Allergies? Must Be Pollen Corona Season Again

A multi-ringed, oval shaped corona around the Sun on May 30, 2015 seen from northern Minnesota. The white spots are aspen seeds better known as "cotton fluff". Credit: Bob King

Don’t be surprised if you look up in the Sun’s direction and squint with itchy, watery eyes. You might be staring into billows of tree pollen wafting through your town. It’s certainly been happening where I live.

When conditions are right, billions of microscopic pollen grains consort to create small, oval-shaped rings around a bright Moon during the peak of the spring and early summer allergy season. With the Full Moon coming up this week, there’s no better time to watch for them. 

Pollen grains from a variety of different common plants including sunflower, morning glory, prairie hollyhock and evening primrose. Credit: Dartmouth Electron Microscope Facility, Dartmouth College
Pollen grains from a variety of different common plants including sunflower, morning glory, prairie hollyhock and evening primrose magnified 500x and colorized.  The green, bean-shaped grain at lower left is 0.05 mm across. Credit: Dartmouth Electron Microscope Facility

Because they’re often lost in the glare of the Sun or Moon, the key to finding one is to hide the solar or lunar disk behind a thick tree branch, roof or my favorite, the power pole. Look for a telltale oval glow, sometimes tinted with rainbow colors, right up next to the Moon or Sun’s edge. Common halos, those that form when light is refracted by ice crystals, span 44° compared to pollen coronas, which measure just a few degrees in diameter.

To see or photograph coronas, you need plenty of light. The Sun’s ideal, but so is the Moon around full. Fortunately, that happens on June 2, neatly fitting into the sneezing season. Last night, the same grains — most likely pine tree pollen — also stoked a lunar corona. Once my eyes were dark adapted and the Moon hidden by an arboreal occulting instrument (tree branch), it was easy to see.

A lunar pollen corona on May 30, 2015. The Moon was hidden by a utility pole.  Like the solar version, this one is elongated too. The shape is caused by pollen grains' elongated shape and the fact that they tend to orient themselves as they drift in the wind. Credit: Bob King
A lunar pollen corona on May 30, 2015. The Moon was hidden by a utility pole. Like the solar version, this one was also oval and measured about 3.5° across. The shape is caused by elongated pollen grains fact that orient themselves as they drift in the wind. Credit: Bob King

One of things you’ll notice right away about these biological bullseyes is that they’re not circular. Pollen coronas are oval because the pollen particles are elongated rather than spherical like water droplets. When light from the moon or sun strikes pollen, the minute grains diffract the light into a series of closely-spaced colored rings. I’ve read that pine and birch produce the best coronas, but spruce, alder and and others will work, too.

And here’s another amazing thing about these coronas. You don’t need a transparent medium to produce them. No ice, no water. All that’s necessary are very small, similarly-shaped objects. Light waves are scattered directly off their surfaces; the waves interfere with one another to create a diffraction pattern of colored rings.

A lunar pollen corona photographed on June 22, 2008 displays “bumps” or extensions at approximately 90° angles around its periphery. Credit: Bob King

Pollen coronas tend to become more elongated when the Sun or Moon is closer to the horizon, so look be on the lookout during those times for more extreme shapes. For some reason I’ve yet to discover,  pollen disks sometimes exhibit “bumps” or extensions at their tops, bottoms and sides.

So many of us suffer from allergies, perhaps the glowing presence of what’s causing all the inflammation will serve as partial compensation for our misery.

Moon Myths: Looking at Lunar Tall Tales

A waxing crescent Moon+Earthshine setting over southwest London. Image credit and copyright: Roger Hutchinson

Turns out it’s all a big cosmic blame game.

Over the centuries, humans have attempted to link the phases of the Moon—especially the onset of the Full Moon—with terrestrial affairs. Heck, terms such as lunacy have even entered into the common lexicon, citing a supposed connection between insanity brought on by the Moon. And we’ve long heard anecdotal tales from police and late shift delivery room workers, who swear that everything, from crime rates to delivery room admissions increase around a Full Moon.

A 2004 study published in a nursing journal looking at admissions in a hospital in Barcelona, Spain cited a similar phenomenon.

So, what is this lunacy?

A recent study out of the UCLA caught our eye addressing this same issue. UCLA professor of planetary astronomy Jean-Luc Margot took a fresh look at the data from the 2004 study and found not only flaws in the correlation and data analysis in the 2004 study, but no link between the onset of the Full Moon and a spike in hospital admissions. We agree that looking at one hospital unit in Barcelona hardly constitutes a large data set. This also backs up a larger 40 year-old UCLA meta-study which found no correlation between the timing of births and the lunar cycle.

“The Moon is innocent,” Margot said, exonerating our celestial companion in a UCLA press release.

Blame our good friend and logical fallacy confirmation bias. Also known as the gambler’s fallacy, this occurs when we tend to count the hits but not the misses. When a topic such as a link between the Full Moon and a given activity comes up, we search back in our memory—which in and of itself is much more frangible than we’d like to think—and selectively remember all of the times that a Full Moon occurred when (pick your stated bias) occurred. And keep in mind, a Full Moon is only the technical instant when the Moon is opposite to the Sun and merely appears fully illuminated as seen from our Earthly perspective. That’s 180 degrees solar elongation, if you want to be precise. Of course, the orbit of the Moon is tilted about 5 degrees relative to the ecliptic, meaning that it’s only precisely opposite to the Sun during a central total lunar eclipse, when it’s immersed in the shadow of the Earth. Though the Moon approaches it, it never really reaches 100% illumination as seen from the Earth!

The April 4th, 2015 Moon, at 99.8% illuminated and about as 'Full' as it ever gets. Image credit and copyright: Chris Lyons
The April 4th, 2015 Moon, at 99.8% illuminated and about as ‘Full’ as it ever gets. Image credit and copyright: Chris Lyons

So much for werewolves…

The Moon also appears pretty darned close to Full on days it isn’t on the dates surrounding this instant in time. We say the Moon is then either waxing gibbous (headed towards Full) or waning gibbous (after Full).

Here’s what the Full Moon doesn’t do, though we’ve heard ‘em all over the years:  Increase birth rates, criminal activity, cause an increase in car accidents, cause a spike in earthquake activity, or affect fishing expedition outcomes. Well, OK, you might have more success finding your way back to shore using the moonlight as a guide if you stay out after dark…

A 2013 Swiss study in the journal of Current Biology has suggested a possible link between lunar and human sleep cycles, though again, this is very tentative. (thanks to K.E.M Lindblom @the_egghunter on Twitter for bringing this one to our attention.)

Update: Astronomer Jean-Luc Margot has brought it the attention of Universe Today that said lunar sleep study has been debunked last year.

So, what does the Moon do? Well, for one, it does a great job stabilizing the Earth’s rotational axis over the long term. One only has the look at moonless Mars (for the sake of this discussion, the tiny captured asteroids Phobos and Deimos do not count) to see what variations in the axial tilt of our world would be like without the Moon. And certain species of sea turtles along the Florida Gulf Coast do, in fact, hatch right around the time on the spring Full Moon. The Moon also provides us with a nifty celestial timekeeper: a good example is the Muslim calendar, which is based solely on the cycle of the Moon. The Full Moon also provided the human species with a fine study of celestial mechanics 101. Newton would’ve had a much tougher prospect figuring out his laws of gravity in its absence.

And finally, the Full Moon does affect the migratory patterns of deep sky astrophotographers, as they ‘pack it in’ in the weeks around the light polluting Full Moon, perchance to process and clean up images.. .

Headed towards Full... this week's thin waxing crescent Moon. Image credit: David Dickinson
Headed towards Full… this week’s thin waxing crescent Moon. Image credit: David Dickinson

All thoughts to ponder on the next Full Moon, which occurs on June 2nd… at 16:22 UT/12:22 AM EDT, to be precise.

So, as with all things that arc towards the astrological, we’ll defer to Shakespeare, who said, “The fault, dear Brutus, is not in our stars… but in ourselves. “

What other wacky lunar tie-ins have you heard of?

Lunar ‘Fountain of Youth’ Challenge / Mercury Returns with Gusto

A day-old Moon floats over the Spirit Mountain ski hill in Duluth, Minn. this past January. Credit: Bob King

16th century Spanish explorer Juan Ponce de León looked and looked but never did find the Fountain of Youth, a spring rumored to restore one’s youth if you bathed or drank from its waters.  If he had, I might have interviewed him for this story.

Sunday night, another symbol of youth beckons skywatchers the world over. A fresh-faced, day-young crescent Moon will hang in the western sky in the company of the planets Mars and Mercury. While I can’t promise a wrinkle-free life, sighting it may send a tingle down your spine reminding you of why you fell in love with astronomy in the first place. 

Look low in the west-northwest sky Sunday evening April 19 to spot the day-old crescent Moon alongside Mars and returning Mercury. Source: Stellarium
Look low in the west-northwest sky Sunday evening April 19 to spot the day-old crescent Moon alongside Mars and returning Mercury. Brilliant Venus will help you get oriented. This map shows the sky around 40 minutes after sunset but you can start as early as 30 minutes especially if you’re using binoculars. Source: Stellarium

The Moon reaches New Moon phase on Saturday, April 18 during the early afternoon for North and South America. By sunset Sunday, the fragile crescent will be about 29 hours old as seen from the East Coast, 30 for the Midwest, 31 for the mountain states and 32 hours for the West Coast. Depending on where you live, the Moon will hover some 5-7° (three fingers held at arm’s length) above the northwestern horizon 40 minutes after sunset. To make sure you see it, find a location with a wide-open view to the west-northwest.

Earthshine gets easier to see once the Moon moves a little further from the Sun and into a dark sky. Our planet provides enough light to spot some of the larger craters. Credit: Bob King
Earthshine gets easier to see as the Moon moves further from the Sun and the crescent fills out a bit. Our planet provides enough light to spot some of the larger craters. Credit: Bob King

While the crescent is illuminated by direct sunlight, you’ll also see the full outline of the Moon thanks to earthshine. Sunlight reflected off Earth’s globe faintly illuminates the portion of the Moon not lit by the Sun. Because it’s twice-reflected, the light looks more like twilight. Ghostly. Binoculars will help you see it best.

Now that you’ve found the dainty crescent, slide your eyes (or binoculars) to the right. That pinpoint of light just a few degrees away is Mars, a planet that’s lingered in the evening sky longer than you’ve promised to clean out the garage. The Red Planet shone brightly at opposition last April but has since faded and will soon be in conjunction with the Sun. Look for it to return bigger and brighter next May when it’s once again at opposition.

Diagram showing Mercury's position and approximate altitude above the horizon during the current apparition. Also shown are the planet's phases, which are visible in a telescope. Credit: Stellarium, Bob King
Diagram showing Mercury’s position and approximate altitude above the horizon during the current apparition. Also shown are the planet’s changing phases, which are visible in a telescope. Credit: Stellarium, Bob King

To complete the challenge, you’ll have to look even lower in the west to spot Mercury. Although brighter than Vega, it’s only 3° high 40 minutes after sunset Sunday. Its low altitude makes it Mercury is only just returning to the evening sky in what will become its best appearance at dusk for northern hemisphere skywatchers in 2015.

As an inner planet, Mercury goes through phases just like Venus and the Moon. We see it as everything from a crescent to a "full moon" as it angle to the Sun changes during its 88-day orbit. Credit: ESO
As an inner planet, Mercury goes through phases just like Venus and the Moon. We see it morph from crescent to “full moon” as its angle to the Sun changes during its revolution of the Sun. Credit: ESO

Right now, because of altitude, the planet’s a test of your sky and observing chops, but let the Moon be your guide on Sunday and you might be surprised. In the next couple weeks, Mercury vaults from the horizon, becoming easier and easier to see.  Greatest elongation east of the Sun occurs on the evening of May 6. Although the planet will be highest at dusk on that date, it will have faded from magnitude -0.5 to +1.2. By the time it leaves the scene in late May, it will become very tricky to spot at magnitude +3.5.

Mercury’s a bit different from Venus, which is brighter in its crescent phase and faintest at “full”. Mercury’s considerably smaller than Venus and farther from the Earth, causing it to appear brightest around full phase and faintest when a crescent, even though both planets are largest and closest to us when seen as crescents.

Not to be outdone by Venus earlier this month, Mercury passes a few degrees south of the Pleiades star cluster on April 29. The map shows the sky facing northwest about 50 minutes after sunset. Source: Stellarium
Not to be outdone by the Venus-Pleiades conjunction earlier this month, Mercury passes a few degrees south of the star cluster on April 29. The map shows the sky facing northwest about 50 minutes after sunset. Source: Stellarium

Venus makes up for its dwindling girth by its size and close proximity to Earth. It also doesn’t hurt that it’s covered in highly reflective clouds. Venus reflects about 70% of the light it receives from the Sun; Mercury’s a dark world and gives back just 7%. That’s dingier than the asphalt-toned Moon!

Good luck in your mercurial quest. We’d love to hear your personal stories of the hunt — just click on Comments.

SpaceX Dragon Launches on Science Supply Run to Station, Booster Hard Lands on Barge

SpaceX Falcon 9 and Dragon blastoff from Space Launch Complex 40 at Cape Canaveral Air Force Station in Florida on April 14, 2015 at 4:10 p.m. EDT on the CRS-6 mission to the International Space Station. Credit: Ken Kremer/kenkremer.com

KENNEDY SPACE CENTER, FL – After a 24 hour delay due to threatening clouds, a SpaceX Falcon 9 rocket soared spectacularly to orbit from the Florida Space coast today, April 14, carrying a Dragon on a science supply run bound for the the International Space Station that will help pave the way for deep space human missions to the Moon, Asteroids and Mars.

Meanwhile, SpaceX’s bold attempt to land and recover the 14 story tall first stage of the Falcon 9 rocket successfully reached a tiny ocean floating barge in the Atlantic Ocean, but tilted over somewhat over in the final moments of the approach, and tipped over after landing and broke apart. Here’s a Vine video posted on Twitter by Elon Musk:

See the video of the launch, below.

SpaceX will continue with attempt to soft land and recover the rocket on upcoming launches, which was a secondary goal of the company. SpaceX released some imagery and video with a few hours of the landing attempt.

“Looks like Falcon landed fine, but excess lateral velocity caused it to tip over post landing,” tweeted SpaceX CEO Elon Musk.

Falcon 9 first stage approaches Just Read the Instructions. Image of SpaceX Falcon 9 first start booster in final moments of hard landing on ocean going barge after CRS-6 launch. Credit: SpaceX
Falcon 9 first stage approaches Just Read the Instructions. Image of SpaceX Falcon 9 first start booster in final moments of hard landing on ocean going barge after CRS-6 launch. Credit: SpaceX

The Falcon 9 first stage was outfitted with four landing legs and grid fins to enable the landing attempt, which is a secondary objective of SpaceX.

The top priority was to safely launch the Falcon 9 and deliver critical supplies to the station with the Dragon cargo vessel.

“Five years ago this week, President Obama toured the same SpaceX launch pad used today to send supplies, research and technology development to the ISS,” said NASA Administrator Charles Bolden.

“Back then, SpaceX hadn’t even made its first orbital flight. Today, it’s making regular flights to the space station and is one of two American companies, along with The Boeing Company, that will return the ability to launch NASA astronauts to the ISS from U.S. soil and land then back in the United States. That’s a lot of progress in the last five years, with even more to come in the next five.”

“Looks like Falcon landed fine, but excess lateral velocity caused it to tip over post landing,” tweeted SpaceX CEO Elon Musk.

A chase plane captured dramatic footage of the landing on the ocean going platform known as the ‘autonomous spaceport drone ship’ (ASDS).

It was pre-positioned some 200 to 250 miles offshore of the Carolina coast in the Atlantic Ocean along the rockets flight path flying along the US Northeast coast to match that of the ISS.

The ASDS measures only 300 by 100 feet, with wings that extend its width to 170 feet.

SpaceX Falcon 9 and Dragon blastoff from Space Launch Complex 40 at Cape Canaveral Air Force Station in Florida on April 14, 2015 at 4:10 p.m. EDT  on the CRS-6 mission to the International Space Station. Credit: Ken Kremer/kenkremer.com
SpaceX Falcon 9 and Dragon blastoff from Space Launch Complex 40 at Cape Canaveral Air Force Station in Florida on April 14, 2015 at 4:10 p.m. EDT on the CRS-6 mission. to the International Space Station. Credit: Ken Kremer/kenkremer.com

Overall CRS-6 is the sixth SpaceX commercial resupply services mission and the seventh trip by a Dragon spacecraft to the station since 2012.

CRS-6 marks the company’s sixth operational resupply mission to the ISS under a $1.6 Billion contract with NASA to deliver 20,000 kg (44,000 pounds) of cargo to the station during a dozen Dragon cargo spacecraft flights through 2016 under NASA’s original Commercial Resupply Services (CRS) contract.

The SpaceX Falcon 9 with the Dragon vessel for the CRS-6 launch lifts off for the International Space Station at 4:10 PM eastern time on 4/14/15 from Cape Canaveral.  Credit: Alex Polimeni/AmericaSpace
The SpaceX Falcon 9 with the Dragon vessel for the CRS-6 launch lifts off for the International Space Station at 4:10 PM eastern time on 4/14/15 from Cape Canaveral. Credit: Alex Polimeni/AmericaSpace

Dragon is packed with more than 4,300 pounds (1915 kilograms) of scientific experiments, technology demonstrations, crew supplies, spare parts, food, water, clothing and assorted research gear for the six person Expedition 43 and 44 crews serving aboard the ISS.

After a three day orbital chase, the Dragon spacecraft with rendezvous with the million post Earth orbiting outpost Friday morning April 17.

After SpaceX engineers on the ground maneuver the Dragon close enough to the station, European Space Agency (ESA) astronaut Samantha Cristoforetti will use the station’s 57.7-foot-long (17-meter-long) robotic arm to reach out and capture Dragon at approximately 7 a.m. EDT on April 17.

Cristoforetti will be assisted by fellow Expedition 43 crew member and NASA astronaut
Terry Virts, as they work inside the stations seven windowed domed cupola to berth Dragon at the Earth-facing port of the Harmony module.

The series of images shows the journey the SpaceX Falcon 9 rocket and Dragon spacecraft from its launch at 4:10 p.m. EDT on Tuesday April 14, 2015 from Space Launch Complex 40 at Cape Canaveral Air Force Station in Florida, to solar array deployment. Credit: NASA TV
The series of images shows the journey the SpaceX Falcon 9 rocket and Dragon spacecraft from its launch at 4:10 p.m. EDT on Tuesday April 14, 2015 from Space Launch Complex 40 at Cape Canaveral Air Force Station in Florida, to solar array deployment. Credit: NASA TV

Watch for Ken’s continuing onsite coverage of the CRS-6 launch from the Kennedy Space Center and Cape Canaveral Air Force Station.

Stay tuned here for Ken’s continuing Earth and planetary science and human spaceflight news.

Ken Kremer

………….

Learn more about SpaceX, Mars rovers, Orion, Antares, MMS, NASA missions and more at Ken’s upcoming outreach events:

Apr 18/19: “Curiosity explores Mars” and “NASA Human Spaceflight programs” – NEAF (NorthEast Astronomy Forum), 9 AM to 5 PM, Suffern, NY, Rockland Community College and Rockland Astronomy Club

Was This Past Weekend’s Lunar Eclipse Really Total?

Totality... or not? Image credit and copyright: Héctor Barrios

Millions of viewers across the western United States and across the Pacific, to include Australia and New Zealand were treated to a fine Easter weekend lunar eclipse on Saturday. And while this was the third of the ongoing tetrad of four lunar eclipses, it was definitely worth getting up early for and witnessing firsthand.

But was it truly total at all?

To Recap: The April 4th eclipse featured the shortest advertised duration for totality for the 21st century, clocking in at just four minutes and 43 seconds in length. In fact, you’d have to go all the way back to 1529 to find a shorter span of totality, at one minute and 42 seconds. And you’ll have to wait until September 11th, 2155 to find one that tops it in terms of brevity.

The April 4th lunar eclipse over the Las Vegas strip. Image credit and copyright: John Lybrand
The April 4th lunar eclipse over the Las Vegas strip. Image credit and copyright: John Lybrand

We wrote recently about the saros cycle, and how this past weekend’s eclipse was the first in lunar saros series 132 to feature totality.

A fascinating discussion as to whether this was a de facto total lunar eclipse has recently sprung up on the message boards and a recent Sky and Telescope article online.

The geometry that creates a total lunar eclipse. Credit: NASA
The geometry that creates a total lunar eclipse. Credit: NASA

It all has to do with how you gauge the shape and size of the Earth’s shadow.

This is a surprisingly complex affair, as the Earth’s atmosphere gives the umbra a ragged and indistinct edge. If you’ve ever taken our challenge to determine your longitude using a lunar eclipse — just as mariners such as Christopher Columbus did while at sea — then you know how tough it is to get precise contact timings. There has been an ongoing effort over the years to model the size changes in Earth’s shadow using crater contact times during a lunar eclipse.

Many observers have commented in forums and social media that the northern limb of the Moon stayed pretty bright throughout the brief stretch of totality for Saturday’s eclipse.

What happens (in the skies over) Vegas... the lunar eclipse captured from the Luxor Hotel. Image credit and copyright: Rob Sparks
What happens (in the skies over) Vegas… the lunar eclipse captured from the Luxor Hotel. Image credit and copyright: Rob Sparks

“There are 3 ways of computing the magnitude of a lunar eclipse,” Eclipse expert David Herald mentioned in a recent Solar Eclipse Message List (SEML) posting:

The ‘traditional’ way as used in the Astronomical Almanac is attributed to Chauvenet – where the umbral radius is increased by a simple 2% – with the radius being based on the Earth’s radius at 45 deg latitude (and otherwise the oblateness of the Earth is ignored). For this eclipse the Chauvenet magnitude was 1.005.

 The second way (used in the French Almanac, and more recently by Espenak & Meeus in their ‘Five Millennium Canon of Lunar Eclipses’ is the Danjon method. It similarly uses the Earth’s radius at 45 deg (and otherwise the oblateness is ignored), and increases the Earth’s radius by 75km. For this eclipse the Danjon magnitude is 1.001

The most recent approach (Herald & Sinnott JBAA 124-5 pgs 247-253, 2014) is based on the Danjon approach; however it treats the Earth as oblate, allows for the varying inclination of the Earth relative to the Sun during the year, and increases the Earth’s radius by 87km – being the best fit to 22,539 observations made between 1842 and 2011. For this eclipse the magnitude is computed as 1.002.

“As for eclipses, to me it is total when sliver of light comes through the edge of the Earth’s profile,” eclipse chaser Patrick Poitevin told Universe Today. “Once a minimum of light passes through any of the lunar dales (as it does during a total solar eclipse) I do not concede it as a total. Same for a lunar eclipse.”

A partial phase for the April 4th lunar eclipse above a silo. Image credit and copyright: Brian who is called Brian
A partial phase for the April 4th lunar eclipse above a silo. Image credit and copyright: Brian who is called Brian

Michael Zeiler at the Great American Eclipse also had this to say to Universe Today about the subject:

This is a complex question because the shape of the Earth’s umbra upon the Moon is diffuse due to the effects of the Earth’s atmosphere. The various models used (with corrected radii for the Earth) are empirically based on crater timings of past lunar eclipses, of which there is some uncertainty. I’m sure this accounted for the difference between the USNO duration of eclipse and NASA.

The comment (in the recent Sky & Telescope post online) by Curt Renz is valid; correcting for the Earth’s flattening (meaning that the Earth’s radius from pole to pole is about a third of a percent shorter than the radius across the equator) might influence whether this very low magnitude eclipse is total or not. I haven’t made the calculation whether the Earth’s flattening tips this eclipse from total to partial, but it’s plausible.

Totality! Image credit and copyright: Rolf Wahl Olsen
Totality! Image credit and copyright: Rolf Wahl Olsen

 There is another wrinkle: due to parallactic shifts of the Moon when observing from either pole of the Earth, it might be that for a lunar eclipse right on the knife edge of total/partial, that it may indeed be total from one polar region and partial from another. This is a kind of libration, but it would be a very subtle difference and probably unobservable. 

 It is only possible to conclusively define Saturday’s eclipse as total or partial if you define a brightness threshold for the Sun’s photosphere illuminating an edge of the Moon. The problem here is that this line is indistinct and fuzzy. I watched the lunar eclipse carefully with this question in mind and I could not decide for myself whether this lunar eclipse was total or partial. I think it would require a photometer to make this distinction.

 Certainly, there’s little record of just how the 102 second long lunar eclipse of 1529 appeared. Ironically, it too was a total eclipse near sunrise as seen from Europe. On the other side of the coin, the deep partial eclipse of August 26th, 1961 just missed totality at 98.6% obscuration… and the two lunar eclipses in 2021 have similar circumstances, with a barely total lunar eclipse just 15 minutes long on May 26th and a 97.4% partial lunar eclipse on November 19th.

The circumstances for the 1529 total solar eclipse. Image credit: F.Espenak/NASA/GSFC
The circumstances for the 1529 total solar eclipse. Image credit: F.Espenak/NASA/GSFC

So maybe we won’t have to wait until 2155 to see another brief lunar eclipse that blurs the lines and refuses to play by the rules.

The eclipse as seen from Coral Towers Observatory. Image credit and copyright: Joseph Brimacombe
The eclipse as seen from Coral Towers Observatory. Image credit and copyright: Joseph Brimacombe

What do you, the readers think? What did you see last Saturday morn, a bright total lunar eclipse, or a deep partial?

There Could Be Lava Tubes on the Moon, Large Enough for Whole Cities

Rima Ariadaeus as photographed from Apollo 10. The crater to the south of the rille in the left half of the image is Silberschlag. The dark patch at the top right is the floor of the crater Boscovich. Credit: NASA

Every year since 1970, astronomers, geologists, geophysicists, and a host of other specialists have come together to participate in the Lunar and Planetary Science Conference (LPCS). Jointly sponsored by the Lunar and Planetary Institute (LPI) and NASA’s Johnson Space Center (JSC), this annual event is a chance for scientists from all around the world to share and present the latest planetary research concerning Earth’s only moon.

This year, one of the biggest attention-grabbers was the findings presented on Tuesday, March 17th by a team of students from Purdue University. Led by a graduate student from the university’s Department of Earth, Atmospheric and Planetary Sciences, the study they shared indicates that there may be stable lava tubes on the moon, ones large enough to house entire cities.

In addition to being a target for future geological and geophysical studies, the existence of these tubes could also be a boon for future human space exploration. Basically, they argued, such large, stable underground tunnels could provide a home for human settlements, shielding them from harmful cosmic radiation and extremes in temperature.

The Hadley Rille, at the foot of the Apennine Mountains encircling the Mare Imbrium where Apollo 15 landed (NASA/JAXA)
The Hadley Rille, at the foot of the Apennine Mountains encircling the Mare Imbrium where Apollo 15 landed. Credit: NASA/JAXA

Lava tubes are natural conduits formed by flowing lava that is moving beneath the surface as a result of a volcanic eruption. As the lava moves, the outer edges of it cools, forming a hardened, channel-like crust which is left behind once the lava flow stops. For some time, Lunar scientists have been speculating as to whether or not lava flows happen on the Moon, as evidenced by the presence of sinuous rilles on the surface.

Sinuous rilles are narrow depressions in the lunar surface that resemble channels, and have a curved paths that meanders across the landscape like a river valley. It is currently believed that these rilles are the remains of collapsed lava tubes or extinct lava flows, which is backed up by the fact they usually begin at the site of an extinct volcano.

Those that have been observed on the Moon in the past range in size of up to 10 kilometers in width and hundreds of kilometers in length. At that size, the existence of a stable tube – i.e. one which had not collapsed to form a sinuous rille – would be large enough to accommodate a major city.

For the sake of their study, the Purdue team explored whether lava tubes of the same scale could exist underground. What they found was that the stability of a lava tube depended on a number of variables- including width, roof thickness and the stress state of the cooled lava. he researchers also modeled lava tubes with walls created by lava placed in one thick layer and with lava placed in many thin layers.

The city of Philadelphia is shown inside a theoretical lunar lava tube. A Purdue University team of researchers explored whether lava tubes more than 1 kilometer wide could remain structurally stable on the moon. (Purdue University/courtesy of David Blair)
The inside of a theoretical lunar lava tube, with the city of Philadelphia shown for scale. Credit: Purdue University/David Blair

David Blair, a graduate student in Purdue’s Department of Earth, Atmospheric and Planetary Sciences, led the study that examined whether empty lava tubes more than 1 kilometer wide could remain structurally stable on the moon.

Our work is somewhat unique in that we’ve combined the talents of people from various Departments at Purdue,” Blair told Universe Today via email. “With guidance from Prof. Bobet (a civil engineering professor) we’ve been able to incorporate a modern understanding of rock mechanics into our computer models of lava tubes to see how they might actually fail and break under lunar gravity.”

For the sake of their research, the team constructed a number of models of lava tubes of different sizes and with different roof thicknesses to test for stability. This consisted of them checking each model to see if it predicted failure anywhere in the lava tube’s roof.

“What we found was surprising,” Blair continued, “in that much larger lava tubes are theoretically possible than what was previously thought. Even with a roof only a few meters thick, lava tubes a kilometer wide may be able to stay standing. The reason why, though, is a little less surprising. The last work we could find on the subject is from the Apollo era, and used a much simpler approximation of lava tube shape – a flat beam for a roof.

 Mons Rümker rise on the Oceanus Procellarum was taken from the Apollo 15 while in lunar orbit.
Mons Rümker, an extinct volcanic formation on the Moon’s surface, as imaged by the Apollo 15 spacecraft while in orbit. Credit: NASA

The study he refers to, “On the origin of lunar sinuous rilles“, was published in 1969 in the journal Modern Geology. In it, professors Greeley, Oberbeck and Quaide advanced the argument that sinuous rilles formation was tied to the collapse of lava flow tubes, and that stable ones might still exist. Calculating for a flat-beam roof, their work found a maximum lava tube size of just under 400 m.

“Our models use a geometry more similar to what’s seen in lava tubes on Earth,” Blair said, “a sort of half-elliptical shape with an arched roof. The fact that an arched roof lets a larger lava tube stay standing makes sense: humans have known since antiquity that arched roofs allow tunnels or bridges to stay standing with wider spans.”

The Purdue study also builds on previous studies conducted by JAXA and NASA where images of “skylights” on the Moon – i.e. holes in the lunar surface – confirmed the presence of caverns at least a few tens of meters across. The data from NASA’s lunar Gravity Recovery And Interior Laboratory (GRAIL) – which showed big variations in the thickness of the Moon’s crust  is still being interpreted, but could also be an indication of large subsurface recesses.

As a result, Blair is confident that their work opens up new and feasible explanations for many different types of observations that have been made before. Previously, it was unfathomable that large, stable caverns could exist on the Moon. But thanks to his team’s theoretical study, it is now known that under the proper conditions, it is least possible.

The thickness of the moon's crust as calculated by NASA's GRAIL mission. The near side is on the left-hand side of the picture, and the far side on the right. Credit: NASA/JPL-Caltech/S. Miljkovic
NASA’s lunar Gravity Recovery And Interior Laboratory (GRAIL) mission calculated the thickness of the moon’s crust. Credit: NASA/JPL-Caltech/S. Miljkovic

Another exciting aspect that this work is the implications it offers for future exploration and even colonization on the Moon. Already, the issue of protection against radiation is a big one. Given that the Moon has no atmosphere, colonists and agricultural operations will have no natural shielding from cosmic rays.

“Geologically stable lava tubes would absolutely be a boon to human space exploration,” Blair commented. “A cavern like that could be a really ideal place for building a lunar base, and generally for supporting a sustained human presence on the Moon. By going below the surface even a few meters, you suddenly mitigate a lot of the problems with trying to inhabit the lunar surface.”

Basically, in addition to protecting against radiation, a subsurface base would sidestep the problems of micrometeorites and the extreme changes in temperature that are common on the lunar surface. What’s more, stable, subsurface lava tubes could also make the task of pressurizing a base for human habitation easier.

“People have studied and talked about all of these things before,” Blair added, “but our work shows that those kinds of opportunities could potentially exist – now we just have to find them. Humans have been living in caves since the beginning, and it might make sense on the Moon, too!”

In addition to Melosh, Blair and Bobet, team members include Loic Chappaz and Rohan Sood, graduate students in the School of Aeronautics and Astronautics; Kathleen Howell, Purdue’s Hsu Lo Professor of Aeronautical and Astronautical Engineering; Andy M. Freed, an associate professor of earth, atmospheric and planetary sciences; and Colleen Milbury, a postdoctoral research associate in the Department of Earth, Atmospheric and Planetary Sciences.

Further Reading: Purdue News

Don’t Blink! April 4th Lunar Eclipse Shortest of the Century

The phases of a total lunar eclipse. Credit: Keith Burns / NASA

Get ready for one awesome total lunar eclipse early Saturday morning April 4th. For the third time in less than a year, the Moon dips into Earth’s shadow, its dazzling white globe turning sunset red right before your eyes.  All eclipses are not-to-miss events, but Saturday’s totality will be the shortest in a century. Brief but beautiful – just like life. Read on to find out how to make the most of it.

Four total lunars in succession is called a tetrad. During the 21st century there are nine sets of tetrads. Credit: NASA
Four total lunar eclipses in succession with no partials in between is called a tetrad. The April 4th eclipse is part of a tetrad that started last April and will wrap up on September 28. During the 21st century there will be eight sets of tetrads. Credit: NASA

Lunar eclipses don’t usually happen in any particular order. A partial eclipse is followed by a total is followed by a penumbral and so on. Instead, we’re in the middle of a tetrad, four total eclipses in a row with no partials in between. The final one happens on September 28.  Even more remarkable, part or all of them are visible from the U.S. Tetrads will be fairly common in the 21st century with eight in all. We’re lucky — between 1600 and 1900 there were none! For an excellent primer on the topic check out fellow Universe Today writer David Dickinson’s “The Science Behind the Blood Moon Tetrad“.

The Moon moves out of total eclipse and into partial phases during the second of the four tetrad eclipses on October 8, 2015. Credit: Bob King
The partially eclipsed Moon on October 8, 2015.  For skywatchers across the eastern half of North America, this is about how the Moon will appear shortly before it sets. Those living further west will see totality. Credit: Bob King

Lots of people have taken to calling the tetrad eclipses Blood Moons, referring to the coppery color of lunar disk when steeped in Earth’s shadow and the timing of both April events on the Jewish Passover. Me? I prefer Bacon-and-Eggs Moon. For many of us, the eclipse runs right up till sunrise with the Moon setting in bright twilight around 6:30 a.m. What better time to enjoy a celebratory breakfast with friends after packing away your gear?

Map showing where the April 4 lunar eclipse will be penumbral, partial and total. Inset shows a world map. Credit: Larry Koehn / shadowandsubstance.com
Map showing where the April 4 lunar eclipse will be penumbral, partial and total. World map shown in inset. Credit: Larry Koehn / shadowandsubstance.com Inset: Fred Espenak

But seriously, Saturday morning’s eclipse will prove challenging for some. While observers in far western North America, Hawaii, Japan, New Zealand and Australia will witness the entire event, those in the mountain states will see the Moon set while still in totality. Meanwhile, skywatchers in the Midwest and points East will see only the partial phases in a brightening dawn sky. Here are the key times of eclipse events by time zone:

A total lunar eclipse occurs only during Full Moons when the Sun, Earth and Moon form a straight line. The Moon slips directly behind Earth into its shadow. The outer part of the shadow or penumbra is a mix of sunlight and shadow. The inner cone, called the umbra, the Sun is completely blocked from view. However, light refracted by Earth's atmosphere is bent into the umbra where it colors the eclipsed Moon red.
A total lunar eclipse occurs only during full moon phase when the Sun, Earth and Moon lie in a straight line. The Moon slips directly behind Earth into its shadow. The outer part of the shadow or penumbra is a mix of sunlight and shadow and only partially dark. From  the inner shadow, called the umbra, the Sun is completely blocked from view. A small amount of sunlight refracted or bent by Earth’s atmosphere into the umbra, spills into the shadow, coloring the eclipsed Moon red.

Eclipse Events                                     EDT              CDT              MDT             PDT

Penumbra eclipse begins 5:01 a.m. 4:01 a.m. 3:01 a.m. 2:01 a.m.
Partial eclipse begins 6:16 a.m. 5:16 a.m. 4:16 a.m. 3:16 a.m.
Total eclipse begins ——– ——– 5:58 a.m. 4:58 a.m.
Greatest eclipse ——– ——– 6:00 a.m. 5:00 a.m.
Total eclipse ends ——– ——– 6:03 a.m. 5:03 a.m.
Partial eclipse ends ——— ——– ——– 6:45 a.m.
Penumbra eclipse ends ——— ——— ——– ——–

* During the penumbral phase, shading won’t be obvious until ~30 minutes before partial eclipse.

Partial eclipse, when the Moon first enters Earth's dark, inner shadow called the umbra, begins at 5:16 a.m. CDT near the start of morning twilight. Totality begins at 6:58 a.m. with the Moon already set for the eastern half of the country.  Credit: Fred Espenak
Partial eclipse, when the Moon first enters Earth’s dark umbral shadow, begins at 5:16 a.m. CDT near the start of morning twilight. Totality begins at 6:58 a.m. with the Moon already set for the eastern half of the country. Credit: Fred Espenak

This eclipse will also be the shortest total eclipse of the 21st century; our satellite spends just 4 minutes and 43 seconds inside Earth’s umbra or shadow core. That’s only as long as a typical solar eclipse totality. Ah, the irony.

Better have your camera ready or you’ll miss it. The maps below show the maximum amount of the Moon visible shortly before setting from two eastern U.S. cities and the height of the totally eclipsed Moon from two western locations. Click each panel for more details about local circumstances.

The Earth's shadow will take only a small bite out of the Moon before sunrise (6:47 a.m.) as seen from Washington D.C. Source: Stellarium
The Earth’s shadow will take only a small bite out of the Moon before sunrise (6:47 a.m.) as seen from Washington D.C. From all mainland U.S. locations Virgo’s brightest star Spica will appear about 10° to the left of the Moon. Source: Stellarium
Here's the view from Chicago where sunrise occurs at 6:27 a.m. Source: Stellarium
Here’s the view from Chicago where sunrise occurs at 6:27 a.m.  Source: Stellarium
Totality will be visible From Denver, Colorado with the Moon low in the western sky. Source: Stellarium
Totality will be visible From Denver, Colorado with the Moon low in the western sky in morning twilight. Sunrise is 6:42 a.m. Source: Stellarium
Seattle and the West Coast get a great view of totality in a dark sky. The final partial phases will also be visible. Sunrise there is 6:40 a.m. Source: Stellarium
Seattle and the West Coast get a great view of totality in a dark sky. The final partial phases will also be visible. Sunrise there is 6:40 a.m. Source: Stellarium

Now that you know times and shadow coverage, let’s talk about the fun part — what to look for as the event unfolds. You’ll need to find a location in advance with a good view to the southwest as most of the action happens in that direction. Once that detail’s taken care of and assuming clear weather, you can kick back in a folding chair or with your back propped against a hillside and enjoy.

During the early partial phases you may not see the shadowed portion of the Moon with the naked eye. Binoculars and telescopes will show it plainly. But once the Moon's about 50% covered, the reddish-orange tint of the shadowed half becomes obvious. Credit: Jim Schaff
During the early partial phases you may not see the shadowed portion of the Moon with the naked eye. Binoculars and telescopes will show it plainly. But once the Moon is about 50% covered, the reddish-orange tint of the shadowed half becomes obvious. During total eclipse (right), the color is intense.  Credit: Jim Schaff

The entire eclipse can be enjoyed without any optical aid, though I recommend a look through binoculars now and then. The eclipsed Moon appears distinctly three-dimensional with only the slightest magnification, hanging there like an ornament among the stars. The Earth’s shadow appears to advance over the Moon, but the opposite is true; the Moon’s eastward orbital motion carries it deeper and deeper into the umbra.

Nibble by nibble the sunlit Moon falls into shadow. By the time it’s been reduced to half, the shaded portion looks distinctly red even to the naked eye. Notice that the shadow is curved. We live on a spherical planet and spheres cast circular shadows. Seeing the globe of Earth projected against the Moon makes the roundness of our home planet palpable.

Artist view of Earth totally eclipsing the sun as viewed from the moon. Low angled sunlight filtered by our atmosphere is reddened in exactly the same way a setting sun is reddened. That red light bathes the moon’s surface which reflects a bit of it back toward Earth, giving us a red moon during totality.
A simulated view looking back at Earth from the Moon during a total lunar eclipse on Earth. Sunlight grazing Earth’s circumference gets filtered by our atmosphere in exactly the same way the setting or rising Sun looks red. All the cooler colors have been scattered away by air and Red light, bent into the umbra by atmospheric refraction, bathes the lunar surface in red. As you might have guessed, when we see a total lunar eclipse on Earth, lunar inhabitants see a total eclipse of the Sun by Earth. Source: Stellarium

When totality arrives, the entire lunar globe throbs with orange, copper or rusty red. These sumptuous hues originate from sunlight filtered and bent by Earth’s atmosphere into the umbral shadow. Atmospheric particles have removed all the cooler colors, leaving the reds and oranges from a billion sunrises and sunsets occurring around the planet’s circumference. Imagine for a moment standing on the Moon looking back. Above your head would hang the black disk of Earth, nearly four times the size of the Moon in our sky, ringed by a narrow corona of fiery light.

Color varies from one eclipse to the next depending on the amount of water, dust and volcanic ash suspended in Earth’s atmosphere. The December 30, 1982 eclipse was one of the darkest in decades due to a tremendous amount of volcanic dust from the eruption of the Mexican volcano El Chichon earlier that year.

The more particles and haze, the greater the light absorption and darker the Moon. That said, this eclipse should be fairly bright because the Moon does not tread deeply into Earth’s shadow. It’s in for a quick dip of totality and then resumes partial phases.

The Moon's color can vary from yellow-orange to dark, smoky brown during totality depending on the state of the atmosphere. You can also see lots of stars in the sky right up to the Moon's edge when it's in Earth's shadow. This photo from last April's eclipse. Credit: Bob King
The Moon’s color can vary from yellow-orange to dark, smoky brown during totality depending on the state of the atmosphere. You can also see lots of stars in the sky right up to the Moon’s edge when it’s in Earth’s shadow. This photo from last April’s eclipse. Spica is below the Moon and Mars to the right. Credit: Bob King

It’s northern edge, located close to the outer fringe of Earth’s umbra, should appear considerably brighter than the southern, which is closer to the center or darkest part of the umbra.

Earth's shadow exposed! During a lunar eclipse that occurs at dusk or dawn (like  the April 4th one and this one last October) we have the rare opportunity to see Earth's shadow on the distant Moon at the same time it's visible as a dark purple band cast on the upper atmosphere as seen here on October 8, 2015. Credit: Bob King
Earth’s shadow exposed! When a lunar eclipse occurs at dusk or dawn we have the rare opportunity to see Earth’s shadow on the distant Moon at the same time it’s visible as a dark purple band cast on the upper atmosphere as seen here on October 8, 2015. Credit: Bob King

Besides the pleasure of seeing the Moon change color, watch for the sky to darken as totality approaches. Eclipses begin with overwhelming moonlight and washed out, star-poor skies. As the Moon goes into hiding, stars return in a breathtaking way over a strangely eerie landscape. Don’t forget to turn around and admire the glorious summer Milky Way rising in the eastern sky.

Lunar eclipses remind us we live in a Solar System made of these beautiful, moving parts that never fail to inspire awe when we look up to notice.

In case you can’t watch the eclipse from your home due to weather or circumstance, our friends at the Virtual Telescope Project  and SLOOH will stream it online.

Slender Moonspotting, Occultations, Daytime Planets and More

Credit and copyright:

One of nature’s grandest ‘occultations’ of all is coming right up this Friday, as the Moon passes in front of the Sun for viewers in the high Arctic for a total solar eclipse. And although 99.999+% percent of humanity will miss totality, everyone can trace the fascinating path of the Moon as it moves back into the evening sky this weekend.

As of this writing, it looks like the fickle March weather is going to keep us guessing right up to eclipse day. Fear not, as the good folks over at the Virtual Telescope Project promise to bring us views of the eclipse live.  Not only does this eclipse fall on the same day as the start of astronomical spring in the northern hemisphere known as the vernal (northward) equinox, but it also marks the start of lunation 1141.

Ever try hunting for the slender crescent Moon in the dawn or dusk sky? The sport of thin Moon-spotting on the days surrounding the New Moon can push visual skills to the very limit. Binoculars are your friend in this endeavor, as you sweep back and forth attempting to see the slim fingernail of a Moon against the low contrast background sky.  Thursday morning March 19th provides a great chance for North American observers to spy an extremely thin Moon about 24 hours prior to Friday’s eclipse.

Credit:
Projected locales for the first sightings of the slim crescent Moon on the evening of March 20th. Credit: Created by author.

Unfortunately, most of North America misses the eclipse, though folks on the extreme east coast of Newfoundland might see a partially eclipsed sunrise if the day dawns clear.

The Moon will first be picked up in the evening sky post-eclipse this weekend. On Friday evening, folks in the southern United States might just be able to spy a 15 hour old Moon with optical assistance if skies are clear.

As the Moon fattens, expect to see it at its most photogenic as Ashen light or Earthshine illuminates its nighttime side. What you’re seeing is sunlight from the Earth being reflected back in a reverse (waning gibbous) phase as seen from the earthward side of the Moon. The prominence of Earthshine can vary depending on the amount of cloud and snow cover currently turned moonward, though of course, if it’s cloudy from your location, you won’t see a thing…

Credit
The universe smiles back: A skewed emoticon grouping of Venus, Mars and the Moon plus Earthshine on February 20th. Photo by author.

Watch that Moon over the coming weeks, as it has a date with destiny.

The Moon occults (passes in front of) two planets and one bright star in the coming week. First up is an occultation of Uranus on March 21st at around 11:00 UT/7:00 AM EDT. Sure, this one is for the most part purely academic and unobservable, as it occurs over central Africa in the daytime and is only 15 degrees east of the Sun. Still, if you can pick up the Moon on the evenings of March 20th or March 21st, you might just be able to spy nearby Uranus shining at +6th magnitude nearby before it heads towards solar conjunction on April 6th.

Credit:
The visibility footprint of the March 21st occultation of Mars by the Moon. Credit: Occult 4.1.

Next, the Moon occults Mars on March 21st at 22:00 UT/6:00 PM EDT for the southern Pacific coast of South America. North America will see an extremely close photogenic pairing of Luna and the Red Planet. This is one of seven occultations of a naked eye planet by the Moon for 2015, and the first of two for Mars for the year, the next falling on December 6th.

Credit
The Moon pairs with Venus on the evening of March 22nd. Credit: Stellarium.

Next up, the Moon has a tryst with brilliant Venus, passing 2.8 degrees from the Cytherean world on March 22nd. Can you spy -4th magnitude Venus near the two day old Moon before sunset? This is the stuff that has inspired astronomically-themed flags and skewed emoticon ‘smiley face conjunctions’ of yore, including the close pairing of Mars, Venus and the Moon seen worldwide last month.

Credit:
The occultation of Aldebaran by the Moon on March 25th. Credit: Occult 4.1.

Next up, the 30% illuminated Moon occults the bright star Aldebaran for Alaskan viewers at dusk on March 25th. This is the third occultation of the star by the Moon in the ongoing cycle, and to date, no one has, to our knowledge, successfully caught an occultation of Aldebaran in 2015… could this streak be broken next week?

Credit:
The daytime Moon paired with Jupiter on March 30th. Credit: Starry Night Education software.

And speaking of daytime planet-spotting, Jupiter will sit only five degrees south of the waxing gibbous Moon on the evening of March 30th. Can you spy the giant planet near the daytime Moon in the afternoon sky using binocs? And finally, watch that Moon, as it heads for the third total lunar eclipse of the last 12 months visible from the Americas and the Pacific region on the morning of April 4th

More to come!

Most Powerful Solid Rocket Booster Ignites in Milestone Test, Propelling NASA on Path to Deep Space

At the Orbital ATK test facility, the booster for NASA’s Space Launch System rocket was fired for a two minute test on March 11. The test is one of two that will qualify the booster for flight before SLS begins carrying NASA’s Orion spacecraft and other potential payloads to deep space destinations. Image Credit: NASA

At the Orbital ATK test facility, the booster for NASA’s Space Launch System rocket was fired for a two minute test on March 11. The test is one of two that will qualify the booster for flight before SLS begins carrying NASA’s Orion spacecraft and other potential payloads to deep space destinations. Image Credit: NASA
Watch the complete test firing video below[/caption]

KENNEDY SPACE CENTER, FL – NASA’s goal of sending humans back to deep space in the next decade advanced a major step forward today, March 11, with the successful ground test firing of the largest and most powerful solid rocket booster ever built that will be used to propel NASA’s Space Launch System (SLS) rocket and manned Orion spacecraft to destinations including the Moon, Asteroids and Mars.

The two minute long, full duration static test firing of the motor marked a major milestone in the ongoing development of NASA’s SLS booster, which is the most powerful rocket ever built in human history.

The booster known as qualification motor, QM-1, is the world’s largest solid rocket motor and was ignited at about 11:30 a.m. EST by prime contractor Orbital ATK at the newly merged firms test facility in Promontory, Utah.

Video caption: Space Launch System Booster Passes Major Ground Test on Mar. 11, 2015. The 5 segment solid rocket booster being developed for the SLS rocket fired for two minutes, the same amount of time it will fire when it lifts the SLS off the launch pad, and produced about 3.6 million pounds of thrust. The test was conducted at the Promontory, Utah test facility of commercial partner Orbital ATK. Credit: NASA

It burned for exactly the same amount of time as it will during flights of the SLS booster which will lift off from Launch Complex 39B at the Kennedy Space Center in Florida.

The booster test firing was the second of two major do or die tests conducted by NASA in the past three months in support of the agency’s “Journey to Mars” strategy to develop the infrastructure required to send astronauts to an asteroid in the next decade and beyond to the Red Planet in the 2030s.

“The work being done around the country today to build SLS is laying a solid foundation for future exploration missions, and these missions will enable us to pioneer far into the solar system,” said William Gerstenmaier, NASA’s associate administrator for human exploration and operations, in a statement.

“The teams are doing tremendous work to develop what will be a national asset for human exploration and potential science missions.”

Orbital ATK’s five segment rocket motor is assembled in its Promontory, Utah, test stand where it is being conditioned for the March 11 ground test.  Credit: Orbital ATK
Orbital ATK’s five segment rocket motor is assembled in its Promontory, Utah, test stand
where it is being conditioned for the March 11 ground test. Credit: Orbital ATK

The 5-segment booster produces 3.6 million lbs of maximum thrust which equates to more than 14 Boeing 747-400s at full takeoff power!

The new 5-segment booster was derived from the 4-segment booster used during NASA’s three decade long Space Shuttle program. One segment has been added and therefore the new, longer and more powerful booster must be requalified to launch the SLS and humans.

A second test is planned a year from now and will qualify the boosters for use with the SLS.

“This test is a significant milestone for SLS and follows years of development,” said Todd May, SLS program manager.

“Our partnership with Orbital ATK and more than 500 suppliers across the country is keeping us on the path to building the most powerful rocket in the world.”

Solid rocket boosters separate from SLS core stage in this artists concept. Credit: NASA
Solid rocket boosters separate from SLS core stage in this artists concept. Credit: NASA

The QM-1 booster weighs in at 1.6 million pounds and required several month of conditioning to heat to the 90 degrees temperature required to conduct the static fire test and thereby qualify the booster design for high temperature launch conditions. It was mounted horizontally in the test stand and measured 154 feet in length and 12 feet in diameter and weighs 801 tons.

Temperatures inside the booster exceeded over 5,600 degrees F.

The static fire test was exquisitely planned to collect data on 103 design objectives as measured through more than 534 instrumentation channels on the booster as it was firing.

The second booster test in March 2016 will be conducted to qualify the propellant temperature range at the lower end of the launch conditions at 40 degrees F.

The first stage of the SLS will be powered by a pair of the five-segment boosters and four RS-25 engines that will generate a combined 8.4 million pounds of liftoff thrust.

The maiden test flight of the SLS is targeted for no later than November 2018 and will be configured in its initial 70-metric-ton (77-ton) version with a liftoff thrust of 8.4 million pounds. It will boost an unmanned Orion on an approximately three week long test flight beyond the Moon and back.

NASA plans to gradually upgrade the SLS to achieve an unprecedented lift capability of 130 metric tons (143 tons), enabling the more distant missions even farther into our solar system.
The first SLS test flight with the uncrewed Orion is called Exploration Mission-1 (EM-1) and will launch from Launch Complex 39-B at the Kennedy Space Center.

NASA’s first Orion spacecraft blasts off at 7:05 a.m. atop United Launch Alliance Delta 4 Heavy Booster at Space Launch Complex 37 (SLC-37) at Cape Canaveral Air Force Station in Florida on Dec. 5, 2014.   Launch pad remote camera view.   Credit: Ken Kremer - kenkremer.com
NASA’s first Orion spacecraft blasts off at 7:05 a.m. atop United Launch Alliance Delta 4 Heavy Booster at Space Launch Complex 37 (SLC-37) at Cape Canaveral Air Force Station in Florida on Dec. 5, 2014. Launch pad remote camera view. Credit: Ken Kremer – kenkremer.com

Orion’s inaugural mission dubbed Exploration Flight Test-1 (EFT) was successfully launched on a flawless flight on Dec. 5, 2014 atop a United Launch Alliance Delta IV Heavy rocket Space Launch Complex 37 (SLC-37) at Cape Canaveral Air Force Station in Florida.

Orion’s inaugural mission dubbed Exploration Flight Test-1 (EFT) was successfully launched on a flawless flight on Dec. 5, 2014 atop a United Launch Alliance Delta IV Heavy rocket Space Launch Complex 37 (SLC-37) at Cape Canaveral Air Force Station in Florida.

Wide view of the new welding tool at the Vertical Assembly Center at NASA’s Michoud Assembly Facility in New Orleans at a ribbon-cutting ceremony Sept. 12, 2014.  Credit: Ken Kremer – kenkremer.com
Wide view of the new welding tool at the Vertical Assembly Center at NASA’s Michoud Assembly Facility in New Orleans at a ribbon-cutting ceremony Sept. 12, 2014. Credit: Ken Kremer – kenkremer.com

Stay tuned here for Ken’s continuing Earth and Planetary science and human spaceflight news.

Ken Kremer
. ………….

Learn more about MMS, Mars rovers, Orion, SpaceX, Antares, NASA missions and more at Ken’s upcoming outreach events:

Mar 11: “MMS, Orion, SpaceX, Antares, Curiosity Explores Mars,” Kennedy Space Center Quality Inn, Titusville, FL, evenings

World’s Most Powerful Solid Booster Set for Space Launch System Test Firing on March 11

Orbital ATK’s five segment rocket motor is assembled in its Promontory, Utah, test stand where it is being conditioned for the March 11 ground test. Credit: Orbital ATK

All systems are go for the inaugural ground test firing on March 11 of the world’s most powerful solid rocket booster ever built that will one day power NASA’s mammoth new Space Launch System (SLS) heavy lift rocket and propel astronauts to deep space destinations.

The booster known as qualification motor, QM-1, is the largest solid rocket motor ever built and will be ignited on March 11 for a full duration static fire test by prime contractor Orbital ATK at the newly merged firms test facility in Promontory, Utah.

Ignition of the horizontally mounted motor is planned for 11:30 a.m. EDT (9:30 a.m. MDT) on Wednesday, March 11 on the T-97 test stand.

The test will be broadcast live on NASA TV.

Engineers at Orbital ATK in Promontory, Utah, prepare to test the booster that will help power NASA’s Space Launch System to space to begin missions to deep space, including to an asteroid and Mars. A test on March 11 is one of two that will qualify the booster for flight.  Image Credit:  Orbital ATK
Engineers at Orbital ATK in Promontory, Utah, prepare to test the booster that will help power NASA’s Space Launch System to space to begin missions to deep space, including to an asteroid and Mars. A test on March 11 is one of two that will qualify the booster for flight. Image Credit: Orbital ATK

The two minute long, full duration static test firing of the motor marks a major milestone in the ongoing development of NASA’s SLS booster, which is the most powerful rocket ever built in human history.

The 5-segment booster produces 3.6 million lbs of maximum thrust which equates to more than 14 Boeing 747-400s at full takeoff power!

The new 5-segment booster is directly derived from the 4-segment booster used during NASA’s three decade long Space Shuttle program. One segment has been added and therefore the new, longer and more powerful booster must be requalified to launch the SLS and humans.

A second test is planned a year from now and will qualify the boosters for use with the SLS.

Teams of engineers, operators, inspectors and program managers across Orbital ATK’s Flight Systems Group have spent months getting ready for the QM-1 test. To prepare they started countdown tests on Feb 25.

“The crew officially starts daily countdown test runs of the systems this week, at T-15 days,” said Kevin Rees, director, Test & Research Operations at Orbital ATK.

“These checks, along with other test stand calibrations, will verify all systems are ready for the static test. Our team is prepared and we are proud to play such a significant role on this program.”

The first qualification motor for NASA's Space Launch System's booster is installed in ATK's test stand in Utah and is ready for a March 11 static-fire test.   Credit:  ATK
The first qualification motor for NASA’s Space Launch System’s booster is installed in ATK’s test stand in Utah and is ready for a March 11 static-fire test. Credit: ATK

The QM-1 booster is being conditioned to 90 degrees and the static fire test will qualify the booster design for high temperature launch conditions. It sits horizontally in the test stand and measures 154 feet in length and 12 feet in diameter and weighs 801 tons.

The static fire test will collect data on 103 design objectives as measured through more than 534 instrumentation channels on the booster it is firing.

The second booster test in March 2016 will be conducted at lower temperature to qualify the lower end of the launch conditions at 40 degrees F.

The first stage of the SLS will be powered by a pair of the five-segment boosters and four RS-25 engines that will generate a combined 8.4 million pounds of liftoff thrust.

The SLS is designed to propel the Orion crew capsule to deep space destinations, including the Moon, asteroids and the Red Planet.

The maiden test flight of the SLS is targeted for no later than November 2018 and will be configured in its initial 70-metric-ton (77-ton) version with a liftoff thrust of 8.4 million pounds. It will boost an unmanned Orion on an approximately three week long test flight beyond the Moon and back.

NASA plans to gradually upgrade the SLS to achieve an unprecedented lift capability of 130 metric tons (143 tons), enabling the more distant missions even farther into our solar system.

The first SLS test flight with the uncrewed Orion is called Exploration Mission-1 (EM-1) and will launch from Launch Complex 39-B at the Kennedy Space Center.

Solid rocket boosters separate from SLS core stage in this artists concept. Credit: NASA
Solid rocket boosters separate from SLS core stage in this artists concept. Credit: NASA

Orion’s inaugural mission dubbed Exploration Flight Test-1 (EFT) was successfully launched on a flawless flight on Dec. 5, 2014 atop a United Launch Alliance Delta IV Heavy rocket Space Launch Complex 37 (SLC-37) at Cape Canaveral Air Force Station in Florida.

Orion’s inaugural mission dubbed Exploration Flight Test-1 (EFT) was successfully launched on a flawless flight on Dec. 5, 2014 atop a United Launch Alliance Delta IV Heavy rocket Space Launch Complex 37 (SLC-37) at Cape Canaveral Air Force Station in Florida.

NASA’s first Orion spacecraft blasts off at 7:05 a.m. atop United Launch Alliance Delta 4 Heavy Booster at Space Launch Complex 37 (SLC-37) at Cape Canaveral Air Force Station in Florida on Dec. 5, 2014.   Launch pad remote camera view.   Credit: Ken Kremer - kenkremer.com
NASA’s first Orion spacecraft blasts off at 7:05 a.m. atop United Launch Alliance Delta 4 Heavy Booster at Space Launch Complex 37 (SLC-37) at Cape Canaveral Air Force Station in Florida on Dec. 5, 2014. Launch pad remote camera view. Credit: Ken Kremer – kenkremer.com

Stay tuned here for Ken’s continuing Earth and Planetary science and human spaceflight news.

Ken Kremer

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Learn more about MMS, Mars rovers, Orion, SpaceX, Antares, NASA missions and more at Ken’s upcoming outreach events:

Mar 9-11: “MMS, Orion, SpaceX, Antares, Curiosity Explores Mars,” Kennedy Space Center Quality Inn, Titusville, FL, evenings

NASA Administrator Charles Bolden officially unveils world’s largest welder to start construction of core stage of NASA's Space Launch System (SLS) rocket at NASA Michoud Assembly Facility, New Orleans, on Sept. 12, 2014. SLS will be the world’s most powerful rocket ever built.  Credit: Ken Kremer - kenkremer.com
NASA Administrator Charles Bolden officially unveils world’s largest welder to start construction of core stage of NASA’s Space Launch System (SLS) rocket at NASA Michoud Assembly Facility, New Orleans, on Sept. 12, 2014. SLS will be the world’s most powerful rocket ever built. Credit: Ken Kremer – kenkremer.com