Astro-Challenge: Nabbing Venus… at Inferior Conjunction

Venus as seen on the morning of inferior conjunction January 11th from Rekyavik, Iceland. Created by the author using Stellarium

Residents of high northern latitudes can take heart this frigid January: this coming weekend offers a chance to replicate a unique astronomical sighting.

Veteran sky watcher Bob King recently wrote a post for Universe Today describing what observers can expect from the planet Venus for the last few weeks of this current evening apparition leading  up to Venus’s passage between the Earth and the Sun on January 11th. Like so many other readers, we’ve been holding a nightly vigil to see when the last date will be that we can spot the fleeing world… and some great pics have been pouring in.

But did you know that when the conditions are just right, that you can actually spy Venus at the moment of inferior conjunction?

No, we’re not talking about a rare transit of Venus as last occurred on June 6th, 2012, when Venus crossed the disk of the Sun as seen from our Earthly perspective… you’ll have to wait until 2117 to see that occur again. What we’re talking about is a passage of Venus high above or below the solar disk, when spying it while the Sun sits just below the horizon might just be possible.

The disk of Venus at inferior conjunction. Simulation created by the author using Starry Night.
The disk of Venus at inferior conjunction. Simulation created by the author using Stellarium.

Not all inferior conjunctions of Venus are created equal. The planet’s orbit is tilted 3 degrees with respect to our own and can thus pass a maximum of eight degrees north or south of the Sun. Venus last did this on inferior conjunction in 2009 and will once again pass a maximum distance north of the Sun in 2017. For the southern hemisphere, the red letter years are 2007, and next year in 2015.

You’ll note that the above periods mark out an 8-year cycle, a period after which a roughly similar apparition of the planet Venus repeats. This is because Venus takes just over 224 days to complete one orbit, and 13 orbits of Venus very nearly equals 8 Earth years.

And while said northern maximum is still three years away, this week’s inferior conjunction is close at five degrees from the solar limb. The best prospects to see Venus at or near inferior conjunction occur for observers “North of the 60”. We accomplished this feat two Venusian 8-year cycles ago during the inferior conjunction of January 16th, 1998 from latitude 65 degrees north just outside of Fairbanks, Alaska. We set up on the Chena Flood Channel, assuring as low and as flat a horizon as possible… and we kept the engine of our trusty Jeep Wrangler idling as a refuge from the -40 degrees Celsius temperatures!

A daytime Venus just over five days from inferior conjunction. Credit
A 1.3% illuminated daytime Venus just over five days from inferior conjunction. Credit Shahrin Ahmad www.shahgazer.net

It took us several frigid minutes of sweeping the horizon with binoculars before we could pick up the dusky dot of Venus through the low atmospheric murk and pervasive ice fog. We could just glimpse Venus unaided afterward, once we knew exactly where to look!

This works because the ecliptic is at a relatively shallow enough angle to the horizon as seen from the high Arctic that Venus gets its maximum ~five degree “boost” above the horizon.

A word of warning is also in order not to attempt this sighting while the dazzling (and potentially eye damaging) Sun is above the horizon. Start sweeping the horizon for Venus about 30 minutes before local sunrise, with the limb of the Sun safely below the horizon.

Venus presents a disk 1’ 02” across as seen from Earth during inferior conjunction, the largest of any planet and the only one that can appear larger than an arc minute in size. Ironically, both Venus and Earth reach perihelion this month. Said disk is, however, only 0.4% illuminated and very near the theoretical edge of visibility known as the Danjon Limit. And although the technical visual magnitude of Venus at inferior conjunction is listed as -3.1, expect that illumination scattered across that razor thin crescent to be more like magnitude -0.6 due to atmospheric extinction.

The mid-January passage of Venus through the field of view of SOHO's LASCO C3 imager. Field orientation is set for January 7th. Created using Starry Nite Software.
The mid-January passage of Venus through the field of view of SOHO’s LASCO C3 imager. Field orientation is set for January 7th. Created using Starry Nite Software.

Are you one of the +99% of the world’s citizens that doesn’t live in the high Arctic? You can still watch the passage of Venus from the relative warmth of your home online, via the Solar Heliospheric Observatory’s (SOHO) vantage point in space. SOHO sits at the sunward L1 point between the Earth and the Sun and has been monitoring Sol with a battery on instruments ever since its launch in 1995. A great side benefit of this is that SOHO also catches sight of planets and the occasional comet that strays near the Sun in its LASCO C2 and C3 cameras. Venus will begin entering the 15 degree wide field of view for SOHO’s LASCO C3 camera on January 7th, and you’ll be able to trace it all the way back out until January 14th.

Venus post solar transit as seen in SOHO's LASCO C3 imager. Credit-ESA/NASA
Venus post solar transit as seen in SOHO’s LASCO C3 imager. Credit-ESA/NASA

From there on out, Venus will enter the early morning sky. When is the first date that you can catch it from your latitude with binoculars and /or the naked eye? Venus spends most of the remainder of 2014 in the dawn, reaching greatest elongation 46.6 degrees west of the Sun on March 22nd, 2014 and is headed back towards superior conjunction on the farside of the Sun on October 25th, 2014. But there’s lots more Venusian action in 2014 in store…. more to come!

Ultra-Thin “Young” Crescent Moon Sighted from U.S. Southwest

Can you spot the razor thin crescent Moon? Image credit: Rob Sparks.

 Earlier this week, Universe Today challenged North American readers to spot the slender, exceptionally “young” crescent Moon on the evening of New Year’s Day.

Three visual athletes based in Arizona took up the challenge on Wednesday evening, with amazing results. Mike Weasner, Rob Sparks and Jim Cadien managed to spot the razor thin crescent Moon just 13 hours and 48 minutes after it passed New phase earlier on January 1st. The sighting was made using binoculars, and they even managed to image the wisp of a crescent hanging against the desert sky.

This is a difficult feat, even under the best of conditions. Weasner and Sparks observed from Mike’s Cassiopeia observatory based just outside of Oracle, Arizona.

Credit: Mike Weasner/Cassiopeia observatory
A thin crescent Moon (arrowed) Credit: Mike Weasner/Cassiopeia observatory

Concerning the feat, Weasner wrote on his observing blog:

“At 1800 Mountain Standard Time (MST), Rob reported that he had located the young Moon using his 8×42 binoculars. At 18:02 MST, I picked it up in the 12×70 binoculars. With the New Moon occurring at 11:14 Universal Time (UT), my observation occurred with the Moon only 13 hours and 48 minutes old. A new record for me (and Rob and Jim as well). Our DSLRs were clicking away!”

We can personally attest to just how hard it is to pick out the uber-thin crescent Moon against the twilight sky. Low contrast is your enemy, making it tough to spot and even tougher to photograph. Add to that a changing twilight sky that alters hue from moment to moment.

Though this isn’t a world record, its close to within about two hours. The youngest confirmed Moon spotting using binoculars stands at 11 hours and 40 minutes accomplished by Mohsen G. Mirsaeed in Iran back in September 7th, 2002, and the youngest Moon sighted with the unaided eye goes to Steven James O’Meara in May 1990, who spotted a 15 hour 32 minute old crescent.

Mike Cadien (left) and Rob Sparks (right) setting up to catch the crescent Moon. Credit- Mike Weasner.
Jim Cadien (left) and Rob Sparks (right) setting up to catch the crescent Moon. Credit– Mike Weasner.

And of course, you can see the Moon at the moment of New during a a solar eclipse. Unfortunately, no total solar eclipses occur in 2014, just an usual non-central annular eclipse brushing Australia and Antarctica on April 29th  and a deep 81% partial eclipse crossing North America on October 23rd.

Weasner also noted that a bright Venus aided them in their quest. It’s strange to think that Venus, though visually tiny, is actually intrinsically brighter than the limb of the Moon, owing to its higher albedo. In fact, some great pictures have also been pouring in to Universe Today of Venus as it heads towards inferior conjunction this month on January 11th. And don’t forget, that quoted magnitude of the lunar crescent (about magnitude -3.4) was also scattered along the lunar disk which was only 0.4% illuminated, and subject to atmospheric extinction to boot!

Our own modest attempt to catch the waning crescent Moon 29 hours prior to New back in August 2012. Photo by author.
Our own modest attempt to catch the waning crescent Moon 29 hours prior to New back in August 2012. Photo by author.

And yes, it is possible to catch the Moon photographically during a non-eclipse at the moment of New phase. The Moon can wander up to 5 degrees – about ten times its average apparent diameter as seen from the Earth – above or below the ecliptic and appear a corresponding distance from the limb of the Sun. Unlike many moons in the solar system, Earth’s moon has a fixed inclination to our orbit (as traced out by the ecliptic,) not our rotational axis. Thierry Legault accomplished this challenging photographic feat last year. Of course, this should only be attempted by seasoned astrophotographers, as aiming a camera near the Sun is not advised.

The January 2nd 2014, waxing crescent Moon plus "Earthshine" as captured by Ron Cottrell from Oro Valley, Arizona. Ron also notes that this illumination of the night time side of the the Moon is also known as "da Vinci's glow".
The January 2nd 2014 waxing crescent Moon plus “Earthshine” as captured by Ron Cottrell from Oro Valley, Arizona. Ron also notes that this illumination of the nighttime side of the the Moon is also known as the “da Vinci” glow. Credit-Ron Cottrell.

Why attempt to spot the razor thin New Moon? What’s the benefit? Well, several lunar based dating systems, such as the Islamic calendar, rely on the spotting of the new crescent Moon to mark the beginning of a new month. Being strictly lunar-based, the Islamic calendar moves an average of -11 days out of sync each year versus the modern day Gregorian calendar. On some years, there can even be a bit of ambiguity as to exactly when key months such as Ramadan will begin based on when the Moon is first sighted.

Also, such a feat demonstrates what the human eye is capable of when pushed to its physiological limits. In fact, French astrophysicist Andre Danjon theorized that the lunar crescent is formed at about 5 degrees elongation from the Sun, a point beyond which a lunar crescent can be sighted — usually quoted at about 7 degrees elongation from the Sun — and has become known as the Danjon Limit. Danjon also gave his namesake to the characterization of total lunar eclipses by color and hue, known as the Danjon Number. Accounting for the motion of the Moon, this places the theoretical limit that the forming crescent can be sighted with optical assistance at just over 11 hours.

Optimal sighting locations through the end of September 2014.
Optimal sighting locations through the end of September 2014. Positions are marked for where the Moon is visible at local sunset and becomes visible with optical assistance around 14 hours after New. Prospects for a “first sighting” get better westward of each location on the dates noted. Note that the March 1st event offers decent prospects for the US northeast and the Canadian Maritimes. Graphic created by author.

And you don’t have to wait until the Moon passes New… a similar attempt can be made in the dawn skies as the waning crescent Moon slides towards the Sun at the end of each lunation.

But perhaps the true reward is simply catching a glimpse of the ethereal for yourself, a delicate and airy Moon clinging briefly on the horizon. Kudos to Mike and Rob on a great catch!

Follow the further adventures of Mike Weasner and Rob Sparks on Twitter as @mweasner & @halfastro.

Wonder what the sighting opportunities are for the next waxing crescent Moon are worldwide? Two great online resources are the HM Nautical Office’s Einstein Moonwatch Project and Moonsighting.com.

The South African Astronomical Observatory also maintains a site with predictions worldwide.

Space Science Stories to Watch in 2014

Orion moves towards its first EFT-1 spaceflight later this year. (Credit: NASA).

There’s an old Chinese proverb that says, “May you live in interesting times,” and 2013 certainly fit the bill in the world of spaceflight and space science. The past year saw spacecraft depart for Mars, China land a rover on the Moon, and drama in low Earth orbit to repair the International Space Station. And all of this occurred against a landscape of dwindling budgets, government shutdowns that threatened launches and scientific research, and ongoing sequestration.

But it’s a brave new world out there. Here are just a few space-related stories that we’ll watching in 2014:

An artist's conception of ESA's Rosetta and Philae spacecraft approaching comet 67P/Churyumov-Gerasimenko. (Credit: ESA-J. Huart, 2013)
An artist’s conception of ESA’s Rosetta and Philae spacecraft approaching comet 67P/Churyumov-Gerasimenko. (Credit: ESA-J. Huart, 2013)

Rosetta to Explore a Comet: On January 20, 2014, the European Space Agency will hail its Rosetta spacecraft and awaken it for its historic encounter with comet 67P/Churyumov-Gerasimenko later this year in August. After examining the comet in detail, Rosetta will then dispatch its Philae lander, equipped complete with harpoons and ice screws to make the first ever landing on a comet. Launched way back in 2004, Rosetta promises to provide the cosmic encounter of the year.

The October 19th, 2014 passage of comet C/2013 A1 Siding Springs past Mars. (Credit: NASA/JPL-Caltech)
The October 19th, 2014 passage of comet C/2013 A1 Siding Springs past Mars. (Credit: NASA/JPL-Caltech)

A1 Siding Springs vs. Mars: A comet discovery back in 2013 created a brief stir when researchers noted that comet C/2013 A1 Siding Springs would make a very close passage of the planet Mars on October 19th, 2014. Though refinements from subsequent observations have effectively ruled out the chance of impact, the comet will still pass 41,300 kilometres from the Red Planet, just outside the orbit of its outer moon Deimos. Ground-based observers will get to watch the +7th magnitude comet close in on Mars through October, as will a fleet of spacecraft both on and above the Martian surface.

A recent tweet from @NewHorizons_2015, a spacecraft that launched just weeks before Twitter in 2006.
A recent tweet from @NewHorizons_2015, a spacecraft that, ironically, launched just weeks before Twitter in 2006.

Spacecraft En Route to Destinations: Though no new interplanetary missions are set to depart the Earth in 2014, there are lots of exciting missions currently underway and headed for worlds yet to be explored. NASA’s Dawn spacecraft is headed towards its encounter with 1 Ceres in February 2015. Juno is fresh off its 2013 flyby of the Earth and headed for orbital insertion around Jupiter in August 2016. And in November of this year, New Horizons will switch on permanently for its historic encounter with Pluto and its retinue of moons in July 2015.    

LUX & the Hunt for Dark Matter: It’s all around us, makes up the bulk of the mass budget of the universe, and its detection is THE name of the game in modern astrophysics. But just what is dark matter? Some tantalizing– and hotly contested –data came out late last year from of an unusual detector deep underground near Lead, South Dakota. The Large Underground Xenon experiment (LUX) looks for Weakly Interacting Massive Particles (WIMPs) interacting with 370 kilograms of super-cooled liquid Xenon. LUX requires its unique locale to block out interference from incoming cosmic rays. LUX is due to start another 300 day test run in 2014, and the experiment will add another piece to the puzzle posed by dark matter to modern cosmology, whether or not detections by LUX prove to be conclusive.   

The LIGO Livingston Observatory. (Photos by Author)
The LIGO Livingston Observatory. (Photos by Author)

 The Hunt for Gravity Waves: Another story to watch may come out of Caltech’s twin gravity wave observatories when its Advanced LIGO system goes online later this year. Established in 2002, the Laser Interferometer Gravitational-Wave Observatory (LIGO) is comprised of two detectors: one in Hanford Washington and one outside of Livingston, Louisiana. The detectors look for gravity waves generated by merging binary pulsars and black holes. Though no positive detections have yet been made, Advanced LIGO with boast ten times the sensitivity and may pave the way for a new era of gravitational wave astronomy.

An artist concept of MAVEN in orbit around Mars. (Credit: NASA's Goddard Spaceflight Center).
An artist concept of MAVEN in orbit around Mars. (Credit: NASA’s Goddard Spaceflight Center).

 Spacecraft reach Mars: 2014 is an opposition year for the Red Planet, and with it, two new missions are slated to begin operations around Mars: India’s Mars Orbiter Mission (MOM) also known as Mangalyaan-1 is slated to enter orbit on September 24th, and NASA’s MAVEN or Mars Atmosphere and Volatile Evolution Mission is set to arrive just 2 days earlier on September 22nd. MOM and MAVEN will join the Curiosity and Opportunity rovers, ESA’s Mars Express,  NASA’s Odyssey spacecraft and  the Mars Reconnaissance Orbiter in the quest to unlock the secrets of the Red Planet.

Space Tourism Takes Off: Virgin Galactic’s SpaceShipTwo passed a key milestone test flight in late 2013. Early 2014 may see the first inaugural flights by Virgin Galactic out of the Mohave Spaceport and the start of sub-orbital space tourism. SpaceShipTwo will carry two pilots and six passengers, with seats going for $250,000 a pop. Hey, room for any space journalists in there? On standby, maybe?

The First Flight of Orion: No, it’s not the first flight of the proposed sub-light interplanetary spacecraft that was to be propelled by atomic bombs… but the September launch of the Orion Multi-Purpose Crew Vehicle is the first step in replacing NASA’s capability to launch crews into space. Exploration Flight Test 1 (EFT-1) will be a  short uncrewed flight and test the capsule during reentry after two orbits. It’s to be seen if the first lunar orbital mission using an Orion MPCV will occur by the end of the decade.

Launch of the SpaceX CRS-2 mission to the ISS in early 2013. (Photo by author).
Launch of the SpaceX CRS-2 mission to the ISS in early 2013. (Photo by author)

 The First Flight of the Falcon Heavy: 2014 will be a busy year for SpaceX, starting with the launch of Thaicom-6 out of Cape Canaveral this Friday on January 3rd. SpaceX is now “open for business,” and expect to see them conducting more satellite deployments for customers and resupply missions to the International Space Station in the coming year. They’ll also be moving ahead with tests of their crew-rated version of the Dragon capsule in 2014. But one of the most interesting missions to watch for is the demo flight of the Falcon 9 Heavy slated to launch out of Vandenberg Air Force Base by the end of 2014.… more to come!

The Sunjammer Space Sail: An interesting mission moves in 2014 towards a January 2015 launch: LGarde’s Sunjammer solar sail. Sunjammer will test key solar sail technologies as well as deliver the Solar Wind Analyzer (SWAN) and the MAGIC Magnetometer to the L1 Earth-Sun Lagrange point. Sunjammer will launch on a Falcon-9 rocket and deploy a 1200 square metre solar sail weighing only 32 kilograms. This will be a great one for ground satellite-spotters to track as well as it heads out!

Gaia Opens for Business: Launched on a brilliant night-shot out of the Kourou Space Center in French Guiana on December 19th of last year, the European Space Agency’s Gaia space observatory will begin its astrometry mission in 2014, creating most accurate map yet constructed of our Milky Way Galaxy. But we also anticipate exciting new discoveries due to spin-offs from this mission, to include the discovery of new exoplanets, asteroids, comets and much more.

And as in years previous, the quest to explore brave new worlds will be done against the backdrop of tightening budgets. Just like in household budgets, modern spaceflight is a continual conflict between what we would wish and what we can afford. In recent years, no mission seems to be safe, and there have even been occasional congressional rumblings to pull the plug on missions already underway. Interesting times, indeed… 2014 promises to be an extraordinary time in spaceflight and space science, both on Earth and beyond.

The Quadrantid Meteor Shower-One of the Best Bets for 2014

The modern radiant of the Quadrantid meteor shower. (Photo and grahpics by author).

If there’s one thing we love, it’s a good meteor shower from an obscure and defunct constellation.

Never heard of the Quadrantids?  It may well be because this brief but intense annual meteor shower occurs in the early days of January. Chilly temps greet any would be meteor watchers with hardly the balmy climes of showers such as the August Perseids. Still, 2014 presents some good reasons to brave the cold in the first week of January, to just possibly catch the best meteor shower of the year.

The Quadrantids – sometimes simply referred to as “the Quads” in hipster meteor watcher inner circles – peak on January 3rd around 19:30 Universal Time (UT) or 2:30 PM Eastern Standard Time (EST). This places the northern Asia region in the best position to watch the show, though all northern hemisphere observers are encouraged to watch past 11 PM local worldwide. Remember: meteor showers are fickle beasties, with peak activity often arriving early or late. The Quadrantids tie the December Geminids for the highest predicted Zenithal Hourly Rate (ZHR) for 2014 at 120.

A 2012 Quadrantid meteor in the bottom left side of the frame. (Photo by Author).
A 2012 Quadrantid meteor in the bottom left side of the frame. (Photo by Author).

Though the Quads are active from January 1st to the 10th, the enhanced peak only spans an average of six to ten hours. Though high northern latitudes have the best prospects, we’ve seen Quads all the way down in  the balmy January climes of Florida from around 30 degrees north.

Rates for the Quads are typically less than 10 per hour just a day prior to the sharp peak. The moonless mornings of Friday, January 3rd and Saturday, January 4th will be key times to watch. The radiant for the Quads stands highest just hours before local sunrise.

So, what’s up with the unwieldy name? Well, the Quadrantids take their name from a constellation that no longer exists on modern star charts. Along with the familiar patterns such as Leo and Orion, exist such archaic and obscure patterns as “The Printing Office” and the “Northern Fly” that, thankfully, didn’t make the cut. Quadrans Muralis, or the Mural Quadrant, established by Jérome de Lalande in the 1795 edition of Fortin’s Celestial Atlas was one such creation.  A mural quadrant was a large arc-shaped astronomical tool used for measuring angles in the sky. Apparently, Renaissance astronomers were mighty proud of their new inventions, and put immortalized them in the sky every chance they got as sort of the IPhone 5’s of their day.

The outline of the Mural Quadrant against the backdrop of modern day constellations. (Photo and graphic by author).
The outline of the Mural Quadrant against the backdrop of modern day constellations. (Photo and graphic by author).

The Mural Quadrant spanned the modern day constellations of Draco, Hercules and Boötes. The exact radiant of the Quads lies at Right Ascension 15 Hours 18’ and declination 49.5 degrees north, in the modern day constellation Boötes just 15 degrees east of the star Alkaid.

Previous year’s maximum rates as per the IMO have been as follows:

2013: ZHR=129

2012: ZHR=83

2011: ZHR=90

2010: ZHR=No data (Bright waning gibbous Moon)

2009: ZHR=138

The parent source of the Quadrantids went unknown, until Peter Jenniskens proposed that asteroid 2003 EH1 is a likely suspect. Possibly an extinct comet, 2003 EH1 reaches perihelion at 1.2 AUs from the Sun in 2014 on March 12th, another reason to keep an eye on the Quads in 2014. 2003 EH1 is on a 5.5 year orbit, and it’s been proposed that the asteroid may have a connection to comet C/1490 Y1 which was observed and recorded by 15th century astronomers in the Far East.

The Quadrantids were first identified as a distinct meteor shower in the 1830s by European observers. Owing to their abrupt nature and their climax during the coldest time of the year, the Quadrantids have only been sporadically studied. It’s interesting to note that researchers modeling the Quadrantid meteor stream have found that it undergoes periodic oscillations due to the perturbations from Jupiter. The shower displays a similar orbit to the Delta Aquarids over a millennia ago, and researchers M. N. Youssef and S. E. Hamid proposed in 1963 that the parent body for the shower may have been captured into its present orbit only four thousand years ago.

The orbital path of Amor NEO asteroid 196256 2003 EH1. (Credit: NASA/JPL Solar System Dynamics Small-Body Database Browser).
The orbital path of Amor NEO asteroid 196256 2003 EH1. (Credit: NASA/JPL Solar System Dynamics Small-Body Database Browser).

2003 EH1 is set to resume a series of close resonnance passes of Earth and Jupiter in 2044, at which time activity from the Quads may also increase. It’s been proposed that the shower may fade out entirely by the year 2400 AD.

And the Quadrantids may not be the only shower active in the coming weeks. There’s been some discussion that the posthumous comet formerly known as ISON might provide a brief meteor display on or around the second week of January.

Be sure to note any meteors and the direction that they’re coming from: the International Meteor Organization and the American Meteor Society always welcomes any observations. Simple counts of how many meteors observed and from what shower (Quads versus sporadics, etc) from a given location can go a long way towards understanding the nature of this January shower and how the stream is continually evolving.

Stay warm, tweet those meteors to #Meteorwatch, and send those brilliant fireball pics in to Universe Today!

 

101 Astronomical Events for 2014

An early Draconid meteor caught by astrophotographer Cory Schmitz. (Used with permission?)

It’s here!

As 2013 draws to a close, we once again cast our thoughts to all things astronomical for the coming year. For the past five years, I’ve been constructing this list of all things astronomical for the coming year, lovingly distilling the events transpiring worldwide down to a 101 “best events of the year”. This is the first year this list has been featured on Universe Today, so we’ll lay out our ground rules and reasoning a bit as to selection criteria.

Events selected run the gamut from conjunctions and eclipses that are visible worldwide or over a good swath of the planet, to asteroid occultations of stars that are only visible along a thin path along the surface of the Earth. Geocentric conjunction times for occultations are quoted. Generally, only conjunctions involving bright stars, planets & the Moon are noted. The intent of this list is to bridge the gap between the often meager “10 Best Astronomy Events of 2014” listicles that make their rounds this time of year and the more tedious laundry lists of Moon phases and wide conjunctions.

As always, we look at the coming year with an eye out for the astronomically curious and the bizarre. Times are quoted in Universal Time (UT) using a 24-hour clock, which is identical to Greenwich Mean Time (GMT) and Zulu for those in the military.

Some caveats as to how selections were made:

-To make the cut, asteroid occultations must have a rank of 99 or greater, and occult a star brighter than +8th magnitude.

– We only selected major annual meteor showers with a Zenithal Hourly Rate (ZHR) projected to be 20 or greater.

– Only lunar occultations of planets and bright stars are listed.

– Solstice seasons where the International Space Station reaches full illumination are approximate; the ISS gets boosted periodically, and therefore it’s impossible to project its precise orbit months in advance.

– Comets come and go. The comets included on this list are some of the “best bets” that are forcasted to reach binocular visibility for 2014. A big bright one could come up and steal the show at any time!

This list was meant to “whet the appetite” for what’s coming to skies worldwide in 2014 with a succinct rapid fire listing by month. Where an online resource exists that expands on the event, we linked to ‘em. A full resource list, both paper and cyber, is given at the end of the post. Print these events, post it on your refrigerator and/or observatory wall, and expect us to feature many these fine events on Universe Today in the coming year!

Some notes on 2014:

2014 sees Mars reach opposition in early April, which is sure to be a highlight as we head towards an exceptionally close opposition in 2018.

The month of February is also missing a New Moon, which last occurred in 1995 and won’t happen again until 2033. February is the only calendar month which can be missing the same moon phase twice!

We’re also coming off a profoundly weak solar maximum in 2014, though as always, the Sun may have some surprises in store for solar observers and aurora watchers worldwide.

The motion of the Moon in 2014 is headed towards a “shallow” year in 2015 relative to the ecliptic; it will then begin to slowly open back up and ride high around 2025.

2014 also contains the minimum number of eclipses that can occur in one year, 2 solar and 2 lunar. And while there are no total solar eclipses in 2014, there are two fine total lunar eclipses, both visible from North America.

And here’s the month by month rundown:

Moon Jan 1
The view looking west from the US east coast at 6 PM on January 1st from latitude 30 degrees north. (Created in Stellarium).

January

01- The extremely thin crescent 12-15 hour old Moon will present a challenge for North American viewers low to the west at dusk.

03- Quadrantid meteors peak with a ZHR=120 at ~05:00 UT, best seen from the Atlantic region. Favorable in 2014, with the Moon a 2 day old waxing crescent.

04- Earth reaches perihelion at 12:00 UT, 147.1 million kilometres from the Sun.

04- Mars passes 1.3’ from the +11.5th magnitude galaxy NGC 4684.

05- Jupiter reaches opposition for 2014 and shines at magnitude -2.7.

10- A Possible meteor shower due to dust from the Comet (formerly known as) ISON over the next few days?

11- Venus reaches inferior conjunction between the Sun and the Earth, shining at -4th magnitude. It may be just possible to spot it five degrees north of the solar limb from high northern latitudes.

13- Moon reaches its farthest northern declination for 2014 a 19.4 degrees.

16- The most distant Full Moon, and visually smallest Full Moon of 2014 occurs, with the Moon reaching Full within two hours of apogee. MiniMoon!

25- The Moon occults Saturn for the South Pacific at ~13:58 UT.

27- The Moon reaches its farthest southern declination for 2014, at -19.3 degrees.

30- A Black Moon occurs, as reckoned as the second New Moon in a month with two.

31- Mercury reaches a favorable elongation, shining at magnitude -0.9, 18.4 degrees east of the Sun.

Venus occultation footprint for
Venus occultation footprint for February 26th. (Created using Occult v4.1.0).

February

06- Two shadows transit the cloud tops of Jupiter from 10:20 UT-12:44 UT, favoring western North America.

21- The Moon occults Saturn for the Indian Ocean at ~22:18 UT.

26- The 14% waning crescent Moon occults Venus for central Africa at ~5:23 UT.

March

07- Asteroid 9 Metis occults a +7.9 magnitude star for Europe ~3:14 UT.

10- The 70% illuminated waxing gibbous Moon occults the +3.6 magnitude star Lambda Geminorum for North America in the evening sky.

14- Mercury reaches greatest morning elongation at 27.5 degrees west of the Sun shining at magnitude +0.1. Mercury’s best morning apparition in 2014 for southern hemisphere observers.

16- A double shadow transit of Jupiter’s moons occurs from 22:20 to 00:35 UT, visible from Atlantic Canada after sunset.

20- The Northward Equinox occurs at 16:57 UT.

20- GEO satellite eclipse season occurs, as geostationary satellites enter Earth’s shadow near the equinox.

20- Regulus is occulted by asteroid 163 Erigone for the NE United States and Canada at ~6:07 UT, The brightest star occulted by an asteroid in 2014.

21- The Moon occults Saturn for the South Atlantic at ~3:18 UT.

24- A double shadow transit of Jupiter’s moons occurs from 2:08 to 2:28 UT, favoring eastern North America.

24- Asteroid 172 Baucis occults a +6.7 magnitude star for South America at ~9:27 UT.

22- Venus reaches greatest morning elongation, at 47 degrees west of the Sun.

28- Asteroid 51 Nemausa occults a +7.7 magnitude star for Africa at 20:02 UT.

30- A Black Moon occurs, as reckoned as the second New Moon in one month.

The viewing prospects for the April 15th Total Lunar Eclipse. (Credit: NASA/GSFC/
The viewing prospects for the April 15th Total Lunar Eclipse. (Credit: NASA/GSFC/Espenak/Meeus).

April

08- Mars reaches opposition for 2014, shining at magnitude -1.5.

12- A close conjunction of Venus and Neptune occurs, with the planets just 0.7 degrees apart at 2:00 UT.

15- A Total Lunar Eclipse occurs, visible from the Americas and centered on 7:47 UT.

17- The Moon occults Saturn for South America at ~7:19 UT.

29- An Annular Solar Eclipse visible from Australia and the southern Indian Ocean occurs, centered on 6:05 UT. This is a unique, non-central antumbral eclipse!

May

03- Asteroid 105 Artemis occults a +7.7 magnitude star for NW Brazil and Peru at ~9:17 UT.

04- Asteroid 34 Circe occults a +7.4 magnitude star for Peru and Ecuador at ~10:12 UT.

06- The closest lunar apogee of 2014 occurs at 404,318 km distant at 10:23 UT.

07- Eta Aquariid meteors peak, with a ZHR=55 at 4:00 UT. Best observed from the Atlantic Region. Favorable in 2014, with the 7-day old Moon at waxing gibbous.

07- Asteroid 206 Hersilia occults a +7.5 magnitude star for Australia and Indonesia at ~17:49 UT.

10- Saturn reaches opposition for 2014, shining at magnitude +0.1. Saturn’s rings are tipped open a maximum of 23 degrees to our line of sight on February 11th, and widening overall in 2014.

13- A double shadow transit of Jupiter’s moons occurs from 9:20-9:32 UT favoring NW North America.

14- The Moon occults Saturn for Australia and New Zealand at ~12:18 UT.

24- A meteor shower outburst may be in the offing, courtesy of Comet 209P LINEAR. Will the “Camelopardalids” perform?

24- Asteroid 33 Polyhymnia occults a +5.5 magnitude star for South America at ~8:30 UT.

25- Mercury reaches maximum dusk elongation, 22.7 degrees east of the Sun. Mercury’s best evening apparition for 2014 for northern hemisphere viewers.

The triple shadow transit of June 3rd, as seen at 18:00 UT. (Created by the author using Starry Night).
The triple shadow transit of June 3rd, as seen at 19:00 UT. (Created by the author using Starry Night).

 June

3- A triple Jovian shadow transit occurs from 18:05-19:44 UT, favoring eastern Europe and Africa. This is the only triple shadow transit for 2014.

10- The Moon occults Saturn for the southern Indian Ocean at ~18:48 UT.

21- The Northward Solstice occurs at ~10:51 UT.

22- The International Space Station enters a period of full illumination near the June solstice, favoring multiple views for northern hemisphere viewers.

24- The waning crescent Moon passes within a degree of Venus, a great time for spotting the planet in the daytime.

26- The Moon occults Mercury just 20 hours prior to New… a tough catch, but may visible from the SE US and Venezuela just before sunrise.

27- The June Boötid meteors peak, with a ZHR variable from 0-100 at ~15:00 UT, favoring the Central Pacific. Optimal in 2014, as the Moon is at New phase.

July

04- Earth reaches aphelion at 2:00 UT, at 152,098,232 kilometres from the Sun.

04- Pluto reaches opposition at 3:00 UT.

05– 1 Ceres passes just 10’ from 4 Vesta in the constellation Virgo.

06– The Moon occults Mars for South America at ~01:21 UT

08– The Moon occults Saturn for Argentina & Chile at ~2:25 UT.

12- Mercury reaches its maximum elongation of 20.9 degrees west of the Sun, shining at magnitude +0.4 in the dawn.

12– The first Full Proxigean “Super” Moon (1 of 3) for 2014 occurs at 11:27 UT. The Moon reaches Full 21 hours prior to perigee.

30– The Southern Delta Aquarids peak, with a ZHR=20. Time variable, favorable in 2014 with the waxing crescent Moon 4 days past New.

20– Asteroid 451 Patientia occults a +7.1 magnitude star for South Africa at ~17:15 UT.

28- The farthest lunar apogee of 2014 occurs, with the Moon 406,568 kilometres distant at 3:28 UT.

30– Asteroid 103 Hera occults a +6.1 magnitude star for west Africa and central South America at ~1:11 UT.

A tri-conjunction of the Moon, Venus & Jupiter- A "Skewed Smiley face" conjunction!" Credit:  Stellarium
A tri-conjunction of the Moon, Venus & Jupiter on the morning of August 23rd- A “Skewed Smiley face” conjunction!” Credit: Stellarium).

August

02– A close conjunction of Mercury and Jupiter occurs, with the planets just 0.9 degrees apart at 19:00 UT. Visible in SOHO’s LASCO C3 camera.

04- The Moon occults Saturn for Australia at ~10:31 UT.

10– The closest lunar perigee of 2014 occurs, with the Moon 356,896 kilometres distant at 17:44 UT.

10- The Closest Full Moon of the year & “Super” Moon (2 of 3) for 2014 occurs, with Full Moon occurring just 27 minutes after perigee.

13– The Perseid meteors peak, with a ZHR=100 at ~04:00 UT favoring The Atlantic region. Unfavorable in 2014, with the 17 day old Moon at waning gibbous.

18- A conjunction of Venus and Jupiter occurs 5:00 UT, the closest conjunction of two naked eye planets in 2014, with the two just 15’ apart.

29- Neptune reaches opposition at 14:00 UT, shining at +7.8 magnitude.

31– The Moon occults Saturn for Africa and the eastern US (in the daytime) at ~18:59.

September

05- Venus passes 0.7 degrees from the bright star Regulus.

09– The final Full “Super” Moon (3 of 3) for 2014 occurs at 1:39 UT, just 22 hours after perigee.

15– Comet C/2013 V5 Oukaimeden may reach +5.5th magnitude for southern hemisphere observers.

20– Mercury passes 0.5 degrees south of the bright star Spica at 21:00 UT.

21- Mercury reaches its greatest elongation of 26.4 degrees east of the Sun shining at magnitude +0.0 in the dawn sky. Mercury’s best sunset apparition for 2014 for southern hemisphere observers.

23- The Southward Equinox occurs at 2:29 UT.

23- GEO satellite eclipse season occurs, as geostationary satellites enter Earth’s shadow near the equinox.

28– The Moon occults Saturn for the northern Pacific at ~4:25 UT. The Moon also occults 1 Ceres and 4 Vesta on the same day!

The path of Comet C/2013 A1 Siding Springs versus the planet Mars through October, 2014. (Created by the author using Stellarium).
The path of Comet C/2013 A1 Siding Springs versus the planet Mars through October, 2014. (Created by the author using Starry Night).

 October

04- 1 Ceres passes just 30’ north of Saturn.

06- Possible Draconid meteor shower, highly variable in terms of rates and timing, but unfavorable in 2014, with the Moon just two days from Full.

08- A Total Lunar Eclipse visible from the Pacific Rim region occurs, centered on 10:56 UT. The planet Uranus will also lie less than a degree away from the eclipsed Moon!

14- Comet C/2012 K1 PanSTARRS may reach +5th magnitude for southern hemisphere viewers.

13– The Moon reaches it shallowest northern declination for 2014 at +18.5 degrees.

19- Comet C/2013 A1 Siding Spring passes just 7’ from the planet Mars. Globular cluster NGC 6401 also lies nearby.

22– The Orionid meteor shower peaks at ~05:00 UT, with a predicted ZHR=25 favoring the Americas. Optimal in 2014, with the Moon at waning crescent.

22– The Moon occults Mercury for Australia just 24 hours prior to New as seen from Australia.

23- A Partial Solar Eclipse visible from western North America occurs centered on 21:46 UT.

25- The Moon occults Saturn for the northern Atlantic at ~15:43 UT.

25- The Moon reaches its shallowest southern point for 2014, at a declination of -18.6 degrees.

The partial solar eclipse of October 23rd, 2014. (Credit: NASA/GSFC/Fred Espenak).
The partial solar eclipse of October 23rd, 2014. (Credit: NASA/GSFC/Fred Espenak).

 November

01- Mercury reaches its greatest elongation 18.7 degrees west of the Sun, shining at magnitude -0.5. The best morning apparition of Mercury for 2014 as seen from the northern hemisphere.

18– Leonid meteors peak at 05:00 UT with a ZHR=20 favoring the Atlantic region. Optimal in 2014, with the 25 day old Moon at waning crescent phase.

20- Asteroid 3 Juno occults a +7.4 magnitude star for the US NE and eastern Canada.

27- The farthest lunar perigee of 2014 occurs with the Moon 369,824 km distant at 23:12 UT.

December

09- A double shadow transit of Jupiter’s moons occurs from 4:18 to 4:27 UT favoring eastern North America.

12- A double shadow transit of Jupiter’s moons occurs from 16:19 to 16:44 UT favoring NW North America.

13- The Geminid meteors peak with a ZHR=120 at ~01:00 UT, favoring the Middle East & Eastern Europe. Unfavorable in 2014, with the 20 day old  Moon at waning gibbous.

18- Asteroid 702 Alauda occults a +6.2 magnitude star at 14:12 UT for eastern Australia.

21- The Southward Solstice occurs at 23:03 UT.

21- The International Space Station enters period of full illumination around the solstice, with multiple nightly views favoring the southern hemisphere.

21- A double shadow transit of Jupiter’s moons occurs from 14:17 to 15:55 UT, favoring the Far East and Australia.

Don’t see your favorite or most anticipated event of 2014 on the list? Drop us a line and let us know!

Links & Resources Used:

-The American Meteor Society list of 2014 showers

-NASA’s Eclipse Website

-The United States Naval Observatory’s Astronomical Almanac Online

-Guy Ottewell’s 2014 Astronomical Calendar

-The Royal Astronomical Society of Canada’s 2014 Observer’s Calendar

-Steve Preston’s list of asteroid occultation events for 2014

Stellarium

Starry Nite

-Seiichi Yoshida’s Comet website

-Fourmilab’s Lunar Apogee and Perigee calculator

Heavens-Above

-The International Occultation Timing Association’s list of lunar occultations for 2014.

And finally, thanks to all of those too numerous to name who provided discussions/diatribes/input via Twitter/G+/message boards/etc to make this listing possible… let another exciting year of astronomy begin!

 

 

 

 

‘Tis the Season to Spot Jupiter: A Guide to the 2014 Opposition

Jupiter+moon imaged recently by Paul Cotton (@paultbird66) of Lincolnshire, England. Used with permission.

Lovers of planetary action rejoice; the king of the planets is returning to the evening skies.

One of the very first notable astronomical events for 2014 occurs on January 5th, when the planet Jupiter reaches opposition. You can already catch site of Jove in late December, rising in the east about an hour after local sunset. And while Venus will be dropping faster than the ball in Times Square on New Year’s Eve to the west in early 2014, Jupiter will begin to dominate the evening planetary action.

Orbiting the Sun once every 11.9 years, oppositions of Jupiter occur about once every 13 months or about 400 days, as the speedy Earth overtakes the gas giant on the inside track. This means that successive oppositions of the planet move roughly one astronomical constellation eastward. In fact, this year’s opposition is it’s northernmost in 12 years, occurring in the constellation Gemini. “Opposition” means that an outer planet is rising “opposite” to the setting Sun. As this opposition of Jupiter occurs just weeks after the southward solstice, Jupiter now lies in the direction that the Sun will occupy six months from now during the June Solstice.

This all means that Jupiter will ride high in the sky for northern hemisphere observers towards local midnight, a boon for astrophotographers looking to catch the planet high in the sky and out of the low horizon murk.

Jupiter will reach its most northern point for 2014 at a declination of +23.3 degrees on March 11th.

Jupiter also “skipped” 2013, in the sense that it was an “oppositionless year” for the giant world, as said 13 month span fell juuusst right, first on December 2nd, 2012 and then on January 5th, 2014. The next opposition of Jupiter will occur on… you guessed it… February 6th, 2015. The last year missing an opposition of Jupiter was 2001.

Jupiter and Io (arrowed) as imaged on the evening of December 22nd, 2013 by the author.
Jupiter and Io (arrowed) as imaged on the evening of December 22nd, 2013 by the author.

The exact timing of Jupiter’s opposition to the Sun in right ascension occurs at 21:00 UT/4:00 PM EST on January 5th. Its closest approach to Earth, however, arrives 27 hours prior, owing to a slight outward curvature of the approach of the two worlds. Jupiter will then lie about 4.21 astronomical units (AUs) or 629 million kilometres distant. This is just about down the middle of how close it can pass; Jupiter was just under 4 AUs distant in September 2010, and can pass almost 4.5 AUs from Earth, as happened in April 2005.

Jupiter also reaches a maximum brightness of magnitude -2.7 at opposition in 2014 and presents a disk 46.8” arc seconds wide. The coming month also provides a great chance to catch Jupiter in the daytime sky just before sunset, when the waxing gibbous Moon passes 4.9 degrees south of the planet on the evening of January 14th.

The Moon and Jupiter on the evening of January 14th shortly before sunset. (Created by the Author using Stellarium).
The Moon and Jupiter on the evening of January 14th shortly before sunset. (Created by the Author using Stellarium).

The very first thing you’ll notice looking at Jupiter, even at low power with binoculars or a telescope, is it retinue of moons. Though the planet has 67 discovered moons and counting, only the four large Galilean moons of Io, Europa, Ganymede and Callisto are readily apparent in a telescope. It’s fun to see orbital mechanics in action and watch them from night to night as they change position, just as Galileo first did over four centuries ago. This provided him with evidence that there is much more to universe than meets the eye, though we can consider ourselves fortunate that his proposal to name them the “Medician Moons” after his Medici benefactors was never widely adopted.

Crank up the magnification, and you’ll notice the large twin stripes of the northern and southern equatorial cloud belts crossing the disk of Jupiter. While the northern belt is stable, the southern belt has been known to submerge and disappear from view about every decade or so, as last happened in 2009-2010. You’ll also notice the Great Red Spot, a massive storm system over three times larger than the Earth that has been tracked by astronomers since it was recorded by Samuel Schwabe in 1831. The planet has the fastest rotation of any world in our solar system at 9.9 hours, and you’ll notice this swift rotation tracking Jupiter over the course of a single evening.

Transits and occultations of Jupiter’s moons are also always interesting to watch. The variation in the timing of these events at differing distances led Danish astronomer Ole Rømer to make the first attempts at measuring the speed of light in 1676.

Europa just beginning to cast a shadow off to one side shortly after opposition on January 8th at 7:30PM EST. (Created by the author using Stellarium).
Europa just beginning to cast a shadow off to one side shortly after opposition on January 8th at 7:30 PM EST. (Created by the author using Starry Night).

It’s interesting to note that Jupiter and its moons cast a shadow nearly straight back from our line of sight around opposition. You can see this change as the planet heads towards quadrature on April 1st, 2014 and Jupiter and its moons cast shadows off to one side. We’re also in the midst of a plane crossing, as the orbits of the Jovian moons appear edge-on to our line of sight in 2014 headed into early 2015. The outermost Jovian moon Callisto began a series of transits in 2013 and will continue to do so through 2014.

This is a great time to begin following all of the Jovian action, as we head into another exciting year of astronomy!

Tonight: The Rise of the 2013 “Mini-Moon”

The December 2010 Solstice Moon.

  The final Full Moon of 2013 occurs tonight, and along with it comes something special: the most distant and visually smallest Full Moon of 2013.

Why doesn’t the annual “mini-moon” receive the same fanfare and hype that the yearly perigee – or do you say Proxigean to be uber-obscure – “supermoon” does? The smallest Full Moon of the year does appear to have a public relations problem in this regard. But as you’ll see, the circumstances for this week’s Full Moon are no less fascinating.

The exact timing of tonight’s Full Moon occurs at 4:28 AM EST/9:28 Universal Time (UT) on Tuesday, December 17th. This occurs just two days and 14 hours prior to the Moon reaching apogee on December 19th at 6:50PM EST/23:50 UT at 406,267 kilometres distant. This is one of the three most distant apogees of 2013, and the closest to Full for the year. It’s also with 500 kilometres of the most distant apogee than can occur, as the Moon’s apogee can vary between ~404,000 and 406,700 kilometres distant.

Tonight’s Full Moon will have an apparent angular diameter of around 29.8’ arc minutes, just a shade lower than the usual value quoted of around half a degree or 30’. The visual size of the Moon as seen from the Earth varies about 12% from 34.1’ to 29.3’. Also, the Moon is also about half an Earth radius more distant when it’s on the local horizon versus at the zenith overhead!

This is also the closest Full Moon to the December solstice, which occurs four days later on Saturday, December 21st at 12:11 PM EST/17:11 UT. This marks the start of astronomical summer in the southern hemisphere and the beginning of the winter season in the north. Think of tonight’s Full Moon as a sort of “placeholder,” marking the point at which the Sun will occupy during the June solstice on the Gemini-Taurus border.

This all means that tonight’s Full Moon rides high for northern hemisphere residents towards local midnight. But the “Long Night’s Moon” of 2013 is rather lackluster in terms of declination. While it’s the northernmost Full Moon of 2013 at a declination of +18.7 degrees, it’s a far cry from the maximum declination of +28.72 degrees (the angle of the ecliptic plus the tilt of the Moon’s orbit) that it can achieve. This only occurs every 18.6 years and last occurred in 2006 and will happen again around 2025. We’re currently headed towards a shallow minimum for the Moon’s orbit in 2015. Ancient European and Native American cultures both knew of this cycle of high-flying moons.

Not weird enough? The next “most distant Full Moon of the Year” happens only one lunation later on January 16th… within just 2 hours of apogee! Perhaps January’s Full Moon is due notoriety as a “Super-Mini Moon?” Such a pairing of “mini-moons” last occurred on 2004-2005 and will next occur on 2021-2022.

The footprint for the lunar occultation of M67. (Created by the author using Occult 4.0)
The footprint for the lunar occultation of M67. (Created by the author using Occult 4.1)

The Moon also visits some other celestial sights this week. After passing five degrees north of Jupiter on December 19th, the Moon heads towards an occultation of the open cluster M67 in the constellation Cancer on December 21st for northern North America. Though the Moon will be waning gibbous, it might just be possible to note the reappearance of the cluster on the Moon’s dark limb. Other occultations for the remainder of December by the Moon include an occultation of Spica on December 27th for northern Asia, Saturn on December 29th for Antarctica, and +3.6th magnitude star Lambda Geminorum for Canada on December 18th.

The passing of the Full Moon also means it will be entering into the morning sky, which also means bad news for viewers of the Ursid meteor shower which peaks on December 22nd and hunters of Comet C/2013 R1 Lovejoy, currently shining at +5th magnitude in the constellation Hercules low in the dawn.

Moon crossing Orion.
Moon crossing Orion this week. (Credit: Stellarium).

The keen-eyed may notice the Moon also transits through the northern end of the non-zodiacal constellation of Orion on Tuesday, December 17th. Did you know that the Moon can actually stray far enough away from the ecliptic to cross through 18 constellations? The Six non-zodiacal constellations it can transit are: Orion, Ophiuchus, Corvus, Sextans, Auriga and Cetus.

Other names for the December Full Moon include the Yule, Oak, and Cold Moon.

Finally, a new Earthly ambassador is now roaming the lunar surface.

China’s Chang’E-3 spacecraft landed on the Moon just outside of the Bay of Rainbows (Sinus Iridum) near Montes Recti in the northern section of the Mare Imbrium on Saturday, December 14th. The landing site is visible now on the lunar nearside, and can be seen with that new Christmas telescope you’ve been itching to try out. Look for the Sinus Iridum as a wide crescent scarp, a sort of “notch” in the top of Mare Imbrium:

Finding the landing site of Chang'e-3. Photos and graphics by author.
Finding the landing site of Chang’e-3. Photos and graphics by author.

China’s Yutu or “Jade Rabbit” rover has been beaming back some splendid images of the lunar surface!

So don’t let the cold temperatures deter you from exploring the lunar surface, and the strange but fascinating motions of our nearest natural celestial neighbor. Dress warm and be sure this Christmas season to raise a glass of ye ole Nog to the Solstice/Yule Moon.

IRIS Glimpses an Elusive Region of the Sun

An innovative solar observatory is adding a key piece to the puzzle of the enigma that is our Sun.

Its two of key questions in heliophysics: why does our Sun have a corona? And why is the temperature of the corona actually higher than the surface of the Sun?

This week, researchers released results from the preliminary first six months of data from NASA’s Interface Region Imaging Spectrograph, known as IRIS. The findings were presented at the Fall American Geophysical Union Meeting this past Monday.

IRIS was launched on June 27th of this year on a Pegasus-XL rocket deployed from the belly of a Lockheed L-1011 aircraft flying out of Vandenberg Air Force Base. IRIS can focus in on a very specific interface region of the Sun sandwiched between the dazzling solar photosphere and the transition to the corona. To accomplish this, IRIS employs an ultraviolet slit spectrograph looking at ionized gas spectra.

IRIS in the clean room. The spacecraft is only about 2 metres in length, about the height of a person. (Credit: Lockheed Martin).
IRIS in the clean room. The spacecraft is only about 2 metres in length, about the height of a person. (Credit: Lockheed Martin).

“The quality of images and spectra we are receiving is amazing,” IRIS Principal Investigator Alan Title said in a recent press release from the NASA Goddard Space Flight Center. While other missions may take over a decade to go from the drawing board to the launch pad, IRIS was developed and deployed into Low Earth Orbit in just 44 months.

IRIS offers scientists a new tool to probe the Sun and a complimentary instrument to platforms such as Hinode, the Solar Heliospheric Observatory (SOHO) and NASA’s Solar Dynamics Observatory. In fact, IRIS has a better resolution than SDO’s AIA imagers or Hinode when it comes to this key solar interface region. IRIS has a 20x greater resolution in time, and 25x the spatial resolution of any former space-based UV spectrometer deployed.

“We are seeing rich and unprecedented images of violent events in which gases are accelerated to very high velocities while being rapidly heated to hundreds of thousands of degrees,” said Lockheed Martin science lead on the IRIS mission Bart De Pontieu. These observations are key to backing up theoretical models of solar dynamics as well as testing and formulating new ones of how our Sun works.

IRIS bridges this crucial gap between the photosphere and the lower chromosphere of the Sun. While the solar surface roils at relatively placid  6,000 degrees Celsius, temperatures rise into the range of 2-3 million degrees Celsius as you move up through the transition region and into the corona.

Two key solar phenomena that are of concern to solar researchers can be examined by IRIS in detail. One is the formation of prominences, which show up as long looping swirls of solar material rising up from the surface of the Sun. Prominences can be seen from backyard telescopes at hydrogen alpha wavelengths. IRIS can catch and track their early modeling with unprecedented resolution. Images released from IRIS show the fine structure of targeted prominences as they evolve and rise off the surface of the Sun. When a prominence and accompanying coronal mass ejection is launched in our direction, disruption of our local space environment caused by massive solar storm can result.

Slit jaw spectra images (the two strips to the left) and imaging a spicules 9to the right as seen by IRIS. (Credit: NASA/IRIS).
Slit jaw spectra images (the two strips to the left) and imaging of spicules (to the right) as seen by IRIS. (Credit: NASA/IRIS).

The second phenomenon targeted by IRIS is the formation of spicules, which are giant columns of gas rising from the photosphere. Although the spicules look like hair-fine structures through Earth-based solar telescopes, they can be several hundred kilometres wide and as long as the Earth. Short-lived, spicules race up from the surface of the Sun at up to 240,000 kilometres per hour and seem to play a key role in energy and heat transfer from the solar surface up through the atmosphere. IRIS is giving us a view of the evolution of spicules for the first time, and they’re proving to be even more complex than theory previously suggested.

“We see discrepancies between these observations and the models, and that is great news for advancing knowledge. By seeing something we don’t understand, we have a chance of learning something new,” Said University of Oslo astrophysicist Mats Carlsson.

Like SDO and SOHO, data and images from IRIS are free for the public to access online. Though the field of view for IRIS is a narrow 2’ to 4’ arc minutes on a side – the solar disk spans about 30’ as seen from the Earth – IRIS gives us a refined view of “where the action is.”

Where is IRIS looking? This snapshot gives some context of the IRIS field of view (green and red boxes) and black and white insets versus SDO's AIA full disk view of the Sun. (Credit: NASA/SDO/IRIS).
Where is IRIS looking? This snapshot gives some context of the IRIS field of view (green and red boxes) and black and white insets versus SDO’s AIA full disk view of the Sun. (Credit: NASA/SDO/IRIS).

And this all comes at an interesting time, as our nearest star crosses the sputtering solar maximum for Cycle #24.

The equivalent of 50 million CPU hours were utilized in constructing and modeling what IRIS sees. The reconstruction was an international effort, spanning the Partnership for Advanced Computing in Europe, the Norwegian supercomputing collaboration, and NASA’s Ames Research Center.

IRIS also faced the additional challenge of weathering a 2.5 week period of inactivity due to the U.S. government shutdown this fall. Potential impacts due to sequestration remain an issue, though small explorer missions such as IRIS demonstrate how we can do more with less.

“We’ve made a giant step forward in characterizing the heat transfer properties of this region between the visible surface and the corona, which is key to understanding how the outer atmosphere of the Sun exists, and is key to understanding the outer atmosphere that the Earth lies in,” said Alan Title, referring to the tenuous heliosphere of the Sun extending out through the solar system.

Understanding the inner working of our Sun is vital: no other astronomical body has as big an impact on life here on Earth.

IRIS is slated for a two-year mission, though as is the case with most space-based platforms, researchers will work to get every bit of usefulness out of the spacecraft that they can. And it’s already returning some first-rate science at a relatively low production cost. This is all knowledge that will help us as a civilization live with and understand our often tempestuous star.

 

Get Ready for the 2013 Geminid Meteor Shower

The rising radiant of the Geminids-Looking east at 9PM local from latitude 30 degrees north. (Credit-Stellarium).

One of the best annual meteor showers occurs this coming weekend.

The 2013 Geminid meteors peak this coming Saturday on December 14th. This shower has a broad maximum, assuring that observers worldwide get a good look. In 2013, the maximum for the Geminids is forecast to span from 13:00 Universal Time (UT) on Friday, December 13th to 10:00UT/5:00AM EST on Saturday, December 14th, with a projected maximum centered a few hours earlier at 2:00 UT Saturday morning.

This is good news  for observers spanning both sides of the Atlantic, who should be well placed to catch the event. Keep in mind, meteor showers often peak hours before or after predictions… we certainly don’t know everything that a given meteor stream might have in store!

An all-sky composite of the 2008 Geminid meteor shower. (Credit: NASA/MSFC/Bill Cooke, NASA's Meteoroid Environment Office).
An all-sky composite of the 2008 Geminid meteor shower. (Credit: NASA/MSFC/Bill Cooke, NASA’s Meteoroid Environment Office).

But the time to start watching is now. We’ve already seen a few early Geminids this past weekend, and this shower is notable for showing early activity for northern hemisphere observers before local midnight. This is because the radiant, or the direction that the meteors seem to emanate from lies at a high northern declination of 33 degrees north near the star Castor, also known as Alpha Geminorum.

The typical Zenithal Hourly Rate for the Geminids is 80-120, or about 1 to 2 per minute. Keep in mind, the ZHR is an ideal rate, assuming dark skies, with the radiant positioned directly overhead. Most observers will see significantly less activity.

The 2013 Geminids also have to contend with the waxing gibbous Moon, which reaches Full just 3 days after the shower’s expected maximum. This will give observers a dwindling window between moonset and the start of dawn twilight to catch the Geminids at their best.

We always thought that the Geminids had a bit of an undeserved PR problem among annual showers. This no doubt stems from the fact that they arrive in the chilly month of December, a time when fingers go numb, camera batteries die, and conducting a vigil for meteors is challenging.

A 2012 Geminid captured by the author from Mars Hill. North Carolina.
A 2012 Geminid captured by the author from Mars Hill, North Carolina.

This shower is an interesting one though, with an equally interesting history and source. The Geminids were first identified as a distinct meteor shower by R.P. Greg of Manchester UK in 1862, and the estimated ZHR rose from about 20 to 80 through the 20th century. The parent source of the Geminids remained unknown until 1983, when astronomer Fred Whipple linked them to the strange “rock-comet” body 3200 Phaethon. An Apollo asteroid also thought to be a member of the Pallas family of asteroids, 3200 Phaethon seems to be shedding enough material to produce the annual Geminid meteor shower. This makes the annual shower rare as one not produced by a comet. It’s worth noting that 3200 Phaethon also passes extremely close – 0.14 AU – from the Sun at perihelion, and gets periodically “baked” during each 1.4 year passage.

In the 21st century, rates for the Geminids have stayed above a ZHR of 120, currently the highest of any annual shower. It’s worth noting that an extrapolated ZHR of almost 200 were seen in 2011 when the Moon was at an equally unfavorable waning gibbous phase! The Geminids always produce lots of fireballs, capable of being seen even under moonlit skies.

There are also two other showers currently active to watch for this week. One is the Ursid meteors, which radiate from the Little Dipper (Ursa Minor) with a peak ZHR of 10-50 occurring on December 22nd. Also, keep an eye out for Andromedid meteors this week, a defunct shower that may be making a comeback. The source of several great meteor storms in the late 19th century, the Andromedid parent source is the shattered comet formerly known as 3D/Biela.

An early Geminid crosses pathes with Comet 2013 R1 Lovejoy. (Credit: Jason Hullinger).
An early Geminid crosses paths with Comet 2013 R1 Lovejoy. (Credit: Jason Hullinger).

Though the Geminids appear to radiate from the constellation Gemini, they can appear anywhere in the sky. Tracing the path back can determine the source constellation and the “membership” of a given meteor. Random meteors not associated with any identified shower are known as “sporadics.” Block that pesky light-polluting Moon behind a building or hill to optimize your chances of catching sight of a meteor. Employing a friend or two to watch in different directions will also maximize the number seen. The International Meteor Organization always welcomes reports from observers… this is real science that you can contribute to using nothing more sophisticated than your eyes!

The Geminids are medium-speed meteors with an average atmospheric velocity of about 35 kilometres per second, often leaving long, glowing trails worth examining with a pair of binoculars. You might note an apparent surge in speed to this shower past local midnight, as your vantage point turns into the oncoming shower, adding the velocity of the Earth to the approaching Geminids.

Photographing meteors is fun and easy to do; all you’ll need is a DSLR camera mounted on a tripod. Take several manual setting exposures to get the combination of ISO,F-stop, and shutter speed correct for your local sky conditions.  Then simply set the focus to infinity, and use the widest field of view possible. Catching meteors is surreptitious, as they can appear anywhere – and at any time – in the sky. Be sure to thoroughly review those images afterwards… nearly every meteor we’ve caught photographically went unnoticed during observation!

Also, remember that cold weather plus long exposure times can conspire to drain camera batteries in a hurry. Be sure to keep a spare set of charged batteries ready to go in a warm pocket!

How powerful will the Geminids become? Are we in for a “return of the Andromedids” moving towards 2014? One thing is for sure: you won’t see any meteors if you don’t try. So be sure to get out there, pour a mug of your favorite warming beverage, and don’t miss the 2013 Geminid meteor shower!

–      Got meteors? Be sure and tweet ‘em to #Meteorwatch.

–      Be sure to send those pics of Geminids and more in to Universe Today.

A Naked Eye Nova Erupts in Centaurus

Nova Centuari 2013 (Credit:

If you live in the southern hemisphere, the southern sky constellation of Centaurus may look a little different to you tonight, as a bright nova has been identified in the region early this week.

An animation showing a comparison between the constellation Centaurus before and after a nova eruption. Credit and copyright: Ernesto Guido, Nick Howes and Martino Nicolini/Remanzacco Observatory. Click for larger version.
An animation showing a comparison between the constellation Centaurus before and after a nova eruption. Credit and copyright: Ernesto Guido, Nick Howes and Martino Nicolini/Remanzacco Observatory. Click for larger version.

The initial discovery of Nova Centauri 2013 (Nova Cen 2013) was made by observer John Seach based out of Chatsworth Island in New South Wales Australia. The preliminary discovery magnitude for Nova Cen 2013 was magnitude +5.5, just above naked eye visibility from a good dark sky site. Estimates by observers over the past 24 hours place Nova Cen 2013 between magnitudes +4 and +5 “with a bullet,” meaning this one may get brighter still as the week progresses.

Nova Cen 2013
Nova Cen 2013 as imaged from the Siding Spring observatory on December 3rd. (Credit: Ernesto Guido, Nick Howes & Martino Nicolini/Remanzacco Observatory).

We first got wind of the discovery via the American Association of Variable Star Observers yesterday afternoon when alert notice 492 was issued. Established in 1911, the AAVSO is a great resource for info and a fine example of amateur collaboration in the effort to conduct real scientific observation.

Follow-up spectra measurements by Rob Kaufman in White Cliffs Australia and Malcolm Locke in Christchurch New Zealand demonstrated the presence of strong hydrogen alpha and hydrogen beta emission lines, the classic hallmark of an erupting nova. Like Nova Delphini 2013 witnessed by observers in the northern hemisphere, this is a garden variety nova located in our own galaxy, going off as seen along the galactic plane from our Earthbound perspective. A handful of galactic novae are seen each year, but such a stellar conflagration reaching naked eye visibility is worthy of note. In fact, Nova Cen 2013 is already knocking on the ranks of the 30 brightest novae observed of all time.

Nova Cen 2013
A narrow field image (inverted B/W) of  Nova Cen 2013. (Credit: Ednilson Oliveira).

This is not to be confused with a supernova, the last of which observed in our galaxy was Kepler’s Supernova in 1604, just before the advent of the telescope in modern astronomy.  Supernovae are seen in other galaxies all the time, but here at home, you could say we’re “due”.

So, who can see Nova Cen 2013, and who’s left out? Well, the coordinates for the nova are:

Right Ascension: 13 Hours 54’ 45”

Declination: -59°S 09’ 04”

That puts it deep in the southern celestial hemisphere sky where the constellation Centaurus meets up with the constellations of Circinus, Musca and the Crux. Located within three degrees of the +0.6th magnitude star Hadar — also named Beta Centauri — it would be possible to capture the southern deep sky objects of the Coal Sack and Omega Centauri with Nova Cen 2013 in the same wide field of view.

Stellarium
The field of view of Nova Centauri 2013 with a five degree Telrad “bullseye” added for scale. Note that magnitude for selected comparison stars are quoted, minus the decimal points. (Created using Stellarium).

Though Nova Cen 2013 technically peeks above the southern horizon from the extreme southern United States, the viewing circumstances aren’t great. In fact, the nova only rises just before the Sun as seen from Miami in December, at 25 degrees north latitude. The Centaurus region is much better placed in northern hemisphere during the springtime, when many southern tier states can actually glimpse the celestial jewels that lie south, such as Omega Centauri.

But the situation gets better, the farther south you go. From Guayaquil, Ecuador just below the equator, the nova rises to the southeast at about 3 AM local, and sits 20 degrees above the horizon at sunrise.

11PM local from latitude (Created by the author using Starry Night Education Software).
11PM local, from latitude 40 degrees south looking to the southeast. (Created by the author using Starry Night Education Software).

The nova will be circumpolar for observers south of -30 degrees latitude, including cities of Buenos Aires, Cape Town, Sydney and Auckland. Remember, its springtime currently in the southern hemisphere, as we head towards the solstice on December 21st and the start of southern hemisphere summer. We’ve been south of the equator about a half dozen times and it’s a unique experience – for northern star gazers, at least – to see familiar northern constellations such as Orion and Leo hang “upside down” as strange a wonderful new constellations beckon the eye to the south. Also, though the Sun still rises to the east, it transits to the north as you get deep into the southern hemisphere, a fun effect to note!

Latitudes, such as those on par with New Zealand, will get the best views of Nova Cen 2013. Based near latitude 40 degrees south, observers will see the nova about 10 degrees above the southern horizon at lower culmination at a few hour after sunset, headed towards 40 degrees above the southeastern horizon at sunrise.

All indications are that Nova Cen 2013 is a classical nova, a white dwarf star accreting matter from a binary companion until a new round of nuclear fusion occurs. Recurrent novae such as T Pyxidis or U Scorpii may erupt erratically in this fashion over the span of decades.

As of yet, there is no firm distance measurement for Nova Cen 2013, though radio observations with southern sky assets may pin it down. One northern hemisphere based program, known as the EVLA Nova Project, seeks to do just that.

Congrats to John Seach on his discovery, and if you find yourself under southern skies, be sure to check out this astrophysical wonder!

Got pics of Nova Centauri 2013? Be sure to send ‘em in to Universe Today!