Posted on by Nancy Atkinson

November 2016 Super Moon Images from Around the World

Moonrise over the London, as see from Waterloo Bridge on Nov. 13, 2016. Credit and copyright: Owen Llewellyn.

Now updated with more great images!

Although there’s been quite a bit of hype about the Super Moon on November 13, 2016, to many, the full Moon tonight may have appeared quite similar to other full Moon’s you’ve seen. Yes, the “super-ness” of this Moon, while noteworthy, is fairly imperceptible. While, as our own David Dickinson noted in his preview article, this full Moon is not only the closest for the year, but the nearest Full Moon for a 80 year plus span. However, the closest full moon of 2017 will be only 0.02% farther away than this one.

But any chance to get the public to look up at the night sky is a good one! And we’ll also take this opportunity to share some of the great images from around the world posted on Universe Today’s Flickr page, as well as on social media. Enjoy!

Here’s a “classic” but gorgeous look at the Moon:

The Moon just before full on November 13, 2016 imaged through cloud from London. Credit and copyright: Roger Hutchinson.
The Moon just before full on November 13, 2016 imaged through cloud from London. Credit and copyright: Roger Hutchinson.
Supermoon over Glastonbury Tor, Somerset, England on Nov. 13, 2016. Credit and copyright: Tim Graham/TJG Photography.
Supermoon over Glastonbury Tor, Somerset, England on Nov. 13, 2016. Credit and copyright: Tim Graham/TJG Photography.
Some astrophotographers took this opportunity to take close-ups of the Moon's surface. Pythagoras and Babbage Craters are seen here in this image from the UK on Nov. 13, 2016. Credit and copyright: Alun Halsey.
Some astrophotographers took this opportunity to take close-ups of the Moon’s surface. Pythagoras and Babbage Craters are seen here in this image from the UK on Nov. 13, 2016. Credit and copyright:
Alun Halsey.
The 'Super Moon' over Rome on November 14, 2016. Credit and copyright: Gianluca Masi.
The ‘Super Moon’ over Rome on November 14, 2016. Credit and copyright: Gianluca Masi.
A view of the supermoon as seen from Lahore, Pakistan, with color added for contrast. Credit and copyright: Roshaan Bukhari.
A view of the supermoon as seen from Lahore, Pakistan, with color added for contrast. Credit and copyright: Roshaan Bukhari.
Moon and clouds as seen from the UK on Nov. 13, 2016. Credit and copyright: Sculptor Lil on Flickr.
Moon and clouds as seen from the UK on Nov. 13, 2016. Credit and copyright: Sculptor Lil on Flickr.

Pale Moon rising, as seen from North Bedfordshire, UK on Nov. 13, 2016. Credit and copyright: Dawn Sunrise on Flickr.
Pale Moon rising, as seen from North Bedfordshire, UK on Nov. 13, 2016. Credit and copyright: Dawn Sunrise on Flickr.

Noted NASA photographer Bill Ingalls is in Russia for the next launch of astronauts to the International Space Station. He took this image from Baikonur, Kazakhstan and also provided some tips on photographing the Moon.

And former astronaut Clayton Anderson shared this images from Houson, Texas:

Moonrise near Keene, Ontario on November 13, 2016. Credit and copyright: Rick Stankiewicz.
Moonrise near Keene, Ontario on November 13, 2016. Credit and copyright: Rick Stankiewicz.

A comparison of ‘super’ and ‘mini’ Moons and how they appear in the sky:

A perigee 'Supermoon' versus an apogee 'Minimoon'. Image credit and copyright: Raven Yu.
A perigee ‘Supermoon’ versus an apogee ‘Minimoon’. Image credit and copyright: Raven Yu.

Thanks to everyone for sharing their images, and be sure to check out UT’s Flickr pool for the most recent shots.

Link to the lead image by Owen Llewellyn can be found here.

Posted on by David Dickinson

November’s Supermoon 2016 – Closest of a Lifetime?

The 2015 Supermoon. Image credit and copyright: Wils 888.

What’s that, rising in the sky?

By now, you’ve heard the news. We’ll spare you the “it’s a bird, it’s a plane…” routine to usher in the Supermoon 2016. This month’s Full Moon is not only the closest for the year, but the nearest Full Moon for a 80 year plus span.

Like Blue and Black Moons, a Supermoon is more of a cultural phenomenon than a true astronomical event. The Moon’s orbit is elliptical, taking it from 362,600 to 405,400 km from the Earth in the course of its 27.55 day anomalistic orbit from one perigee to the next. For the purposes of this week’s discussion, we consider a Supermoon as when the Full Moon occurs within 24 hours of perigee, and a Minimoon as when the Full Moon occurs within 24 hours of apogee. From the Earth, the Moon varies in apparent size from 29.3” to 34.1” across. This month, the Moon reaches perigee on November 14th at 356,511 kilometers distant, 2 hours and 22 minutes before Full.

A perigee 'Supermoon' versus an apogee 'Minimoon'. Image credit and copyright: Raven Yu.
A perigee ‘Supermoon’ versus an apogee ‘Minimoon’. Image credit and copyright: Raven Yu.

This is the closest perigee Moon for 2016, beating out the April 7th, 2016 perigee Moon by just 652 kilometers. Perigee can vary over a span of 2,800 kilometers. In the 21st century, the farthest lunar perigee (think the ‘most distant near point’) occurs on January 3rd, 2100 at 370,356 kilometers distant, while the closest perigee of the century (356,425 kilometers) occurs on December 6th , 2052.

When the Moon reaches Full on November 14th at 13:51 UT, it’s just 356,520 kilometers distant, (that is , as measured from the Earth’s center) the closest Full Moon since January 26th, 1948 (356,490 km) and until November 25th , 2034 (356,446 km) losing out to either dates by just 21 kilometers.

Why does perigee vary? Well, as the Moon orbits the Earth, the Sun tugs our large natural satellite’s orbit around as well, in an 8.85 year cycle known as the precession of the line of apsides. Earth’s orbit is elliptical as well, and the tugging of the Sun (and to a much lesser degree, the other planets in the solar system) alters the perigee and apogee points slightly based on where the Earth-Moon pair fall in their swing about a common barycenter.

The November Full Moon is also known as the Full Beaver Moon by the Algonquin Native Americans, a good time to ensure a supply of winter furs before the swamps froze over. A good sign that even in 2016, ‘Winter is Coming.’

Does the Moon look any larger to you than usual as it rises to the east opposite to the setting Sun on Monday night? When the Moon reaches Full, it passes the zenith as seen from the central Indian Ocean region just south of Sri Lanka, 354,416 km distant. Of course, as the Moon rises, it’s actually one full Earth radii more distant than when straight overhead at the zenith.

A side-by-side 'Super' vs 'Minimoon.' Image credit and copyright: Marco Langbroek.
A side-by-side ‘Super’ vs ‘Minimoon.’ Image credit and copyright: Marco Langbroek.

Would you notice any difference in the size of the November Full Moon, if you didn’t know better? The 4′ odd difference between an apogee and perigee Full Moon is certainly discernible in side-by-side images… but it’s interesting to note that early cultures did not uncover the elliptical nature of the Moon’s motion, though it certainly would have been possible. Crystalline spheres ruled the day, a sort of perfection that was just tough to break in the minds of many.

Be sure to enjoy the rising Full Moon on Monday night, the largest for many years to come.

Posted on by Nancy Atkinson

Some Of The Deepest & Sharpest Shots of The Moon from Earth

An incredibly sharp image of Copernicus Crater on the Moon, as seen from the Alps. Credit and copyright: Thierry Legault. Used by permission.

Who doesn’t love to gaze at the Moon on a clear night? But astrophotographer Thierry Legault now taken Moon-gazing to new heights. Legault traveled to the Alps in August and set up his Celestron C14 Edge HD and ZWO ASI1600MM camera. The results are absolutely stunning.

“These are the largest and sharpest quarters ever,” Legault said via email, adding that he created mosaic images of 10 fields for a definition of 150 million pixels!

Above you can see incredible detail in the 58 mile-wide (93 km) impact crater Copernicus.

Below is a lunar quarter taken on August 24, 2016:

Image of the Moon taken on August 24, 2016 from the Alps. Credit and copyright: Thierry Legault. Used by permission.
Image of the Moon taken on August 24, 2016 from the Alps. Credit and copyright: Thierry Legault. Used by permission.

Legault has been known to travel wherever it takes to get the best shots, for example traveling through Germany, France and Spain to capture shots of space shuttle Endeavour on its final mission, or finding the best locations for stunning and sometimes ground-breaking shots of the International Space Station crossing the Sun or Moon, or views of spy satellites in orbit.

In his book, “Astrophotography,” Legault said that for clear close-ups of the Moon, good atmospheric conditions are a must, as well as having a finely tuned or collimated telescope. Below is a close-up view of Triesnecker crater and the surrounding region near the central part of the Moon’s near side, including sharp view of the rilles.

Triesnecker crater in the central part of the Moon's near side is 26 km in diameter and 2.7 km deep. A system of rilles can also be seen. Credit and copyright: Thierry Legault. Used by permission.
Triesnecker crater in the central part of the Moon’s near side is 26 km in diameter and 2.7 km deep. A system of rilles can also be seen. Credit and copyright: Thierry Legault. Used by permission.

For processing these images Legault used AutoStakkert!2 (AS!2), PTGui stitching software and Photoshop.

You can see more of these stunning shots at Legault’s website, where he says he’ll have posters of these images available soon.

Of course, you can try seeing these features on the Moon yourself. Even binoculars or a small telescope can provide wonderful views of our closest companion in space. An upcoming full Moon (Super Moon!) on November 14, 2016, will feature the closest full Moon (356,509 kilometers away) until November 25, 2034 (356,448 kilometers away.)

Our thanks to Thierry Legault for sharing these wonderful new images of the Moon!

Posted on by Bob King

November Opens with a Splendid Gathering of Moon and Planets

Crescent Moon and flag. Credit: Bob King
Look how pretty. This will be the scene from your yard, apartment window or driving west along the freeway Tuesday evening about 45 minutes after sundown. Saturn and the Moon will be in conjunction about 3 degrees apart with Venus 6 degrees to the southeast of the crescent. Source: Stellarium
Look how pretty. This will be the scene from your yard, apartment window or driving west along a freeway Tuesday evening about 45 minutes after sundown. Saturn and the Moon will be in conjunction about 3 degrees apart with Venus 6 degrees to the southeast of the crescent. Source: Stellarium

I love easy and bright. While I often spend time seeking faint nebulae and wandering comets, there’s nothing like just looking up and seeing a beautiful scene aglow in the night sky. No binoculars or telescope needed. That’s exactly what will happen Tuesday November 2, when an attractive crescent Moon will join Saturn and Venus at dusk in the southwestern sky.

The supermoon of March 19, 2011 (right), compared to an average moon of December 20, 2010 (left). Note the size difference. Image Credit: Marco Langbroek, the Netherlands, via Wikimedia Commons.
The Supermoon of March 19, 2011 (right), compared to an average moon of December 20, 2010 (left). November’s Supermoon will be 14% bigger and 30% brighter than a regular Full Moon. Credit: Marco Langbroek / Wikimedia Commons

What a fine threesome they’ll make: Venus the white-hot spark shining at magnitude –4.0; Saturn a mellow magnitude +0.5, some 20 times fainter and the Moon a fingernail crescent above them both. The Moon will be  just two days past apogee, the furthest point in its orbit from Earth. Does it look a little smaller than the usual crescent? If you’re a keen watcher of crescents, you just might notice the difference.

In less than two weeks, on November 14,  the crescent will have waxed to full, swung around to the opposite end of its orbit, where it will be at perigee, its closest point to Earth. When a Full Moon occurs at perigee, we call it a Supermoon because it’s closer and correspondingly bigger and brighter than a typical Full Moon.

For a variety of reasons, the November Supermoon will come exceptionally close to Earth, the closest one in 70 years as a matter of fact. The last time Earth and Moon embraced each other so tightly was January 26, 1948, the year baseball great Babe Ruth died. But I’m getting ahead of myself. We’ll have much more on the Supermoon soon!

This photo shows the contrast between the bright, sunlit crescent and the ghostly earth-lit Moon. Several prominent craters are identified. Credit: Bob King
This photo shows the contrast between the bright, sunlit crescent and the ghostly earth-lit Moon. Several prominent craters are identified. Credit: Bob King

Tuesday night you have the pleasure of an eye-catching crescent filled with darkly luminous earthshine, sunlight reflected off our jolly blue and white globe into space that reflects from the Moon and back to Earth. Being twice reflected, the returning light is feeble, giving the Moon a haunted look.

The phases of the Moon and Earth are complementary; when one's a crescent, the other's nearly full. Credit: Bob King, Source: Stellarium
The phases of the Moon and Earth are complementary; when one’s a crescent, the other’s nearly full. Credit: Bob King, Source: Stellarium

Crescent phase is when earthshine is brightest. Why? Phases of Earth and Moon are complementary — when we see a crescent, an astronaut on the Moon would look back to see a nearly Full Earth in the sky. As you’ve already guessed, a Full Earth reflects a great deal more light than a half or crescent. Be sure to point your binoculars at the earth-lit Moon; the contrast of dusky earthlight adjacent to the sunlit crescent gives the scene a striking 3D look.

And if your glass can magnify ten times or more, you’ll get a sneak preview of several of the dark lunar seas or maria in the smoky light. Seas that will by and by ease into sunlight as the lunar terminator, the line separating day from night, rolls ever westward.

Through a small telescope, Venus appears three-quarters full in waning gibbous phase. Saturn's rings are still tipped wide open, and it's brightest moon, Titan, should be easy to spot Tuesday night in a small telescope. Source: Stellarium
Through a small telescope, Venus appears three-quarters full in waning gibbous phase. Saturn’s rings are still tipped wide open, and its brightest moon, Titan, should be easy to spot Tuesday night in a small telescope. Appearances are shown for Nov. 2. North is up and west to the right. Source: Stellarium

Have a small telescope? This may be one of your last easy chances at seeing the planet Saturn before it’s gobbled up by the western horizon. The ringed one has been sinking westward the past couple months and will soon be in conjunction with the Sun. I hate to see a good planet go, that’s why I’m happy to share that Venus will be with us a long, long time. Watch for this most brilliant of planets to rise higher in the southwestern sky as we approach Christmas and then swing to the north through early winter before dropping out of the evening sky in March 2017.

Thank you Venus for lighting our path on the snowy nights that lie ahead!

*** If you’d like learn more about how to find the planets, check out my new book, Night Sky with the Naked Eye. It covers all the wonderful things you can see in the night sky without special equipment. The book publishes on Nov. 8, but you can pre-order it right now at these online stores. Just click an icon to go to the site of your choice – Amazon, Barnes & Noble or Indiebound. It’s currently available at the first two outlets for a very nice discount:

night-sky-book-cover-amazon-anno-150x150night-sky-book-cover-bn-150x150night-sky-book-cover-indie-150x150

Posted on by David Dickinson

Boo! A Black Moon Halloween Weekend

Black Moon
A razor thin Moon from October 22nd, 2014. Image credit and copyright: David Blanchflower.

This Halloween weekend’s top astronomical event features something that you won’t see in the sky.

By now, you’ve probably seen the stories circulating ’round ye ole web about how this month features a ‘Black Moon.’ The internet seems to love promulgating the passing of such curious calendrical oddities as Moons both Black, Blue and otherwise.

What’s all of the hoopla about? Well, simply put, the Moon reaches New phase this weekend on October 30th at 17:38 Universal Time (UT), marking the start of lunation 1161. This is the second New Moon for the month, as the first fell on October 1st, just 11 minutes into the month as reckoned in Universal Time.

Now, this isn’t at all rare or unusual; the synodic period of the Moon (that is, the time it takes to return to a similar phase, such as New back to New) is 29.5 days long, a period that shoehorns well in to a 31 day month like October, or occasionally, a 30 day month.

More Fun With Calendars

February is the only month that cannot contain a ‘repeat phase,’ leap year or no. Occasionally, a given phase such as New or Full can be absent from short February all together… sometimes, this oddity is also sometimes referred to as a ‘Black Moon.’ 2014 and 2033 are the nearest years to 2016 that are missing New Moons in February.

And then there’s the relict definition of a Blue Moon as the ‘3rd in an astronomical season with 4…‘ that can also be ascribed to a Black Moon as relates to New phase, as if we already lack enough multi-hued Moons in or lives.

Keep in mind, the moment of New is but an instant, a point a which the Moon’s longitude along the ecliptic plane equals the Sun’s. The Moon makes a miss of the Sun on most lunations, and only directly passes between the Sun and the Earth during an annular or solar eclipse. We’ve got one each coming up in 2017: an annular solar eclipse crossing the southern tip of South America on February 26th, and the historic return of totality to the United States on August 21st, 2017.

Said high profile solar eclipse next August also has a lesser role, as it fits that old-timey definition of the 3rd New Moon in an astronomical season with four. Of course, this is only the juxtaposition of the lunar cycle on our current Gregorian calendar, using time reckoned in UT/GMT.

Don’t fear the Black Moon. This year’s New Moon just misses Halloween. The next New Moon on Halloween (which, of course, is always a ‘Black Moon’) occurs in 2035.

The view looking eastward on the morning of Friday, October 28th. Image credit: Stellarium
The view looking eastward on the morning of Friday, October 28th. Image credit: Stellarium

And we’ll let you in on a secret: astronomers don’t spend nights in mountaintop observatories discussing Black or Blue Moons… the term has more of an astrological tinge to it. Even in amateur astronomy circles, you sometimes hear the term ‘the dark of the Moon’ used to refer to the weeks surrounding New Moon, a prime time for deep sky astrophotography.

Looking for a New Moon-related observing challenge? Spotting the razor thin waxing or waning Moon is a fun feat of visual athletics. Look for a thin waning crescent Moon hanging near Jupiter on the morning of Friday, October 28th. This weekend, the first shot at catching the uber-thin Moon occurs for observers along a curve from southeastern Asia at dusk on October 31st westward at dusk. For Spain (and Astroguyz basecamp) the Moon will be 24 hours past New, and for the United States, the Moon will be 28 to 32 hours old at sunset for roaming Halloween ghouls and goblins, an easy catch.

First sighting opportunities for the waxing crescent Moon on Halloween evening. Graphic created by the author.
First sighting opportunities for the waxing crescent Moon on Halloween evening. Graphic created by the author.

A time change is also afoot this weekend, as folks in Europe and the UK ‘fall back’ one hour to standard time. This setback falls nearly as late as it can in 2016, and we now enter that wacky oneeek period where the world slowly slips back to standard time. Blame ‘Big Sugar’ for the latency in most of North America, as prospective trick-or-treaters now make their rounds during daylight hours. In most of the US and Canada, the switch occurs on Sunday, November 6th.

And there’s one more astronomical tie-in for Halloween: the holiday traces its roots back as one of the four cross-quarter days of yore, including Lammas Day, Groundhog Day, and May Day. Of course, the fixing of Hallow’s Eve on October 31st makes the midway date only approximate: in 2016, the actual mid-point occurs on November 10th.

Out of this world stuff to consider, as you inventory the night’s sugary bounty and contemplate the night sky.

Posted on by David Dickinson

Photobomb: The Moon Occults Aldebaran Wednesday

An occultation of Aldebaran by the Moon: before and after. Image credit and copyright: Eliot Herman.

How about that Hunter’s Supermoon this past weekend, huh? Follow that Moon, as it’s meeting up with the Hyades again this week, and occults (passes in front of) Aldebaran Tuesday night into Wednesday morning.

Here’s the lowdown on the event:

The 86% illuminated waning gibbous Moon occults the +0.9 magnitude star Aldebaran across North America, the Northern Atlantic and Europe. The Moon is three days past Full during the event. Both are located 136 degrees west of the Sun at the time of the event. The central time of conjunction is ~6:40 Universal Time (UT). The event occurs during the daylight hours over western Europe and northwestern Africa and under darkness for southeastern North America, including the eastern United States and Mexico. The Moon will next occult Aldebaran on November 15th, 2016. This is occultation 24 in the current series of 49 running from January 29th, 2015 to September 3rd 2018.

The occultation of Aldebaran by the Moon as seen from London on December 23rd, 2015. Image credit and copyright: Roger Hutchinson.
The occultation of Aldebaran by the Moon as seen from London on December 23rd, 2015. Image credit and copyright: Roger Hutchinson.

The graze line is of particular interest during this event. We’re talking about the very edge of the footprint of the Moon’s ‘shadow’ cast by Aldebaran, running through Canada and bisecting the United States. Observers based along this line could see a spectacular ‘grazing occultation’ of Aldebaran by the Moon. We usually think of the limb of the Moon as a smooth curve, but it’s actually jagged. What you may see is Aldebaran wink in and out as light shines down those lunar valleys and is alternately blocked out behind peaks and crater rims. This is an unforgettable sight, and makes for great video. A record of a grazing occultation by multiple observers can also be used to create a profile of the lunar limb. That light from Aldebaran took 65 years to get here, only to be blocked by our Moon at the very last second.

The occultation footpring for tonight's event. The solid lines denote where the occultation occurs under dark night time skies, while the blue lines denote twilight and the broken lines describe where the event occurs in the daytime. Image credit: Occult 4.2.
The occultation footprint for tonight’s event. The solid lines denote where the occultation occurs under dark nighttime skies, while the blue lines denote twilight, and the broken lines describe where the event occurs in the daytime. Image credit: Occult 4.2.

And observers (myself one of them) based in Europe shouldn’t count themselves out. Like brighter planets, you can spy a +1 magnitude star such as Aldebaran near the daytime Moon using binoculars or a telescope… if, of course, you have a high contrast deep blue sky and know exactly where to look for it. The International Occultation Timing Association has a page for the event with a complete list of ingress and egress times for key cities on three continents in the path. We’ll be watching the Wednesday event – clear skies willing — from our present basecamp in the Andalusian foothills just outside of Jimena de la Frontera, Spain.

The northern graze line for tonight's occultation. Note that several major cities lie along the crucial path. Image credit: Dave Dickinson.
The northern graze line for tonight’s occultation. Note that several major cities lie along the crucial path. Image credit: Dave Dickinson.

During our current epoch, the Moon can only occult four +1st magnitude stars: Regulus, Spica, Antares and Aldebaran. The slow motion movement of the Moon, the Earth and the background stars make this prestigious A-list change over time: until about two millennia ago, you could also count the bright star Pollux in Gemini among them.

In the current century, (2001-2100 AD) the Moon occults Aldebaran 247 times, topped only by Antares (386 times) and barely beating out Spica (220 times).

Timing an occultation is fun and as easy as shooting video of the Moon through a telescope at the appointed time of ingress or egress. Practice on framing the dazzling Moon first well in advance — probably the toughest part is getting the exposure of the bright limb stopped down enough to still see and image the star. We find that shooting anywhere from 1/100th to 1/500th frame rate for a gibbous Moon is about right. Don’t be afraid to crank up the magnification a bit, so you can place the bulk of the Moon out of view. Also, catching occultations of stars and planets during waning Moon phases are more challenging than waxing, as the star will ingress behind the bright leading limb and later reappear behind the dark trailing limb (waxing is vice versa).

Observing: Running an audible time hack in the background such as WWV radio out of Fort Collins, Colorado can provide a precise record of the occultation.

But wait, there’s more. When the Moon occults Aldebaran, its also crossing the background V-shaped open star cluster known as the Hyades. Worldwide the waning gibbous Moon also occults Gamma, 51, and Theta^1 and Theta^2, SAO 93975, and 119 Tauri. Chances are, there’s an occultation for YOU to catch this week, regardless of your location.

Want more? Well, the Moon continues to occult Aldebaran every lunation through 2017, and will also start a cycle of passes in front of Regulus on December 18th. In fact, the next occultation of Aldebaran on November 15th favors central Asia, and the event two lunations from now on December 13th brings the path back around the North America.

A great close out for 2016, for sure. Don’t miss this week’s occultation!

Posted on by Bob King

The Moon Is Getting Slammed Way More Than We Thought

A brand new crater on the Moon! This new 12 meter (39 foot) diameter impact crater formed between 25 October 2012 and 21 April 2013 Credit: NASA/GSFC/Arizona State University].
Animation of a temporal pair of the new 39-foot (12-meter) impact crater on the moon photographed by NASA's Lunar Reconnaissance Orbiter Credit: NASA/GSFC/Arizona State University
Animation of a temporal pair of the new 39-foot (12-meter) impact crater on the moon photographed by NASA’s Lunar Reconnaissance Orbiter Credit: NASA/GSFC/Arizona State University

We often hear how the Moon’s appearance hasn’t changed in millions or even billions of years. While micrometeorites, cosmic rays and the solar wind slowly grind down lunar rocks, the Moon lacks erosional processes such as water, wind and lurching tectonic plates that can get the job done in a hurry.

After taking the first boot print photo, Aldrin moved closer to the little rock and took this second shot. The dusty, sandy pebbly soil is also known as the lunar ‘regolith’. Click to enlarge. Credit: NASA
One of a series of photos Apollo 11 astronaut Edwin Aldrin made of his bootprint in the dusty, sandy lunar soil, called regolith. Based on a newy study, the impression may disappear in a few tens of thousands of years instead a few million. Credit: NASA

Remember Buzz Aldrin’s photo of his boot print in the lunar regolith? It was thought the impression would last up to 2 million years. Now it seems that estimate may have to be revised based on photos taken by the Lunar Reconnaissance Orbiter (LRO) that reveal that impacts are transforming the surface much faster than previously thought.

Distribution of new impact craters (yellow dots) discovered by analyzing 14,000 NAC temporal pairs. The two red dots mark the location of the 17 March 2013 and the 11 September 2013 impacts that were recorded by Earth-based video monitoring [NASA/GSFC/Arizona State University]
This map shows the distribution of new impact craters (yellow dots) discovered by analyzing 14,000 narrow-angle camera (NAC) temporal pairs. The two red dots mark the location of the March 17, 2013 and September 11, 2013 impacts that were recorded by Earth-based video monitoring. LRO’s mission was recently extended an addition two years through September 2018. Credit: NASA/GSFC/ASU
The LRO’s high resolution camera, which can resolve features down to about 3 feet (1-meter) across, has been peering down at the Moon from orbit since 2009. Taking before and after images, called temporal pairs, scientists have identified 222 impact craters that formed over the past 7 years. The new craters range from 10 feet up to 141 feet (3-43 meters) in diameter.

By analyzing the number of new craters and their size, and the time between each temporal pair, a team of scientists from Arizona State University and Cornell estimated the current cratering rate on the Moon. The result, published in Nature this week, was unexpected: 33% more new craters with diameters of at least 30 feet (10 meters) were found than anticipated by previous cratering models.

their brightest recorded flash occurred on 17 March 2013 with coordinates 20.7135°N, 335.6698°E. Since then LRO passed over the flash site and the NAC imaged the surrounding area; a new 18 meter (59 feet) diameter crater was found by comparing images taken before and after the March date.
LRO before and after images of an impact event on March 17, 2013. The newly formed crater is 59 feet (18 meters) in diameter. Subsurface regolith not exposed to sunlight forms a bright halo around the new crater. There also appears to be a larger nimbus of darker reflectance material visible much further beyond but centered on the impact. Credit: NASA/GSFC/Arizona State University

Similar to the crater that appeared on March 17, 2013 (above), the team also found that new impacts are surrounded by light and dark reflectance patterns related to material ejected during crater formation. Many of the larger impact craters show up to four distinct bright or dark reflectance zones. Nearest to the impact site, there are usually zone of both high and low reflectance.  These two zones likely formed as a layer of material that was ejected from the crater during the impact shot outward to about 2½ crater diameters from the rim.

An artist's illustration of a meteoroid impact on the Moon. (Credit: NASA).
An artist’s illustration of a meteoroid impact on the Moon. Impacts dig up fresh material from below as well as send waves of hot rock vapor and molten rock across the lunar landscape, causing a much faster turnover of the moon soil than previously thought. Credit: NASA

From analyzing multiple impact sites, far flung ejecta patterns wrap around small obstacles like hills and crater rims, indicating the material was traveling nearly parallel to the ground. This kind of path is only possible if the material was ejected at very high speed around 10 miles per second or 36,000 miles per hour! The jet contains vaporized and molten rock that disturb the upper layer of lunar regolith, modifying its reflectance properties.


How LRO creates temporal pairs and scientists use them to discover changes on the moon’s surface.

In addition to discovering impact craters and their fascinating ejecta patterns, the scientists also observed a large number of small surface changes they call ‘splotches’ most likely caused by small, secondary impacts. Dense clusters of these splotches are found around new impact sites suggesting they may be secondary surface changes caused by material thrown out from a nearby primary impact. From 14,000 temporal pairs, the group identified over 47,000 splotches so far.

Example of a low reflectance (top) and high reflectance (bottom) splotch created either by a small impactor or more likely from secondary ejecta. In either case, the top few centimeters of the regolith (soil) was churned [NASA/GSFC/Arizona State University].
Here are two examples of a low reflectance (top) and high reflectance (bottom) splotch created either by a small impactor or more likely from secondary ejecta. In either case, the top few inches of the regolith (soil) was churned Credit: NASA/GSFC/Arizona State University
Based on estimates of size, depth and frequency of formation, the group estimated that the relentless churning caused by meteoroid impacts will turn over 99% of the lunar surface after about 81,000 years. Keep in mind, we’re talking about the upper regolith, not whole craters and mountain ranges. That’s more than 100 times faster than previous models that only took micrometeorites into account. Instead of millions of years for those astronaut boot prints and rover tracks to disappear, it now appears that they’ll be wiped clean in just tens of thousands!

Posted on by David Dickinson

This Weekend: A Hunter’s Full Moon Kicks Off Supermoon Season

The #MemoriesInDNA project intends to create an archive of human knowledge which will be sent to the Moon. Credit and copyright: John Brimacombe.

Ready for some lunar action of proxigean proportions? This weekend’s Full Moon ushers in that most (infamous?) of internet ready cultural memes: that of the Supermoon. This moniker stands above the Blood, Mini, and Full Moons both Black and Blue as the Full Moon of the year that folks can’t seem to get enough of, and astronomers love to hate.

But wait a minute: is this weekend’s Full Moon really the closest of the year?

Nope, though it’s close. But this month’s Full Moon does, however, usher in what we like to call Supermoon season.

Let us explain.

First, we’ll let you in on the Supermoon’s not so secret history. Yes, the meme arose over the last few decades, mostly due to the dastardly deeds of astrologers. Y’know, that well meaning friend/coworker/relative/anonymous person on Twitter that constantly mistakes your passion for the night sky as ‘astrology.’ Anyhow, the idea of the Supermoon has gained new life via the internet, and loosely translates as the closest Full Moon of the year. Sometimes, its dressed up with the slightly science-y sounding ‘a Full Moon along the closest 90% of its orbit’ (!) definition.

Now, to know the orbit of the Moon is to understand celestial mechanics. The Moon’s orbit is indeed elliptical, ranging from an average perigee (its closest point to the Earth) of 362,600 kilometers, to an apogee of 405,400 kilometers distant.

Fun fact: the time it takes the Moon to go from one perigee to the next (27.55 days) is one anomalistic month, a fine pedantic point to bring up to said relative/coworker the next time they refer to you as an astrologer.

And yes, the perigee Full Moon is a thing. We even like to throw about the quixotic term of the proxigean Moon, a time when tidal variations are at an extreme. Plus, all perigees are not created equal, but range from 356,400 kilometers to 370,400 kilometers distant, as the Earth-Moon system not only swings around its common barycenter, but the Sun also drags the entire orbit of the Moon around the Earth, completing one complete revolution every 8.85 years in what’s known as the precession of the line of apsides. Note that the nodes of the Moon’s orbit actually move in the opposite direction, with an 18.6 year period.

The complex motion of the Moon. Image credit: Wikimedia Commons/Geologician/Homunculus2.
The complex motion of the Moon. Image credit: Wikimedia Commons/Geologician/Homunculus2.

Yup, the motion of the Moon has given humanity a fine study in Celestial Mechanics 101. Anyhow, we contend that a more succinct definition for a perigee ‘Supermoon’ is simply a Full Moon that falls within 24 hours of perigee. Under this definition, the Full Moon this Sunday on October 16th occurring at 4:23 Universal Time (UT) certainly meets the criterion, occurring 19 hours and 24 minutes before perigee… as does the Full Moon of November 14th (2.4 hours from perigee) and December 13th (just under 24 hours from perigee).

For extra fun, said November 14th perigee Full Moon is the closest in 30 years; expect Supermoon lunacy to ensue.

A fun place to play with Full and New Moons vs perigee and apogee past present and future is Fourmilab’s Lunar Apogee and Perigee Calculator. Hey, it’s what we do for fun. Looking over these cycles, you’ll notice a pattern of ‘supermoon seasons’ emerge, which moves forward along the calendar about a lunation a year. (that’s our friend the precession of the line of apsides at work again).

(another fun fact: the time it takes for the Moon to return to a similar phase—for example, Full back to Full—is 29.5 days, and known as a synodic month.)

The Full Moon does appear slightly larger at perigee than apogee, to the tune of 29.3′ versus 34.1′ across. This change is enough to notice with the unaided eye, though the Moon is deceptively smaller than it appears: you could, for example, line up 654 ‘Supermoons’ around the local horizon from end to end.

A 'super' vs average Full Moon. Image credit: Marco Langbroek.
A ‘super’ vs average Full Moon. Image credit: Marco Langbroek.

The October Moon is also referred to by the Algonquin Native Americans as the ‘Hunter’s Moon,’ a time to use that extra illumination to track down vital sustenance as the harsh winter approaches. Very occasionally, the Harvest Full Moon falling near the September southward equinox falls in early October (as occurs next year in 2017) and bumps the Hunter’s Moon from its monthly slot.

Be sure to stalk the rising Hunter’s Moon near perigee this weekend. Of course, we’ll be shooting at our prey with nothing more than a camera, as the Full Moon rises from behind the Andalusian foothills.

Posted on by Susie Murph

Celebrate International Observe the Moon Night on Saturday, Oct. 8 2016!

A full moon captured July 18, 2008. Credit: NASA/Sean Smith

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This Saturday, October 8, 2016, is International Observe the Moon Night (InOMN), an annual worldwide public event that encourages observation, appreciation, and understanding of our Moon and its connection to NASA planetary science and exploration. InOMN is sponsored by NASA’s Lunar Reconnaissance Orbiter, NASA’s Solar System Exploration Research Virtual Institute (SSERVI), and the Lunar and Planetary Institute.

LROC WAC image of the Moon. Credit: NASA/LRO
LROC WAC image of the Moon. Credit: NASA/LRO

Everyone on Earth is invited to join the celebration by hosting or attending an InOMN event — and uniting on one day each year to look at and learn about the Moon together. We encourage you to go to InOMN events near you, such as at your local planetariums or museums, or to go out and observe the moon yourself! You can find events near you at the InOMN site. You can also follow the InOMN Twitter feed to see what everyone is doing to celebrate!

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Our friends over at CosmoQuest are proud to be partners in this celebration of Earth’s natural satellite. There you can “Observe the Moon” all year long by taking part in lunar-themed activities, such as our Moon Mappers citizen science program, where you’ll get to look at some of the most detailed images taken by the LRO, and help our scientists study the moon and it’s surface. This excellent program is available free of charge, no matter the weather, time of day or your location – you get the best views of the Moon ever!

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Take some photos of your activities, whether outdoors observing or indoors mapping craters, and share them online at the CosmoQuest Twitter and Facebook feeds using the hashtag #observethemoon, and CosmoQuest will repost their favorites!

leif looking at the moon

Here are just a few of the media celebrations that have already been posted for InOMN!

One of CosmoQuest’s partners, the Astronomical Society of the Pacific, has a great document here celebrating recent lunar discoveries.

“The Moon and More” is a music video starring musicians Javier Colon (Season 1 winner of NBC’s “The Voice”), and Matt Cusson in collaboration with NASA’s Goddard Space Flight Center and the Lunar Reconnaissance Orbiter (LRO) mission.
Credits: NASA’s Goddard Space Flight Center/David Ladd, producer

Posted on by Ken Kremer

NASA’s First SLS Mars Rocket Fuel Tank Completes Welding

Welding is complete on the largest piece of the core stage that will provide the fuel for the first flight of NASA's new rocket, the Space Launch System, with the Orion spacecraft in 2018. The core stage liquid hydrogen tank has completed welding on the Vertical Assembly Center at NASA's Michoud Assembly Facility in New Orleans. Credit: NASA/MAF/Steven Seipel
Welding is complete on the largest piece of the core stage that will provide the fuel for the first flight of NASA's new rocket, the Space Launch System, with the Orion spacecraft in 2018. The core stage liquid hydrogen tank has completed welding on the Vertical Assembly Center at NASA's Michoud Assembly Facility in New Orleans. Credit: NASA/MAF/Steven Seipel
Welding is complete on the largest piece of the core stage that will provide the fuel for the first flight of NASA’s new rocket, the Space Launch System, with the Orion spacecraft in 2018. The core stage liquid hydrogen tank has completed welding on the Vertical Assembly Center at NASA’s Michoud Assembly Facility in New Orleans. Credit: NASA/MAF/Steven Seipel

The first of the massive fuel tanks that will fly on the maiden launch of NASA’s SLS mega rocket in late 2018 has completed welding at the agency’s rocket manufacturing facility in New Orleans – marking a giant step forward for NASA’s goal of sending astronauts on a ‘Journey to Mars’ in the 2030s.

Technicians have just finished welding together the liquid hydrogen (LH2) fuel tank in the Vertical Assembly Center (VAC) welder at NASA’s Michoud Assembly Facility (MAF) in New Orleans. The VAC is the world’s largest welder.

Welding is nearly complete on the liquid hydrogen tank will provide the fuel for the first flight of NASA's new rocket, the Space Launch System, with the Orion spacecraft in 2018. The tank has now has now completed welding on the Vertical Assembly Center at NASA's Michoud Assembly Facility in New Orleans. Credit: Ken Kremer/kenkremer.com
Welding is nearly complete on the liquid hydrogen tank will provide the fuel for the first flight of NASA’s new rocket, the Space Launch System, with the Orion spacecraft in 2018. The tank has now has now completed welding on the Vertical Assembly Center at NASA’s Michoud Assembly Facility in New Orleans. Credit: Ken Kremer/kenkremer.com

This flight version of the hydrogen tank is the largest of the two fuel tanks making up the SLS core stage – the other being the liquid oxygen tank (LOX).

In fact the 130 foot tall hydrogen tank is the biggest cryogenic tank ever built for flight.

“Standing more than 130 feet tall, the liquid hydrogen tank is the largest cryogenic fuel tank for a rocket in the world,” according to NASA.

And it is truly huge – measuring also 27.6 feet (8.4 m) in diameter.

The liquid hydrogen tank qualification test article for NASA’s new Space Launch System (SLS) heavy lift rocket lies horizontally after final welding was completed at NASA’s Michoud Assembly Facility in New Orleans in July 2016. Credit: Ken Kremer/kenkremer.com
The liquid hydrogen tank qualification test article for NASA’s new Space Launch System (SLS) heavy lift rocket lies horizontally after final welding was completed at NASA’s Michoud Assembly Facility in New Orleans in July 2016. Credit: Ken Kremer/kenkremer.com

I recently visited MAF to see this giant tank when it was nearly finished welding in the VAC. I also saw the very first completed test tank version of the hydrogen tank, called the qualification tank which is virtually identical.

The precursor qualification tank was constructed to prove out all the manufacturing techniques and welding tools being utilized at Michoud.

The first liquid hydrogen tank, also called the qualification test article, for NASA's new Space Launch System (SLS) heavy lift rocket lies horizontally beside the Vertical Assembly Center robotic weld machine on July 22, 2016 after final welding was just completed at NASA’s Michoud Assembly Facility in New Orleans. Credit: Ken Kremer/kenkremer.com
The first liquid hydrogen tank, also called the qualification test article, for NASA’s new Space Launch System (SLS) heavy lift rocket lies horizontally beside the Vertical Assembly Center robotic weld machine on July 22, 2016 after final welding was just completed at NASA’s Michoud Assembly Facility in New Orleans. Credit: Ken Kremer/kenkremer.com

SLS is the most powerful booster the world has even seen and one day soon will propel NASA astronauts in the agency’s Orion crew capsule on exciting missions of exploration to deep space destinations including the Moon, Asteroids and Mars – venturing further out than humans ever have before!

NASA’s agency wide goal is to send humans to Mars by the 2030s with SLS and Orion.

The LH2 and LOX tanks sit on top of one another inside the SLS outer skin. Together the hold over 733,000 gallons of propellant.

The SLS core stage – or first stage – is mostly comprised of the liquid hydrogen and liquid oxygen cryogenic fuel storage tanks which store the rocket propellants at super chilled temperatures. Boeing is the prime contractor for the SLS core stage.

The SLS core stage stands some 212 feet tall.

The SLS core stage is comprised of five major structures: the forward skirt, the liquid oxygen tank (LOX), the intertank, the liquid hydrogen tank (LH2) and the engine section.

The LH2 and LOX tanks feed the cryogenic propellants into the first stage engine propulsion section which is powered by a quartet of RS-25 engines – modified space shuttle main engines (SSMEs) – and a pair of enhanced five segment solid rocket boosters (SRBs) also derived from the shuttles four segment boosters.

NASA engineers successfully conducted a development test of the RS-25 rocket engine Thursday, Aug. 18 at NASA’s Stennis Space Center near Bay St. Louis, Miss. The RS-25 will help power the core stage of the agency’s new Space Launch System (SLS) rocket for the journey to Mars. Credit: Ken Kremer/kenkremer.com
NASA engineers successfully conducted a development test of the RS-25 rocket engine Thursday, Aug. 18 at NASA’s Stennis Space Center near Bay St. Louis, Miss. The RS-25 will help power the core stage of the agency’s new Space Launch System (SLS) rocket for the journey to Mars. Credit: Ken Kremer/kenkremer.com

The vehicle’s four RS-25 engines will produce a total of 2 million pounds of thrust.

The tanks are assembled by joining previously manufactured dome, ring and barrel components together in the Vertical Assembly Center by a process known as friction stir welding. The rings connect and provide stiffness between the domes and barrels.

The LH2 tank is the largest major part of the SLS core stage. It holds 537,000 gallons of super chilled liquid hydrogen. It is comprised of 5 barrels, 2 domes, and 2 rings.

The LOX tank holds 196,000 pounds of liquid oxygen. It is assembled from 2 barrels, 2 domes, and 2 rings and measures over 50 feet long.

The maiden test flight of the SLS/Orion is targeted for no later than November 2018 and will be configured in its initial 70-metric-ton (77-ton) Block 1 configuration with a liftoff thrust of 8.4 million pounds – more powerful than NASA’s Saturn V moon landing rocket.

Although the SLS-1 flight in 2018 will be uncrewed, NASA plans to launch astronauts on the SLS-2/EM-2 mission slated for the 2021 to 2023 timeframe.

NASA’s Space Launch System (SLS) blasts off from launch pad 39B at the Kennedy Space Center in this artist rendering showing a view of the liftoff of the Block 1 70-metric-ton (77-ton) crew vehicle configuration. Credit: NASA/MSFC
NASA’s Space Launch System (SLS) blasts off from launch pad 39B at the Kennedy Space Center in this artist rendering showing a view of the liftoff of the Block 1 70-metric-ton (77-ton) crew vehicle configuration. Credit: NASA/MSFC

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

Ken Kremer

The newly assembled first liquid hydrogen tank, also called the qualification test article, for NASA's new Space Launch System (SLS) heavy lift rocket lies horizontally beside the Vertical Assembly Center robotic weld machine (blue) on July 22, 2016. It was lifted out of the welder (top) after final welding was just completed at NASA’s Michoud Assembly Facility in New Orleans. Credit: Ken Kremer/kenkremer.com
The newly assembled first liquid hydrogen tank, also called the qualification test article, for NASA’s new Space Launch System (SLS) heavy lift rocket lies horizontally beside the Vertical Assembly Center robotic weld machine (blue) on July 22, 2016. It was lifted out of the welder (top) after final welding was just completed at NASA’s Michoud Assembly Facility in New Orleans. Credit: Ken Kremer/kenkremer.com