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!

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!

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!

Remembering John Houbolt: the Man Who Gave Us Lunar Orbit Rendezvous

John Houbolt demonstrating Lunar Orbit Rendezvous circa 1962. Credit: NASA.

The space community lost a colossus of the of the Apollo era last week, when John Houbolt passed away last Tuesday just five days after his 95th birthday.

Perhaps the name isn’t as familiar to many as Armstrong or Von Braun, but John Houbolt was a pivotal figure in getting us to the Moon.

Born in Altoona, Iowa on April 10th, 1919, Houbolt spent most of his youth in Joliet, Illinois. He earned a Masters degree in Civil Engineering from the University of Illinois at Urbana-Champaign in 1942 and a PhD in Technical Sciences from ETH Zurich in Switzerland in 1957. But before that, he would become a member of the National Advisory Committee for Aeronautics (NACA) in 1942, an organization that would later become the National Aeronautics and Space Administration or NASA in 1958.

It was 1961 when Houbolt made what would be his most enduring mark on the space program. He was working as an engineer at the Langley Research Center, at a time when NASA and the United States seriously needed a win in the space race. The U.S.S.R. had enjoyed a long string of firsts, including first satellite in orbit (Sputnik 1, October 1957), first spacecraft to photograph the lunar farside (Luna 3 in October 1959) and first human in space with the launch of Yuri Gagarin aboard Vostok 1 in April 1961. A young President Kennedy would make his now famous “We choose to go to the Moon…” speech at Rice University later the next year in late 1962. Keep in mind, in U.S. astronaut John Glenn had just made his first orbital flight months before Kennedy’s speech, and total accumulated human time in space could be measured in mere hours. Unmanned Ranger spacecraft were having a tough time even getting off of the pad, and managing to crash a space probe into the Moon was considered to be a “success”. The task of sending humans “by the end of this decade” was a daunting one indeed…

NASA would soon have a mandate to sent humans to the Moon: but how could they pull it off?

Early ideas for manned lunar missions envisioned a single gigantic rocket that would head to the Moon and land, Buck Rodgers style, “fins first.” Such a rocket would have to be enormous, and carry the fuel to escape Earth’s gravity well, land and launch from the Moon, and return to Earth.

A second approach, known as Earth-orbit rendezvous, would see several launches assemble a mission in low Earth orbit and then head to the Moon. Curiously, though this was an early idea, it was never used in Apollo, though it was briefly resurrected during the now defunct Constellation Program.

Credit: NASA
Three plans to go to the Moon. Credit: NASA.

But it was a third option that intrigued Houbolt, known as Lunar Orbit Rendezvous. LOR had been proposed by rocket pioneers Yuri Kondratyuk and Hermann Oberth in 1923, but had never been seriously considered. It called for astronauts to depart the Earth in a large rocket, and instead, use a small lander designed only to land and launch from the Moon while the spacecraft for Earth return orbited overhead.

Houbolt became a staunch advocate for the idea, and spent over a year convincing NASA officials. In one famous letter to NASA associate administrator Robert Seamans, Houbolt was known to have remarked “Do we want to go to the Moon or not?”

It’s interesting to note that it was probably only in a young organization like the NASA of the early 1960s that, in Houbolt’s own words, a “voice in in the wilderness” could be heard. Had NASA become a military run organization — as many advocated for in the 1950s — a rigid chain of command could have meant that such brash ideas as Houbolt’s would have never seen the light of day. Thank scientists such as James Van Allen for promoting the idea of a civilian space program that we take for granted today.

Even then, selling LOR wasn’t easy. The idea looked preposterous: astronauts would have to learn how to undock and dock while orbiting a distant world, with no chance of rescue. There was no second chance, no backup option. Early plans called for an EVA for astronauts to enter the Lunar Module prior to descent which were later scrapped in favor of extracting it from atop the third stage and boarding internally before reaching the Moon.

Once Houbolt had sold key visionaries such as Wernher von Braun on the idea in late 1962, LOR became the way we would go to the Moon. And although Houbolt’s estimations of the mass required for the Lunar Module were off by a factor of three, the story is now the stuff of early Apollo era legend. You can see Houbolt (played by Reed Birney) and the tale of the LM and LOR in the  From Earth to the Moon episode 5 entitled “Spider”.

Credit: NASA
The ascent stage of the lunar module on approach to the command module with the Earth in the background. Credit: NASA.

Houbolt was awarded NASA’s medal for Exceptional Scientific Achievement in 1963, and he was in Mission Control When Apollo 11 touched down in the Sea of Tranquility.

He passed away in a Scarborough, Maine nursing home last Tuesday, and joins other unsung visionaries of the early space program such as Mary Sherman Morgan. It’s sad to think that we may soon live in a world where those who not only walked on the Moon, but those who also sent us and knew how to get there, are no longer with us.

Thanks, John… you gave us the Moon.

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!

Seeing Red: Spectacular Views of this Morning’s Total Lunar Eclipse

Photos by author.

Did the Moon appear a little on crimson side to you last night? It’s not your imagination, but it was a fine textbook example of a total lunar eclipse. This was the first total lunar eclipse visible from the Earth since late 2011, and the first of four visible from the Americas over the next 18 months.  

And although much of the U.S. and Canadian eastern seaboard was under cloud cover, those west of the Mississippi River were treated to a fine show. We were the lucky exception here at Astroguyz HQ just north of Tampa Bay in Florida, as the storm front held off juuusst long enough to witness the eclipse in its entirety.

We will admit, though, that there were some tense moments. A wave of thick clouds threatened to end our session altogether just moments before the onset of totality before finally abating. We shot stills, streamed video, made observations, and heck, just stepped back once in a while to stare at the ruby-tinged beauty that was totality.

And judging from the flurry of web traffic, the odd late Monday night/ early Tuesday morning timing for this eclipse did little to stem folks interest. We noted to Virtual Star Party co-host that the excitement was reminiscent to the early morning landing of Curiosity on the Red Planet.

Anyhow, here’s just a sampling of some of the great pics currently pouring in to Universe Today:

 Credit: Henry Weiland of Honolulu, Hawaii
An eclipsed Moon+Spica. Credit: Henry Weiland of Honolulu, Hawaii

Visually, we’d place this morning’s eclipse between a Danjon value of 3 and 4, with a bright yellowish rim contrasting with a dark, coppery core near the center of the umbra. One astute viewer noted during the webcast that the eclipsed Moon took on a decidedly 3-D appearance, versus its usual flat look when nearing Full.

The eclipsed Moon, Mars and Spica. Credit: @Astrocolors
The eclipsed Moon, Mars and Spica. Credit: @Astrocolors

And speaking of Mars, we fielded lots of “what are those bright stars nearby?” questions as well. The bright blue-white star Spica and the planet Mars “photobombed” many eclipse images. Spica just missed being occulted by the Moon during the eclipse by less than two degrees, And Mars just passed opposition this week and was at its closest approach to the Earth for 2014 on the night of the eclipse.

Approaching totality as seen from Jacksonville, Florida. Credit Richard Hay @WinObs
Approaching totality as seen from Jacksonville, Florida. Credit: Richard Hay @WinObs.

As totality approached, shutter-speeds became longer as the red edge of the Moon became apparent. It always amazes me to think that the Earth casts that long red shadow back into the void of space every night, but its only during a lunar eclipse that you actually get to see it. We’re always told that the Earth is round, but during a lunar eclipse is one of the only times that you can really witness this curve, up close and personal.

NYC Credit: AstroVal1
A gathering of red objects, both celestial and terrestrial. Credit: AstroVal1, New York City.

This eclipse was placed reasonably high in the sky for Northern hemisphere viewers, though that also meant a lack of pics with foreground, except of course for creative shots like the one above. And with the explosion of digital imaging technology, its amazing what folks are doing to image eclipses, even using mobile phones:

IPhone eclipse. Credit: Mike Weasner.
An IPhone eclipse. Credit: Mike Weasner.

We’ve come a long way since the days of film and doing back of the envelope calculations for afocal SLR photography of the Moon, that’s for sure. Unlike solar totality, lunar eclipses are a long at stately affair. In fact, totality during this eclipse lasted for one hour and 18 minutes, about 29 minutes short of the theoretical maximum. This morning’s eclipse won’t be topped in length until 2018.

Credit: Rob Sparks.
A brick red Moon in eclipse. Credit: Rob Sparks.

This also marked our first attempts at adventures in live-streaming an eclipse both on UStream and G+, which was a blast. Thanks to co-hosts and saros chasers Scott Lewis, Fraser Cain, Thad Szabo and Katie Mack (@AstroKatie) for making the broadcast a success!

As of yet, there’s no images of the eclipse from space-based assets, though some may surface. Universe Today’s Elizabeth Howell noted that NASA engineers took precautions to protect the Lunar Reconnaissance Orbiter during the event: an extended lack of sunlight is a bad thing for solar-powered spacecraft. As of yet, there’s no word as to how the LADEE spacecraft also in orbit around the Moon fared, though its due to complete its mission and crash into the Moon this month.

Moon and Spica. Photo by Author.
The eclipsed Moon and Spica. Photo by Author.

And like the “Blue,” “Super” and “Mini” Moon, the Blood Moon meme is now — for better or worse — here to stay. We’ve already fielded  multiple queries for media sources asking if the current tetrad of eclipses has any special significance, and the answer is no; I would still file your taxes on this April the 15th. Eclipses happen, as do wars, earthquakes and lost car keys… each and every year.

Credit: John O'Connor, Fort Pierce, Florida.
Approaching totality. Credit: John O’Connor, Fort Pierce, Florida.

Want more? There’s no word yet as to if anyone caught any of the more bizarre challenges during this eclipse, such as completing a triple saros exeligmos, catching an ISS transit, spotting a selenelion or catching a stellar occultation during the eclipse. If you did any of the above, let us know!

And finally, the biggest post-eclipse question on everyone’s mind is always: when’s the next one? Well, Australians only have to wait two weeks until a partial solar eclipse graces their continent on April 29th… and the next total lunar eclipse once again favors North America and the Pacific region on October 8th, 2014.

T’was a great kickoff this morning of eclipse season 1 of 2 for 2014!

 

 

 

 

 

 

 

Webcasts and Forecasts for Tonight’s Total Lunar Eclipse

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

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

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

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

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

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

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

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

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

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

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

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

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

Video streaming by Ustream

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

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

Video streaming by Ustream

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

Live streaming video by Ustream

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Starry Night
One degree fields of view worldwide showing Venus and Lambda Aquarii at 7AM local. Credit: Starry Night.

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

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

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