Skywatching Archives

March 5, 2014April 26, 2016 by David Dickinson

Daylight Saving Time: A Spring Forward or a Step Back?

The tricky business of keeping time... the Astronomical Clock in Prague, Czech Republic.

The time to change clocks is once again nigh.

We’ll put our unabashed bias as a lover of the night sky right up front: we loathe Daylight Saving Time. And it’s not just because of the biannual hunt through our home for the dozen-odd non-networked clocks that it instigates twice a year. For astronomers, the shift to DST means that true darkness falls much later in the evening, marking the abrupt end of the school star party season not long after March. You don’t have to go far north to about latitude 45 degrees to find areas where it doesn’t get dark until about 11PM local towards mid-summer. And sure, we gain back an extra hour of morning darkness, albeit that too soon dwindles towards summer as well.

In 2014 we (as in a majority of North America) spring forward one hour on March 9^th at 2:00 AM local. That’s just one day shy of the earliest that we can now spring forward, as the current convention established by the Energy Policy Act of 2005 during the Bush administration that was enacted in 2007 now sets the beginning of DST as the 2^nd Sunday in March.

We’re now on DST for about roughly eight months or 67% of the calendar year. The European Union still shifts forward on the last Sunday of March, meaning that for a span of three weeks every March, the time lag between, say, Eastern Daylight Time and British Standard Time closes briefly to four hours before opening up again to five hours.

Current DST usage worldwide. Regions in blue currently use DST, orange have scrapped DST, and regions in red have never used DST. Credit: Paul Eggert under a wikimedia Creative Commons Attribution-Share Alike 3.0 Unported license. — Current DST usage worldwide. Regions in blue currently use DST, orange have scrapped DST, and regions in red have never used DST. Credit: Paul Eggert under a Wikimedia Creative Commons Attribution-Share Alike 3.0 Unported license.

And that’s just for starters.

Of course, there are holdouts even among DST observing countries worldwide. The states of Arizona and Hawaii do not observe DST, nor did a portion of Indiana until 2006. When DST is in effect, you can touch on three time zones in just a few hours’ drive from southeastern Arizona crossing southern New Mexico and into Texas east of El Paso. And you can really mix things up driving across the Navajo nation in northeastern Arizona – which observes DST, unlike the rest of the state – into the Hopi Reservation embedded within it, which rejects DST.

In Canada, most of Saskatchewan ignores DST, as do small portions of British Columbia, Quebec and Nunavut. In 2011, Russia opted to remain on Daylight Saving Time year round, and Australia is sharply divided on the issue of keeping DST. Of course, in the southern hemisphere, astronomical spring and fall are reversed, making UK/US/Australia teleconference scheduling even more confusing this time of year, not to mention the often bewildering state of affairs faced by computer programmers seeking to include every new rule and nuisance concerning local timekeeping worldwide.

1918 Poster espousing the benifits of the first DST shift for the U.S. Credit: U.S. Library of Congress image in the Public Domain. — 1918 Poster espousing the benefits of the first DST shift for the U.S. Credit: U.S. Library of Congress image in the Public Domain.

Most folks trace the notion of daylight saving time back to Benjamin Franklin, though DST saw its first implementation by Axis powers in 1916 as a cost saving measure. In the United States, the Standard Time Act of 1918 put DST into effect for the first time, and it was an on again, off again affair through most of the 20^th century.

And it’s not just your imagination: we do spring forward earlier and fall back later in the year than we used to. The Uniform Time Act was amended in 1986 to begin DST on the first Sunday in April and run until the last Sunday in October. And as mentioned previously, the Energy Policy Act of 2005 modified this even further under President George W. Bush to our present state of affairs, starting DST on the second Sunday of March through the first Sunday in November.

The primary rational behind DST use is to cut energy consumption. Studies done by the U.S. Department of Transportation during the adoption of DST during the 1970’s OPEC Oil Embargo and the energy crisis showed a small but measurable net savings during the implementation of DST, as well as a small decrease in the crime rate. On the down side, many find it difficult to adjust their body clocks to the shift, with many morning commuters now confronted with darkness.

Is DST a conspiracy of the golf crowd and/or the candy lobby? Anecdotal tales abound that some senators simply wanted few more hours on the course each evening, and “Big Sugar” (a great pro-wrestling name, BTW) was all too willing to oblige. Certainly, we do our trick-or-treating in the daylight now on the last day of October, and will soon be waiting later and later each Sunday evening for astronomical darkness and the start of the Virtual Star Party.

But there are some rumblings of change. This year, Idaho is pushing to scrap DST altogether. And, as is the norm in the often curious state of Florida, lawmakers have proposed to swing even further in the other direction, with a bill dubbed the “Sunshine Protection Act” looking to put the entire state on permanent DST year round in hopes of increasing tourism.

And just last year, a failed White House petition brought up the issue of ending DST. Perhaps their misspelling of DST as “Daylight Savings” (a frequent mistake) detracted from its credibility. What is it that makes us just want to throw that spurious “s” in there?

And that’s the wacky state of time we’re stuck with. Yes, we’ll be ferreting out those non-networked clocks around Astroguyz HQ Sunday morning, bleary from the loss of an hours’ sleep.

Our modest proposal is to do away with DST and time zones entirely, and adopt the use of Universal Time (also referred to as Zulu or Greenwich Mean Time) across the board. I know, it’s a tall order. In the meantime, we’ll be saying #DownWithDST on Twitter, as we await true astronomical darkness at an ever later hour.

And with that, we’ll open the debate up to you, the astute and intelligent readership of Universe Today. Is Daylight Saving Time worth it?

March 4, 2014December 23, 2015 by David Dickinson

Watch the Close Pass of NEO Asteroid 2014 DX110 Wednesday Night

The orbital path and position of Apollo NEO asteroid 2014 DX110 just a week prior to disocvery. Credit- Created using NASA/JPL's Solar System Dynamics Small-Body Database Browser.

BREAKING- No sooner than the cyber-ink was dry on this post than we got notice of another 10-metre NEO asteroid 2014 EC passing Earth at just under 0.2 times the Earth-Moon distance – less than 64,000 kilometres – on Thursday, March 6th at 21:18 UT/4:18 PM EST. And the Virtual Telescope will be carrying this passage live as well on March 6th starting at 19:00 UT/2:00 PM EST. Bring in on, universe!

The Earth-Moon system gets a close shave on the night of Wednesday, March 5^th 2014 when Near Earth Object (NEO) asteroid 2014 DX110 passes our fair planet at 216,000 miles or about 345,600 distant at around 21:06 Universal Time (UT)/ 4:06 PM EST.

About 30 metres in diameter, 2014 DX110 was discovered by the Pan-STARRS 1 survey on February 28^th, and its orbit was initially refined using follow up observations made by the Great Shefford Observatory in West Berkshire, England.

And although the asteroid is no threat to Earth or the Moon – it makes a pass 232,800 miles from our natural satellite one hour and 22 minutes after its closest passage from the Earth – the asteroid is currently listed on NASA’s risk page for a 1 in 10,000,000 chance of impact with Earth on March 4^th, 2046.

Of course, additional observations usually lower this remote possibility even further in the case of most newly discovered near Earth asteroids. Visually, 2014 DX110 isn’t expected to brighten above +15^th magnitude as it glides northward through the constellation of Camelopardalis at closest approach Wednesday night.

But the good news is, you can catch the passage of 2014 through the Earth-Moon system Wednesday night courtesy of our friends at the Virtual Telescope Project:

The webcast of the event is expected to go live at 20:30 UT, and will include live commentary.

Its been a busy last few weeks in terms of asteroid flybys, including a passage of Amor NEO asteroid 2014 DU110 earlier today at 15:54 UT/10:54 AM EST at 0.14 A.U.s or just over 20 million kilometres distant. And the folks at the Virtual Telescope Project will be covering another asteroid flyby on Sunday, March 9^th starting at 23:00 UT/6:00 PM EST to track the 180 meter asteroid 2014 CU13. This large Apollo NEO is projected to pass 8 lunar distances or over 3 million kilometres away from the Earth on March 11^th at 9:05 UT/4:05 AM EST.

It should be easy to pick out the motion of 2014 DX110 moving against the starry background at closest approach in real time. 2014 DX110 is an Apollo-class asteroid, and has an orbital period of 1192 days or about 3.26 years. It also has a fairly shallow inclined orbit relative to the ecliptic traced out by Earth’s path around the Sun, with a tilt of just over 5.7 degrees. This means that 2014 DX110 is approaching the Earth from just southward and behind it in its orbit around the Sun before crossing just inside of our orbit and northward of the ecliptic plane.

The discovery of asteroid 2014 DX110 was announced by the Minor Planet Center on Sunday, March 2^nd in electronic circular 2014-E22. The orbit of 2014 DX110 takes it just interior of Earth’s at a perihelion of 0.83 A.U.s from the Sun and out to an aphelion of 3.6 A.U.s into the realm of the asteroid belt between Mars and Jupiter.

Generally speaking, asteroids passing interior to the Moon’s orbit grab our attention for further scrutiny. Looking back through the European Space Agency’s Near-Earth Objects Dynamics Site, asteroid 2014 DX110 also made an undocumented close passage of Earth on March 17^th, 1998 at a minimum possible miss distance of 102,300 miles/163,680 kilometres distant, and a similar passage March 22^nd, 1982. 2014 DX110 passed sufficiently close enough to Earth on these passages to alter its orbit so that it now returns to our terrestrial neighborhood every 13 odd years during the span of the 21^st century. 2014 DX110 will be moving at a velocity of 14.8 kilometres per second relative to Earth on closest approach Wednesday night and will be inside the Earth’s Hill sphere of gravitational influence from March 4^th to March 7^th, though of course, it’s moving much too fast for capture.

2014 DX110 will be interior of the Moon’s orbit from 18:06 UT/1:06 PM EST on March 5^th until 00:07 UT March 6^th (7:07 PM EST on the night of March 5^th). The large size – about the size of an office block – and the nature of its orbit, coupled with its relatively large velocity relative to the Earth rule out any potential for 2014 DX110 being space junk in solar orbit returning to Earth’s vicinity, though such objects from the Apollo missions and the Chinese Chang’e-2 Moon mission have been recovered as Earth asteroids before.

Such an impact risk, however remote, merits further study to refine the orbit of this potentially hazardous space rock. Surveys such as PanSTARRS, the Catalina Sky Survey and the B612 Foundation’s asteroid hunting Sentinel space telescope slated for launch as early as 2017 are working to identify dangerous space rocks. The next and more difficult step will be mitigation and working to nudge these asteroids out of harm’s way, hopefully years in advance.

But you can breathe a sigh of relief Wednesday night as asteroid 2014 DX110 passes us at a safe distance. Thanks to Gianluca Masi at the Virtual Telescope Project for bringing this one to our attention!

February 26, 2014December 23, 2015 by David Dickinson

Spectacular Views of Venus and the “Decrescent” Moon Worldwide

Did you see it? Earlier this week, we wrote about the spectacular conjunction of the planet Venus and the waning crescent Moon this week, which culminated in a fine occultation of the planet by our large natural satellite on Wednesday morning. The footprint of the occultation crossed northern Africa in the predawn hours to greet daytime observers across southern Asia. And although the pass was a near miss for many, viewers worldwide were treated to a fine photogenic pairing of Venus and the Moon.

Credit: SculptorLil — An “aircraft/Moon/Venus tri-conjunction” captured February 26th from London, UK. Credit: Sculptor Lil

This was a highlight event of the 2014 dawn apparition of Venus, and some great pics have been pouring in to us here at Universe Today via Twitter, Google+ and our Flickr pool. We also learned a new word this week while immersed in astronomical research: a decrescent Moon. We first thought this was a typo when we came across it, but discovered that it stands for a waning crescent Moon going from Last Quarter phase to New. Hey, it’s got a great ring to it, and its less characters than “waning crescent” and thus comes ready Tweet-able.

Venus and the Moon in the predawn sky captured from Israel. Credit: Gadi Eidelheit @gadieid

Some great video sequences have emerged as well, including this fine grazing sequence of a daytime crescent Venus brushing past the crescent Moon taken by Shahrin Ahmad:

Shahrin journeyed to the northern tip of Peninsular Malaysia to the town of Perlis near near the Thai border to capture the graze. “It was a really close event,” he noted. “Today, the clouds began to appear and posed some real tense moments during the occultation.”

And although many weren’t fortunate enough to be in the path of the occultation, many observers worldwide captured some very photogenic scenes of the conjunction between the Moon and Venus as the pair rose this morning, including this great video sequence from Ryan Durnall:

And clear skies greeted a series of early morning astronomers worldwide, who shared these amazing images with us:

This morning’s conjunction as imaged from Newark, New York. Credit- Brad Timerson @btimerson

Venus and the Moon the day prior to the occultation, shot by Ken Lord from Maple Ridge, British Columbia. Credit- Ken Lord.

The Moon approaching Venus on February 25th as seen from Carbon County, Pennsylvania. Credit: Tom Wildoner.

Venus and the Moon rising through the fog: Credit: Joanie Boloney @jstabila

John Chumack was also up early this morning and was able to capture this fine image of the pair rising above the University of Dayton’s PAC Center:

Venus and the Moon as seen from Dayton, Ohio. Credit: John Chumack, www.galacticimages.com

“All I had available was a point and shoot camera (not even mine!)” Chumack told Universe Today. “I’m surprised it came out okay, considering all the ambient light on Campus!!!” Chumack used a Fujifilm Finepix S1000 point and shoot camera, and went sans tripod, doing a 2″ exposure with the camera perched atop a trash can. The results of this ad hoc setup look great!

Astrophotographer Giuseppe Petricca based in Pisa, Italy north of the occultation path also grabbed this outstanding closeup image of the crescent pair:

Taken using a Nikon Coolpix P90 Bridge camera on a tripod mount. Credit: Giuseppe Petricca

“This morning was awesome!” Petricca told Universe Today. “The weather forecast showed a compact high layer of clouds, but there were enough gaps between them that allowed me to see the conjunction in a lot of different moments.”

You can compare and contrast the twin crescents of Venus and the Moon evident in the above image. “You can easily see the phase of the Planet Venus and a lot of details on the lunar surface, despite the high clouds that partially blocked the view sometimes!” Petricca noted.

And finally, I give you our own humble entry, a conjunction over suburbia snapped pre-caffeination:

We think its great that you can sometimes catch a memorable glimpse of the celestial even from your own doorstep.

And when is the next occultation of a planet by the Moon? That would be next month, when Saturn is occulted by the waxing gibbous Moon for South Africa and Brazil after sunset on March 21^st, 2014. We’re in the midst of a cycle of occultations of the ringed planet by the Moon, occurring every lunation through the final one this year on October 25th.

The next occultation of Venus occurs on October 23^rd 2014, but is only one degree from the Sun and is unobservable. The next observable event occurs on July 19^th 2015 for northern Australia in the daytime, and for a remote stretch of the South Pacific at dusk.

And its still not too late to spy Venus in the daytime today, using the nearby Moon as a guide. Here’s a handy simulation to aid you in your quest generated for mid-noon, February 26th:

stellarium — The orientation of the Moon and Venus at ~17:00UT, including a five degree Telrad bullseye. Created by the author using Stellarium.

And finally here’s handy chart of maps of occultations of Venus by the Moon for the current decade, just click to enlarge:

Occultations of Venus by the Moon from 2011-2020. Created using Occult 4.0.

Enjoy!

February 24, 2014April 26, 2016 by David Dickinson

Watch the Moon Meet Venus in the Dawn this Wednesday

The view of Wednesday's conjunction from selected sites based on four separate continents. Credit: Created by the author using Stellarium.

Are you ready for some lunar versus planetary occultation action? One of the best events for 2014 occurs early this Wednesday morning on February 26^th, when the waning crescent Moon — sometimes referred to as a decrescent Moon — meets up with a brilliant Venus in the dawn sky. This will be a showcase event for the ongoing 2014 dawn apparition of Venus that we wrote about recently.

This is one of 16 occultations of a planet by our Moon for 2014, which will hide every naked eye classical planet except Jupiter and only one of two involving Venus this year.

An occultation occurs when one celestial body passes in front of another, obscuring it from our line of sight. The term is used to refer to planets or asteroids blocking out distant stars or the Moon passing in front of stars or planets.

Wednesday’s event has a central conjunction time of 5:00 Universal. Viewers in northwestern Africa based in Mali and southern Algeria and surrounding nations will see the occultation occur in the dawn sky before sunrise, while viewers eastward across the Horn of Africa, the southern Arabian peninsula, India and southeast Asia will see the occultation occur in the daylight.

A comparison of Venus versus the Moon in the daytime taken by Sharin Ahmad (@shahgazer) from Malaysia during the last lunation on January 29th, 2014.

Observers worldwide, including those based in Australia, Europe and the Americas will see a near miss, but early risers will still be rewarded with a brilliant dawn pairing of the second and third brightest objects in the night sky. This will also be a fine time to attempt to spot Venus in the daytime, using the nearby crescent Moon as a guide. It’s easier than you might think! In fact, Venus is actually brighter than the Moon per apparent square arc second of surface area, owing to its higher average reflectivity (known as albedo) of 80% versus the Moon’s dusky 14%.

The International Occultation Timing Association also maintains a chart of ingress and egress times for specific locations along the track of the occultation.

Credit: Created using Occult 4.0.11. — The footprint of the Wednesday occultation of Venus by the Moon. Solid lines indicate where the occultation occurs before sunrise, while the dashed area denotes where the occultation occurs after sunrise. Credit: Created using Occult 4.1.0.11.

The Moon occults Venus 21 times in this decade. The last occultation of Venus by the Moon occurred on September 8^th, 2013, and the next occurs October 23rd 2014 over the South Pacific in daylight skies very close to the Sun, and is unobservable.

Wednesday’s event also offers a unique opportunity to catch a crescent Venus emerging from behind the dark limb of the Moon. On Wednesday, Venus presents a 34” diameter disk that is 35% illuminated and shining at magnitude -4.3, while the Moon is a 12% illuminated crescent three days from New. Fun fact: February 2014 is missing a New Moon, meaning that both January and March will each contain two!

Apparent path of Venus in relation to the Moon Wednesday morning as seen from a theoretical geocentric (Earth-centered) location. Created using Starry Night Education software.

This also means that a well positioned observer in northwestern Africa would be able to see able to catch the dark limb of Venus creeping out from behind the nighttime side of the Moon against a dark sky. Such favorable occurrences only happen a handful of times per decade, and this week would be a great time to try and briefly spot – or perhaps even video or photograph – a phenomenon know as the ashen light of Venus as the dazzling crescent daytime side of the planet lay obscured by the Moon. Is this effect reported by observers over the years a fanciful illusion, or a real occurrence?

Perhaps, due to the remote location, this chance to spy and record this elusive effect will go unnoticed this time ‘round. The next chance with optimal possibilities to catch a crescent Venus occulted by the Moon against a dark sky occurs next year on October 8th, 2015, favoring the Australian outback. Anyone out there down for an observing expedition to prove or disprove the ashen light of Venus once and for all? Astronomy road trip!

Photo by Author — April 22nd, 2009 conjunction of Venus and the Moon as seen from Hudson, Florida. The Photo by author.

This event also provides optimal circumstances as Venus heads towards greatest elongation west of the Sun on March 22^nd and the Moon-Venus pair lay 43 degrees west of the Sun during Wednesday’s event. Compare this to the impossible to observe occultation this October, when the pairing is only one degree east of the Sun! The next occultation of Venus for North America occurs next year on December 7th, 2015 and will be visible in the daytime across the extent of the track except for Alaska and Northwestern Canada.

Vexillographers may also want to take note: this week’s Venus-Moon pairing will closely emulate the familiar crescent Moon plus star pairing seen on many national flags worldwide. Did an ancient and unrecorded occultation of Venus by the Moon inspire this meme? Tradition has it that Sultan Alp Arslan settled on the star and crescent for the flag of the Turks after witnessing a close conjunction after the defeat of the Byzantine Army at the Battle of Manzikert on August 26^th, 1071 A.D. This tale, however, is almost certainly apocryphal, as no occultations of planets or bright stars by the Moon occurred on or near that date, and only two occultations of Venus by the Moon occurred that year. And Venus was less than two degrees from the Sun on that date, yet another strike against it. In fact, the only occultations of Venus by the Moon in 1071 occurred on June 29^th and November 27^th. Perhaps Arslan just took a while to decide…

Still, this week’s event provides a great photo-op to have “Fun with Flags” and capture the pair behind your favorite astronomical conjunction-depicting banner. And be sure to send those pics into Universe Today… methinks there’s a good chance of us running a post occultation photo-essay later this week!

February 19, 2014December 23, 2015 by David Dickinson

Dazzling New Views of a Familiar Cluster

Wow. It’s always amazing to get new views of familiar sky targets. And you always know that a “feast for the eyes” is in store when astronomers turn a world-class instrument towards a familiar celestial object.

Such an image was released this morning from the European Southern Observatory (ESO). Astronomers turned ESO’s 2.2-metre telescope towards Messier 7 in the constellation Scorpius recently, and gave us the star-studded view above.

Also known as NGC 6475, Messier 7 (M7) is an open cluster comprised of over 100 stars located about 800 light years distant. Located in the curved “stinger” of the Scorpion, M7 is a fine binocular object shining at a combined magnitude of about +3.3. M7 is physically about 25 light years across and appears about 80 arc minutes – almost the span of three Full Moons – in diameter from our Earthly vantage point.

One of the most prominent open clusters in the sky, M7 lies roughly in the direction of the galactic center in the nearby astronomical constellation of Sagittarius. When you’re looking towards M7 and the tail of Scorpius you’re looking just south of the galactic plane in the direction of the dusty core of our galaxy. The ESO image reveals the shining jewels of the cluster embedded against the more distant starry background.

Messier 7 is middle-aged as open clusters go, at 200 million years old. Of course, that’s still young for the individual stars themselves, which are just venturing out into the galaxy. The cluster will lose about 10% of its stellar population early on, as more massive stars live their lives fast and die young as supernovae. Our own solar system may have been witness to such nearby cataclysms as it left its unknown “birth cluster” early in its life.

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Other stars in Messier 7 will eventually mature, “join the galactic car pool” in the main sequence as they disperse about the plane of the galaxy.

But beyond just providing a pretty picture, studying a cluster such as Messier 7 is crucial to our understanding stellar evolution. All of the stars in Messier 7 were “born” roughly around the same time, giving researchers a snapshot and a chance to contrast and compare how stars mature over there lives. Each open cluster also has a unique spectral “fingerprint,” a chemical marker that can even be used to identify the pedigree of a star.

For example, there’s controversy that the open cluster Messier 67 may actually be the birth place of our Sun. It is interesting to note that the spectra of stars in this cluster do bear a striking resemblance in terms of metallicity percentage to Sol. Remember, metals in astronomer-speak is any element beyond hydrogen and helium. A chief objection to the Messier 67 “birth-place hypothesis” is the high orbital inclination of the open cluster about the core of our galaxy: our Sun would have had to have undergone a series of improbable stellar encounters to have ended up its current sedate quarter of a billion year orbit about the Milky Way galaxy.

Still, this highlights the value of studying clusters such as Messier 6. It’s also interesting to note that there’s also data in what you can’t see in the above image – dark gaps are thought to be dust lanes and globules in the foreground. Though there is some thought that this dust is debris that may also be related to the cluster and may give us clues as to its overall rotation, its far more likely that these sorts of “dark spirals” related to the cluster have long since dispersed. M7 has completed about one full orbit about the Milky Way since its formation.

Another famous binocular object, the open cluster Messier 6 (M6) also known as the Butterfly Cluster lies nearby. Messier 7 also holds the distinction as being the southernmost object in Messier’s catalog. Compiled from Parisian latitudes, Charles Messier entirely missed southern wonders such as Omega Centauri in his collection of deep sky objects that were not to be mistaken for comets. We also always thought it curious that he included such obvious “non-comets” such as the Pleiades, but missed fine northern sky objects as the Double Cluster in the northern constellation Perseus.

Finding Messier 6: the view from latitude 30 degrees north before dawn in mid-February. Credit: Stellarium.

Messier 7 is also sometimes called Ptolemy’s Cluster after astronomer Claudius Ptolemy, who first described it in 130 A.D. as the “nebula following the sting of Scorpius.” The season for hunting all of Messier’s objects in an all night marathon is coming right up in March, and Messier 7 is one of the last targets on the list, hanging high due south in the early morning sky.

Interested in catching how Messier 7 will evolve, or might look like up close? Check out Messier 45 (the Pleiades) and the V-shaped Hyades high in the skies in the constellation Taurus at dusk to see what’s in store as Messier 7 disperses, as well as the Ursa Major Moving Group.

And be sure to enjoy the fine view today of Messier 7 from the ESO!

Got pics of Messier 7 or any other deep sky objects? Send ’em, in to Universe Today!

February 18, 2014December 23, 2015 by David Dickinson

Now’s the Time to See Asteroid Pallas at its Best

Looking for something off of the beaten celestial path to observe? The coming weeks will offer telescope users a rare chance to catch a well known asteroid, as it puts on its best show for over two decades.

Over the coming weeks, 2 Pallas, one of the “big four” asteroids – or do you say minor/dwarf planet/planetoid? – reaches a favorable observing point known as opposition. Gliding northward through the constellations of Hydra and Sextans through February and March 2014, 2 Pallas presents a favorable binocular challenge for both northern and southern hemisphere observers as it rises to the east opposite to the setting Sun and transits the local meridian around midnight.

And although 2 Pallas reaches opposition roughly every 16 months as seen from our Earthly vantage point, 2014 provides a chance to catch it under exceptional circumstances. And to top it off, the other “Big 4” asteroids – 1 Ceres, 3 Juno and 4 Vesta – are all currently visible as well and reach opposition in the January through April time frame.

Pallas HST — 2 Pallas as imaged by the Hubble Space Telescope. Credit: NASA

Pallas and its brethren also have a checkered history though the course of 19^th century astronomy. The second minor planet to be discovered, Heinrich Wilhelm Olbers spied 2 Pallas near opposition on the night of March 28^th, 1802. Olbers made this discovery observing from his home rooftop observatory in Bremen, Germany using a five foot – telescopes were often measured in focal length rather than aperture in those days – Dollond refractor.

Olbers discovered 2 Pallas on the border of the astronomical constellations of Virgo and Coma Berenices shining at magnitude +7.5.

Pallas orbit — A simulation of the orbit of 2 Pallas near opposition this month. Credit: NASA/JPL Horizons.

If the name Olbers sounds familiar, it’s because he also lent it to the paradox that now bears his name. Obler’s paradox was one of the first true questions in cosmology posed in a scientific framework that asked: if the universe is actually infinite in time and space, then why isn’t the sky infinitely bright? And, on a curious side note, it was American horror author Edgar Allan Poe that delivered the answer.

But now back to our solar system. Olbers also discovered 4 Vesta just five years after Pallas.

He was definitely on a roll. The discoveries of these space rocks also grabbed the attention of Olbers contemporary, Johann Bode. Bode had formulated a law now known as the Titus-Bode Law that seemed to put the spacing of then known bodies of the solar system in tidy order. In fact, the Titus-Bode law seemed to predict that a body should lie between Mars and Jupiter, and for a brief time in the 18^th century — and again in 2006 when the International Astronomical Union let Eris and Pluto in the door before kicking them back out — Ceres, Pallas, Juno and Vesta were all considered planets.

Comparison — A size comparison of the first ten asteroids discovered compared to Earth’s moon. Wikimedia Commons graphic in the Public Domain.

Today, we now know that 2 Pallas is a tiny world about 575 kilometres in diameter. 2 Pallas orbits the Sun once every 4.62 years and has a relatively high inclination of 34.8 degrees relative to the ecliptic. Pallas has no confirmed satellites, though one was once hinted at during a May 29th, 1979 stellar occultation. And though we’ve yet to send a mission to examine Pallas up close, there were early planning considerations to send NASA’s Dawn spacecraft there after its visit to 1 Ceres.

wide — The path of 2 Pallas from February 16th though March 21st. Created by the author using Stellarium.

This month, look for 2 Pallas as a +7^th magnitude wandering star at dusk. Mid-February finds 2 Pallas in the constellation Hydra, and it crosses briefly into Sextans starting on March 22^nd until it passes just three degrees east of the 2nd magnitude Alphard (Alpha Hydrae) on March 1^st, making a good guidepost to find it at its brightest.

2 Pallas last broke +7^th magnitude visibility as seen from Earth in 1991 and won’t do so again til 2028. This is because 18.5 Earth years very nearly equals four orbits of Pallas around the Sun, bringing the two worlds back “into sync.” According to calculations by Belgian astronomer Jean Meeus, the 2014 opposition season offers the closest passage to Earth for Pallas from 1980-2060. Pallas can appear at a maximum brightness of magnitude +6.5 — just on the threshold of naked eye visibility — as seen from Earth.

Narrow — A narrow field finder chart for 2 Pallas with sample comparison magnitudes, decimal points omitted. Created by the author using Stellarium.

Opposition for Pallas occurs on February 22^nd, 2014, when the asteroid is 1.23 AUs distant from our fair planet. Watch for 2 Pallas near opposition this year moving at just under half a degree a day — about the diameter of the Full Moon — headed northward at closest approach.

Hunting asteroids at the eyepiece can be a challenge, as they visually resemble pinpoint stars and show no apparent disks even at high magnification. Sketching or photographing the field of view on successive nights is a fun and easy way to cross this object off of your life list. For those who own scopes with digital setting circles, Heavens-Above is a great quick look source for current coordinates.

2 Pallas just passed perihelion at 2.13 Astronomical Units from the Sun on December 6^th, 2013, and passes closest to Earth on February 24^th at 1.2 A.U.s distant.

Don’t miss the chance to spy this fascinating an enigmatic worldlet coming to a sky near you this season!

-Got pics of 2 Pallas and friends? Be sure to send ‘em in to Universe Today!

February 12, 2014December 23, 2015 by David Dickinson

Space Station to Get a ‘Laser Cannon’

CATS in the laboratory. Credit: NASA/GSFC.

What’s a space station without a laser cannon?

The International Space Station will be getting its very own laser at the end of 2014. And unlike the planet-smashing capabilities of the Death Star of Star Wars fame, this laser will to be enlisted for the purpose of science.

It’s called CATS, and no, it isn’t the latest attempt to put feline astronauts in space. CATS stands for the Cloud Aerosol Transport System. The goal of CATS is to study the distribution of tiny particles of dust and air contaminants known as aerosols.

Developed by research scientist Matt McGill at NASA’s Goddard Space Flight Center in Greenbelt Maryland, CATS is slated to head to the International Space Station later this year on September 12th aboard SpaceX’s CRS-5 flight of the Dragon spacecraft. CATS will be installed on the Japanese Experiment Module-Exposed Facility (JEM-EF) and will demonstrate the utility of state-of-the-art multi-wavelength laser technology to study aerosol distribution and transport in the atmosphere.

Such knowledge is critical in understanding the path and circulation of aerosols and pollutants worldwide. When the Eyjafjallajökull volcano erupted in Iceland back in 2010, many trans-Atlantic flights were grounded as a precaution. These measures are necessary as several flights have suffered engine failures in the past due to encounters with volcanic ash clouds, such as the four engine failure of KLM Fight 867 in 1989 and the British Airways Flight 9 incident over Southeast Asia in 1982. Knowing where these dangerous ash clouds are is crucial to the safety of air travel.

The expanding ash cloud spewing from Iceland's Eyjafjallajökull volcano as seen from space in 2010. Credit: NASA. — The expanding ash cloud spewing from Iceland’s Eyjafjallajökull volcano as seen from space in 2010. Credit: NASA.

To accomplish this, CATS will emit 5,000 1 milliJoule laser pulses a second at the 1064, 532 and 355 nanometer wavelengths. This represents a vast improvement in power requirements and thermal capabilities over a similar instrument currently in service aboard the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) Earth remote sensing spacecraft.

And it’s that third 355 nanometer wavelength that will make CATS stand out from CALIPSO. This will also allow researchers to differentiate between particle size and measure the horizontal and vertical distribution of aerosol particles in the atmosphere. CATS will also be capable of measuring the number of individual photons being reflected back at it, which will provide a much better resolution and understanding of current atmospheric activity.

“You get better data quality because you make fewer assumptions, and you get, presumably, a more accurate determination of what kind of particles you’re seeing in the atmosphere,” McGill said in a recent press release.

The International Space Station also provides a unique vantage point for CATS. In a highly inclined 51.7 degree orbit, the station passes over a good swath of the planet on 16 orbits daily on a westward moving ground track that repeats roughly every three days. This will assure CATS has coverage over a large percentage of the planet, including known pollutant transport routes across the northern Pacific and down from Canada over the U.S. Great Lakes region.

While the first two lasers will operate in the infrared and visual wavelengths, said third laser will work in the ultraviolet. And while this will give CATS an enhanced capability, engineers also worry that it may also be susceptible to contamination. “If you get contamination on any of your outgoing optics, they can self-destruct, and then your system is dead. You end up with a very limited instrument lifetime,” McGill said.

Still, if CATS is successful, it may pave the way for larger, free-flying versions that will monitor long-range atmospheric patterns and shifts in climate due to natural and man-made activity. And the ISS makes a good platform to test pathfinder missions like CATS at low cost. “In our current budget-constrained environment, we need to use what we already have, such as the [station], to do more with less,” McGill said.

CALIPSO's LiDAR imaged from the ground by Gregg Hendry in 2008. Used with permission. — CALIPSO’s LiDAR imaged from the ground by Gregg Hendry in 2008. Used with permission.

The advent of a LiDAR system aboard the ISS has also generated a spirited discussion in the satellite tracking community concerning prospects for spotting CATS in operation from the ground. The CALIPSO LiDAR has been captured by ground spotters in the past. However, CALIPSO fires a much more powerful 110 milliJoule pulse at a rate of 20 times a second. Still, the lower power CATS system will be firing at a much faster rate, delivering a cumulative 5,000 milliJoules a second. CATS won’t be bright enough to show up on an illuminated pass of the ISS, but it just might be visible during darkened passes of the ISS through the Earth’s shadow. And, unlike CALLIPSO — which is part of the difficult to observe A-Train of Earth-observing satellites — the ISS passes in view of a majority of humanity. At very least, activity from CATS will be worth watching out for, and may well be seen either visually or photographically.

We’ll soon be adding CATS to the long list of outstanding science experiments being conducted aboard the International Space Station, and the sight of this “fully armed and operational battle station” may soon be coming to a dark sky site near you!

February 10, 2014December 23, 2015 by David Dickinson

Enter the Red Planet: A Guide to the Upcoming Mars 2014 Opposition Season

Astrophotographers are already getting some great images of Mars, such as this sequence captured by Efrain Morales Rivera on January 9th, 2014.

Get those telescopes ready: the coming months offer Earthbound viewers some great views of the planet Mars.

Mars reaches opposition for 2014 on April 8^th. This is approaching season represents the best time to observe Mars, as the Red Planet is closest to us in April and rises in the east as the Sun sets opposite to it in the west. Mars reaches 10” in apparent size this week. Mars is already beginning to show surface detail through a moderate-sized telescope as it continues to grow. In mid-February, Mars currently rises at around midnight local, and rides high to the south at local sunrise.

Mars imaged by Leo Aerts on February 3rd. Shot using a Celestron 14" scope, DMK 21AU618 webcam with a 2.5 powermate projection and a RGB Baader filter set. — Mars imaged by Leo Aerts on February 3rd. Shot using a Celestron 14″ scope, DMK 21AU618 webcam with a 2.5 powermate projection and a RGB Baader filter set.

The 2014 opposition of Mars offers a mixed bag for observers. Hanging around 5-10 degrees south of the celestial equator just east of the September equinoctial point in Virgo, viewing opportunities are roughly equal for both northern and southern hemisphere observers. At opposition, Mars will shine at magnitude -1.5 and present a 15.2” disk, only slightly larger than the near minimum apparition of 2012, when it appeared 13.9” across. This is a far cry from the historic 2003 appearance, when Mars nearly maxed out at 25.1” across.

Why such a difference? Because the planet Mars has an exceptionally eccentric orbit. In fact, the eccentricity for Mars is 9.3% compared to 1.7% for the relatively sedate Earth.

A decade of Mars oppositions. — A decade plus of Mars oppositions, from 2012 through 2025. Graphic created by the author.

This guarantees that all oppositions of Mars – which occur roughly 26 months/780 days apart – are not created equal. In our current epoch, Mars can pass anywhere from 0.683 to 0.373 Astronomical Units (A.U.s) from the Earth. This year’s passage sees Mars overtake us at 0.62 A.U.s or over 96 million kilometres from Earth on the night of opposition. Mars is slightly closer to us at 0.618 A.U.s six nights later on April 14^th.

Why the slight difference? Well, the speedier Earth is on the inside track headed towards aphelion in July, while Mars is lagging but headed slightly inward towards perihelion just afterwards in September. This combined motion makes for a slightly closer approach just after opposition until the Earth begins to pull away.

And this also means that Mars will make its apparent retrograde loop through Virgo on the months surrounding opposition:

Mars retrograde credit-Starry Night — The motion of Mars through Virgo from March 1st through July 31st. Created by the author using Starry Night Education software.

Now for the good news. Oppositions of Mars also follow a rough 15-year cycle, meaning that they get successively closer or more distant with every two year passage. For example, the 1999 opposition of Mars had a very similar geometry to this year’s, as will to the future opposition in 2029.

And we’re currently on an improving trend: the next opposition in 2016 is much better than this year’s at 18.6” in size, and during the 2018 opposition, Mars will present a disc 24.3” across and will be nearly as favorable as the one in 2003!

It’s also worth noting that Mars sits within four degrees of the rising Moon on the evening of April 14^th. The bright star Spica also sits even closer to the Full Moon on the same evening, at less than two degrees away. This particular evening is also noteworthy as it hosts the first of two lunar eclipses for 2014, both of which favor North America.

Mars April 14th. — Mars, the Full Moon and Spica rising in the east on April 14th. Created using Stellarium.

Can you catch Mars near the Moon before sundown on the 14^th using binoculars? The Moon will also occult Mars on July 6^th for viewers across central and South America.

Though Mars is nicknamed the Red Planet, we’ve seen it appear anywhere from a pumpkin orange to a sickly yellow hue. In fact, such a jaundiced color change can be a sign that a planet-wide dust storm is under way. Such a variation can be readily seen with the naked eye. What color does Mars appear like to you tonight?

On Mars, northern hemisphere summer starts on February 15^th, 2014. This means that the northern pole cap of the planet is tipped towards us at opposition during 2014. The day on Mars is only slightly longer than Earth’s at 24 hours and 37 minutes, meaning that Mars will have seemed to rotated only an extra ~8 degrees if you observe it at the same time on each successive evening.

The white pole caps of the planet are the first feature that becomes apparent to the observer at the eyepiece. In February, Mars shows a noticeable gibbous phase in February as we get a peek at the edge of the nighttime side of the planet. Mars will be nearly “full” at opposition, after which it’ll once again take on a slightly distorted football shape.

A growing Mars. — A growing (& shrinking) Mars through the 2014 opposition season. Created by the author using Starry Night Education software.

Tracking the features of the Red Planet is also possible at moderate magnification. One of the largest features apparent is the dark area known as Syrtis Major. Sky & Telescope has an excellent and easy to use application named Mars Previewer that will show you which longitude is currently facing Earth.

Sketching the regions of Mars is a fun exercise. You’ll find that drawing planetary features at the eyepiece can sharpen your observing skills and give you a more critical eye to discern subtle detail. And this season also provides an excellent reason to turn that newly constructed planetary webcam towards Mars.

Up for a challenge? Opposition is also a great time to try and observe the moons of Mars.

moons Starry Night — The moons of Mars as seen on April 8th at around 9:00 Universal Time. Created by the author using Starry Night Education software.

Phobos and Deimos are a tough catch, but are indeed within range of amateur instruments. The chief problem lies in their close proximity to dazzling Mars: +11.5 magnitude, Phobos never strays 14” from the Red Planet in 2014, and 12.4 magnitude Deimos never travels farther than 45” away. Phobos orbits Mars once 7.7 hours — faster than the planet rotates beneath it — and Deimos orbits once every 30.3 hours. The best strategy for a successful Martian moon hunt is to either place Mars just out of the field of view at high power when a moon reaches greatest elongation or block it from view using an eyepiece equipped with an occulting bar.

Extra credit for anyone who nabs pics of the pair!

And opposition is also “Visit Mars season,” as MAVEN and India’s Mars Orbiter Mission arrive later this year. In 2016, NASA’s Mars InSight mission is slated to make the trip, and the window is fast-closing for Dennis Tito’s proposed crewed fly-by mission of Mars in 2018.

And finally, to aid you in your quest for those elusive Martian moons, reader and human astronomical calculator extraordinaire Ed Kotapish was kind enough to compile a list of favorable apparitions of the moons of Mars on the weeks surrounding opposition. (see below)

Good luck, and be sure to send in those pics of Mars and more to Universe Today!

ELONGATIONS OF THE MARTIAN MOONS DATES AND TIMES IN UT STARTING 3/30/2014
MAR 30 PHOBOS 0300 W PHOBOS 0645 E DEIMOS 0900 W PHOBOS 1040 W PHOBOS 1425 E PHOBOS 1815 W PHOBOS 2205 EMAR 31 DEIMOS 0005 E PHOBOS 0155 W PHOBOS 0545 E PHOBOS 0935 W PHOBOS 1320 E DEIMOS 1515 W PHOBOS 1715 W PHOBOS 2100 E APR 01 PHOBOS 0055 W PHOBOS 0440 E DEIMOS 0620 E PHOBOS 0830 W PHOBOS 1220 E PHOBOS 1610 W PHOBOS 2000 E DEIMOS 2130 W PHOBOS 2350 W APR 02 PHOBOS 0340 E PHOBOS 0730 W PHOBOS 1115 E DEIMOS 1235 E PHOBOS 1510 W PHOBOS 1855 E PHOBOS 2245 W APR 03 PHOBOS 0235 E DEIMOS 0345 W PHOBOS 0625 W PHOBOS 1015 E PHOBOS 1405 W PHOBOS 1755 E DEIMOS 1855 E PHOBOS 2145 W APR 04 PHOBOS 0130 E PHOBOS 0525 W PHOBOS 0910 E DEIMOS 1000 W PHOBOS 1305 W PHOBOS 1650 E PHOBOS 2040 W APR 05 PHOBOS 0030 E DEIMOS 0110 E PHOBOS 0420 W PHOBOS 0810 E PHOBOS 1200 W PHOBOS 1550 E DEIMOS 1615 W PHOBOS 1940 W PHOBOS 2325 E	APR 06 PHOBOS 0320 W PHOBOS 0705 E DEIMOS 0725 E PHOBOS 1055 W PHOBOS 1445 E PHOBOS 1835 W PHOBOS 2225 E DEIMOS 2230 WAPR 07 PHOBOS 0215 W PHOBOS 0605 E PHOBOS 0955 W PHOBOS 1340 EDEIMOS 1340 E (Mutual) PHOBOS 1735 W PHOBOS 2120 E APR 08 PHOBOS 0115 W DEIMOS 0445 W PHOBOS 0500 E PHOBOS 0850 W PHOBOS 1240 E PHOBOS 1630 W DEIMOS 1955 E PHOBOS 2020 E APR 09 PHOBOS 0010 W PHOBOS 0355 E PHOBOS 0750 W DEIMOS 1100 W PHOBOS 1135 E PHOBOS 1530 W PHOBOS 1915 E PHOBOS 2305 W APR 10 DEIMOS 0210 E PHOBOS 0255 E PHOBOS 0645 W PHOBOS 1035 E PHOBOS 1425 W DEIMOS 1715 W PHOBOS 1815 E PHOBOS 2205 W APR 11 PHOBOS 0150 E PHOBOS 0545 W DEIMOS 0825 E PHOBOS 0930 E PHOBOS 1320 W PHOBOS 1710 E PHOBOS 2100 W DEIMOS 2330 W	APR 12 PHOBOS 0050 E PHOBOS 0440 W PHOBOS 0830 E PHOBOS 1220 W DEIMOS 1440 E PHOBOS 1605 E PHOBOS 2000 W PHOBOS 2345 EAPR 13 PHOBOS 0340 W DEIMOS 0550 W PHOBOS 0725 E PHOBOS 1115 W PHOBOS 1505 E PHOBOS 1855 W DEIMOS 2055 E PHOBOS 2245 E APR 14 PHOBOS 0235 W PHOBOS 0620 E PHOBOS 1015 W DEIMOS 1205 W PHOBOS 1400 E PHOBOS 1755 W PHOBOS 2140 E APR 15 PHOBOS 0130 W DEIMOS 0310 E PHOBOS 0520 E PHOBOS 0910 W PHOBOS 1300 E PHOBOS 1650 W DEIMOS 1820 W PHOBOS 2040 E APR 16 PHOBOS 0030 W PHOBOS 0415 E PHOBOS 0810 W DEIMOS 0925 E PHOBOS 1155 E PHOBOS 1545 W PHOBOS 1935 E PHOBOS 2325 W APR 17 DEIMOS 0035 W PHOBOS 0315 E PHOBOS 0705 W PHOBOS 1055 E PHOBOS 1445 W DEIMOS 1540 E PHOBOS 1830 E PHOBOS 2225 W APR 18 PHOBOS 0210 E PHOBOS 0605 W DEIMOS 0650 W PHOBOS 0950 E PHOBOS 1340 W PHOBOS 1730 E PHOBOS 2120 W DEIMOS 2200 E

February 5, 2014December 23, 2015 by Elizabeth Howell

Astronomy Podcast Enters Sixth Year — And We’d Love For You To Contribute!

A part of the Small Magellanic Cloud galaxy is dazzling in this new view from NASA's Great Observatories. The Small Magellanic Cloud, or SMC, is a small galaxy about 200,000 light-years way that orbits our own Milky Way spiral galaxy. Credit: NASA.

If you love talking about space — and as a reader of Universe Today, I really hope you do — there’s an awesome podcast for you to add to your playlist. 365 Days of Astronomy puts out an astronomy-themed episode every single day of the year, covering everything from recent discoveries, to folklore, to community events.

If you’ve got a microphone and a desire to contribute, or have at least some coffee money to contribute to charity, they’d really love to hear from you as they enter a sixth (sixth!) year of operation. More details are below the jump.

Full disclosure here: Universe Today is a big supporter of 365 Days of Astronomy, and I’ve been contributing podcasts myself since last year. It is an awesome experience. Pamela Gay (who oversees the project through her astronomy education organization, Cosmoquest) is inspiring to work for as she is a tireless supporter of bringing the joy of space to the general public.

Nancy Atkinson (a fellow contributor and UT senior editor) joked to me today, “It’s kind of like the Mars rovers — the Energizer Bunny of podcasts.” And it’s through your support that we can keep going, and going, and going. Here’s the official press release with information about contributions:

365 Days of Astronomy will continue its service in 2014! This time we will have more days available for new audio. Have something to share? We’re looking for content from 10 minutes long up to an hour! Since 2009, 365 Days of Astronomy has brought a new podcast every day to astronomy lovers around the world to celebrate the International Year of Astronomy. Fortunately, the project has continued until now and we will keep going for another year in 2014. This means we will continue to serve you for a 6th year.

Through these years, 365 Days Of Astronomy has been delivering daily podcasts discussing various topics in the constantly changing realm of astronomy. These include history of astronomy, the latest news, observing tips and topics on how the fundamental knowledge in astronomy has changed our paradigms of the world. We’ve also asked people to talk about the things that inspired them, and to even share their own stories, both of life doing astronomy and science fiction that got them imagining a more scientific future.

365 Days of Astronomy is a community podcast that relies on a network of dedicated podcasters across the globe who are willing to share their knowledge and experiences in astronomy with the world and it will continue that way. In 2013, 365 Days of Astronomy started a new initiative with CosmoQuest. We now offer great new audio every weekend, while on weekdays we serve up interesting podcasts from CosmoQuest and other dedicated partners. We also have several monthly podcasts from dedicated podcasters and have started two new series: Space Stories and Space Scoop. The former is a series of science fiction tales, and the latter is an astronomy news segment for children.

From the universe to the solar system, we’ve had an interesting journey, especially the ostensibly legendary comet ISON which finally ended its days by breaking apart and vaporizing. We hope we won’t end like ISON did! As for 2014, we will have more available days for new podcasts.

A widefield view of Comet ISON, taken from New Mexico Skies at 11h 59m UT using an FSQ 106 ED telescope and STL11K camera on a PME II mount. 1 x 10 min exposures. Credit and copyright: Joseph Brimacombe.

For this upcoming year, the 365 Days of Astronomy podcast is looking for individuals, organizations, schools, companies, and clubs to sign-up for their 5 – 60 minutes of audio for the new daily podcast which will be aired on Tuesday, Thursday, Saturday, and Sunday. As for Monday, Wednesday, and Friday, we will air audio podcasts from CosmoQuest and partners’ Google+ hangouts. We’ll also post the matching video submissions on our YouTube Channel.

We will once again continue our quest in the podcasting arena, but we need your support to be a success. The project is now accepting financial support from individuals as well as organizations to cover our audio engineering and website support costs. The podcast team invites people and organizations to sponsor shows by donating to support one day of the podcast. It costs us about $45 per show. For your donation of $30, a dedication message will be announced in the beginning of the show. For a $15 donation a sponsorship message will be heard at the end of the show. Alternatively, for a $100 donation a sponsor may request a dedication message at the end of a whole week of programs. These donations are essential to cover the price for editing and posting podcasts.

The 365 Days of Astronomy podcast is heard by 5,000 listeners per day and by 2013 we have surpassed 6,8 million downloads. In 2009, the project was awarded a Parsec Award as “The Best Infotainment” podcast and a year later, in 2010-2012, it was nominated for the “Best Fact Behind the Fiction” award.

February 3, 2014December 23, 2015 by David Dickinson

Watch Venus as it Wanders Through the Dawn in 2014

Venus as captured by Shahrin Ahmad (@shahgazer) on January 31st, 2014. Credit- Shahgazer.net.

Are you a chronic early riser? Observational astronomy often means late nights and early mornings as daylight lengths get longer for northern hemisphere residents in February through March. But this year offers another delight for the early morning crowd, as the Venus is hanging out in the dawn skies for most of 2014.

You may have already caught sight of the brilliant world: it’s hard to miss, currently shinning at a dazzling -4.5 magnitude in the dawn. Venus is the brightest planet as seen from Earth and the third brightest natural object in the night sky after the Sun and the Moon.

Venus just passed between the Earth and the Sun last month on January 11th at inferior conjunction. Passing over five degrees north of the Sun, this was a far cry from the historic 2012 transit of the solar disk, a feat that won’t be replicated again until 2117 AD.

But February and March offer some notable events worth watching out for as Venus wanders in the dawn.

The path of Venus from February 4th to September 23rd, 2014. The first (top) graphic lays out the path as seen at dawn from latitude 30 degrees north, while the bottom lays out the path of Venus as seen from latitude 30 degrees south. Note that the orientation of the ecliptic in the top frame is set for September 23rd, while the bottom frame is set for February 4th, respectively. Created using Starry Night Education software.

This week sees Venus thicken as a 48” 16% illuminated waxing crescent as it continues to present more of its daytime side to the Earth. We’ve always thought that it was a bit of cosmic irony that the closest planet too us presents no surface detail to observers: Venus is a cosmic tease. This assured that astronomers knew almost nothing about Venus until the dawn of the Space Age — guesses at its rotational speed and surface conditions were all widely speculative. Ideas of a vast extraterrestrial jungle or surface-spanning seas of seltzer water oceans gave way to the reality of a shrouded hellish inferno with noontime temps approaching 460 degrees Celsius. Venus is also bizarre in the fact that it rotates once every 243 Earth days, which is longer than its 224.7 day year — you could easily out walk a Venusian sunrise, that is if you could somehow survive to see it from its perpetually clouded surface!

Venus also passes 4.3 degrees from faint Pluto this week on February 5^th. And while Pluto is a tough catch at over a million times fainter than Venus, it’s interesting to consider that NASA’s New Horizons and ESA’s Rosetta spacecraft are also currently off in the same general direction:

Venus and the invisible lineup of deep space missions in the same general direction this week. Also note that Venus has been skirting the non-zodiac constellation of Scutum this season! Created using Starry Night Education Software, — Venus and the invisible lineup of deep space missions in the same general direction this week. Also note that Venus has been skirting the non-zodiacal constellation of Scutum this season! Created using Starry Night Education Software.

Venus also reaches greatest brilliancy at magnitude -4.6 next week on February 11^th. Venus is bright enough to cast a shadow onto a high contrast background, such as freshly fallen snow. Can you see your “Venusian shadow” with the naked eye? How about photographically?

Venus then goes on to show its greatest illuminated extent to us on February 15^th. This combination occurs because although the crescent of Venus is fattening, the apparent size of the disk is shrinking as the planet pulls away from us in its speedy interior orbit. Can you spy the elusive “ashen light of Venus” through a telescope? Long a controversy, this has been reported by observers as a dim “glow” on the nighttime hemisphere of Venus. Proposed explanations for the ashen light of Venus over the years have been airglow, aurorae, lightning, Venusian land clearing activity (!) or, more likely, an optical illusion.

And speaking of which, the crescent Venus gets occulted by the waning crescent Moon on February 26^th. Observers in western Africa will see this occur in the predawn skies, and the rest of us will see a close pass of the pair worldwide. Can you spot Venus near the crescent Moon in the daytime sky on the 26^th?

The Moon and Venus at dawn on February 25th for observers along the U.S. Eastern Seaboard. Created using Stellarium.

In March, Venus begins the slide southward towards the point occupied by the Sun months earlier and heads towards its greatest westward elongation for 2014 on March 22^nd at 46.6 degrees west of the Sun. Interestingly, Venus is tracing out roughly the same track it took 8 years ago in 2006 and will trace again in 2022, when it will also spend a majority of the year in the dawn once again. The 8-year repeating cycle of Venus is a result of the planet completing very nearly 13 orbits of the Sun to our 8. Ancient cultures, including the Maya, Egyptians, and Babylonian astronomers all knew of this period.

Through the telescope, Venus appears at a tiny “half-moon” phase 50% illuminated at greatest elongation, a point known as dichotomy. It’s interesting to note that theoretical and observed dichotomy can actually vary by several days surrounding greatest elongation. An optical phenomenon, or a true observational occurrence? When do you judge that dichotomy occurs in 2014?

In April, one of the closest planetary conjunctions occurs of 2014 on the 12^th involving Neptune and Venus at just 40’ apart, a little over the span of a Full Moon. Can you squeeze both into an eyepiece field of view? At +7.7th magnitude, Neptune shines at over 25,000 times fainter than Venus. Neith, the spurious “moon” of Venus described by 18th century astronomers lives!

But two even more dramatic conjunctions occur late in the summer, when Jupiter passes just 15’ from Venus on August 18^th and Regulus stands just 42’ from Venus on September 5^th. Fun fact: Venus actually occulted Regulus last century on July 7th, 1959!

From there on out, Venus heads toward superior conjunction on the far side of the Sun on October 25th, to once again emerge into the dusk sky through late 2014 and 2015.

Be sure to check out these dawn exploits of Venus through this Spring season and beyond!