David Dickinson, Author at Universe Today

April 14, 2014December 23, 2015 by David Dickinson

Webcasts and Forecasts for Tonight’s Total Lunar Eclipse

The December 21st 2010 Solstice eclipse. Photos by author.

Are you ready for some eclipse action? We’re now within 24 hours of the Moon reaching its ascending node along the ecliptic at 13:25 Universal Time (UT)/ 9:25 AM EDT on Tuesday morning and meeting the shadow of the Earth just over seven hours earlier.

We’ve written about viewing prospects for tonight’s lunar eclipse. This eclipse is the first total lunar eclipse since December 10^th, 2011 and is the first in a series of four — known as an eclipse tetrad — visible from North America in 2014 and 2015. Totality lasts 1 hour and 18 minutes and falls just 29 minutes short of the theoretical maximum, which was last neared on January 21^st, 2000 and won’t be topped until July 27^th, 2018.

This will be an early morning event for U.S. East Coasters spanning 2:00 to 5:30 AM local (from the start of the partial umbral phases and totality), and a midnight spanning-event for the Pacific coast starting at 11:00 PM Monday night until 2:30 AM Tuesday morning on the 15^th.

And as always with celestial events, the chief question on every observer’s mind is: will the skies be clear come show time? Should I stay put, or ponder going mobile?

When it comes to astronomical observing, a majority a mainstream weather resources only tell part of the story, often only listing cloud cover and precipitation percentages. Seeing, transparency, and low versus middle and high cloud decks can often mean the difference between a successful observing session and deciding to pack it in and watch Cosmos reruns online. But the good news is, you don’t need crystal clear skies to observe a total lunar eclipse, just a view of the Moon, which can easily “burn through” a high cirrus cloud deck. We’re going to share a few sites that are essential tools for planning an observing session and what they say about the prospects for seeing tonight’s eclipse.

Cloud cover prospects. Credit: NOAA. — Cloud cover prospects towards the end of tomorrow morning’s lunar eclipse. Credit: NOAA.

Now the bad news: things aren’t looking good for eastern North America. In fact, the dividing line between “cloudy” and “clear” runs right down through central Ontario and follows the Mississippi River at mid-eclipse, which occurs at 7:47 UT/3:47 AM EDT. There’s a high pressure front sweeping eastward, bringing rain and cloudy skies with it. The Florida peninsula and parts of New England and the Canadian Maritimes may have shots at viewing the eclipse through partly cloudy skies.

The National Oceanic and Atmospheric Administration maintains a great interactive site with graphical interactive forecasts, to include satellite maps. Another long-standing source of good info is the Weather Underground. For tailor-made astronomy forecasts, we’re checking Clear Sky Chart (formerly Clear Sky Clock) and SkippySky daily for upcoming prospects. A great feature in SkippySky is that it not only gives you cloud cover maps, but layers them with high versus middle and low clouds… again, a thin high cloud deck during the lunar eclipse could still mean game on!

Clouded out? There’s a half dozen webcasts planned for tonight’s lunar eclipse as well.

Dependable Slooh will have a live broadcast with commentary on the eclipse starting at 2AM EDT/6:00 UT:

Also, our good friends at the Virtual Telescope Project will be covering the lunar eclipse as part of their ongoing Global Astronomy Month campaign and will utilize several North American observers to cover the event:

NASA is also planning a broadcast out of the Marshall Space Flight Center of the eclipse along with a discussion on Reddit with NASA planetary scientist Renee Weber also starting at 2:00 AM EDT:

Video streaming by Ustream

The Coca-Cola Space Science Center and Columbus State University also plans host a webcast of the lunar eclipse starting at 3:00 UT/11:00 PM EDT.

Also, the PBS Star Gazers project is planning on hosting a broadcast of the eclipse starting at 1:30 AM EDT/5:30 UT:

Video streaming by Ustream

And finally, we hope to launch our very own initiation into the world of eclipse webcasting with an hour-long broadcast of the crucial phase transition from partial to total eclipse starting at 2:30 AM EDT/6:30 UT, weather willing:

Live streaming video by Ustream

And hey, word is that doomsday purveyor John Hagee is planning a broadcast of a more “End of the World” bent tonight as well. We didn’t know he was an astronomy fan…

Prospects call for a brighter than normal eclipse, as atmospheric sciences professor at the University of Colorado Richard Keen notes that the Earth’s stratosphere is currently relatively clear of dust and volcanic ash. Still, we’ve been surprised before. The darkness and color of the eclipsed Moon is expressed on what’s known as the Danjon scale. As during eclipses previous, we’ll be data-mining Twitter for estimates and averages to see how they stack up… tweet those observations to #DanjonNumber.

Opportunities to catch the ISS transiting the Moon... during tonight's eclipse. Credit: CALSky. — Opportunities to catch the ISS transiting the Moon during tonight’s eclipse. Credit: CALSky.

We also ran the possibilities for catching a shadow transit of the International Space Station in front of the eclipsed Moon for North American observers. To our knowledge, this has never been done before. Live near one of the two paths depicted above? You may be the first to accomplish this unusual feat. Check in with CALSky for specifics.

Our backyard "eclipse broadcasting station." — Our backyard “eclipse broadcasting station.”

Finally, ever wonder when the next eclipse will occur during the Sunday night Virtual Star Party? If you’re like us, you consider and ponder such astronomical occurrences… and it turns out, the very last lunar eclipse in the current tetrad next year on September 28^th, 2015 does just that. And stick around until July 13^th, 2037 and we’ll have the first ever total solar eclipse occurring during the show… we just need someone in Australia to stream it!

Tonight’s eclipse is number 56 of saros 122. Reader Rob Sparks notes that the last eclipse (55) in this series occurred on April 4^th 1996 and also hosted an extra-special celestial treat, as Comet Hyakutake was just beginning to put on its memorable performance.

In short, don’t fear the “Blood Moon,” but do get out and catch tonight’s fine lunar eclipse… we’ll be doing a post-eclipse photo roundup tomorrow, so be sure to send those pics in to Universe Today!

April 10, 2014December 23, 2015 by David Dickinson

Two Observing Challenges: Catch Venus Passing Neptune And Occulting a Bright Star

The Milky Way, The Large and Small Magellanic Clouds, Zodiacal Light, and Venus as seen from the Karoo Desert in South Africa early this month. Credit: Cory Schmitz.

Have you been following the planet Venus this season? 2014 sees the brightest planet in our Earthly skies spend a majority of its time in the dawn. Shining at magnitude -3.8, it’s hard to miss in the morning twilight. But dazzling Venus is visiting two unique celestial objects over the next week, and both present unique observing challenges for the seasoned observer.

First up is an interesting close conjunction of the planets Venus and Neptune on the morning of Saturday, April 12^th. Closest conjunction occurs at 3:00 Universal Time (UT) April 12th favoring Eastern Europe, the Middle East and eastern Africa, when the two worlds appear to be just 40 arc minutes apart, a little over – by about 10’ – the apparent size of a full Moon. Shining at magnitude +7.8 and 30,000 times fainter than Venus, you’ll need a telescope to tease out Neptune from the pre-dawn sky. Both objects will, however, easily fit in a one degree field of view, in addition to a scattering of other stars.

Looking to the east the morning of April 12th from the U.S. East Coast near latitude 30 degrees north. Nearby stars are annotated in red by magnitude with decimals omitted. Created using Stellarium, click to enlarge.

At low power, Venus will display a 59% illuminated gibbous phase 20” across on the morning of the 12^th, while Neptune will show a tiny disk barely 2” across. Still, this represents the first chance for viewers to recover Neptune since solar conjunction behind the Sun on February 23^rd, 2014, using dazzling Venus as a guide.

Both sit 45 degrees west of the Sun and currently rise around 3 to 4 AM local dependent on latitude.

This is one of the closest planet-planet conjunctions for 2014. The closest is Venus and Jupiter at just 0.2 degrees apart on August 18^th. This will represent the brightest planet versus planet conjunction for the year, and is sure to illicit multiple “what’s those two bright stars in the sky?” queries from morning commuters… hopefully, such sightings won’t result in any border skirmishes worldwide.

Now, for the mandatory Wow factor. On the date of conjunction, Earth-sized Venus is 0.84 Astronomical Units (A.U.s) or over 130 million kilometres distant. Ice giant Neptune, however, is 30.7 AUs or 36 times as distant, and only appears tiny though it’s almost four times larger in diameter. Sunlight reflected from Venus takes 7 minutes to reach Earth, but over four hours to arrive from Neptune. We’ve visited Venus lots, and the Russians have even landed there and returned images from its smoldering surface, but we’ve only visited Neptune once, during a brief flyby of Voyager 2 in 1989.

From Neptune looking back on April 12th, Earth and Venus would appear less than 1 arc minute apart…. though they’d also be just over one degree from the Sun!

The "shadow path" of the occultation of Lambda Aquarii by Venus on April 16th. Credit: IOTA/Steve Preston/www.asteroidoccultation/Occult 4.0. — The “shadow path” of the occultation of Lambda Aquarii by Venus on April 16th. Credit: IOTA/Steve Preston/www.asteroidoccultation/Occult 4.0.

But an even more bizarre event happens a few days later on April 16^th, though only a small region of the world in the South Pacific may bare witness to it.

Next Wednesday from 17:59 to 18:13 UT Venus occults the +3.7 magnitude star HIP 112961 also known as Lambda Aquarii on the morning of April 16^th 2014.

Venus will be a 61% illuminated gibbous phase 19” in diameter. Unfortunately, although North America is rotated towards the event, it’s also in the middle of the day.

The best prospects to observe the occultation are from New Zealand and western Pacific at dawn. The star will disappear behind the bright limb of Venus in dawn twilight before emerging on its dark limb 5 minutes later as seen from New Zealand.

The path of Lambda Aquarii behind Venus as seen from New Zealand the morning of the 16th. Created in Starry Night.

Note: New Zealand switched back to standard time on April 6^th – it’s currently Fall down under – and local sunrise occurs around ~7:40 AM.

Lambda Aquarii is a 3.6 solar mass star located 390 light years distant. As far as we know, it’s a solitary star, though there’s always a chance that a companion could make itself known as it emerges on the dark limb of Venus. Such an observation will, however, be extremely difficult, as Venus is still over 700 times brighter than the star!

North Americans get to see the pair only 20’ apart on the morning of the 12^th.

And further occultation adventures await Venus in the 21^st century. On October 1^st, 2044 it will occult Regulus… and on November 22^nd, 2065 it will actually occult Jupiter!

Such pairings give us a chance to image Venus with a “pseudo-moon.” Early telescopic observers made numerous sightings of a supposed Moon of Venus, and the hypothetical object even merited the name Neith for a brief time. Such sightings were most likely spurious internal reflections due to poor optics or nearby stars, but its fun to wonder what those observers of old might’ve seen.

… and speaking of moons, don’t miss a chance to see Venus near the daytime Moon April 25^th. Follow us as @Astroguyz on Twitter as we give shout outs to these and other strange pairings daily!

April 9, 2014December 23, 2015 by David Dickinson

Mars Opposition Season 2014: Images From Around the World

Mars as seen on from Aguadilla, Puerto Rico on Mars 25th, 2014, two weeks prior to opposition. Credit-Efrain Morales Rivera.

Did you see it? Last night, the Red Planet rose in the east as it passed opposition for 2014, and astrophotographers the world over were ready to greet it. And although Mars gets slightly closer to us over the coming week, opposition marks the point at which Mars is 180 degrees “opposite” to the setting Sun in Right Ascension as viewed from our Earthly vantage point and denotes the center of the Mars observing season. Opposition only comes around once about every 26 months, so it’s definitely worth your while to check out Mars through a telescope now if you can. We’ve written about prospects for observing Mars this season, and the folks at Slooh and the Virtual Telescope Project also featured live views of the Red Planet last night. We also thought we’d include a reader roundup of pics from worldwide:

Mars and Spica rising over the telescope domes at Kitt Peak, Arizona. The 2.1 metre dome is on the left, and the 0.9 metre dome is to the right. Credit-Rob Sparks @halfastro.

Even near opposition, Mars presents a challenge to observers. In 2014, Mars only reaches 15 arc seconds maximum in apparent size, a far cry from its 25″ appearance during the historic 2003 opposition. Now for the good news: we’re in a cycle of improving oppositions… the next one on May 22nd, 2016 will be better still, and the 2018 opposition will be nearly as favorable as the 2003 appearance!

Mars as seen from the Netherlands at 0:26 UT... about 3 hours past opposition. Credit- Christian Fröschlin. — Mars as seen from the Netherlands at 0:26 UT… about 3 hours past opposition. Credit- Christian Fröschlin @chrfde.

And you can see just how technology in the amateur astronomy community has improved with each successive appearance of Mars over the years. Early observers were restricted to sketching features glimpsed during fleeting moments of steady seeing. Even during the film era of photography, absurdly long focal lengths were required to yield even a tiny speck of a dot. And even then, the “graininess” of the film tended to smear and yield a blurry image with few details to be seen.

The advent of digital photography opened new vistas on planetary imaging. Now backyard astrophotographers are routinely taking images using stacking techniques and processing to “grab” and align those moments of good seeing. These images are often now better that what you’d see in a text book taken from professional observatories only a few decades ago!

And you can now easily modify a webcam to take decent planetary images that can then be stacked and processed with software freely available on the web.

…And check out this video animation also by Christian Fröschlin that shows the rotation (!) of Mars:

Mars as seen from Ottawa, Canada, taken using an IPhone 4S through a NexStar 8SE telescope on April 4th, 2014. Awesome! Credit-Andrew Symes @FailedProtostar

Shahrin Ahmad made an excellent video from Malaysia that demonstrates just what raw captured images of Mars look like before processing:

Note that the large dark triangular region is Syrtis Major.

Mars annotated, a stack of 1128 frames shot at 666x. Credit-Mike Weasner/Cassiopeia Observatory.

The northern polar cap is currently tipped towards us, as it’s northern hemisphere summertime on Mars. Many images reflect this prominent feature, as well as the orographic clouds skirting the Hellas basin that have been the hallmark of the Mars opposition of 2014. These are also apparent visually at the eyepiece. It’s worth staying up a bit towards local midnight to observe and image Mars, as it transits at its maximum elevation — and is above the murk of the sky low to the horizon — right around this time.

Mars captured through a Celestron C6 SCT telescope on April 5th, 2014. Credit: Joel Tonyan.

Mars: a study of color contrasts on the eve of opposition. Credit-Laura Austin @LAismylady

And Mars observing season doesn’t end this week. Mars makes its closest passage to the Earth for 2014 next Monday on April 14th at 0.618 Astronomical Units (A.U.s) distant. Mars will occupy the evening sky for the remainder of 2014 before finally reaching solar conjunction on June 14th, 2015. Mars will still be greater than a respectable 10″ in apparent size until June 24th and will continue to offer observers a fine view at the eyepiece.

Mars as seen from Rhode Island on the night of opposition. Credit-Cherie @KelieAna

And don’t forget, that waxing gibbous Moon is now homing in on Mars and will only sit a few degrees away from the Red Planet and Spica on the night of the April 14th/15th, 2014 during a fine total lunar eclipse. And no, a “red” planet + a “blood red” eclipsed Moon does not equal doomsday… but it’ll make a great photo op!

Mars imaged using a 150 mm scope. Credit-Sergei Golyshev under a Creative Commons Share-Alike 2.0 Generic License.

… and finally, Mars and the bright blue-white star Spica offered us a fine morning view as the storm front passed over Astroguyz HQ here in Florida this AM:

Author — Mars, Spica, and our partly cloudy terrestrial atmosphere. Photo by author.

Want something more? Have you ever seen Mars… in the daytime? Currently shining at magnitude -1.5, its just possible if you known exactly where to look for it low to the east about 10 minutes or so before local sunset. In fact, near opposition is the only time you can carry this unusual feat of visual athletics out. The best chance in 2014 is on the evening of April 13th and 14th, when the waxing gibbous Moon lies nearby:

Looking east on the evening of April 13th, just before sunset. Credit: Starry Night education software.

Good luck, and thanks to everyone who imaged Mars this season!

April 8, 2014December 23, 2015 by David Dickinson

The USAF’s Super-Secret X-37B Approaches a Milestone

An artists' conception of the X-37B in Earth orbit. Credit: The U.S. Air Force.

A secretive mission will pass a quiet milestone at the end of this month when the U.S. Air Force’s unmanned spaceplane the X-37B surpasses 500 days in space.

Launched atop an Atlas V rocket flying in a 401 configuration from Cape Canaveral Florida after several delays on December 11^th, 2012 on OTV-3, the X-37B has already surpassed its own record of 469 days in space set on OTV-2. Said milestone was crossed last month. If the current mission stays in space until April 25^th of this year, it will have surpassed 500 days in space.

Two X-37Bs were built for the USAF, and the first test mission flew in 2010. NASA performed drop glide tests with an early variant of the X-37A in 2005 and 2006, and DARPA is thought to be a primary customer for the program as well.

Measuring just 8.8 metres in length, the X-37B is tiny compared to its more famous spaceplane cousin the U.S. Space Shuttle. The X-37B has a maximum weight at liftoff of 4,990 kilograms and features a payload bay 2.1 by 1.2 metres in size.

The spacecraft itself is solar powered, as it unfurls a panel — as depicted in many artists’ conceptions — once it’s in orbit. Of course, its mission profile is classified, and the X-37B could land unannounced at any time. The previous landings occurred at Vandenberg Air Force Base in California and were only announced shortly thereafter.

Not only is this the longest continuous mission for any spaceplane, but the ATV-3 is also the smallest, lightest and only the second spaceplane to land autonomously, the first being the Russian space shuttle Buran that flew one mission and landed after one orbit at the Baikonur Cosmodrome on November 15^th, 1988.

The X-37B awaiting encapsulation for launch. Credit: U.S. Air Force.

The idea of a reusable spaceplane has been around since the dawn of the Space Age. The U.S. Space Shuttle program was the most high profile of these, having flown 135 missions from 1981 to 2011. But even the space shuttle launch system wasn’t fully reusable, expending its large orange external fuel tank after every mission and requiring extensive refurbishment for the solid rocket motors and orbiter after each and every flight. The Soviets abandoned Buran in 1988, and other examples of spaceplanes such as North American’s X-15 surpassed the 100 kilometre in altitude Kármán line marking the boundary to space, but were suborbital only. And this year, customers may get a chance to make similar suborbital hops into space aboard Virgin Galactic’s SpaceShipTwo spaceplane at $250,000 dollars a ticket.

But the most ambitious design for a true spaceplane was conceived in the 1960’s: Boeing’s X-20 Dyna-Soar, which was never built.

Classified satellites such as the X-37B are part of a longstanding and fascinating “secret space race” that has paralleled and shadowed the more well known space programs of various nations over the decades. These include the Corona program which ran from 1959 to 1972 and was only declassified in 1995, and satellites such as Lacrosse 5, which is notorious among satellite sleuths for the orbital “vanishing act” it sometimes pulls.

And speaking of which, you can track the X-37B from your backyard, tonight. Ground spotters first pegged its position in low Earth orbit during OTV-1 on May 22^nd 2010, and the spacecraft currently sits in a 392 x 296 kilometre (nearly circular) orbit in an 43.5 degree inclination, making it visible from latitudes 55 degrees north to south. On a favorable overhead pass, the X-37B is easily visible shining at greater than magnitude +1. OTV-3’s NORAD ID designation is 39025 or 2012-071A, and although – like most classified payloads – it’s not available to the public on Space-Track, Heavens-Above does list upcoming sighting opportunities. Be sure to start watching a bit early, as the X-37B has been known to maneuver a bit in its orbit on occasion.

Of course, just what the X-37B is doing in orbit is anybody’s guess. Speculation is that it’s serving as a test bed for new technologies. Certainly, the ability to place interchangeable payloads in orbit is immediately apparent. It’s also worth noting that the X-37B makes multiple daily passes on its northward apex over North Korea and China. There’s also been speculation that the X-37B was designed to keep tabs on the Chinese space station Tiangong-1, although this can easily be refuted as they both lie in different orbits. There’s no word as to what’s to become of Tiangong-1, though China had said it was set to deorbit the station at the end of 2013, and it is still in space.

Looking ahead into the future, there has been talk about a larger crewed variant known as the X-37C, which will undoubtedly fly much shorter missions. For now, we can watch and wonder what it’s up to, as the X-37B glides silently overhead. Perhaps one day, its mission will declassified, and its tale can be told.

-For more info sat-tracking, check out our how-to post and also read about the fascinating true role that amateurs played during the Cold War and Operation Moonwatch.

April 7, 2014December 23, 2015 by David Dickinson

The Science Behind the “Blood Moon Tetrad” and Why Lunar Eclipses Don’t Mean the End of the World

A mosaic of the 2003 total lunar eclipse. photos by author.

By now, you may have already heard the latest tale of gloom and doom surrounding the upcoming series of lunar eclipses.

This latest “End of the World of the Week” comes to us in what’s being termed as a “Blood Moon,” and it’s an internet meme that’s elicited enough questions from friends, family and random people on Twitter that it merits addressing from an astronomical perspective.

Like the hysteria surrounding the supposed Mayan prophecy back in 2012 and Comet ISON last year, the purveyors of Blood Moon lunacy offer a pretty mixed and often contradictory bag when it comes down to actually what will occur.

But just like during the Mayan apocalypse nonsense, you didn’t have to tally up just how many Piktuns are in a Baktun to smell a rat. December 21^st 2012 came and went, the galactic core roughly aligned with the solstice — just like it does every year — and the end of the world types slithered back into their holes to look for something else produce more dubious YouTube videos about.

Here’s the gist of what’s got some folks wound up about the upcoming cycle of eclipses. The April 15^th total lunar eclipse is the first in series of four total eclipses spanning back-to-back years, known as a tetrad. There are eight tetrads in the 21^st century: if you observed the set total lunar eclipses back in 2003 and 2004, you saw the first tetrad of the 21^st century.

The eclipses in this particular tetrad, however, coincide with the Full Moon marking Passover on April 15^th and April 4^th and the Jewish observance of Sukkot on October 8^th and September 28^th. Many then go on to cite the cryptic biblical verse from Revelation 6:12, which states;

“I watched as he opened the sixth seal. There was a great earthquake. The Sun turned black like sackcloth made of goat hair. The whole Moon turned blood red.”

Whoa, some scary allegory, indeed… but does this mean the end of the world is nigh?

I wouldn’t charge that credit card through the roof just yet.

First off, looking at the eclipse tetrads for the 21^st century, we see that they’re not really all that rare:

21^st century eclipse tetrads:

Eclipse #1	Eclipse #2	Eclipse #3	Eclipse #4
May 16^th, 2003	November 9^th, 2003	May 4^th , 2004	October 28^th, 2004
April 15^th, 2014*+	October 8^th, 2014	April 4^th, 2015*+	September 28^th, 2015
April 25^th, 2032	October 18^th, 2032	April 14^th, 2033*+	October 8^th, 2033
March 25^th, 2043*	September 19^th, 2043	March 13^th, 2044	September 7^th, 2044
May 6^th, 2050	October 30^th, 2050	April 26^th, 2051	October 19^th, 2051
April 4^th, 2061*+	September 29^th, 2061	March 25^th, 2062*	September 18^th, 2062
March 4^th, 2072	August 28^th, 2072	February 22^nd, 2073	August 17^th, 2073
March 15^th, 2090	September 8^th, 2090	March 5^th, 2091	August 29^th, 2091
*Paschal Full Moon
+Eclipse coincides with Passover

Furthermore, Passover is always marked by a Full Moon, and a lunar eclipse always coincides with a Full Moon by definition, meaning it cannot occur at any other phase. The Jewish calendar is a luni-solar based calendar that attempts to mark the passage of astronomical time via the apparent course that the Sun and the Moon tracks through the sky. The Muslim calendar is an example of a strictly lunar calendar, and our western Gregorian calendar is an example of a straight up solar one. The Full Moon marking Passover often, though not always, coincides with the Paschal Moon heralding Easter. And for that matter, Passover actually starts at sunset the evening prior in 2014 on April 14^th. Easter is reckoned as the Sunday after the Full Moon falling after March 21^st which is the date the Catholic Church fixes as the vernal equinox, though in this current decade, it falls on March 20^th. Easter can therefore fall anywhere from March 22^nd to April 25^th, and in 2014 falls on the late-ish side, on April 20^th.

To achieve synchrony, the Jewish calendar must add what’s known as embolismic or intercalculary months (a second month of Adar) every few years, which in fact it did just last month. Eclipses happen, and sometimes they occur on Passover. It’s rare that they pop up on tetrad cycles, yes, but it’s at best a mathematical curiosity that is a result of our attempt to keep our various calendrical systems in sync with the heavens. It’s interesting to check out the tally of total eclipses versus tetrads over a two millennium span:

Century	Number of Total Lunar Eclipses	Number of Tetrads	Century	Number of Total Lunar Eclipses	Number of Tetrads
11^th	62	0	21^st	85	8
12^th	59	0	22^nd	69	4
13^th	60	0	23^rd	61	0
14^th	77	6	24^th	60	0
15^th	83	4	25^th	69	4
16^th	77	6	26^th	87	8
17^th	61	0	27^th	79	7
18^th	60	0	28^th	64	0
19^th	62	0	29^th	57	0
20^th	81	5	30^th	63	1

Note that over a five millennium span from 1999 BC to 3000 AD, the max number of eclipse tetrads that any century can have is 8, which occurs this century and last happened in the 9^th century AD.

Of course, the visual appearance of a “Blood of the Moon” that’s possibly alluded to in Revelation is a real phenomena that you can see next week from North and South America as the Moon enters into the dark umbra or core of the shadow of the Earth. But this occurs during every total lunar eclipse, and the redness of the Moon is simply due to the scattering of sunlight through the Earth’s atmosphere. Incidentally, this redness can vary considerably due to the amount of dust, ash, and particulate aerosols aloft in the Earth’s atmosphere, resulting in anything from a bright cherry red eclipse during totality to an eclipsed Moon almost disappearing from view altogether… but it’s well understood by science and not at all supernatural.

The changing colors of a lunar eclipse: a mosaic of four eclipses. Photos by author.

Curiously, the Revelation passage could be read to mean a total solar eclipse as well, though both can never happen on the same day. Lunar and solar eclipses occur in pairs two weeks apart at Full and New Moon phases when the nodes of the Moon’s ecliptic crossing comes into alignment with the Sun — known as a syzygy, an ultimate triple word score in Scrabble, by the way — and this eclipse season sees a non-central annular eclipse following the April 15^th eclipse on April 29^th.

And yes, earthquakes, wars, disease, relationship breakups and lost car keys are on tap to occur in 2014 and 2015… just like during any other year. Lunar eclipses marked the fall of Constantinople in 1453 and the World Series victory of the Red Sox in 2004, but they’re far from rare. We humans love to see patterns, and sometimes this habit works against us, making us see them where none exists. This is simply a case of the gambler’s fallacy, counting the hits at the cost of the misses. We could just as easily make a case that the upcoming eclipse tetrad of April 15th, October 8^th, April 4^th and September 28th marks US Tax Day, Croatian Independence Day, The Feast of Benedict of the Moor & — Michael Scott take note — International World Rabies Day… perhaps the final 2015 eclipse should be known as a “Rabies Moon?”

So, what’s the harm in believing in a little gloom and doom? The harm in believing the world ends tomorrow comes when we fail to plan for still being here the day after. The harm comes when something like the Heavens Gate mass suicide goes down. We are indeed linked to the universe, but not in the mundane and trivial way that astrologers and doomsdayers would have you believe. Science shows us where we came from and where we might be headed. We’ve already fielded queries from folks asking if it’s safe (!) to stare at the Blood Moon during the eclipse, and the answer is yes… don’t give in to superstition and miss out on this spectacular show of nature because of some internet nonsense.

The upcoming lunar eclipse next week won’t mean the end of the world for anyone, except, perhaps, NASA’s LADEE spacecraft… be sure not to miss it!

April 3, 2014December 23, 2015 by David Dickinson

Night of the Red Planet: Mars Opposition 2014 Coming Soon!

Coming to you on April 8th courtesy of the Virtual Telescope!

Mars attacks and comes to a night sky near you this month, and the folks at the Virtual Telescope Project and Slooh are bringing it to you live and in color. Unlike most planets, “Mars viewing season” comes around only once about every two years. And while Mars is shining bright in the sky right now, the “official” event of Mars being closest to Earth happens next week on April 8^th, when the Red Planet reaches opposition and shines at magnitude -1.5 in the constellation Virgo.

We’ve written about the prospects and circumstances for viewing Mars this opposition season; now it’s time to watch it live. The webcast starts at 23:00 Universal Time (UT) or / 7:00 PM EDT on the night of Tuesday April 8^th, and will feature real-time images brought to you via robotic telescopes worldwide. Hosted by astrophysicist Gianluca Masi and run in conjunction with Astronomers Without Borders, this online observing session of Mars also occurs during Global Astronomy Month. Anyone who tuned in for their recent online Messier Marathon and live broadcasts of several recent Near-Earth Asteroids past our fair planet knows that they’re in for quite a treat!

Want more? Or simply want dual screen live views of “all Mars, all the time?” Our dependable friends over at Slooh will be chronicling the Mars opposition on the same night, starting at a slightly different bat-time at 02:00 UT (the morning of the 9^th) which is 10:00 PM EDT the evening of the 8^th. Slooh will be presenting a live feed from its automated telescopes based in the Canary Islands off of the coast of West Africa and will feature live commentary from hosts Paul Cox and astronomer and author of The Sun’s Heartbeat Bob Berman.

“Mars has held disproportionate focus for humans since ancient times,” Berman said in a recent press release. “It is neither the closest planet, nor the largest, nor the most detailed through telescopes. Nonetheless, it is the only planet in the universe that shows distinct and sometimes detailed surface features through our telescopes. It is also the most Earthlike body in the known universe, with oxygen bound into its soil and water contained in its ices. Therefore, during the brief two weeks when it comes near us every 26 months, it deserves the limelight.”

Indeed, Mars has captivated observers ever since Christiaan Huygens sketched the first blurry surface feature Syrtis Major back in 1659. Percival Lowell enthralled the public imagination with his sketches of what he thought were canals built by an intelligent and ancient civilization on the Red Planet, and astronomer David Peck Todd once proposed to signal said Martians via balloon aloft in 1909. The SETI Institute’s Seth Shostak noted in his book Confessions of an Alien Hunter that to the average person on the street in the early 20^th century, the idea that Mars was inhabited was a given.

Of course, the reality revealed to us by the early Mariner missions in the 1960s onwards paints a bleak picture of a cratered world with a tenuous atmosphere inhospitable to life as we know it.

Still, Mars is a real world, somewhere that rovers are rolling across and exploring even as we peer at it though the eyepiece this month. Six months prior to opposition also the best opportunity to send spacecraft to Mars, and later this year, NASA’s MAVEN and India’s Mars orbiter Mangalyaan both launched in late 2013 will complete the trip.

Mars approaches Earth during the month of April. Credit: Efrain Morales Rivera/Jaicoa Observatory/Aguadilla, Puerto Rico.

Observing the Red Planet through the eyepiece is easy. The most conspicuous feature is the white northern pole cap, currently tipped towards us. Orographic clouds have also been imaged by amateurs recently over the Hellas basin, and a planet wide dust storm could always crop up at any time. A Martian day is only 37 minutes longer than the Earth’s, meaning you’re only seeing Mars rotated by about 15 degrees of longitude if you observe it at the same time each night. At about 15” across, you could stack 120 Mars diameters as seen this week from Earth across a Full Moon. And no, Mars NEVER appears as big as a Full Moon as seen from the Earth, not this week, every August, or EVER, despite those pesky chain-emails from well meaning co-workers/friends/relatives who just know that you’re into that “space thing…”

All oppositions of Mars are not created equal. In fact, we’re coming off of a series of lackluster oppositions that’ll see Mars getting successively better until 2018, when it’ll nearly top the historic opposition of 2003. For ephemerides buffs, Mars reaches opposition — that is, it’s 180 degrees opposite to the Sun as reckoned in right ascension — on April 8^th at 21:00 UT/5:00 PM EDT. It is not quite, however, at its closest to us for 2014: it has still got 0.003 AU (465,000 kilometres, a little over the distance from the Earth to the Moon) and just over 5 days before its closest approach to Earth on the night of April 14^th/15^th, when a total eclipse of the Moon lies just nine degrees away. The reason opposition and the closest approach of Mars to Earth are not quite in sync is because the orbits of both planets are elliptical, and while Mars is currently moving towards perihelion, Earth is heading toward aphelion on July 4^th.

A photo-montage leading up to the 2003 opposition. Photos by author using a webcam turned planetcam.

Can’t wait until the 8^th? Universe Today hosts a Virtual Star Party every Sunday evening at 11:00 PM EDT / 03:00 UT on Google+ featuring telescopes and commentary by observers and astronomers worldwide. Weather willing, Mars should be a centerpiece object for the show this Sunday night on April 6^th.

Be sure to check out Mars at its best this week for 2014, either in a sky near you or online… hey, maybe we’ll be live casting the transit of Earth, the Moon and Phobos someday from Mars on the slopes of Elysium Mons on November 10^th, 2084:

Let’s see, hopefully they’ll have perfected that whole Futurama “head in a jar” thing by then…

Enjoy!

April 2, 2014December 23, 2015 by David Dickinson

Get Ready for the April 15, 2014 Total Lunar Eclipse: Our Complete Guide

Totality! A seen during the "December solstice eclipse" of 2010. Photo by author.

April the 15^th: In the United States, it’s a date dreaded by many, as the date to file taxes – or beg for an extension – looms large. But this year, Tax Day gives lovers of the sky something to look forward to, as the first of four total lunar eclipses for 2014 and 2015 occurs on the night of April 14^th/15^th favoring North and South America.

The circumstances for the April 15th, 2105 eclipse. — The circumstances for the April 15th, 2014 eclipse. The top chart shows the path of the Moon through the umbra, and the bottom chart shows the visibility region (light to shaded areas) Click here for a technical description. Credit: Eclipse Predictions by Fred Espenak, NASA/GSFC.

This marks the first total lunar eclipse visible from since December 10^th 2011, which was visible at moonset from North America, and marks the start of the first of two eclipse seasons for 2014. Totality will last 1 hour, 17 minutes and 48 seconds, and will be visible in its entirety from the central Atlantic westward to eastern Australia. Unlike a total solar eclipse, which occurs along a narrow track, a total lunar eclipse can be viewed by the entire moonward facing hemisphere of the Earth.

Tracing the umbra: a mosaic of the December 2010 eclipse. Photos by author.

The action begins at 4:37 Universal Time (UT)/12:37 AM EDT, when the Moon enters the western edge of the Earth’s shadow known as the penumbra. The Moon will be completely immersed in the penumbra by 5:58 UT/1:58 AM EDT, but don’t expect to see anything more than a faint tan shading that’s slightly darker on the Moon’s northeastern edge.

The real action begins moments later, as the Moon encounters the ragged edge of the umbra, or the inner core of the Earth’s shadow. When does the umbra first become apparent to you? Totality then begins at 7:06 UT/3:06 AM EDT and lasts until 8:24 UT/4:24 AM EDT, with mid-eclipse occurring just south of the center of the Earth’s shadow at 7:46 UT/3:46 AM EDT.

Finally, the eclipse ends as the Moon slides out of the penumbra at 10:37 UT/ 6:37 AM EDT. Michael Zeiler (@EclipseMaps) has complied a fine video guide to the eclipse:

Field guide to the total lunar eclipse of April 14 – 15, 2014 from Michael Zeiler on Vimeo.

This eclipse is also notable for being part of a series of four lunar eclipses in 2014 & 2015, known as a “tetrad.” NASA eclipse expert Fred Espenak notes that this series of eclipses is also notable in that all four are visible in part or in their entirety from the United States. We’re in a cycle of 9 sets of tetrads for the 21^st century, which began with the first set in 2003. Before that, you have to go all the way back to the 16^th century for the last set of eclipse tetrads!

4AM EDT. Credit Starry Night Education software. — The position of the Moon within the Earth’s umbra on the morning of April 15th at 4AM EDT/8UT. Credit: Starry Night Education software.

For saros buffs, the April 15^th eclipse is Member 56 of 75 of saros 122, which began on August 14^th 1022 A.D. and runs out until a final penumbral eclipse of the series on October 29^th, 2338. There are only two total eclipses left in this particular saros, one in 2032 and 2050. If you caught the total lunar eclipse of April 4^th, 1996, you saw the last lunar eclipse in this same saros series.

Lunar eclipses have turned up at some curious junctures in history. For example, a lunar eclipse preceded the fall of Constantinople in 1453. A 2004 lunar eclipse also fell on the night that the Red Sox won the World Series after an 86 year losing streak, though of course, lunar eclipses kept on occurring during those losing years as well. Christopher Columbus was known to evoke an eclipse on occasion to get him and his crew out of a jam, and also attempted to use a lunar eclipse to gauge his position at sea using a method first described by Ptolemy while studying the lunar eclipse of September 20^th, 331 B.C.

A handful of stars in the +8^th to +12^thmagnitude range will be occulted by the eclipsed Moon as well. Brad Timerson of the International Occultation Timing Association (IOTA) has put together a list, along with graze line prospects across the United States. The brightest star to be occulted by the eclipsed Moon is +5th magnitude 76 Virginis across western South America and Hawaii:

The occultation footprint of 76 Virginis during the April 15th lunar eclipse. Credit: Occult 4.0

Note that the bright star Spica will be only just over a degree from the eclipsed Moon, and Mars will also be nearby, just a week past its 2014 opposition. And to top it off, Saturn is just one constellation to the east in Libra!

During the partial phases of the eclipse, watch for the Moon to take on a “Pacman-like” appearance. The Earth’s umbra is just under three times the size of the Moon, and the Greek astronomer Aristarchus of Samos used this fact and a little geometry to gauge the distance to our natural satellite in the 3^rd century B.C.

As totality approaches, expect the innermost rim of the Moon to take on a ruddy hue. This is the famous “combination of all the sunrises and sunsets” currently underway worldwide as light is bent through the Earth’s atmosphere into its shadow. It’s happening every night, and during the totality of a lunar eclipse is the only chance that we get to see it.

4AM Credit: Stellarium — Looking to the southwest at 4 AM EDT from latitude 30 degrees north on the morning of April 15th. Credit: Stellarium.

You don’t need anything more sophisticated than the naked eye or “Mark 1 eyeball” to enjoy a lunar eclipse, though it’s fun to watch through binoculars or a low-power telescope field of view. One interesting project that has been ongoing is to conduct timings for the moment when the umbra contacts various craters on the Moon. It’s a curious mystery that the Earth’s shadow varies by a small (1%) but perceptible amount from one eclipse to the next, and efforts by amateur observers may go a long way towards solving this riddle.

Said color of the fully eclipsed Moon can vary considerably as well: the Danjon scale describes the appearance of the eclipsed Moon, from bright and coppery red (Danjon 4) to so dark as to almost be invisible (Danjon 0). This is a product of the amount of dust, volcanic ash and aerosols currently aloft in the Earth’s atmosphere. During the lunar eclipse of December 9^th, 1992 the Moon nearly disappeared all together, due largely to the eruption of Mount Pinatubo the year prior.

A lunar eclipse also presents a chance to nab what’s known as a Selenelion. This occurs when the Sun and the totally eclipsed Moon appear above the local horizon at the same time. This is possible mainly because the Earth’s shadow is larger than the Moon, allowing it to linger a bit inside the umbra after sunrise or before sunset. Gaining some altitude is key to making this unusual observation. During the April 15^th eclipse, selenelion sightings favor the Mid-Atlantic and Greenland where totality is underway at sunrise and eastern Australia, where the reverse is true at sunset.

Want to have a go at measuring the brightness or magnitude of the eclipsed Moon? Here’s a bizarre but fun way to do it: take a pair of binoculars and compare the pinpoint Moon during totality to the magnitude of a known star, such as Antares or Spica.

Note that to do this, you’ll first need to gauge the magnitude extinction of your particular binoculars: NASA’s got a table for that, or you could field test the method days prior on Venus, currently shining at a brilliant -4.2 in the dawn. Hey, what’s a $1,000 pair of image-stabilized binocs for?

And of course, weather prospects are the big question mark for the event. Mid-April weather for North America is notoriously fickle. We’ll be watching the Clear Sky Chart and Skippy Sky for prospects days before the eclipse.

Photography during an eclipse is fun and easy to do, and you’ll have the waxing gibbous Moon available to practice on days prior to event. Keep in mind, you’ll need to slow down those shutter speeds as the Moon enters into totality, we’re talking going down from 1/60^th of a second down to ¼” pretty quickly. In the event of a truly dark eclipse, the Moon may vanish in the view finder all together. Don’t be afraid to step exposures up to the 1 to 4 second range in this instance, as you’ve got over an hour to experiment.

Our “eclipse hunting rig…” the DSLR is piggy-backed to shoot stills on the main scope, which will shoot video. Note that the “f/34 field stop” will most likely be removed! Photo by author

Thus far, only one webcast for the eclipse has surfaced, courtesy of the venerable Slooh. We’ll most likely be doing a follow up roundup of eclipse webcasts as they present themselves, as well as a look at prospects for things like a transit of the ISS in front of the eclipsed Moon and weather forecasts closer to show time.

And speaking of spacecraft, China’s Chang’e 3 lander and Yutu rover will have a fine view of a solar eclipse overhead from their Mare Imbrium vantage point, as will NASA’s LRO and LADEE orbiters overhead. In fact, NASA hinted last year that the April 15^th eclipse might spell the end of LADEE entirely…

And thus marks the start of eclipse season one of two for 2014. Next up will be a curious non-central annular solar eclipse over Antarctica on April 29th, followed by another total lunar eclipse on October 8^th, and a fourth and final partial solar eclipse of the year for North America of October 23rd.

Watch this space and follow us on Twitter as @Astroguyz, as we’ll be “all eclipses, all the time,” for April… no new taxes guaranteed!

Next up: Heard the one about the Blood Moon? Yeah, us too… join us as we debunk the latest lunacy surrounding the eclipse tetrad!

– Got pics of the lunar eclipse? Send ‘em in to Universe Today, as a post-eclipse photo round up is a very real possibility!

March 31, 2014December 30, 2015 by David Dickinson

Observing Alert: Watch the Moon Cross the Hyades This Week

A photogenic grouping greets evening sky watchers this week providing a fine teaser leading up to a spectacular eclipse.

On the evening of Thursday, April 3^rd headed into the morning of the 4^th, the waxing crescent Moon crosses in front of the Hyades open star cluster. This is the V-shaped asterism that marks the head on Taurus the Bull, highlighted by the brilliant foreground star Aldebaran as the bull’s “eye”. Viewers across North America will have a ring-side seat to this “bull-fight” as the 20% illuminated Moon stampedes over several members of the Hyades in its path.

The brightest stars to be occulted are the Delta Tauri trio of stars ranging in magnitudes from +3.8 (Delta Tauri^1) to +4.8(2) and +4.3(3). Such occlusions – known in astronomy as occultations – are fun to watch, and can reveal the existence of close binary companions as they wink out behind the lunar limb. Several dozen occultations of stars brighter than +5^th magnitude by the Moon happen each year, and the best events occur when the Moon is waxing and the stars disappear against its dark leading edge. We recently caught one such event last month when the Moon occulted the bright star Lambda Geminorum:

We are currently seeing the Moon cross the Hyades during every lunation until the year 2020, though it’s a particularly favorable time to catch the event in April 2014 as the Moon is a slender crescent. Notice that you can just make out the dark limb of the Moon with the naked eye? What you’re seeing is termed Earthshine, and that’s just what it is: the nighttime side of the Moon being illuminated by sunlight that is reflected off of the Earth. Standing on the Earthward side of the Moon, an observer would see a waning gibbous Earth about two degrees across. Yutu has a great view!

The Moon will cross its descending node where its apparent path intersects the ecliptic on April 1^st (no joke, we swear) at 2:30 Universal Time or 10:30 PM EDT on March 31^st. The next nodal crossing now occurs in just two weeks, and the Earth’s shadow will be there to greet the Moon on the morning of April 15^th in the first of four total lunar eclipses that span 2014 and 2015. The month of April also sees the Moon’s orbit at its least eccentric, a time at which perigee – the Moon’s closest point to Earth – is at its most distant and apogee – its farthest point – is at its closest. This currently happens near the equinoxes, through the nodes slowly travel across the ecliptic completing one revolution every 18.6 years. Perigee can vary from 356,400 to 370,400 kilometres, and apogee can span a distance from 404,000 to 406,700 kilometres.

We’re also headed towards a “shallow year” in 2015 when the Moon has the least variability in respect to its declination. This trend will then reverse, climaxing with a “Long Nights Moon” riding high in the sky in 2025, which last occurred in 2006. The Moon will inch ever closer to Aldebaran on every successive lunation now, and begins a series of occultations of Aldebaran on January 29^th, 2015 through the end of 2018. Occultations of Aldebaran always occur near these shallow years, and will be followed by a cycle of occultations of Regulus starting in 2017. We caught an excellent daytime occultation of Aldebaran by the Moon from North Pole, Alaska during the last cycle in the late 1990s.

Photos by Author — The Moon passing between the Hyades and Pleiades in 2011 with Earthshine highlighted. Photos by author.

Now for the wow factor. Our Moon is 3,474 kilometres across and located just over one light second away. The Hyades star cluster covers about 6 ½ degrees of sky – about 7 times the size of the Full Moon – but is the closest open cluster to the Earth at 153 light years distant and has a core diameter of about 18 light years across. As mentioned previous, Aldebaran isn’t physically associated with the Hyades, but is merely located in the same direction at 65 light years distant.

The Hyades star cluster also provided early 20^thastronomers with an excellent study in galactic motion. At an estimated 625 million years in age, the Hyades are slowly getting disbanded and strewn about the Milky Way galaxy in a process known as evaporation. The Hyades are also part of a larger stellar incorporation known as the Taurus Moving Cluster. Moving at an average of about 43 kilometres a second, the members of the Hyades are receding from us towards a divergent point near the bright star Betelgeuse in the shoulder of Orion. 50 million years hence, the Hyades will be invisible to the naked eye as seen from Earth, looking like a non-descript open cluster and providing a much smaller target for the Moon to occult at 20’ across. Astronomer Lewis Boss was the first to plot the motion of the Hyades through space in 1908, and the cluster stands as an essential rung on the cosmic distance ladder, with agreeing measurements independently made by both Hubble and Hipparcos and soon to be refined by Gaia.

Photographing and documenting this week’s passage of our Moon across the Hyades is easy with a DSLR camera: don’t be afraid to vary those ISO and shutter speeds to get the mix of the brilliant crescent Moon, the fainter earthshine, and background stars just right. The more adventurous might want to try actually catching the numerous occultations of bright stars on video. And U.S. and Canadian west coast observers are well placed to catch the Moon cross right though the core of the Hyades… a video animation of the event is not out of the question!

And from there, the Moon heads on to its date with destiny and a fine total lunar eclipse on April 15^th which favors North American longitudes. We’ll be back later this week with our complete and comprehensive eclipse guide!

March 28, 2014May 25, 2023 by David Dickinson

Adventures in (Radio) Amateur Astronomy

Is there truly anything new under the Sun? Well, when it comes to amateur astronomy, many observers are branching out beyond the optical. And while it’s true that you can’t carry out infrared or X-ray astronomy from your backyard — or at least, not until amateurs begin launching their own space telescopes — you can join in the exciting world of amateur radio astronomy.

We’ll admit right out the gate that we’re a relative neophyte when it comes to the realm of radio astronomy. We have done radio observations of meteor showers in tandem with optical observations, and have delved into the trove of information on constructing radio telescopes over the years. Consider this post a primer of sorts, an intro into the world of radio amateur astronomy. If there’s enough interest, we’ll follow up with a multi-part saga, constructing and utilizing our own ad-hoc “redneck array” in our very own backyard with which to alarm the neighbors and probe the radio cosmos.

Repurposing a TV Dish for amatuater astronomy. Credit: NSF/NRAO/Assoc. Universities, Inc. — The “Itty-Bitty Array”- Re-purposing a TV Dish for amateur astronomy. Credit: NSF/NRAO/Assoc. Universities, Inc.

…And much like our exploits in planetary webcam imaging, we’ve discovered that you may have gear kicking around in the form of an old TV dish – remember satellite TV? – in your very own backyard. A simple radio telescope setup need not consist of anything more sophisticated than a dish (receiver), a signal strength detector (often standard for pointing a dish at a satellite during traditional installation) and a recorder. As you get into radio astronomy, you’ll want to include such essentials as mixers, oscillators, and amplifiers to boost your signal.

Frequency is the name of the game in amateur radio astronomy, and most scopes are geared towards the 18 megahertz to 10,000 megahertz range. A program known as Radio-SkyPipe makes a good graphic interface to turn your laptop into a recorder.

Radio astronomy was born in 1931, when Karl Jansky began researching the source of a faint background radio hiss with his dipole array while working for Bell Telephone. Jansky noticed the signal strength corresponded to the passage of the sidereal day, and correctly deduced that it was coming from the core of our Milky Way Galaxy located in the constellation Sagittarius. Just over a decade later, Australian radio astronomer Ruby Payne-Scott pioneered solar radio astronomy at the end of World War II, making the first ever observations of Type I and III solar bursts as well as conducting the first radio interferometry observations.

A replica of Jansky's first steerable antanta at Green Bank, West Virginia. — A replica of Jansky’s first steerable antenna at Green Bank, West Virginia. (Public Domain image)

What possible targets exist for the radio amateur astronomer? Well, just like those astronomers of yore, you’ll be able to detect the Sun, the Milky Way Galaxy, Geostationary and geosynchronous communication satellites and more. The simple dish system described above can also detect temperature changes on the surface of the Moon as it passes through its phases. Jupiter is also a fairly bright radio target for amateurs as well.

Radio meteors are also within the reach of your FM dial. If you’ve ever had your car radio on during a thunderstorm, you’ve probably heard the crackle across the radio spectrum caused by a nearby stroke of lightning. A directional antenna is preferred, but even a decent portable FM radio will pick up meteors on vacant bands outdoors. These are often heard as ‘pings’ or temporary reflections of distant radio stations off of the trail of ionized gas left in the wake of a meteor. Like with visual observing, radio meteors peak in activity towards local sunrise as the observer is being rotated forward into the Earth’s orbit.

Amateur SETI is also taking off, and no, we’re not talking about your crazy uncle who sits out at the end of runways watching for UFOs. BAMBI is a serious amateur-led project. Robert Gray chronicled his hunt for the elusive Wow! signal in his book by the same name, and continues an ad hoc SETI campaign. With increasingly more complex rigs and lots of time on their hands, it’s not out of the question that an amateur SETI detection could be achieved.

Another exciting possibility in radio astronomy is tracking satellites. HAM radio operators are able to listen in on the ISS on FM frequencies (click here for a list of uplink and downlink frequencies), and have even communicated with the ISS on occasion. AMSAT-UK maintains a great site that chronicles the world of amateur radio satellite tracking.

Amateur radio equipment that eventually made its way to to ISS aboard STS-106. (Credit: NASA).

Old TV dishes are being procured for professional use as well. One team in South Africa did just that back in 2011, scouring the continent for old defunct telecommunications dished to turn them into a low cost but effective radio array.

Several student projects exist out there as well. One fine example is NASA’s Radio JOVE project, which seeks student amateur radio observations of Jupiter and the Sun. A complete Radio Jove Kit, to include receiver and Radio-SkyPipe and Radio-Jupiter Pro software can be had for just under 300$ USD. You’d have a tough time putting together a high quality radio telescope for less than that! And that’s just in time for prime Jupiter observing as the giant planet approaches quadrature on April 1^st (no fooling, we swear) and is favorably placed for evening observing, both radio and optical.

Fearing what the local homeowner’s association will say when you deploy your very own version of Jodrell Bank in your backyard? There are several online radio astronomy projects to engage in as well. SETI@Home is the original crowd sourced search for ET online. The Zooniverse now hosts Radio Galaxy Zoo, hunting for erupting black holes in data provided by the Karl Jansky Very Large Array and the Australia Telescope Compact Array. PULSE@Parkes is another exciting student opportunity that lets users control an actual professional telescope. Or you can just listen for meteor pings online via NASA’s forward scatter meteor radar based out of the Marshall Space Flight Center in Huntsville, Alabama. Adrian West also hosts live radio meteor tracking on his outstanding Meteorwatch website during times of peak activity.

Forward Scatter — A diagram of a basic forward scatter radar system for meteor observing. Credit: NASA

Interested? Other possibilities exist for the advanced user, including monitoring radio aurorae, interferometry, catching the hiss of the cosmic microwave background and even receiving signals from more distant spacecraft, such as China’s Yutu rover on the Moon.

Think of this post as a primer to the exciting world of amateur radio astronomy. If there’s enough interest, we’ll do a follow up “how-to” article as we assemble and operate a functional amateur radio telescope. Or perhaps you’re an accomplished amateur radio astronomer, with some tips and tricks to share. There’s more to the universe than meets the eye!

-Also be sure to check out SARA, the Society of Amateur Radio Astronomers.

March 24, 2014December 23, 2015 by David Dickinson

Ready, Set, Messier Marathon: A 2014 Guide

Patiently awaiting darkness at the starting line... Credit and copyright: John Chumack.

Have YOU seen all 110?

The passage of the northward equinox last week on March 20^th means one thing in the minds of many a backyard observer: the start of Messier Marathon season. This is a time of year during which a dedicated observer can conceivably spot all of the objects in Charles Messier’s famous deep sky catalog in the span of one night.

We’ve written about some tips and tricks to completing this challenge previously, as well as the optimal dates for carrying a marathon out. Typically, the New Moon weekend nearest the March equinox is the best time of year for northern hemisphere observers to target all of the objects on Messier’s list. This works because a majority of the Messier objects are clustered into two regions: towards the core of our galaxy in Sagittarius — where the Sun sits during the December solstice — up through the summer triangle constellations of Cygnus, Aquila and Lyra, and in the bowl of Virgo asterism and its super cluster of galaxies that extends northward into the constellation of Coma Berenices. In March through early April the Sun sits in the constellation of Pisces, well away from the galactic plane.

The prospects for completing a Messier marathon in 2014 favor the last weekend on March on the 29^th-30^th. The Moon reaches New on Sunday, March 30^th at 18:45 Universal Time/2:45 PM EDT.

Messier marathons first came into vogue in the early 1970s right around the time Schmidt-Cassegrain and large Dobsonian “light bucket” telescopes came into general use.

Charles Messier began noting the curious objects that he would later incorporate into his famous catalog during the summer of 1758, with his description of the Crab Nebula in Taurus, which would become Messier object number one or M1. Messier was a prolific comet hunter and discovered 21 comets in his lifetime. The catalog was compiled over the span of 13 years from 1771 to 1784. Messier’s original list contained 45 objects, and was later expanded in subsequent editions 103, with Messier’s assistant Pierre Méchain adding six more objects to the catalog. The list is generally tallied at 110 objects, with one famous controversy being M102, which is generally cited as a re-observation of M101 or the galaxy NGC 5866.

The catalog itself contains a grab bag of open and globular clusters, galaxies, planetary and diffuse nebulae, and one double star (M40). The Messier catalog spans the sky down to M7, an object also known as the Ptolemy Cluster, which is the southernmost object on the list at latitude -34 degrees 48’ south.

The first page of Messier's third revision of his catalog describing M1 through M5. Image in th Public Domain. — The first page of Messier’s third revision of his catalog, describing M1 through M5. Image in the Public Domain.

Messier observed from Paris at latitude +48 degrees 51’ north using two primary telescopes of the almost one dozen that he owned for his discoveries: a 6.4” Gregorian reflector and a 3.5” refractor. Messier knew nothing of the nature of these “faint fuzzies” that he’d periodically stumbled across in his cometary vigil. His original intent was to compile a list of “comet imposters” in the night sky for comet hunters to be aware of in their quests. In his words:

“What made me produce this catalog was the nebula which I had seen in Taurus while I was observing the comet of that year (1758). The shape and brightness of that nebula reminded me so much of a comet, that I undertook to find more of its kind, to save astronomers from confusing these nebulae with comets.”

“Beware, here doth not lie comets,” Messier admonishes future generations of observers. Still, some peculiarities remain in the catalog: why did Messier, for example, include such obvious “non-comets” as the Pleiades (M45), but skip over the brilliant Double Cluster in Perseus?

Charles Messier's 1771 sketch of the Orion nebula, M42 in the Messier Catalog. Image in the public domain. — Charles Messier’s 1771 sketch of the Orion nebula, M42 in the Messier Catalog. Image in the public domain.

Alas, such mysteries are known only to Messier, who was interred at the famous Père Lachaise cemetery after his death in 1817. When we visit Paris, we’ll bypass Jim Morison to leave a copy of Burnham’s Celestial Handbook at Messier’s grave.

And just like the road variety, “running the Messier marathon” takes all of the stamina and pacing that a visual athlete can muster. You’ll want to grab M77 and M74 immediately after dusk, or the marathon will be over before it starts. From there, move on up north to the famous Andromeda galaxy (M31) and the scattering of objects around it before settling in for a more leisurely observing pace moving westward through the constellations of Orion, Leo and surrounding objects.

An all-sky map showing the distribution of Messier objects. (Click to enlarge). Credit: Jim Cornmell under a Wikimedia Commons Attribution-Share Alike 3.0 Unported license.

Now towards the approach of local midnight comes the first large group: the Virgo cluster of galaxies extending through Coma Berenices, rising to the east. After this batch, you can catch some quick shut-eye before bagging the Messier objects towards the galactic center and up through Cygnus in the pre-dawn. Plan ahead; M52, M2 and M30 are especially notoriously difficult in the spring dawn sky!

It’s also worth noting your “attitude versus latitude” plays a role as well. To this end, Ed Kotapish compiled this nifty perpetual chart of when the entire Messier catalog is visible from respective latitudes:

A chart calculating number of total Messier objects that are visible on the dates (vertical column in month-day format) versus north latitude (top row). Note that this chart is pertpetual for non-leap years, and does not take into account the pahse of the Moon. Click to enlarge. Credit: Edward Kotapish.

“The bounds of the chart are for a variety of objects,” Ed told Universe Today. “I used nautical twilight (when the Sun falls below -12 degrees in elevation) as the starting and ending condition.” Ed also notes that the top curve of the chart on the morning side is bounded by the difficulty in finding troublesome M30, while the left bottom evening boundary is limited by the observability of M110 and M74, which can be a problem for observers at higher latitudes.

Alternate versions of the Messier marathon exist as well, such as imaging or even sketching all 110 objects in one night.

Why complete a Messier marathon? Well, not only does such a feat hone your visual skills as an observer, but it also familiarizes you with the entire catalog… and there’s nothing that says you have to complete it all in one evening, except of course, for bragging rights at the next star party!

Good luck!

-Here’s a handy list of all 110 of the Messier objects in the catalog.

-Be sure to send those pics of Messier objects and more in to Universe Today’s Flickr forum!