger LORRI instrument, which has a diameter and very similar optical configuration to an amateur 8-inch Schmidt-Cassegrain telescope.

Charon as seen from Pluto. Credit: Starry Night.

Don’t look for Pluto now; it just passed solar conjunction on the far side of the Sun on January 7th, 2017. Pluto reaches opposition and favorable viewing for 2017 on July 10th, one of the 101 Astronomical Events for 2017 that you’ll find in our free e-book, out from Universe Today.

And for an encore, New Horizons will visit the 45 kilometer in diameter Kuiper Belt Object 2014 MU69 on New Year’s Day 2019. From there, New Horizons will most likely chronicle the environs of the the distant solar system, as it joins Pioneer 10 and 11 and Voyagers 1 and 2 as human built artifacts cast adrift along the galactic plane.

A pretty pair: Pluto and Charon. Credit: NASA/JPL/New Horizons

And to think, it has taken New Horizons about 18 months for all of its flyby data to trickle back to the Earth. Enjoy, as it’ll be a long time before we visit Pluto and friends again.

Adventures With “Copyscope”

Credit: Dave Dickinson
Presenting… Copyscope. Image credit: Dave Dickinson

Every telescope has a story to tell, and our discovery of Copyscope sent us on an interesting detective tale. We returned back to the U S of A recently, and one of our first tasks upon re-establishing our lives back in Florida was to dig through the archaeological strata that is our storage unit. Headlamp on and Leatherman in hand, we worked our way hacking through layers put in place over years of storage unit drop-off runs.

On one hand, it’s like Xmas all over again, as you rediscover all your stuff anew. But on the other, you realize when you travel long term just how much you can really do without.

Of course, I was eager to dig my telescopes out. I make do with our trusty pair of image-stabilized Canon 15×45’s on the road, but I was ready to get the REAL telescopes back in action. It was then I discovered an interesting piece of telescope making history that I’d inherited for 20$ a few years back.

Now, Amateur Telescope Makers (ATMs) build some pretty amazing things. Before the 1950s and the advent of mass market commercial telescopes, if you wanted an astronomical telescope, you had to build yourself. But a majority of amateur built telescopes are reflectors, as large mirrors are much easier to grind than lenses. ATM-made refractors are almost unheard of.

The body of Copyscope, with the eyepiece removed. Credit: Dave Dickinson

I scarcely knew such a beast existed. A friend of mine pulled a short tube refractor out of the back of his pickup truck and asked if I knew anyone that would give this strange homemade telescope a home.

Now, I didn’t build Copyscope, though I wish I had. I did once build a 5 ½” Newtonian telescope out of surplus parts and a stovepipe for about 20$. As the name suggests, Copyscope is built out of plumbing fixtures, brackets and scrap bench stock around an old photocopier lens. Old timers will remember the temperamental type of pre-laser printer copier we’re talking about, one that might as easily smeared ink all over your resume copies, or spit them out like confetti.

The battered exterior of Copyscope. Credit: Dave Dickinson

Its pedigree a mystery, Copyscope sent me digging into ye ole web, looking for others of its ilk. In addition to several older websites citing similar creations, the search led me back to a 1986 May edition of Astronomy magazine and an article by Ken Bird detailing the construction of just such an instrument, using a surplus photocopier lens and plumbing fixtures. Another resource often cited is an October 1990 article in Sky and Telescope magazine entitled The Tuneable Finderscope. Much like the first caveman who was hungry enough to try eating rotten grapes, you can imagine way back when the first enterprising ATM with a plumbing background decided to re-purpose a used photocopier lens for astronomy.

Looking down the lens of Copyscope. Image credit: Dave Dickinson

The first thing that struck us is just how heavy Copyscope is. Weighing in at 10 pounds, it seems better suited to hurling cannonballs than portable astronomy. The handle is handy in this regard, though it means that a right angle eyepiece holder is mandatory. Hefty Copyscope is definitely on the heavy end of what a typical camera tripod can tolerate.

Now, a refined high end $10,000 refractor it isn’t: images of bright objects such as the Moon have a decidedly bluish cast through Copyscope, and the baffling occasionally produces internal reflections. Still, the generous wide field of view makes it great for sweeping wide swaths of the sky for fuzzy nebulae or comets. In fact, the viewing experience using a standard 24mm eyepiece is more reminiscent of a binocular view than a telescope, at about two degrees across. Copyscope isn’t great for planetary observing, barely resolving Jupiter and Venus as tiny disks. Still, on the plus side, the field of view is so wide that a finderscope isn’t really needed.

A foggy Last Quarter Moon shot through Copyscope with a handheld Android smartphone. Note the slight chromatic aberration. Credit: Dave Dickinson

Copyscope has a fast focal length of about 300 millimeters (f/3) and – get this – the designer build a variable f/stop diaphragm into the scope body:

The f/stop diaphragm. Credit: Dave Dickinson

The word (initials?) ‘JAX’ on the back end of the scope remain a mystery. Perhaps the original builder was in the habit of naming telescopes. Still, Copyscope shows what weird and wonderful creations spring from the minds of amateur telescope builders, and is a great conversation piece. Any other unique constructions out there? Let us know!

Update: A discussion of Copyscope on Twitter led us to the conclusion that the back part of CopyScope is built around a large PVC reducer (thanks @Wrecksdart!)

Venus Rules the Dusk Skies at Greatest Elongation

Venus at dusk
Venus, Mars, and the waxing crescent moon at dusk from the evening of January 3rd, 2017. Image credit and copyright: Alan Dyer.
Venus at dusk
Venus, Mars, and the waxing crescent Moon at dusk from the evening of January 3rd, 2017. Image credit and copyright: Alan Dyer.

“What’s that bright light in the sky?” The planet Venus never fails to impress, and indeed makes even seasoned observers look twice at its unexpected brilliance. The third brightest natural object in the sky, Venus now rules the dusk, a fine sight for wintertime evening commuters. Venus reaches greatest elongation tomorrow, a excellent time to admire this dazzling but shrouded world of mystery.

Venus at greatest elongation

Only the two planets interior to Earth’s orbit – Mercury and Venus – can reach a point known as greatest elongation from the Sun. As the name suggests, this is simply the point at which either planet appears to be at its maximum angular distance from the Sun. Think of a big right triangle in space, with Venus or Mercury at the right angle vertex, and the Sun and Earth at the other two corners. High school geometry can come in handy!

Venus elongation
Venus at greatest elongation (planets and orbits not to scale). Credit: Dave Dickinson

This Thursday on January 12th Venus reaches a maximum of 47 degrees elongation from the Sun at 11:00 Universal Time (UT) / 6:00 AM Eastern Standard Time, shining at magnitude -4.4. The maximum/minimum elongation for Venus that can occur is 47.3 to 45.4 degrees respectively, and this week’s is the widest until 2025.

Here’s some key dates to watch out for:

Jan 12th: Venus passes less than a degree from Neptune.

Jan 14th: Venus reaches theoretical dichotomy?

Jan 14th: Venus passes 3′ from +3.7 the magnitude star Lambda Aquarii.

Jan 17th: Venus crosses the ecliptic plane northward.

Venus and Mars reach ‘quasi-conjunction’ in late January.

January 30th: Venus crosses the celestial equator northward.

January 31st: The Moon passes 4 degrees south of Venus, and the two also form a nice equilateral triangle with Mars on the same date.

Looking west on the evening of January 31st, 2017. Image credit: Stellarium.

February 17th: Venus reaches a maximum brilliancy of magnitude -4.6.

March 26th: Solar conjunction for Venus occurs eight degrees north of the Sun … it is possible to spy Venus at solar conjunction from high northern latitudes, just be sure to block out the Sun.

Through the telescope, Venus displays a tiny 24.4” size half phase right around greatest elongation. You could stack 74 Venuses across the diameter of tomorrow’s Full Moon. When does Venus look to reach an exact half phase to you? This point, known as theoretical dichotomy, is often off by just a few days. This is a curious observed phenomenon, first noted by German amateur astronomer Johann Schröter in 1793. The effect now bears his name. A result of atmospheric refraction along the day/terminator on Venus, or an optical illusion?

Gibbous Venus
Almost there… a waning gibbous Venus from the evening of January 5th, 2017. Image credit and copyright: Shahrin Ahmad (@Shahgazer)

And hey, amateurs are now using ultraviolet filters to get actual detail on the cloud-tops of Venus… we like to use a variable polarizing filter to cut down the dazzling glare of Venus a bit at the eyepiece.

Also, keep an eye out for another strange phenomenon, known as the Ashen Light of Venus. Now,ashen light or Earthshine is readily apparent on dark side of the Moon, owing to the presence of a large sunlight reflector nearby, namely the Earth. Venus has no such large partner, though astronomers in the early age of telescopic astronomy claimed to have spied a moon of Venus, and even went as far as naming it Neith. An optical illusion? Or real evidence of Venusian sky glow on its nighttime side? After tomorrow, Venus will begin heading between the Earth and the Sun, becoming a slender crescent in the process. Solar conjunction occurs on March 25th, 2017. Venus sits just eight degrees north of the Sun on this date, and viewers in high Arctic latitudes might just be able to spy Venus above the horizon before sunrise on the day of solar conjunction. We performed a similar feat of visual athletics on the morning of January 16th, 1998 observing from North Pole, Alaska.

Venus as seen from Fairbanks, Alaska on the morning of solar conjunction, 2017. Image credit: Starry Night.

From there, Venus heads towards a fine dawn elongation on June 3rd, 2017. All of these events and more are detailed in our free e-book: 101 Astronomical Events for 2017.

Spying Venus in the Daytime

Did you know: you can actually see Venus in the daytime, if you know exactly where to look for it? A deep blue, high contrast sky is the key, and a nearby crescent Moon is handy in your daytime quest. Strange but true fact: Venus is actually brighter than the Moon per square arc second, with a shiny albedo of 70% versus the Moon’s paltry 12%. But Venus is tiny, and hard to spot against the blue daytime sky… until you catch sight of it.

The Moon passing Venus on January 31st, 2017 in the daytime sky. Image credit: Stellarium.

There’s another reason to brave the January cold for northern hemisphere residents: Venus can indeed cast a shadow if you look carefully for it. You’ll need to be away from any other light sources (including the Moon, which passes Full tomorrow as well with the first Full Moon of 2017, known as a Full Wolf Moon). And a high contrast surface such as freshly fallen snow can help… a short time exposure shot can even bring the shadow cast by Venus into focus.

If you follow Venus long enough, you’ll notice a pattern, as it visits very nearly the the same sky environs every eight years and traces out approximately the same path in the dawn and dusk sky. There’s a reason for this: 8 Earth years (8x 365.25 = 2922 days) very nearly equals 5 the synodic periods for Venus (2922/5=584 days, the number of days it takes Venus to return to roughly the same point with respect to the starry background, separate from its true orbit around the Sun of 225 days). For example, Venus last crossed the Pleiades star cluster in 2012, and will do so again in – you guessed it — in 2020. Unfortunately, this pattern isn’t precise, and Venus won’t also transit the Sun again in 2020 like it did in 2012. You’ll have to wait until one century from this year on December 10-11th, 2117 to see that celestial spectacle again….

Hopefully, we’ll have perfected that whole Futurama head-in-a-jar thing by then.