The Hunt for KBOs for New Horizons’ Post-Pluto Encounter Continues

An artist’s conception of a KBO encounter by New Horizons. Credit: JHUAPL/SwRI.

Are you ready for the summer of 2015? A showdown of epic proportions is in the making, as NASA’s New Horizons spacecraft is set to pass within 12,500 kilometres of Pluto — roughly a third of the distance of the ring of geosynchronous satellites orbiting the Earth —  a little over a year from now on July 14th, 2015.

But another question is already being raised, one that’s assuming center stage even before we explore Pluto and its retinue of moons: will New Horizons have another target available to study for its post-Pluto encounter out in the Kuiper Belt? Researchers say time is of the essence to find it.

To be sure, it’s a big solar system out there, and it’s not that researchers haven’t been looking. New Horizons was launched from Cape Canaveral Air Force Station on January 19th, 2006 atop an Atlas V rocket flying in a 551 configuration in one of the fastest departures from Earth ever: it took New Horizons just nine hours to pass Earth’s moon after launch.

New Horizons spends its last days on Earth pre-encapsulation. (Credit: NASA/KSC).
New Horizons spends its last days on Earth pre-encapsulation. (Credit: NASA/KSC).

The idea has always been out there to send New Horizons onward to explore and object beyond Pluto in the Kuiper Belt, but thus far, searches for a potential target have turned up naught.

A recent joint statement from NASA’s Small Bodies and Outer Planets Assessment Groups (SBAG and OPAG) has emphasized the scientific priority needed for identifying a possible Kuiper Belt Object (KBO) for the New Horizons mission post-Pluto encounter.  The assessment notes that such a chance to check out a KBO up close may only come once in our lifetimes: even though it’s currently moving at a heliocentric velocity of  just under 15 kilometres a second, it will have taken New Horizons almost a decade to traverse the 32 A.U. distance to Pluto.

The report also highlights the fact that KBOs are expected to dynamically different from Pluto as well and worthy of study. The statement also notes that the window may be closing to find such a favorable target after 2014, as the upcoming observational apparition of Pluto as seen from Earth — and the direction New Horizons is headed afterwards — reaches opposition this summer on July 4th.

But time is of the essence, as it will allow researchers to plan for a burn and trajectory change for New Horizons shortly after its encounter with Pluto and Charon using what little fuel it has left. Then there’s the issue of debris in the Pluto system that may require fine-tuning its trajectory pre-encounter as well. New Horizons will begin long range operations later this year in November, switching on permanently for two years of operations pre-, during and post- encounter with Pluto.

And there currently isn’t a short-list of “next best thing” targets for New Horizons post-Pluto encounter. One object, dubbed VNH0004, may be available for distant observations in January of next year, but even this object will only pass 75 million kilometres — about 0.5 A.U. — from New Horizons at its closest.

Ground based assets such as the Keck, Subaru and Gemini observatories have been repeatedly employed in the search over the past three years. The best hopes lie with the Hubble Space Telescope, which can go deeper and spy fainter targets.

Nor could New Horizons carry out a search for new targets on its own. Its eight inch (20 cm in diameter) LORRI instrument has a limiting magnitude of about +18, which is not even close to what would be required for such a discovery.

New Horizons currently has 130 metres/sec of hydrazine fuel available to send it onwards to a possible KBO encounter, limiting its range and maneuverability into a narrow cone straight ahead of the spacecraft. This restricts the parameters for a potential encounter to 0.35 A.U. off of its nominal path for a target candidate  be to still be viable objective. New Horizons will exit the Kuiper Belt at around 55 A.U. from the Sun, and will probably end its days joining the Voyager missions probing the outer solar system environment. Like Pioneers 10 and 11, Voyagers 1 and 2 and the upper stage boosters that deployed them, New Horizons will escape our solar system and orbit the Milky Way galaxy for millions of years. We recently proposed a fun thought experiment concerning just how much extraterrestrial “space junk” might be out there, littering the galactic disk.

And while the crowd-sourced Ice Hunters project generated lots of public engagement, a suitable target wasn’t found. There is talk of a follow up Ice Investigators project, though it’s still in the pending stages.

Another issue compounding the problem is the fact that Pluto is currently crossing the star rich region of the Milky Way in the constellation Sagittarius. Telescopes looking in this direction must contend with the thousands of background stars nestled towards the galactic center, making the detection of a faint moving KBO difficult. Still, if any telescope is up to the task, it’s Hubble, which just entered its 25th year of operations last month.

Credit Starry Night
The path of Pluto through the constellation Sagittarius through August 2015. Credit: Starry Night.

Shining at +14th magnitude, Pluto will be very near the 3.5th magnitude star Xi2 Sagittarii during the July 2015 encounter.

New Horizons is currently 1.5 degrees from Pluto — about 3 times the angular size of a Full Moon —as seen from our Earthly vantage point, and although neither can be seen with the naked eye, you can wave in their general direction this month on May 18th, using the nearby daytime Moon as a guide.

Credit: Starry Night
The waning crescent Moon lies in the direction of New Horizons and Pluto on May 18th… note the ESA’s Rosetta spacecraft (lower left) and Pioneer 11 (upper center) are also ‘nearby!’ Credit: Starry Night

July 2015 will be an exciting and historic time in solar system exploration. Does Pluto have more undiscovered moons? A ring system of its own? Does it resemble Neptune’s moon Triton, or will it turn out looking entirely different ?

If nothing else, exploration of Pluto will finally give us science writers some new images to illustrate articles on the distant world, rather than recycling the half a dozen-odd photos and artist’s conceptions that are currently available. An abundance of surface features will then require naming as well. It would be great to see Pluto’s discoverer Clyde Tombaugh and Venetia Burney — the girl who named Pluto — get their due. We’ll even assume our space pundit’s hat and predict a resurgence of the “is it a planet?” debate once again in the coming year as the encounter nears…

Onward to Pluto and the brave new worlds beyond!

Comet Jacques Brightens: How to See it in May

Comet Jacques as imaged on March 18th, shortly after discovery. Credit: Efrain Morales Rivera.

A recently discovered comet is headed northward and is set to put on one of two fine performances for binocular observers in 2014 starting this week.

Comet C/2014 E2 Jacques was discovered on March 13th 2014 by Cristóvão Jacques, Eduardo Pimentel and João Ribeiro de Barros while observing from the Southern Observatory for Near Earth Asteroids Research (SONEAR) facility located near Oliveira, Brazil.

The comet was just about at +15th magnitude at the time of discovery as it glided across the southern hemisphere constellation of Centaurus.

While a majority of comet discoveries are destined to remain small and faint, Comet Jacques was immediately shown to be something special. Upon discovery of any new comet, the first task is to gain several observations hours or nights apart to accurately gauge its distance and orbit. Are astronomers looking at a small, garden variety comet close up, or a large, active one far away?

In the case of Comet Jacques, it was something in between: a comet about 1.22 Astronomical Units (A.U.s) distant at time of discovery. Comet Jacques is headed towards perihelion 0.66 A.U. from the Sun in early July and will pass 0.56 A.U. from Earth on August 28th.  Follow up observations carried out using the iTelescope at Siding Spring Australia showed a slightly elongated coma about 2 arc minutes across shortly after discovery, and the comet has recently jumped up to magnitude +8 — ahead of the projected light curve — in just the past week.

Starry Night
The path of Comet Jacques, looking west from latitude 30 degree north 45 minutes after sunset. Credit: Starry Night.

We caught our first good look at Comet Jacques last night while setting up for the Virtual Star Party. While +10 magnitude or brighter is usually a pretty good rule of thumb for binocular visibility, we found that the comet was only apparent as a fuzzy smudge viewing it with a 8” Schmidt-Cassegrain telescope using averted vision at low power. Remember, the brightness of a comet is spread out over its apparent surface area, similar to viewing a diffuse nebula. Our first telescopic views of the ill-fated comet ISON as it breeched +10th magnitude were similar. Certainly, a nearby waxing crescent Moon in Gemini last night didn’t help.

How bright will Comet Jacques get? Current projections call for it to perhaps break naked eye visibility around +6th magnitude after June 1st and reach as bright as +4th magnitude in early July near perihelion. After its first evening act in May and June, Comet Jacques will reemerge in the dawn sky for northern hemisphere observers for Act 2 and trace a path northward paralleling the galactic plane through the star rich fields of Perseus, Cassiopeia, Cepheus and Cygnus in August and September of this year. If our luck holds out, Comet Jacques will remain above 6th magnitude until early September.

Credit JPL
The path of Comet Jacques through the inner solar system. Credit: JPL solar system small body generator.

This comet also created a brief flurry of interest when it was revealed that it will pass just 0.085 AUs or 12,700,000 kilometers from Venus on July 13th, 2014. Though close, this is still 31 times the distance from Earth to the Moon. The only “eyes” that humanity has currently in operation around Venus is ESA’s Venus Express orbiter. During closest approach Comet Jacques will appear just over 3 degrees away from Venus as seen from our Earthly vantage point.

Another comet is also set to photobomb a planet, as Comet A1 Siding Spring passes a nominal distance of 0.0009 A.U.s or 135,000 kilometers from Mars this Fall on October 19th.

Comet Jacques
11 images of Comet Jacques stacked from May 3rd. Credit: Ian Griffin @IanGriffin.

The closest recorded passage of a comet near Earth was Comet  D/1770 L1 Lexell in 1770, which passed us 0.015 A.U.s or 233 million kilometres distant.

Now on to Act 1. May finds Comet Jacques spending most of the month in the long rambling constellation of Monoceros. Currently moving just under 2 degrees a day, Comet Jacques crosses the celestial equator northward this week on May 8th. You’ll note its high orbital inclination of 156.4 degrees as it speeds northward. Comet Jacques has a long orbital period gauged at over 30,000 years — the last time Comet Jacques visited the inner solar system, our ancestors had the Last Glacial Maximum period to look forward to.

Light curve
The projected light curve of comet Jacques with recent observations. Credit: Seiichi Yoshida/aerith.net.

Comet Jacques is currently the brightest comet “with a bullet,” edging out the +9th magnitude comets C/2012 K1 PanSTARRS gilding through Canes Venatici and comet C/2012 X1 LINEAR, currently residing in the constellation of Aquila the Eagle. A great place to keep up with current observations of comets is the Comet Observation Database. We’re also pinging the IAU Minor Planet Center’s quick look page for new discoveries daily.

Here are some highlights to watch out for as Comet Jacques heads towards perihelion. Passages within one degree — twice the size of the Full Moon — near stars brighter than +5th magnitude are noted unless mentioned otherwise:

May 3rd through June 1st
The celestial path of Comet Jacques from May 3rd through June 1st. Credit: Starry Night.

May 8th: Passes the +4.1 magnitude star Delta Monocerotis and crosses north of the celestial equator.

May 10th: Passes planetary nebula NGC 2346.

May 11th: Passes briefly into Canis Minor before reentering the constellation Monoceros.

May 14th: Full Moon occurs, marking the start of a favorable two week period of moonless evenings soon after.

May 24th: Passes the +4.8 magnitude star 17 Monocerotis.

May 28th: New Moon occurs, marking the return of the Moon to early evening skies.

May 29th: Passes the +4.7 magnitude star 15 Monocerotis.

May 30th: Passes the Christmas tree cluster. Photo op!

May 31st: The waxing crescent Moon passes less than 8 degrees from Comet Jacques.

June 1st: Comet Jacques reaches naked eye visibility?

June 6th: Crosses into the constellation Gemini.

June 11th: Crosses into the constellation Taurus.

June 13th: Full Moon occurs.

June 14th: Crosses the galactic plane.

June 21st: Passes into the field of view of SOHO’s LASCO C3 camera.

June 27th: New Moon occurs.

July 2nd: Reaches perihelion at 0.6638 A.U. from the Sun.

July 8th: Crosses north of the ecliptic plane.

July 13th: Passes 0.085 A.U. from Venus.

August 28th: Passes 0.56 A.U. from Earth.

And thus, Comet Jacques joins the parade of fine binocular comets in the 2014 night sky, as the stage is set for Act 2 this fall. And keep in mind, the next “big one” could grace our skies at anytime… more to come!

Revisit Halley’s Comet – Stay Up Late for This Week’s Eta Aquarid Meteor Shower

The Eta Aquarid meteor shower is active in early May and peaks before dawn on Tuesday and Wednesday May 6-7 this year. Watch for it before the start of morning twilight in the eastern sky. Created with Stellarium

UPDATE: Watch a live webcast of the meteor shower, below, from NASA’s Marshall Space Flight Center during the night of Monday, May 5 to the early morning of May 6.

Halley’s Comet won’t be back in Earth’s vicinity until the summer of 2061, but that doesn’t mean you have to wait 47 years to see it. The comet’s offspring return this week as the annual Eta Aquarid meteor shower. Most meteor showers trace their parentage to a particular comet. The Perseids of August originate from dust strewn along the orbit of comet 109P/Swift-Tuttle, which drops by the inner solar system every 133 years after “wintering” for decades just beyond the orbit of Pluto, but the Eta Aquarids (AY-tuh ah-QWAR-ids) have the best known and arguably most famous parent of all – Halley’s Comet. Twice each year, Earth’s orbital path intersects dust and rock particles strewn by Halley during its cyclic 76-year journey from just beyond Uranus to within the orbit of Venus. When we do, the grit meets its demise in spectacular fashion as wow-inducing meteors.



Video streaming by Ustream

Composite of Aquarid meteors from the 2012 shower. Credit: John Chumack
Composite of Aquarid meteors from the 2012 shower. Credit: John Chumack

Meteoroids enter the atmosphere and begin to glow some 70 miles high. The majority of them range from sand to pebble sized but most no more than a gram or two.  Speeds range from 25,000-160,000 mph (11-72 km/sec) with the Eta Aquarids right down the middle at 42 miles per second (68 km/sec). Most burn white though ‘burn’ doesn’t quite hit the nail on the head. While friction with the air heats the entering meteoroid, the actual meteor or bright streak is created by the speedy rock exciting atoms along its path. As the atoms return to their neutral state, they emit light. That’s what we see as meteors. Picture them as tubes of glowing gas.

The farther south you live, the higher the shower radiant will appear in the sky and the more meteors you’ll see. For southern hemisphere observers this is one of the better showers of the year with rates around 30-40 meteors per hour. With no moon to brighten the sky, viewing conditions are ideal. Except for maybe the early hour. The shower is best seen in the hour or two before the start of dawn.

The Eta Aquarid shower originates with material left behind by Halley's Comet when the sun boils dust and ice from its nucleus around the time of perihelion. This photo from May 1986 during its last pass by Earth. Credit: Bob King
The Eta Aquarid shower originates with material left behind by Halley’s Comet when the sun boils dust and ice off its nucleus around the time of perihelion. This photo from May 1986 during Halley’s last visit. Credit: Bob King

From mid-northern latitudes the radiant or point in the sky from which the meteors will appear to originate is low in the southeast before dawn. At latitude 50 degrees north the viewing window lasts about 1 1/2 hours; at 40 degrees north, it’s a little more than 2 hours. If you live in the southern U.S. you’ll have nearly 3 hours of viewing time with the radiant 35 degrees high.

A bright, earthgrazer Eta Aquarids streaks across Perseus May 6, 2013. Because the radiant is low for northern hemisphere observers, earthgrazers - long, bright meteors that come up from near the horizon and have long-lasting trails. Credit: Bob King
A bright, earthgrazing Eta Aquarid meteor streaks across Perseus May 6, 2013. Because the radiant is low for northern hemisphere observers, watch for earthgrazers – long, bright meteors that come up from near the horizon and have long-lasting trails. Credit: Bob King

Northerners might spy 5-10 meteors per hour over the next few mornings. Face east for the best view and relax in a reclining chair. One good thing about this event – it won’t be anywhere near as cold as watching the December Geminids or January’s Quadrantids. We must be grateful whenever we can.

Meteor shower members can appear in any part of the sky, but if you trace their paths in reverse, they’ll all point back to the radiant. Other random meteors you might see are called sporadics and not related to the Eta Aquarids. Because Aquarius is home to at least two radiants, we distinguish the Etas, which radiate from near Eta Aquarii, from the Delta Aquarids, an unrelated shower active in July and August.

Wishing you clear skies and plenty of  hot coffee at the ready.

Spectacular Aurora Sneaks in Quietly, Rages All Night

Auroral arcs are topped by red rays light up the northeast while the moon and Jupiter shine off to the west in this photo taken last night over a small lake north of Duluth, Minn. Both moon and aurora light are reflected in puddles on the ice. Credit: Bob King

Expect the unexpected when it comes to northern lights. Last night beautifully illustrated nature’s penchant for surprise. A change in the “magnetic direction” of the wind of particles from the sun called the solar wind made all the difference. Minor chances for auroras blossomed into a spectacular, night-long storm for observers at mid-northern latitudes.

 

6-hours of data from NASA's Advanced Composition Explorer spacecraft, which measures energetic particles from the sun and other sources from a spot 1.5 million kilometers ahead of Earth toward the sun. By watching the Bz graph, you'll get advance notice of the potential for auroras. Click to visit the site. Credit: NOAA
6-hours of data from NASA’s Advanced Composition Explorer spacecraft, which measures energetic particles from the sun and other sources from a spot 1.5 million kilometers ahead of Earth toward the sun. By watching the Bz graph, you’ll get advance notice of the potential for auroras. Click to visit the site. Credit: NOAA

Packaged with the sun’s wind are portions of its magnetic field. As that material – called the interplanetary magnetic field (IMF) – sweeps past Earth, it normally glides by, deflected by our protective magnetic field, and we’re no worse for the wear. But when the solar magnetic field points south – called a southward Bz – it can cancel Earth’s northward-pointing field at the point of contact, opening a portal. Once linked, the IMF dumps high-speed particles into our atmosphere to light up the sky with northern lights. 

A large red patch briefly glowed above the bright green arc around 11:15 p.m. CDT last night May 3. The color was faintly visible with the naked eye. Credit: Bob King
A large red patch briefly glowed above the bright green arc around 11:15 p.m. CDT last night May 3. The color was faintly visible with the naked eye. Credit: Bob King

Spiraling down magnetic field lines like firefighters on firepoles, billions of tiny solar electrons strike oxygen and nitrogen molecules in the thin air 60-125 miles up. When the excited atoms return back to their normal rest states, they shoot off niblets of green and red light that together wash the sky in multicolor arcs and rays. Early yesterday evening, the Bz plot in the ACE satellite data dipped sharply southward (above), setting the stage for a potential auroral display.

After an intial flurry of bright rays, the aurora scaled back to two bright, diffuse arcs before erupting again around 11:30 p.m. Credit: Bob King
After an initial flurry of bright rays, the aurora scaled back to two bright, diffuse arcs with subtle rayed textures before erupting again around 11:30 p.m. Credit: Bob King

Nothing in the space weather forecast would have led you to believe northern lights were in the offing for mid-latitude skywatchers last night. Maybe a small possibility of a glow very low on the northern horizon. Instead we got the full-blown show. Nearly every form of aurora put in an appearance from multi-layered arcs spanning the northern sky to glowing red patches, crisp green rays and the bizarre flaming aurora. “Flames” look like waves or ripples of light rapidly fluttering from the bottom to the top of an auroral display. Absolutely unearthly in appearance and yet only 100 miles away.


VLF Auroral Chorus by Mark Dennison

I even broke out a hand-held VLF (very low frequency) radio and listened to the faint but crazy cosmic sounds of electrons diving through Earth’s magnetosphere. When my electron-jazzed brain finally hit the wall at 4 a.m., flames of moderately bright aurora still rippled across the north.

Just when you thought it was over, the whole northern sky burst into rays around 1 a.m. CDT. The whole northern sky lit up with green and red rays earlier this morning. While the green color was easy to see, the red was very pale. The human eye is much more sensitive to green light than red, one of the reasons why the aurora rarely appears red except in a camera during a time exposure. Credit: Bob King
Just when you thought it was over, the whole northern sky burst into rays around 1 a.m. CDT this morning. The human eye is much more sensitive to green light than red, one of the reasons why the aurora rarely appears red except in time exposures made with a camera. Credit: Bob King
Around 2 o'clock the northern lights displayed flaming when ripples of light pulse from top to bottom. It's very difficult to photograph, but here it is anyway! Credit: Bob King
Around 2 o’clock, flames pulsed from bottom to top in patchy aurora. It’s very difficult to photograph, but here it is anyway! Credit: Bob King

So what about tonight? Just like last night, there’s only a 5% chance of a minor storm. Take a look anyway –  nature always has a surprise or two up her sleeve.

Amazing Images of Today’s Solar Eclipse from Earth and Space

Virtual Telescope

The images are pouring in. While most of North America slept this AM, Australians were treated to the very first solar eclipse of 2014 earlier today. And while this particular eclipse was a partial one only from the Australian continent, it still offered observers a fine view of an often elusive natural spectacle.

Michael Drew
The partial eclipse as seen from Adelaide. Credit: Michael Drew (@MichaelDrew1234)

Although rain and clouds frustrated attempts to view the eclipse from much of southern Australia, clouds parted long enough in Queensland to the east and areas around Perth to the west to offer observers a fine view. Many eclipse watchers on the Australian east coast had the additional bonus of catching the setting Sun during the eclipse.

Proba-2
A quick screen shot from ESA’s Proba-2 spacecraft during one of the three passes of the solar eclipse. Credit: ESA/Proba-2.

We wrote about the prospects for catching this bizarre eclipse previously. The eclipse was a rare, non-central annular with one limit only, meaning the antumbra or inner core of the Moon’s shadow just grazed the edge of the planet over Antarctica. We haven’t yet heard if anyone witnessed it from the southern polar continent, though two year round research stations were located near the path of annularity. The European Space Agency operates Concordia Station nearby as part of its Human Spaceflight Activities program and they were aware of the upcoming event. We’ll keep you updated if reports or images surface!

David Herne
The eclipse seen through clouds. Photographer David Herne also noted that while he used his D3100 DSLR for the shot, his homemade pinhole camera offered fine views as well! Credit: David Herne(@AunaEridu)/Perth Western Australia.

As predicted, another solar observing sentinel in low Earth orbit did indeed witness the eclipse. ESA’s Proba-2 spacecraft caught the eclipse on three passes in this amazing raw animation from its SWAP-2 camera. The final third pass goes by extremely quick –these are measured in minutes from Proba-2’s swift vantage point – but the Sun looks well nigh to greater than 95% eclipsed by the Moon as it flies by.

Silveryway
The partial solar eclipse as seen from Adelaide, Australia. Credit: Silveryway.

There’s no word as of yet if the joint NASA/JAXA mission Hinode caught the eclipse as well, but we’ll keep you posted!

UPDATE: Courtesy of the European Space Agency and the Royal Observatory of Belgium, we now give you the full YouTube timelapse of the eclipse courtesy of Proba-2:

You’ll note that Proba-2 caught the partial phases on four separate passes… we also checked the sequence frame by frame, and although it looks like Proba-2 “may” have seen an annular – or even total – eclipse from space, it looks like it did so between captures!

This eclipse is one of two solar eclipses and four eclipses total for 2014. An interesting discussion occurred leading up to this eclipse as to the minimum number of eclipses that can occur in a year, which is four. If, however, you exclude faint lunar penumbrals, that number does indeed drop to two, both of which must be solar, which occurs in 2016. This also sparked a lively debate as to the naming of such a year on Twitter, with everything from a “Dwarf Eclipse Year” to “Nano Eclipse Cycle” and “Spurious Eclipse Year” being proposed. We liked the suitably esoteric and ready tweet-able term “declipsy” ourselves… thanks for the proposals and the lively discussion!

Virtual Telescope
Cue Jaws music… a “shark fin” sunset eclipse. Credit: Geoffrey Wyatt/The Virtual Telescope Project.
The partially-eclipsed Sun sinks into the west as seen from Brisbane, Australia on April 29, 2014. Credit and copyright: Teale Britstra.
The partially-eclipsed Sun sinks into the west as seen from Brisbane, Australia on April 29, 2014. Credit and copyright: Teale Britstra.
Partial solar eclipse in Adelaide, South Australia on April 29, 2014. Credit and copyright: Silveryway on Flickr.
Partial solar eclipse in Adelaide, South Australia on April 29, 2014. Credit and copyright: Silveryway on Flickr.

Thanks also to all who sent in pics. We’ll be updating this post as more come in… and although eclipse season 1 of 2 may be over for now, 2014 still has another total lunar eclipse and a good partial solar in October, both visible from North America.

…And we’re only three years out and have just two more total solar eclipses to go until the historic total solar eclipse of August 21st, 2017…

Let the countdown begin!

UPDATE: Missed out on the solar eclipse today? Hey so did we, it happens to the best of us… luckily, YOU can now relive the all of the excitement of the eclipse courtesy of the folks from the Virtual Telescope Project in YouTube Splendor:

And finally: got pics of the partial solar eclipse that you took today and you want to share with the world? Put ’em up on Universe Today’s Flickr community and let us know!

May Meteor Storm Alert: All Eyes on the Sky!

Composite photo of Lyrid meteor shower and non-Lyrids taken with a NASA All-sky camera April 21-23, 2012. Credit: NASA/MSFC/Danielle Moser

On Friday night/early Saturday May 23-24 skywatchers across the U.S. and southern Canada may witness the birth of a brand new meteor shower.  If predictions hold true, Earth will pass through multiple tendrils of dust and pebbly bits left behind by comet 209P/LINEAR, firing up a celestial display on par with the strongest showers of the year. Or better.

Peter Jenniskens of the SETI Institute, who predicted a possible meteor storm associated with comet 209P/LINEAR. Credit: NASA
Peter Jenniskens of the SETI Institute, who predicted a possible meteor storm associated with comet 209P/LINEAR. Credit: NASA

Earlier predictions called for a zenithal hourly rate or ZHR of 1,000 per hour, pushing this shower into the ‘storm’ category. ZHR is an idealized number based on the shower radiant located at the zenith under ideal skies. The actual number is lower depending on how far the radiant is removed from the zenith and how much light pollution or moonlight is present. Meteor expert Peter Jenniskens of the SETI Institute and Finland’s Esko Lyytinen first saw the possibility of a comet-spawned meteor storm and presented their results in Jenniskens’ 2006 book Meteor Showers and Their Parent Comets.

Approximate location of the radiant of the 209P/LINEAR shower at the peak of the brief maximum around 2 a.m. CDT May 24. Between 100-400 meteors may radiate from the dim constellation of Camelopardalis near the North Star. This map shows the sky from Des Moines, Iowa. Created with Stellarium
Approximate location of the radiant (blue) of the 209P/LINEAR shower at the peak of the brief maximum around 2 a.m. CDT May 24. Between 100-400 meteors may radiate from the dim constellation of Camelopardalis near the North Star. This map shows the sky from the central U.S. Created with Stellarium

Quanzhi Ye and Paul Wiegert  (University of Western Ontario) predict a weaker shower because of a decline in the comet’s dust production rate based on observations made during its last return in 2009. They estimate a rate of ~200 per hour.

On the bright side, their simulations show that the comet sheds larger particles than usual, which could mean a shower rich in fireballs. Other researchers predict rates between 200 and 40o per hour. At the very least, the Camelopardalids – the constellation from which the meteors will appear to originate – promise to rival the Perseids and Geminids, the year’s richest showers. Motivation for setting the alarm clock if there ever was.

Comet 209P/LINEAR on April 14, 2014. It’s currently very faint at around magnitude 17. Material shed by the comet during passes between 1898-1919 may spawn a rich meteor shower overnight May 23-24. Credit: Ernesto Guido, Nick Howes, Martino Nicolini
Comet 209P/LINEAR on April 14, 2014. It’s currently very faint at around magnitude +17. Material shed by the comet during passes from 1898-1919 is expected to contribute to a May 23-24 shower. Credit: Ernesto Guido, Nick Howes, Martino Nicolini

Comet 209P/LINEARdiscovered in Feb. 2004 by the automated Lincoln Laboratory Near-Earth Asteroid Research (LINEAR) sky survey, orbits the sun every 5.04 years with an aphelion (most distant point from the sun) near Jupiter. In 2012, during a relatively close pass of that planet, Jupiter perturbed its orbit, bringing it to within 280,000 miles (450,000 km) of Earth’s orbit.

That set up a remarkably close encounter with our planet on May 29 when 209P will cruise just 5 million miles (8 million km) from Earth to become the  9th closest comet ever observed. Multiple debris trails shed by the comet as long ago as the 18th century will intersect our planet’s path 5 days earlier, providing the material for the upcoming meteor shower/storm.

Shining meekly around magnitude +17 at the moment, 209P/LINEAR could brighten to magnitude +11 as it speeds from the Big Dipper south to Hydra during the latter half of May. Closer to the BIG night, we’ll provide helpful maps for you to track it down in your telescope. Cool to think that both the shower and its parent comet will be on display at the same time.

The shaded area shows where the shower will be visible on May 23-24. North of the red line, the moon (a thick crescent) will be up during shower maximum around 2:10 a.m. CDT. Credit: Mikhail Maslov
The shaded area shows where the shower will be visible on May 23-24. North of the red line, the moon (a thick crescent) will be up during shower maximum around 2:10 a.m. CDT. Credit: Mikhail Maslov

The shower’s expected to last only a few hours from about 12:40-3:50 a.m. CDT with the best viewing locations in the U.S. and southern half of Canada. This is where the radiant will be up in a dark sky at peak activity. A thick crescent moon rises around 3-3:30 a.m. but shouldn’t pose a glare problem.

Meteors from 209P/LINEAR are expected to be bright and slow with speeds around 40,000 mph compared to an average of 130,000 mph for the Perseids. Most shower meteoroids are minute specks of rock, but the Camelopardalids contain a significant number of particles larger than 1mm – big enough to spark  fireballs.

The dark streak is a series of filaments of dust and grit left behind by 209P/LINEAR mostly between 1803 and 1924 that Earth (shown on path) will pass through on May 23-24, 2014. Credit:
The dark “finger” represents streams of dust and rocks left behind by 209P/LINEAR during passes made from 1803 to 1924. Earth is shown intersecting the debris on May 23-24, 2014. Credit: Dr. Jeremie Vaubaillon

The farther north you live in the shaded area on the map, the higher the radiant stands in the northern sky and the more meteors you’re likely to see. Skywatchers living in the Deep South will see fewer shooting stars, but a greater proportion will be earthgrazers, those special meteors that skim the upper atmosphere and flare for an unusually long time before fading out.

To see the shower at its best, find a dark place with an open view to the north. Plan your viewing between 12:30 and 4 a.m. CDT (May 24), keeping the 2 a.m. forecast peak in mind. Maximum activity occurs around 3 a.m. Eastern, 1 a.m. Mountain and midnight Pacific  time.

No one’s really certain how many meteors will show, but I encourage you to make the effort to see what could be a spectacular show.

LADEE Sees Zodiacal Light before Crashing into Moon, but Apollo Mystery Remains

The zodiacal light (left) reaches up from the eastern horizon to "touch" the Milky Way at right on Sept. 23, 2012. Credit: Bob King

Sunrise over the surface of the moon: a series of star tracker images taken by LADEE Saturday, April 12. The lunar horizon is ahead, a few minutes before orbital sunrise. Image Credit: NASA Ames.

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NASA’s Lunar Atmosphere and Dust Environment Explorer (LADEE) literally ‘saw the light’ just days before crashing into the lunar farside last Thursday April 17. Skimming just a few kilometers above the moon’s surface, mission controllers took advantage of this unique low angle to gaze out over the moon’s horizon in complete darkness much like the Apollo astronauts did from lunar orbit more than 40 years ago.

The zodiacal light (left) reaches up from the eastern horizon to "touch" the Milky Way at right  on Sept. 23, 2012. Credit: Bob King
The zodiacal light (left), adorned by the planet Venus, reaches up from the eastern horizon to “touch” the Milky Way before sunrise on Sept. 23, 2012. Credit: Bob King

With the glow of Earth well-hidden, any dust in the moon’s scant atmosphere around the time of orbital sunrise should become visible. Scientists also expected to see  the softly luminous glow of the zodiacal light, an extensive cloud of comet and asteroid dust concentrated in the flat plane of the solar system. The zodiacal light gets its name from the zodiac, that familiar band of constellations the planets pass through as they orbit the sun. Back on Earth, the zodiacal light looks like a big thumb of light standing up from the western horizon a couple hours after sunset in spring and before sunrise in fall.

Frame from LADEE's star tracker camera showing the zodiacal light rising on the moon's horizon from its extremely low orbit on April 12, 2014. Credit: NASA
Frame from LADEE’s star tracker camera showing the zodiacal light rising on the moon’s horizon from its extremely low orbit on April 12, 2014. Credit: NASA

So what did LADEE see? As you watch the animation above, comprised of images taken from darkness until sunrise, you’ll see a yellow haze on the horizon that expands into large diffuse glow tilted slightly to the right. This is the zodiacal light along with a smaller measure of light coming from sun’s outer atmosphere or corona.  Together they’re referred to as CZL or ‘coronal and zodiacal light’. At the very end, the sun peaks over the lunar horizon.

This is a sketch of the lunar sunrise seen from orbit by Apollo 17 astronaut Eugene Cernan. On the right, the sketch is highlighted to show the sources of the scattered light: red indicates Coronal and Zodiacal Glow, blue is the Lunar Horizon Glow, perhaps caused by exospheric dust, and green indicates possible "streamers" of light (crepuscular rays) formed by shadowing and scattered light. Credit: NASA
This is a sketch of the lunar sunrise seen from orbit by Apollo 17 astronaut Eugene Cernan. On the right, the sketches are highlighted in color to show the sources of the scattered light: red indicates coronal and zodiacal light (CZL), blue is a glow along the lunar horizon possibly caused by dust suspended in the moon’s exosphere, and green may be crepuscular rays formed by shadowing and scattered light. Credit: NASA/phys.org

What appears to be missing from the pictures are the mysterious rays seen by some of the Apollo astronauts. The rays, neatly sketched by astronaut Eugene Cernan of Apollo 17, look a lot like those beams of light and shadow streaming though holes in clouds called crepuscular rays.

Crepuscular rays form a crown of rays made of alternating shadows and light scattered by dust in the atmosphere. Credit: Bob King
Crepuscular rays form a crown of rays made of alternating shadows and light scattered by dust and moisture in the atmosphere. Credit: Bob King

Only thing is, Earth’s atmosphere is thick enough for cloud beams. The dust in the moon’s atmosphere appears much too thin to cause the same phenomenon. And yet the astronauts saw rays as if sunlight streamed between mountain peaks and scattered off the dust just like home.

Low level horizon glow photos on the moon captured by the Surveyor 7 unmanned lander in 1968. It's possible this low altitude glow is caused by larger dust particles that don't travel as high as the smaller motes. Credit: NASA
Low level horizon glow photos on the moon captured by the Surveyor 7 unmanned lander in 1968. It’s possible this low altitude glow is caused by larger dust particles that don’t travel as high as the smaller motes. Credit: NASA

It’s believed that dust gets lofted into the spare lunar atmosphere via electricity. Ultraviolet light from the sun knocks electrons from atoms in moon dust, giving them a positive charge. Since like charges repel, bits of dust push away from one another and move in the direction of least resistance: up. The smaller the dust particle, the higher it rises until dropping back down to the surface. Perhaps these “fountains” of lunar dust illuminated by the sun are what the astronauts recorded.

Unlike Cernan, LADEE saw only the expected coronal and zodiacal light but no rays. Scientists plan to look more closely at several sequences of images made of lunar sunrise in hopes of finding them.

Saturn at Opposition: Our 2014 Guide

Saturn as imaged from Aguadilla, Puerto Rico on April 15th. Credit: Efrain Morales.

Planet lovers can rejoice: one of the finest jewels of the solar system in returning to the evening night sky.

The planet Saturn reaches opposition next month on May 10th. This means that as the Sun sets to the west, Saturn will rise “opposite” to it in the east, remaining well positioned for observation in the early evening hours throughout the summer season. In fact, we’ll have four of the five naked eye planets above the horizon at once for our evening viewing pleasure in the month of May, as Jupiter also rides high to the west at sunset, Mars just passed opposition last month and Mercury reaches greatest eastern elongation on May 25th. Venus is the solitary holdout, spending a majority of 2014 in the dawn sky.

Saturn will shine at magnitude +0.3 this month and its disk spans an apparent 19,” or 44” if you take into account the apparent width of its rings. The rings are currently tipped open 22 degrees with respect to our line of sight. The ring opening is widening, and will reach a maximum of over 25 degrees in 2017 before the trend reverses. Anyone who remembers observing Saturn back in 2009 will recall that its rings were edge on to our view. This widening of Saturn’s rings also lends itself to a curious effect: although we’re in a cycle of oppositions that are getting farther away — Saturn is 12.5 million kilometres or 0.083 Astronomical Units (A.U.s) more distant in 2014 than it was during opposition last year as it’s headed towards aphelion in 2018 — its widening rings are actually making it appear a bit brighter.

The path of Saturn through the constellation Libra from April through October 2014. Created using Starry Night Education Software.
The path of Saturn through the constellation Libra from April through October 2014. Created using Starry Night Education Software.

This year’s opposition will find Saturn in the astronomical constellation of Libra, where it’ll spend most of 2014. Oppositions of the ringed planet are set to continue to “head south” until 2018, and won’t occur north of the celestial equator again until 2026. I remember when oppositions of Saturn returned to the constellation Virgo a few years back — where I had first looked at it with my 60mm Jason refractor as a teenager — and realizing that I had now been into observational astronomy for roughly one “Saturnian year.”

The ancients had little knowledge of how unique Saturn was. The faintest and slowest moving of the classical planets, even Galileo knew that something was up when he turned his first primitive telescope towards it. His sketches depict Saturn as something similar to a double handled coffee cup, a testament to how poor his view really was. It wouldn’t be until Christiaan Huygens in 1655 that the true nature of Saturn’s rings was deduced as a flat and separate feature from the disk.

At opposition, the disk of the planet casts a shadow straight back from our point of view. This vantage slowly changes as the planet moves towards eastern quadrature on August 9th and we get a glimpse slightly off to one side of the planet. After opposition, the shadow of the disk can again be seen casting back onto the rings.

An outstanding IPhone 4S capture of Saturn on April 20th, 2014. Credit: Andrew Symes, @FailedProtostar.
An outstanding IPhone 4S capture of Saturn on April 20th, 2014. Credit: Andrew Symes, @FailedProtostar.

Another interesting phenomenon to watch out for near opposition is known as the Seeliger effect. Also sometimes referred to as the “opposition surge,” this sudden brightening of the disk and rings is a subtle effect, as the globe of Saturn and all of those tiny little ice crystals reach 100% illumination. This effect can be noted to the naked eye on successive nights around opposition, and will get more prominent towards 2017. Coherent-backscattering of light has also been proposed as a possible explanation of this phenomenon. Perhaps a video sequence capturing this effect is in order for skilled astro-imagers in 2014.

Through a small telescope, the first feature that becomes apparent is Saturn’s glorious system of rings. Crank up the magnification, and you’ll note a dark groove in the ring system. This is the Cassini Division, first described by Giovanni Cassini in 1675.

Here’s a challenge we came across some years back: can you see the disk of Saturn through the Cassini Division? Right around opposition is a good time to attempt this unusual feat of visual athletics.

A sample simulation depicting the orientation of Saturn's observable moons on the night of  May 9th. Created using Starry Night Education software.
A sample simulation depicting the orientation of Saturn’s observable moons on the night of May 9th. Created using Starry Night Education software.

Saturn’s large moon Titan is an easy catch at magnitude +8 in a small telescope. Titan is the second largest moon in the solar system. Place it in a direct orbit about the Sun, and it would be considered a planet, no problem.  7 of Saturn’s 62 known moons are within reach of a small telescope. In addition to Titan, they are, with quoted magnitudes: Mimas (+13), Enceladus (+12), Tethys (+10), Rhea (+10), Dione (+11) and Iapetus. Iapetus is of special interest, as it brightens from +11.9 to magnitude +10.2 as it traces out its 79 day orbit. We always knew there was something unique about this moon, and NASA’s Cassini mission revealed the world to have two distinctly different hemispheres with vastly different albedos during its close 2007 flyby.

The close passage of the Full Moon near Saturn on May 14th. Created using Stellarium.
The close passage of the Full Moon near Saturn on May 14th. Created using Stellarium.

Also, be sure to check out Saturn on the night of May 14th — just 4 nights after opposition — as the Full Moon sits less than a degree south of the ringed planet. Can you see both in the same telescopic field of view? Can you nab Saturn next to the rising daytime Moon low to the horizon just before local sunset? The Moon will actually occult (pass in front of) Saturn for viewers based in Australia and New Zealand on the 14th. This is only one of 11 occultations — nearly one for each lunation — of Saturn by the Moon in 2014. Unfortunately, the best one for North America occurs in the daytime on August 31st, though it too may be observable telescopically.

The foot print of the May 14th occultation of Saturn by the Moon. Credit: Occult 4.0.
The footprint of the May 14th occultation of Saturn by the Moon. Credit: Occult 4.0.

Finally, this evening apparition of the planet runs through northern hemisphere summer and fall until Saturn reaches solar conjunction on November 18th. So get those homemade planetcams out, send those pics in to Universe Today, and be sure to join in to the Virtual Star Party every Sunday Night… Saturn is sure to be featured!

Our Guide to the Bizarre April 29th Solar Eclipse

The 2013 partial eclipse rising over the Vehicle Assembly Building along the Florida Space Coast. This month's solar eclipse will offer comparable sunset views for eastern Australia. Photo by author.

Will anyone see next week’s solar eclipse? On April 29th, an annular solar eclipse occurs over a small D-shaped 500 kilometre wide region of Antarctica. This will be the second eclipse for 2014 — the first was the April 15th total lunar eclipse — and the first solar eclipse of the year, marking the end of the first eclipse season. 2014 has the minimum number of eclipses possible in one year, with four: two partial solars and two total lunars. This month’s solar eclipse is also a rarity in that it’s a non-central eclipse with one limit. That is, the center of the Moon’s shadow — known as the antumbra during an annular eclipse — will juuuust miss the Earth and instead pass scant kilometres above the Antarctic continent.

The "footprint" of the April 29th solar eclipse. Credit:
The “footprint” of the April 29th solar eclipse. Credit: Eclipse predictions by Fred Espenak, NASA/GSFC.

A solar eclipse is termed “non-central with one limit” when the center of the Moon’s umbra or antumbra just misses the Earth and grazes it on one edge. Jean Meeus and Fred Espenak note that out of 3,956 annular eclipses occurring from 2000 BCE to 3000 AD, only 68 (1.7%) are of the non-central variety. An annular eclipse occurs when the Moon is too distant to cover the disk of the Sun, resulting in a bright “annulus” or “ring-of-fire” eclipse. A fine example of just such an eclipse occurred over Australia last year on May 10th, 2013. An annular eclipse crossed the United States on May 10th, 1994 and will next be seen from the continental U.S. on October 14th 2023. But of course, we’ll see an end the “total solar eclipse drought” long before that, when a total solar eclipse crosses the U.S. on August 21st, 2017!

An animated .gif of the April 29th eclipse. Credit: NASA/GSFC/A.T. Sinclair.
An animated .gif of the April 29th eclipse. Credit: NASA/GSFC/A.T. Sinclair.

The “centrality” of a solar eclipse or how close a solar eclipse comes to crossing the central disk of the Earth is defined as its “gamma,” with 0 being a central eclipse, and 1 as the center of the Moon’s shadow passing 1 Earth radii away from central. All exclusively partial eclipses have a gamma greater than 1. The April 29th eclipse is also unique in that its gamma is very nearly 1.000… in fact, combing the 5,000 year catalog of eclipses reveals that no solar eclipse from a period of 2000 B.C. to 3000 A.D. comes closer to this value. The solar eclipses of October 3rd, 2043 and March 18th, 1950 are, however very similar in their geometry. Guy Ottewell notes in his 2014 Astronomical Calendar that the eclipses of August 29th, 1486 and January 8th, 2141 also come close to a gamma of 1.000. On the other end of the scale, the solar eclipse of July 11th 1991 had a gamma of nearly zero. This eclipse is part of saros series 148 and is member 21 of 75. This series began in 1653 and plays out until 2987 AD. This saros will also produce one more annular eclipse on May 9th 2032 before transitioning to a hybrid and then producing its first total solar eclipse on May 31st, 2068. But enough eclipse-geekery. Do not despair, as several southern Indian Ocean islands and all of Australia will still witness a fine partial solar eclipse from this event. Antarctica has the best circumstances as the Sun brushes the horizon, but again, the tiny sliver of “annularity” touches down over an uninhabited area between the Dumont d’Urville and Concordia  stations currently occupied by France… and it just misses both! And remember, its astronomical fall headed towards winter “down under,” another strike against anyone witnessing it from the polar continent. A scattering of islands in the southern Indian Ocean will see a 55% eclipsed Sun. Circumstances for Australia are slightly better, with Perth seeing a 55% eclipsed Sun and Sydney seeing a 50% partial eclipse.

The view of the eclipse from multiple locations across the Australian continent at 7:00 UT on April 29th. Created by the author using Stellarium.
The view of the eclipse from multiple locations across the Australian continent at 7:00 UT on April 29th. Created by the author using Stellarium.

Darwin,  Bali Indonesia and surrounding islands will see the Moon just nick the Sun and take a less than 20% “bite” out of it. Observers in Sydney and eastern Australia also take note: the eclipse occurs low to the horizon to the west at sunset, and will offer photographers the opportunity to grab the eclipse with foreground objects. Viewing a partial solar eclipse requires proper eye protection throughout all phases. The safest method to view a partial solar eclipse is via projection, and this can be done using a telescope (note that Schmidt-Cassegrain scopes are bad choice for this method, as they can heat up quickly!) or nothing more sophisticated than a spaghetti strainer to create hundreds of little “pinhole projectors.”

A simulation of the view that no one will see: the annular eclipse one kilometre above latitude 71S longitude 131E above the Antarctic. Created using Stellarium.
A simulation of the view that no one will see: the annular eclipse as seen hovering one kilometre above the Antarctic at latitude 71S longitude 131E . Created using Stellarium.

And although no human eyes may witness the annular portion of this eclipse, some orbiting automated ones just might. We ran some simulations using updated elements, and the European Space Agency’s Sun observing Proba-2 and the joint NASA/JAXA Hinode mission might just “thread the keyhole” and will witness a brief central eclipse for a few seconds on April 29th: And though there’ll be few webcasts of this remote eclipse, the ever-dependable Slooh is expected to carry the eclipse on April 29th. Planning an ad hoc broadcast of the eclipse? Let us know! As the eclipse draws near, we’ll be looking at the prospects for ISS transits and more. Follow us as @Astroguyz as we look at these and other possibilities and tell our usual “tales of the saros”. And although this event marks the end of eclipse season, its only one of two such spans for 2014… tune in this October, when North America will be treated to another total lunar eclipse on the 8th and a partial solar eclipse on the 23rd… more to come! Send in those eclipse pics to the Universe Today Flickr community… you just might find yourself featured in this space!

Get Ready for the Lyrid Meteor Shower: Our Complete Guide for 2014

A composite of 33 Lyrid meteors captured by the UK Meteor Network cameras in 2012. Credit: @UKMeteorNetwork

The month of April doesn’t only see showers that bring May flowers: it also brings the first dependable meteor shower of the season. We’re talking about the Lyrid meteors, and although 2014 finds the circumstances for this meteor shower as less than favorable, there’s still good reason to get out this weekend and early next week to watch for this reliable shower.

The Lyrid meteor shower typically produces a maximum rate of 10-20 meteors per hour, although outbursts topping over a hundred per hour have been observed on occasion. The radiant, or the direction that the meteors seem to originate from, lies at right ascension 18 hours and 8 minutes and declination +32.9 degrees north. This is just about eight degrees to the southwest of the bright star Vega, which is the brightest star in the constellation of Lyra the Lyre, which also gives the Lyrids its name.

Fun fact: this radiant actually lies juuusst across the border of Lyra in the constellation of Hercules… technically, the “Lyrids” should be the “Herculids!” This is because the shower was identified and named in the 19th century before the International Astronomical Union officially adopted the modern layout we use for the constellations in 1922.

The rising Lyrid radiant, looking to the north east at 2AM local from latitude 30 degrees north. Created using Stellarium.
The rising Lyrid radiant, looking to the northeast at 2AM local from latitude 30 degrees north. Created using Stellarium.

The source of the Lyrids was tracked down in the late 1860s by mathematician Johann Gottfried Galle to Comet C/1861 G1 Thatcher, the path of which came within 0.02 Astronomical Units (A.U.s) of the Earth’s orbit on April 20th, 1861, just six weeks before the comet reached perihelion. Comet G1 Thatcher is on a 415 year orbit and won’t return to the inner solar system until the late 23rd century.

Credit
The orbital path of Comet G1 Thatcher during its 1861 passage. Credit: NASA/JPL Ephemeris Generator.

But we can enjoy the dust grains it left in its wake as they greet the Earth to burn up in its atmosphere every April. The activity of the Lyrids typically spans April 16th to the 25th, with a short 24 hour peak above a ZHR of 10 on April 22nd-23rd. Thus, like the short duration Quadrantids in January, timing is critical; if you happen to observe this shower before or after the peak, you may see nothing at all. This year, the key mornings will be Tuesday, April 22nd, and Wednesday April 23rd. The wide disparity of predictions for the exact arrival of the peak of the Lyrids, as quoted in differing sources speaks to just how poorly this meteor shower is understood. Scanning various reliable resources, we see times quoted from April 22nd at 4:00 Universal Time (UT) from the American Meteor Society, to 17:00 UT on the same date for the Royal Canadian Astronomical Society, to April 23rd at 17:45 UT from Guy Ottewell’s venerable 2014 Astronomical Calendar!

Definitely, more observations of this curious shower are needed.

The position of the Lyrid meteor shower radiant across the border in the constellation Hercules. (Credit Starry Night Education software).
The position of the Lyrid meteor shower radiant across the border in the constellation Hercules. (Credit Starry Night Education software).

Now for the bad news. This year finds the light-polluting Moon in nearly its worst location possible for a meteor shower. Remember this week’s total lunar eclipse? Well, the Moon is now waning gibbous and will reach last quarter phase at 7:52 UT/3:52 AM EDT on April 22nd, and will thus be rising at local midnight and be high in the sky towards dawn. The Lyrid radiant rises at 9:00 PM this week for observers around 40 degrees north and rides highest at 6:00 AM local, about 45 minutes before sunrise.

Looking at the International Meteor Organization’s historical data, here’s what the Lyrids have done over the past few years:

2013- ZHR 22, Moon phase= 88% illuminated, waxing gibbous.

2012– ZHR 25, Moon phase= 2% illuminated, waxing crescent.

2011- ZHR 20, Moon phase= 73% illuminated waning gibbous.

2010- ZHR 32, Moon phase= 62% illuminated waxing gibbous.

2009- ZHR 15, Moon phase= 7% illuminated waning crescent.

A “ZHR” is the Zenithal Hourly Rate, a theoretical maximum number of meteors that an observer could expect to witness under dark skies if the radiant was straight overhead. Note that 2011 had similar circumstances with respect to the Moon as this year, so don’t despair! The Lyrids are approaching the Earth from nearly perpendicular in its orbit and have a head on velocity of about 48 kilometres per second, respectable for a meteor shower. They also present a higher-than-average number of fireballs, with about a quarter leaving persistent trains.

Outbursts have also occurred in 1803, 1849, 1850, 1922, 1945 and 1982. United States observers based in Florida and Colorado noted a brief ZHR approaching 100 per hour back in 1982 under especially favorable New Moon conditions.

The orientation of the Earth on April 22nd at 12UT/08AM EDT. Credit: Stellarium
The orientation of the Earth on April 22nd at 12UT/08AM EDT. Credit: Stellarium.

Ironically, the Lyrids are also one of the oldest meteor showers identified from historic records. In fact, Galle actually traced the shower back to Chinese records dating all the way back to March 16th 687 BC, which describes “Stars (that) dropped down like rain…” clearly, the Lyrids were considerably more active in ancient times.

More recently, attempts were made to link the 2012 Sutter’s Mill meteorite fall to the Lyrids, which were underway at the time. This turned out to be a case of “meteor-wrong,” however, as described by Geoff Notkin of the Meteorite Men who noted that no meteorite fall has ever been linked to a meteor shower, though he does get lots of calls whenever news of a big meteor shower hits the press.

A good strategy for beating the Moon includes blocking it behind a hill or building while observing. Early morning is the best time to watch for Lyrids — or most any meteor shower for that matter — as you’re then on the half of the Earth facing forward into the meteor stream.  And you don’t have to face toward the radiant to see Lyrid meteors, as they can appear anywhere in the sky.

With the advent of DSLRs, photographing meteors is easier than ever before. All you need to do is use a wide angle lens and take periodic time exposures of the sky. Do a few early test shots to get the combination of f-stop, ISO and shutter speed just right for current sky conditions, and be sure to review those images on a full size monitor afterward: nearly every meteor we’ve captured turned up in post-review only.

Looking to contribute to our understanding of the Lyrid meteors? Simply count the number you see and the location and length of your observation and send your report into the International Meteor Organization. And don’t forget to tweet those Lyrids to #Meteorwatch!

…and there’s more to come. Next month, a true “wildcard outburst” may be in the offing from Comet 209P/LINEAR on May 26th… can you say “Camelopardalids?”

Stay tuned!