A view of Earth and its Moon, as seen from Mars. It combines two images acquired on Nov. 20, 2016, by the HiRISE camera on NASA's Mars Reconnaissance Orbiter, with brightness adjusted separately for Earth and the moon to show details on both bodies. Credit: NASA/JPL-Caltech/Univ. of Arizona.
The incredible HiRISE camera on board the Mars Reconnaissance Orbiter turned its eyes away from its usual target – Mars’ surface – and for calibration purposes only, took some amazing images of Earth and our Moon. Combined to create one image, this is a marvelous view of our home from about 127 million miles (205 million kilometers) away.
Alfred McEwen, principal investigator for HiRISE said the image is constructed from the best photo of Earth and the best photo of the Moon from four sets of images. Interestingly, this combined view retains the correct positions and sizes of the two bodies relative to each other. However, Earth and the Moon appear closer than they actually are in this image because the observation was planned for a time at which the Moon was almost directly behind Earth, from Mars’ point of view, to see the Earth-facing side of the Moon.
A view of Earth and its Moon, as seen from Mars. It combines two images acquired on Nov. 20, 2016, by the HiRISE camera on NASA’s Mars Reconnaissance Orbiter, with brightness adjusted separately for Earth and the moon to show details on both bodies. Credit: NASA/JPL-Caltech/Univ. of Arizona.
“Each is separately processed prior to combining (in correct relative positions and sizes), so that the Moon is bright enough to see,” McEwen wrote on the HiRISE website. “The Moon is much darker than Earth and would barely show up at all if shown at the same brightness scale as Earth. Because of this brightness difference, the Earth images are saturated in the best Moon images, and the Moon is very faint in the best (unsaturated) Earth image.”
Earth looks reddish because the HiRISE imaging team used color filters similar to the Landsat images where vegetation appears red.
“The image color bandpasses are infrared, red, and blue-green, displayed as red, green, and blue, respectively,” McEwen explained. “The reddish blob in the middle of the Earth image is Australia, with southeast Asia forming the reddish area (vegetation) near the top; Antarctica is the bright blob at bottom-left. Other bright areas are clouds. We see the western near-side of the Moon.”
HiRISE took these pictures on Nov. 20, 2016, and this is not the first time HiRISE has turned its eyes towards Earth.
Back in 2007, HiRISE took this image, below, from Mars’ orbit when it was just 88 million miles (142 million km) from Earth. This one is more like how future astronauts might see Earth and the Moon through a telescope from Mars’ orbit.
An image of Earth and the Moon, acquired on October 3, 2007, by the HiRISE camera on NASA’s Mars Reconnaissance Orbiter. Credit: NASA/JPL-Caltech/University of Arizona.
If you look closely, you can make out a few features on our planet. The west coast outline of South America is at lower right on Earth, although the clouds are the dominant features. In fact, the clouds were so bright, compared with the Moon, that they almost completely saturated the filters on the HiRISE camera. The people working on HiRISE say this image required a fair amount of processing to make such a nice-looking picture.
You can see an image from a previous Mars’ orbiter, the Mars Global Surveyor, that took a picture of Earth, the Moon and Jupiter — all in one shot — back in 2003 here.
The Moon about to occult Aldebaran on December 23rd, 2015. Image credit and copyright: Paul Campbell.
It’s a busy week for the Moon. While our large solitary natural satellite reaches Full and interferes with the 2016 Geminids, it’s also beginning a series of complex bright star occultations of Aldebaran and Regulus, giving us a taste of things to come in 2017.
First up, here’s the lowdown on this week’s occultation of Aldebaran by the Moon, coming right up tonight:
The footprint for tonight’s occultation of Aldebaran by the Moon. You can find specific ingress and egress times for major cities near you on the IOTA event page. Credit: Occult 4.2.
The 99% illuminated waxing gibbous Moon occults the +0.9 magnitude star Aldebaran on Monday, December 12th. The Moon is just 19 hours and 30 minutes before reaching Full during the event. Both are located 167 degrees east of the Sun at the time of the event. The central time of conjunction is 4:37 Universal Time (UT). The event occurs during the daylight hours over Hawaii at dusk during Moonrise, and under darkness for Mexico, most of Canada and the contiguous United States. The event also includes the United Kingdom and southwestern Europe at Moonset near early dawn. This is the final occultation of Aldebaran by the Moon for 2016; The Moon will next occult Aldebaran on January 9th, 2017. This is occultation 26 in the current series of 49, running from January 29th, 2015 to September 3rd, 2018.
The view from Gibraltar just prior to this week’s occultation of Aldebaran by the Moon. Credit: Stellarium.
Four 1st magnitude stars are along the Moon’s path in the current epoch: Regulus, Aldebaran, Antares and Spica. 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). The Moon also occults Regulus 220 times this century, and occultations of Spica and Antares resume on May 2024 and July 2023, respectively.
And yes, this Supermoon 3 of 3 for 2016, though actual perigee occurs at 23:28 UT tonight, 39 minutes past our own ’24 hour from Full’ rule. The Moon reaches Full on Wednesday, December 14th at just past midnight at 00:07 UT. This is also the closest Full Moon to the December 21st winter solstice next week, and the Full Moon will ride high in the sky this week for northern hemisphere observers on long winter nights.
Keep an eye out for Geminid meteors tonight as well… sure, 2016 may be an off year for this usually spectacular shower, but a few brighter fireballs may still punch through the lunar light pollution.
Clouded out? Be sure to catch the Supermoon action tomorrow night live online starting at 16:00 UT, courtesy of Gianluca Masi and the Virtual Telescope Project.
And there’s more. This coming weekend marks the start of an upcoming new cycle of occultations of Regulus by the Moon. These run right through 2018, as the Moon visits the bright star Regulus five days after crossing the Hyades and occulting Aldebaran for every lunation pass in 2017.
Here’s the specifics for Sunday’s event:
The footprint for Sunday’s occultation of Regulus by the Moon. You can find specific ingress and egress times for major cities near you on the IOTA event page. Credit: Occult 4.2.
The 73% illuminated waning gibbous Moon occults the +1.4 magnitude star Regulus on Sunday, December 18th. The Moon is just four days past Full during the event. Both are located 117 degrees west of the Sun at the time of the event. The central time of conjunction is 18:38 Universal Time (UT). The event occurs during the daylight hours over Tasmania, and under darkness for the southwestern tip of Australia, including Perth. The Moon will next occult Regulus on January 15th, 2017. This is the first occultation in a new series of nineteen, running from this weekend to April 24th, 2018.
The view of Sunday’s event from Perth, Australia. Credit: Stellarium.
It’s worth noting that the graze line for Sunday’s occultation of Regulus by the Moon runs just north of the Australian city of Perth and the Perth Observatory… let us know if anyone ‘Down Under’ witnesses the first occultation of Regulus in the new cycle.
Can you spy Regulus’ white dwarf companion? Located 77 light years distant, the Regulus system has at least four components: a B/C pair shining at a combined magnitude of +8, with an apparent separation of 3”, (5,000 AU physical distance in a ~600 year orbit) and an unseen white dwarf companion in a tight 40 day orbit. We know that said white dwarf companion exists from spectroscopic analysis… and it would shine at an easy magnitude +13, were it not near dazzling Regulus shining over 10,000 times brighter. Could this elusive companion turn up just moments before the reappearance of Regulus from behind the Moon? Remember, the dark limb of the Moon leads the way during waxing phases, then trails as the Moon wanes. These and other amazing facts are included in our forthcoming free guide to 101 Astronomical Events to watch out for in 2017.
Every occultation of Regulus for the upcoming cycle. Credit: Occult 4.2.
Follow that Moon, and don’t miss these fine astro-events coming to sky above you this week!
A partial solar eclipse rising over the VAB. Image by author.
It’s that time of year again… time to look ahead at the top 101 astronomical events for the coming year.
And this year ’round, we finally took the plunge. After years of considering it, we took the next logical step in 2017 and expanded our yearly 101 Astronomical Events for the coming year into a full-fledged guide book, soon to be offered here for free download on Universe Today in the coming weeks. Hard to believe, we’ve been doing this look ahead in one form or another now since 2009.
This “blog post that takes six months to write” will be expanded into a full-fledged book. But the core idea is the same: the year in astronomy, distilled down into the very 101 best events worldwide. You will find the best occultations, bright comets, eclipses and much more. Each event will be interspersed with not only the ‘whens’ and ‘wheres,’ but fun facts, astronomical history, and heck, even a dash of astronomical poetry here and there.
It was our goal to take this beyond the realm of a simple almanac or Top 10 listicle, to something unique and special. Think of it as a cross between two classics we loved as a kid, Burnham’s Celestial Handbook and Guy Ottewell’s Astronomical Calendar, done up in as guide to the coming year in chronological format. Both references still reside on our desk, even in this age of digitization.
And we’ve incorporated reader feedback from over the years to make this forthcoming guide something special. Events will be laid out in chronological order, along with a quick-list for reference at the end. Each event is listed as a one- or two-page standalone entry, ready to be individually printed off as needed. We will also include 10 feature stories and true tales of astronomy. Some of these were culled from the Universe Today archives, while others are new astronomical tales written just for the guide.
Don’t miss 2017’s only total solar eclipse, crossing the United States! Image credit: Michael Zeiler/The Great American Eclipse.
The Best of the Best
Here’s a preview of some of the highlights for 2017:
-Solar cycle #24 begins to ebb in 2017. Are we heading towards yet another profound solar minimum?
-Brilliant Venus reaches greatest elongation in January and rules the dusk sky.
-45P/Honda-Mrkos-Pajdusakova passes 0.08 AU from Earth on February 11th, its closest passage for the remainder of the century.
-An annular solar eclipse spanning Africa and South America occurs on February 26th.
A sample occultation map from the book. Image credit: Occult 4.1.2.
-A fine occultation of Aldebaran by the Moon on March 5th for North America… plus more occultations of the star worldwide during each lunation.
-A complex grouping of Mercury, Venus, Mars and the Moon in mid-September.
-Saturn’s rings at their widest for the decade.
Getting wider… the changing face of Saturn’s rings. Image credit and copyright: Andrew Symes (@FailedProtostar).
-A fine occultation of Regulus for North America on October 15th, with occultations of the star by the Moon during every lunation for 2017.
-Asteroid 335 Roberta occults a +3rd magnitude star for northern Australia…
And that’s just for starters. Entries also cover greatest elongations for the inner planets and oppositions for the outer worlds, the very best asteroid occultations of bright stars, along with a brief look ahead at 2018.
Get ready for another great year of skywatching!
And as another teaser, here’s a link to a Google Calendar download of said events, complied by Chris Becke (@BeckePhysics). Thanks Chris!
Apollo 11 moonwalker Buzz Aldrin trekking across Antarctica as the oldest man to reach the South Pole, prior to emergency medical evacuation on Dec. 1, 2016. Credit: Team Buzz
Apollo 11 moonwalker Buzz Aldrin trekking across Antarctica as the oldest man to reach the South Pole, prior to emergency medical evacuation on Dec. 1, 2016. Credit: Team Buzz
Buzz Aldrin – the second man to walk on the Moon – is recovering nicely today in a New Zealand hospital after an emergency medical evacuation cut short his record setting Antarctic expedition as the oldest man to reach the South Pole – which Team Buzz lightheartly noted would make him “insufferable”!
“He’s recovering well in NZ [New Zealand],” Team Buzz said in an official statement about his evacuation from the South Pole.
Apollo 11 moonwalker Buzz Aldrin, who followed Neil Armstrong in descending to the lunar surface in 1969 on America’s first Moon landing mission, had to be suddenly flown out of the Admunsen-Scott Science Station late last week per doctors orders after suffering from shortness of breath and lung congestion during his all too brief foray to the bottom of the world.
He was flown to a hospital in Christchurch, New Zealand for emergency medical treatment on Dec. 1.
Upon learning from the National Science Foundation (NSF) that Aldrin “now holds the record as the oldest person to reach the South Pole at the age of 86,” his Mission Director Christina Korp jokingly said: ‘He’ll be insufferable now.”
“Buzz Aldrin is resting in hospital in Christchurch, New Zealand. He still has some congestion in his lungs so has been advised not to take the long flight home to the States and to rest in New Zealand until it clears up,” Team Buzz said in an official statement on Dec. 3.
Buzz had been at the South Pole for only a few hours when he took ill, apparently from low oxygen levels and symptoms of altitude sickness.
“I’m extremely grateful to the National Science Foundation (NSF) for their swift response and help in evacuating me from the Admunsen-Scott Science Station to McMurdo Station and on to New Zealand. I had been having a great time with the group at White Desert’s camp before we ventured further south. I really enjoyed the time I spent talking with the Science Station’s staff too,” said Aldrin from his hospital room in a statement.
Apollo 11 moonwalker Buzz Aldrin being evacuated from Antarctica for emergency medical treatment on Dec. 1, 2016. Credit: Team Buzz
Prior to the planned Antarctic journey, his doctors had cleared him to take the long trip – which he views as “the capstone of his personal exploration achievements”.
Apollo 11 moonwalker Buzz Aldrin is seen recovering well in New Zealand hospital on Dec. 2 after medical emergency evacuation from expedition to the South Pole on Dec. 1, 2016. Credit: Team Buzz
Buzz’s goal in visiting the South Pole was to see “what life could be like on Mars” – which he has been avidly advocating as the next goal for a daring human spaceflight journey to deep space.
“His primary interest in coming to Antarctica was to experience and study conditions akin to Mars that are more similar there than any other place on earth,” Team Buzz elaborated.
He had hoped to speak more to the resident scientists about their research but it was all cut short by his sudden illness.
“I started to feel a bit short of breath so the staff decided to check my vitals. After some examination they noticed congestion in my lungs and that my oxygen levels were low which indicated symptoms of altitude sickness. This prompted them to get me out on the next flight to McMurdo and once I was at sea level I began to feel much better. I didn’t get as much time to spend with the scientists as I would have liked to discuss the research they’re doing in relation to Mars. My visit was cut short and I had to leave after a couple of hours. I really enjoyed my short time in Antarctica and seeing what life could be like on Mars,” Aldrin explained.
Buzz also thanked everyone who sent him well wishes.
“Finally, thanks to everyone from around the world for their well wishes and support. I’m being very well looked after in Christchurch. I’m looking forward to getting home soon to spend Christmas with my family and to continue my quest for Cycling Pathways and a permanent settlement on Mars. You ain’t seen nothing yet!”, concluded Aldrin.
Destination Mars is a holographic exhibit at the Kennedy Space Center visitor complex in Florida. Be sure to catch it soon because the limited time run end on New Year’s Day 2017.
Apollo 11 moonwalker Buzz Aldrin discusses the human ‘Journey to Mars with Universe Today at newly opened ‘Destination Mars’ holographic experience during media preview at the Kennedy Space Center visitor complex in Florida on Sept. 18, 2016. Credit: Ken Kremer/kenkremer.com
The new ‘Destination Mars’ limited engagement exhibit magically transports you to the surface of the Red Planet via Microsoft HoloLens technology.
It literally allows you to ‘Walk on Mars’ using real imagery taken by NASA’s Mars Curiosity rover and explore the alien terrain, just like real life scientists on a geology research expedition – with Buzz Aldrin as your guide.
Here’s my Q & A with moonwalker Buzz Aldrin speaking to Universe Today at Destination Mars:
Video Caption: Buzz Aldrin at ‘Destination Mars’ Grand Opening at KSCVC. Apollo 11 moonwalker Buzz Aldrin talks to Universe Today/Ken Kremer during Q&A at ‘Destination Mars’ Holographic Exhibit Grand Opening ceremony at Kennedy Space Center Visitor Complex (KSCVC) in Florida on 9/18/16. Credit: Ken Kremer/kenkremer.com
Learn more about ULA Delta 4 launch on Dec 7, GOES-R weather satellite, Heroes and Legends at KSCVC, OSIRIS-REx, InSight Mars lander, ULA, SpaceX and Orbital ATK missions, Juno at Jupiter, SpaceX AMOS-6 & CRS-9 rocket launch, ISS, ULA Atlas and Delta rockets, Orbital ATK Cygnus, Boeing, Space Taxis, Mars rovers, Orion, SLS, Antares, NASA missions and more at Ken’s upcoming outreach events:
Dec 5-7: “ULA Delta 4 Dec 7 launch, GOES-R weather satellite launch, OSIRIS-Rex, SpaceX and Orbital ATK missions to the ISS, Juno at Jupiter, ULA Delta 4 Heavy spy satellite, SLS, Orion, Commercial crew, Curiosity explores Mars, Pluto and more,” Kennedy Space Center Quality Inn, Titusville, FL, evenings
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.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.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.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.
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.
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.
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.
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.
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.
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!
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). 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
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
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 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:
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
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.
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.
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 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 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.
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!
