Comet US10 Catalina: Our Guide to Act II

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Itching for some cometary action? After a fine winter’s performance from Comet C/2014 Q2 Lovejoy, 2015 has seen a dearth of good northern hemisphere comets. That’s about to change, however, as Comet C/2013 US10 Catalina joins the planetary lineup currently gracing the dawn sky in early November. Currently located in the constellation Centaurus and shining at magnitude +6, Comet US10 Catalina has already put on a fine show for southern hemisphere observers over the last few months during Act I

Currently buried in the dusk sky, Comet US10 Catalina is bashful right now, as it shares nearly the same right ascension with the Sun over the next few weeks, passing just eight degrees from our nearest star as seen from our Earthly vantage point on November 7th — and perhaps passing juuusst inside of the field of view for SOHO’s LASCO C3 camera — and into the dawn sky.

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The altitude of Comet US10 Catalina in November and December at dawn as seen from latitude 30 degrees north. Image credit: Starry Night Education software.

The hunt is on come early November, as Comet US 10 Catalina vaults into the dawn sky. From 30 degrees north latitude here in Central Florida, the comet breaks 10 degrees elevation an hour prior to local sunrise right around November 20th. This should see the comet peaking in brightness right around magnitude +5 near perihelion the same week on November 16th.

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The projected light curve of Comet US10 Catalina, with observations thus far (black dots) Image credit: Adapted from Seiichi Yoshida’s Weekly Information About Bright Comets

The angle of the comet’s orbit is favorable for northern hemisphere viewers in mid-November, as viewers start getting good looks in the early morning from latitude 30 degrees northward and the comet gains about a degree of elevation per day. This will bring it up out of the murk of twilight and into binocular view.

Mark your calendar for the morning of December 7th, as the crescent Moon, Venus and a (hopefully!) +5 magnitude comet US10 Catalina will all fit within a five degree circle.

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The view on the morning of December 7th. Image credit: Starry Night Education software

Here are some key dates with celestial destiny for Comet US10 Catalina for the remainder of 2015:

October

20-Crosses into the constellation Hydra.

November

2-Crosses into the constellation Libra.

16-Crosses into the constellation Virgo.

16-Reaches perihelion at 0.823 AU (127.6 million kilometers) from Sun.

26-Crosses the ecliptic plane northward.

27-Passes less than one degree from the +4.5 magnitude star Lambda Virginis.

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The celestial path of Comet US 10 Catalina through the end of 2015. Image Credit: Starry Night Education software

December

7-Fits inside a five degree circle with Venus and the waning crescent Moon.

8-Passes less than one degree from the +4 magnitude star Syrma (Iota Virginis).

17-Crosses the celestial equator northward.

24-Crosses into the constellation Boötes.

In January, Comet US10 Catalina starts the New Year passing less than a degree from the -0.05 magnitude star Arcturus. From there, the comet may drop below +6 magnitude and naked eye visibility by mid-month, just prior to its closest approach to the Earth at 0.725 AU (112.3 million kilometers) on January 17th. By February 1st, the comet may drop below +10th magnitude and binocular visibility, into the sole visual domain of large light bucket telescopes under dark skies.

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Comet US10 Catalina imaged from Australia on July 21st, 2015. Image credit: Alan Tough

Or not. Comets and predictions of comet brightness are always notoriously fickle, and rely mainly on just how the comet performs near perihelion. Then there’s twilight extinction to contend with, and the fact that the precious magnitude of the comet is diffused over its extended surface area, often causing the comet to appear fainter visually than the quoted magnitude.

But do not despair. Comets frequently under-perform pre-perihelion passage, only to put on brilliant shows after. Astronomers discovered Comet US10 Catalina on Halloween 2013 from the Catalina Sky Survey based just outside of Tucson, Arizona. On a several million year orbit, all indications are that Comet US10 Catalina is a dynamically new Oort Cloud visitor and will probably get ejected from the solar system after this all-too brief fling with the Sun. Its max velocity at perihelion will be 46.4 kilometers per second, three times faster than the New Horizons spacecraft currently on an escape trajectory out of the solar system.

The odd ‘US10’ designation comes from the comet’s initial identification as an asteroidal object, later upgraded to cometary status.  The comet’s high orbital inclination of 149 degrees assured two separate showings, as the comet approached the Sun as seen from the Earth’s southern hemisphere, only to then vault up over the northern hemisphere post-perihelion. As is often the case, the comet was closest to the Sun at exactly the wrong time: had perihelion occurred around May, the comet would’ve passed the Earth just 0.17 AU (15.8 million miles or 26.3 million kilometers) distant! That might’ve placed the comet in the negative magnitudes and perhaps earned it the title of ‘the Great Comet of 2015…’

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The orbit of Comet US10 Catalina and the view during closest Earth approach. Image credit: NASA/JPL

But such was not to be.

Ah, but the next ‘big one’ could come at any time. In 2016, we’re tracking comet C/2013 X1 PanSTARRS, which will ‘perhaps’ become a fine binocular comet next summer…

More to come. Perhaps we’ll draft up an Act III for US10 Catalina in early January if it’s a top performer.

Why Was September’s Lunar Eclipse So Dark?

The September 17, 2015 total lunar eclipse - the last of the recent tetrad of lunar eclipses over the past 17 months - was darker than expected. Several factors described below were in play. This photo was taken in Washington's Olympic National Park. Credit: Rick Klawitter

First off, a huge thank you to everyone who made and sent their Danjon scale estimate of the totally-eclipsed Moon’s brightness to Dr. Richard Keen, University of Colorado atmospheric scientist. Your data were crucial to his study of how aerosols in Earth’s atmosphere and other factors influence the Moon’s appearance.

Grateful for your help, Keen received a total of 28 observations from 7 different countries.

Graphs created by Dr. Richard Keen plotting Danjon L values submitted by Universe Today readers and others that compare expected values (top curve) with observed values. The Moon was about half as bright during totality as expected with L=1.9. Credit: Dr. Richard A. Keen
Graph created by Dr. Richard Keen plotting Danjon L values submitted by Universe Today readers and others that compare predicted values (top curve) with observed values. The Moon was about half as bright during totality as expected with L=1.9. Credit: Dr. Richard A. Keen

Using the Danjon information and estimates of the Moon’s brightness using the reverse binocular method, Keen crunched the data and concluded that the Moon was about 0.6 L (Danjon) units darker than expected and 0.4 magnitude dimmer, a brightness reduction of 33%. This agrees well with my own observation and possibly yours, too. No wonder so many stars sparkled near the Moon that night.

Depending on how clear the atmosphere is, the Moon's color can vary dramatically from one eclipse to another. The numbers, called the Danjon Scale, will help you estimate the color of Sunday night's eclipse. Credit: Bob King
Lunar eclipse brightness is rated on the Danjon scale where “0” equals a dark gray totality and “4” a bright, coppery yellow. Credit: Bob King

I think it’s safe to say, most of us expected a normal or even bright totality. So why was it dark? Several factors were at play — one to do with the Moon’s location in Earth’s shadow, the other with a volcanic eruption and a third with long-term, manmade pollution.

During a perigee eclipse, the moon passes more deeply into Earth’s shadow compared to one that happens near apogee, when the moon is most distant from Earth. Moon distances not to scale and for illustration only. Credit: Bob King
During a perigean eclipse, the Moon passes more deeply into Earth’s shadow compared to one that happens near apogee, when the moon is most distant from Earth. Moon distances not to scale and for illustration only. Credit: Bob King

You’ll recall that the eclipse occurred during lunar perigee, when the Moon swings closest to Earth in its 27-day orbit. Being closer, it also tracked deeper into Earth’s umbra or inner shadow which narrows the farther back of the planet it goes. An apogean Moon (farthest from Earth) passes through a more tapered cone of darkness closer to the penumbra, where sunlight mixes with shadow. A Moon nearer Earth would find the umbral shadow roomier with the light-leaking penumbra further off in the distance.

Around midday on April 24, 2015, the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite acquired this natural-color image of the ash and gas plume from Calbuco volcano in southern Chile. Credit: NASA
On April 24, 2015, NASA’s Terra satellite acquired this photo of the ash and gas plume from Calbuco volcano in southern Chile. Credit: NASA

But there’s more. Working independently, Steve Albers of NOAA and Brazilian astronomer Helio Vital suggested another reason: aerosols in the atmosphere. “Earth’s stratosphere is no longer completely clean of volcanic ashes,” said Vital in an e-mail communication. “In fact, lingering aerosols (ash, dust, sulfuric acid droplets) from the explosion of Calbuco five months ago may be to blame for that excessive darkening.”

With the lunar horizon in the foreground, the Earth passes in front of the Sun on September 27, 2015 in this simulation, revealing the red ring of sunrises and sunsets along the limb of the planet responsible for illuminating the Moon during the eclipse. The clarity of the stratosphere at eclipse time can greatly affect lunar brightness during totality. The Earth and Sun are in Virgo for observers on the Moon with the bright star Beta Virginis at top. Click to see the video. Credit: NASA's Scientific Visualization Studio
With the lunar horizon in the foreground, the Earth passes in front of the Sun on September 27, 2015 in this simulation, revealing the red ring of sunrises and sunsets along the limb of the planet responsible for illuminating the Moon during the eclipse. The clarity of the stratosphere at eclipse time can greatly affect lunar brightness during totality. The Earth and Sun are in Virgo for observers on the Moon with the bright star Beta Virginis at top. Click to see the video. Credit: NASA’s Scientific Visualization Studio

While much of the debris blasted into the stratosphere made for colorful sunsets in the southern hemisphere, some of that material has likely made its way to the northern hemisphere. Albers has noticed an increase in yellow and purple sunsets in his home town of Boulder in recent months, telltale signs of volcanic spew at play.

Forest fires that raged across the western states and Canadian provinces all spring and summer may also have contributed. Most of that smoke usually stays in the lower part of the atmosphere, but some may have found its way to the stratosphere, the very layer responsible for transmitting most of the sunlight that falls into Earth’s shadow and colors the moon.

Graph showing magnitude estimates of the Moon's brightness during totality using the reverse binocular method. The predicted magnitude was -1.7 (a little brighter than Sirius) vs. the observed -1.3. Credit: Dr. Richard A. Keen
Graph showing magnitude estimates of the Moon’s brightness during totality using the reverse binocular method. The predicted magnitude was -1.7 (a little brighter than Sirius) vs. the observed -1.3. Credit: Dr. Richard A. Keen

Sunlight has to pass through these light-absorbing minerals and chemicals on its way through the atmosphere and into Earth’s shadow. Less light means a darker moon during total eclipse. Coincidentally, much of the totally eclipsed Moon passed through the southern half of the umbra which “increased the effectiveness of the Calbuco aerosols (which are still more concentrated in the southern hemisphere than the northern) at dimming the light within the umbra,” writes Keen.

Oceanus Procellarum and Mare Imbrium are large, dark volcanic plains that contributed to the Moon's faintness and dark-hued totality. Credit: Bob King
Oceanus Procellarum and Mare Imbrium are large, dark volcanic plains that contributed to the Moon’s faintness and dark-hued totality. Credit: Bob King

It also so happened that the darkest part of the moon coincided with two vast, dark volcanic plains called Oceanus Procellarum (Ocean of Storms) and Mare Imbrium, artificially enhancing the overall gloom over the northern half of the Moon.

U.S. satellite-derived map of PM2.5 averaged over 2001-2006. Credit: Dalhousie University, Aaron van Donkelaar
U.S. satellite-derived map of PM2.5 (fine particulate matter which includes sulfates and soot) averaged over 2001-2006. Credit: Dalhousie University, Aaron van Donkelaar

Finally, the human hand may also have played a role in lunar color and brightness. The burning of coal and oil has caused a gradual increase in the amount of human-made sulfate aerosols in the atmosphere since the start of the industrial revolution. According to NASA, at current production levels, human-made sulfate aerosols are believed to outweigh the naturally produced sulfate aerosols. No surprise that the concentration of aerosols is highest in the northern hemisphere where most industrial activity is found.

Isn’t it fascinating that one blood-red Moon can tell us so much about the air we breathe? Thank you again for your participation!

Mobile Launcher Upgraded to Launch NASA’s Mammoth ‘Journey to Mars’ Rocket

Looking up from beneath the enlarged exhaust hole of the Mobile Launcher to the 380 foot-tall tower astronauts will ascend as their gateway for missions to the Moon, Asteroids and Mars. The ML will support NASA's Space Launch System (SLS) and Orion spacecraft during Exploration Mission-1 at NASA's Kennedy Space Center in Florida. Credit: Ken Kremer/kenkremer.com

Looking up from beneath the enlarged exhaust hole of the Mobile Launcher to the 380 foot-tall tower astronauts will ascend as their gateway for missions to the Moon, Asteroids and Mars. The ML will support NASA’s Space Launch System (SLS) and Orion spacecraft during Exploration Mission-1 at NASA’s Kennedy Space Center in Florida. Credit: Ken Kremer/kenkremer.com
Story/photos updated[/caption]

KENNEDY SPACE CENTER, FL – NASA’s Mobile Launcher (ML) is undergoing major upgrades and modifications at the Kennedy Space Center in Florida enabling the massive structure to launch the agency’s mammoth Space Launch System (SLS) rocket and Orion crew capsule on a grand ‘Journey to Mars.’

“We just finished up major structural steel modifications to the ML, including work to increase the size of the rocket exhaust hole,” Eric Ernst, NASA Mobile Launch project manager, told Universe Today during an exclusive interview and inspection tour up and down the Mobile Launcher.

Indeed the Mobile Launcher is the astronauts gateway to deep space expeditions and missions to Mars.

Construction workers are hard at work upgrading and transforming the 380-foot-tall, 10.5-million-pound steel structure into the launcher for SLS and Orion – currently slated for a maiden blastoff no later than November 2018 on Exploration Mission-1 (EM-1).

“And now we have just started the next big effort to get ready for SLS.”

SLS and Orion are NASA’s next generation human spaceflight vehicles currently under development and aimed at propelling astronauts to deep space destinations, including the Moon and an asteroid in the 2020s and eventually a ‘Journey to Mars’ in the 2030s.

Floor level view of the Mobile Launcher and enlarged exhaust hole with 380 foot-tall launch tower astronauts will ascend as their gateway for missions to the Moon, Asteroids and Mars.   The ML will support NASA's Space Launch System (SLS) and Orion spacecraft  for launches from Space Launch Complex 39B the Kennedy Space Center in Florida.  Credit: Ken Kremer/kenkremer.com
Floor level view of the Mobile Launcher and enlarged exhaust hole with 380 foot-tall launch tower astronauts will ascend as their gateway for missions to the Moon, Asteroids and Mars. The ML will support NASA’s Space Launch System (SLS) and Orion spacecraft for launches from Space Launch Complex 39B at the Kennedy Space Center in Florida. Credit: Ken Kremer/kenkremer.com

The mobile launcher was originally built several years ago to accommodate NASA’s less powerful, lighter and now cancelled Ares-1 rocket. It therefore requires extensive alterations to accommodate the vastly more powerful and heavier SLS rocket.

“The ML was initially developed for Ares 1, a much smaller rocket,” Ernst explained to Universe Today.

“So the exhaust hole was much smaller.”

Whereas the Ares-1 first stage booster was based on using a single, more powerful version of the Space Shuttle Solid Rocket Boosters, the SLS first stage is gargantuan and will be the most powerful rocket the world has ever seen.

The SLS first stage comprises two shuttle derived solid rocket boosters and four RS-25 power plants recycled from their earlier life as space shuttle main engines (SSMEs). They generate a combined 8.4 million pounds of thrust – exceeding that of NASA’s Apollo Saturn V moon landing rocket.

Therefore the original ML exhaust hole had to be gutted and nearly tripled in width.

“The exhaust hole used to be about 22 x 22 feet,” Ernst stated.

“Since the exhaust hole was much smaller, we had to deconstruct part of the tower at the base, in place. The exhaust hole had to be made much bigger to accommodate the SLS.”

Construction crews extensively reworked the exhaust hole and made it far wider to accommodate SLS compared to the smaller one engineered and already built for the much narrower Ares-1, which was planned to generate some 3.6 million pounds of thrust.

“So we had to rip out a lot of steel,” Mike Canicatti, ML Construction Manager told Universe Today.

“For the exhaust hole [at the base of the tower], lots of pieces of [existing] steel were taken out and other new pieces were added, using entirely new steel.”

“The compartment for the exhaust hole used to be about 22 x 22 feet, now it’s about 34 x 64 feet.”

Looking down to the enlarged 64 foot wide exhaust hole from the top of NASA’s 380 foot-tall Mobile Launch tower.  Astronauts will board the Orion capsule atop the Space Launch System (SLS) rocket for launches from Space Launch Complex 39B the Kennedy Space Center in Florida.  Credit: Ken Kremer/kenkremer.com
Looking down to the enlarged 64 foot wide exhaust hole from the top of NASA’s 380 foot-tall Mobile Launch tower. Astronauts will board the Orion capsule atop the Space Launch System (SLS) rocket for launches from Space Launch Complex 39B the Kennedy Space Center in Florida. Credit: Ken Kremer/kenkremer.com

In fact this involved the demolition of over 750 tons of old steel following by fabrication and installation of more than 1,000 tons of new steel. It was also reinforced due to the much heavier weight of SLS.

“It was a huge effort and structural engineers did their job. The base was disassembled and reassembled in place” – to enlarge the exhaust hole.

“So basically we gutted major portions of the base out, put in new walls and big structural girders,” Ernst elaborated.

“And we just finished up that major structural steel modification on the exhaust hole.”

Top view across the massive 34 foot-wide, 64 foot-long exhaust hole excavated out of NASA’s Mobile Launcher that will support launches of the Space Launch System (SLS) rocket from Space Launch Complex 39B at the Kennedy Space Center in Florida.  Credit: Ken Kremer/kenkremer.com
Top view across the massive 34 foot-wide, 64 foot-long exhaust hole excavated out of NASA’s Mobile Launcher that will support launches of the Space Launch System (SLS) rocket from Space Launch Complex 39B at the Kennedy Space Center in Florida. Credit: Ken Kremer/kenkremer.com

Meanwhile the 380 foot-tall tower that future Orion astronauts will ascend was left in place.

“The tower portion itself did not need to be disassembled.”

IMG_8393_1a_KSC ML_Ken Kremer

The Ares rockets originally belonged to NASA’s Constellation program, whose intended goal was returning American astronauts to the surface of the Moon by 2020.

Ares-1 was slated as the booster for the Orion crew capsule. However, President Obama cancelled Constellation and NASA’s Return to the Moon soon after entering office.

Since then the Obama Administration and Congress worked together in a bipartisan manner together to fashion a new space hardware architecture and granted approval for development of the SLS heavy lift rocket to replace the Ares-1 and heavy lift Ares-5.

Sending astronauts on a ‘Journey to Mars’ is now NASA’s agency wide and overarching goal for the next few decades of human spaceflight.

But before SLS can be transported to its launch pad at Kennedy’s Space Launch Complex 39-B for the EM-1 test flight the next big construction step has to begin.

“So now we have just started the next big effort to get ready for SLS.”

This involves installation of Ground Support Equipment (GSE) and a wide range of launch support services and systems to the ML.

“The next big effort is the GSE installation contract,” Ernst told me.

“We have about 40+ ground support and facility systems to be installed on the ML. There are about 800 items to be installed, including about 300,000-plus feet of cable and several miles of piping and tubing.”

“So that’s the next big effort to get ready for SLS. It’s about a 1.5 year contract and it was just awarded to J.P. Donovan Construction Inc. of Rockledge, Florida.”

“The work just started at the end of August.”

NASA currently plans to roll the ML into the Vehicle Assembly Building in early 2017 for stacking of SLS and Orion for the EM-1 test flight.

View of NASA’s future SLS/Orion launch pad at Space Launch Complex 39B from atop  Mobile Launcher at the Kennedy Space Center in Florida.  Former Space Shuttle launch pad 39B is now undergoing renovations and upgrades to prepare for SLS/Orion flights starting in 2018. Credit: Ken Kremer/kenkremer.com
View of NASA’s future SLS/Orion launch pad at Space Launch Complex 39B from atop Mobile Launcher at the Kennedy Space Center in Florida. Former Space Shuttle launch pad 39B is now undergoing renovations and upgrades to prepare for SLS/Orion flights starting in 2018. Credit: Ken Kremer/kenkremer.com

The SLS/Orion mounted stack atop the ML will then roll out to Space Launch Complex 39B for the 2018 launch from the Kennedy Space Center.

Pad 39B is also undergoing radical renovations and upgrades, transforming it from its use for NASA’s now retired Space Shuttle program into a modernized 21st century launch pad. Watch for my upcoming story.

Artist concept of the SLS Block 1 configuration.  Credit: NASA
Artist concept of the SLS Block 1 configuration mounted on the Mobile Launcher. Credit: NASA

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

Ken Kremer

United Launch Alliance Atlas V rocket with MUOS-4 US Navy communications satellite poised at pad 41 at Cape Canaveral Air Force Station, FL, set for launch on Sept. 2, 2015. EDT. View from atop NASA’s SLS mobile launcher at the Kenned Space Center. Credit: Ken Kremer/kenkremer.com
View from atop NASA’s SLS mobile launcher at the Kennedy Space Center, looking out to United Launch Alliance Atlas V rocket with MUOS-4 US Navy communications satellite poised at pad 41 at Cape Canaveral Air Force Station, FL, ‘prior to launch on Sept. 2, 2015. EDT. Credit: Ken Kremer/kenkremer.com

Challenge-Watch the Daytime Moon Occult Aldebaran for North America This Friday

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How about that total lunar eclipse this past Sunday? Keep an eye of the waning gibbous Moon this week, as it begins a dramatic dive across the ecliptic towards a series of photogenic conjunctions throughout October.

The Main Event: This week’s highlight is an occultation of the bright +0.9 magnitude star Aldebaran (Alpha Tauri) by the waning gibbous Moon on Friday morning October 2nd.

Image credit: Occult 4.0 software
The occultation footprint for Friday’s occultation of Aldebaran by the Moon, with pre-dawn, dawn and post-dawn zones annotated. Image credit: Occult 4.0 software

This occurs in the pre-dawn hours for Alaskan residents, and under favorable dawn twilight skies along the U.S. and Canadian Pacific west coast; the remainder of the contiguous United States and Canada will see the occultation transpire after sunrise.   This is the 10th of 49 occultations of Aldebaran by the Moon worldwide running from January 29th, 2015 through September 3rd, 2018. The Moon will be at 74% waning gibbous phase, and Aldebaran will disappear behind its illuminated limb to reappear from behind its trailing dark limb.

Check out this amazing Vine of the last occultation of Aldebaran by the Moon courtesy of Andrew Symes @FailedProtostar:

It’s interesting to note that the southern graze-line for the occultation roughly follows the U.S./Mexican border. Seeing a bright star wink in and out from behind the lunar valleys can be an unforgettable sight, adding an eerie 3D perspective to the view. A detailed analysis of the event can even help model the rugged limb of the Moon.

Hunting stars and planets in the daytime can be an interesting feat of visual athletics. We’ve managed to spy Aldebaran near the lunar limb with binoculars during an occultation witnessed from Alaska on September 4th, 1996, and can attest that it’s quite possible to see a +1st magnitude star near the Moon with optical aid. A clear blue sky is key.  The Greek philosopher Thales noted that stars could be seen from the bottom of a well (though perhaps he’d fallen down a well or two too many in his time)… Friday’s event should push your local seeing to its limits. Start tracking Aldebaran before local sunrise, and you should be able to follow it all the way to the lunar limb, clear skies willing.

Image credit: Dave Dickinson/Stellarium
The occultation path for various locales across the United States Friday morning. Image credit: Dave Dickinson/Stellarium

Here’s a listing of times for key events for Friday from around the U.S. Check out The International Occultation Timing Association’s page for the event for an extensive listing:

Image credit: Dave Dickinson
Key times for the occultation for the same locales depicted in the graphic above, along with the lunar elevation (altitude) above the local horizon at the time noted. Image credit: Dave Dickinson

And whenever the Moon meets Aldebaran, it has to cross the open star cluster of the Hyades to get there, meaning there’ll be many other worthy occultations of moderately bright stars around October 2nd as well.  Gamma Tauri, 75 Tauri, Theta^1 Tauri, and SAO93975 are all occulted by the Moon on the morning of October 2nd leading up to the Aldebaran occultation; particularly intriguing is the grazing occultation of +5 magnitude 75 Tauri across the Florida peninsula.

The path of the moon through the Hyades this weekend. Image credit: Starry Night Education software
The path of the Moon through the Hyades this weekend. Image credit: Starry Night Education software

Fun fact: the Moon can, on occasion, occult members of the M45 Pleiades star cluster as well, as last occurred in 2010, and will next occur on 2023.

Chasing the Moon through October

Follow that Moon for the following dates with astronomical destiny worldwide:

  • The Moon reaches Last Quarter phase on Sunday, October 4th at 21:06 UT/5:06 PM EDT.
  • A close pass with Venus on October 8th, with a brilliant occultation visible in the pre-dawn hours from Australia.
  • A tight photogenic grouping of the Moon, Mars and Jupiter in a four degree circle on the morning on October 9th;
  • A close pass of the Moon just 36 hours from New near Mercury on the morning of Sunday, October 11th, with another occultation of the planet visible from Chile at dawn;
  • And finally, New Moon (sans eclipse, this time) occurring at 00:06 UT on October 13th, marking the start of lunation 1148.

Why occultations? Consider the wow factor; light from Aldebaran left about 65 years ago, before the start of the Space Age, only to get ‘photobombed’ by the occulting Moon at the last moment. Four bright stars (Regulus, Spica, Antares and Aldebaran) lie along the Moon’s path in our current epoch. Dial the celestial scene back about two millennia ago, and the Moon was also capable of occulting the bright star Pollux in the astronomical constellation of Gemini as well.

We’ll be running video for the event clear skies willing Friday morning here from Hudson, Florida in the Tampa Bay area. And as always, let us know of your tales of astronomical tribulation and triumph!

First Lunar Eclipse Ever Photographed with a Transit of the ISS

A montage of images taken during the lunar eclipse on September 28, 2015, as see from Rambouillet, France. ISS transit duration (total): 1.7 seconds. This is the first time an ISS transit has been photographed during an eclipse. Credit and copyright: Thierry Legault.

To our knowledge, this is the first time anyone has ever photographed a transit of the International Space Station of the Moon DURING a lunar eclipse. And guess who did it?

Not surprisingly, it was the legendary astrophotographer Thierry Legault.
Usually, Thierry will travel up to thousands of miles to capture unique events like this, but this time, he only had to go 10 miles!

“Even if I caught a cold, I could not miss it,” Thierry told Universe Today in an email. “The Moon was very low on the horizon, only 16 degrees, so the seeing was not very good, but at least the sky was clear.”

Still, a stunning — and singularly unique — view of the “Super Blood Moon” eclipse!

See the video below:

It was a quick pass, with the ISS transit duration lasting a total of 1.7 seconds. Thierry uses CalSky to calculate where he needs to be to best capture an event like this, then studies maps, and has a radio synchronized watch to know very accurately when the transit event will happen.

In a previous article on Universe Today, Legault shared how he figures out the best places to travel to from his home near Paris to get the absolute best shots:

“For transits I have to calculate the place, and considering the width of the visibility path is usually between 5-10 kilometers, but I have to be close to the center of this path,” Legault explained, “because if I am at the edge, it is just like an eclipse where the transit is shorter and shorter. And the edge of visibility line of the transit lasts very short. So the precision of where I have to be is within one kilometer.”

Here’s the specs: ISS Speed: 25000 km/h (15500 mph). ISS Distance: 1100 km; Moon distance: 357,000 km (320x).

You can see other imagery from around the world of the lunar eclipse here, with images taken by Universe Today readers and staff.

Earlier this year, Thierry captured an ISS transit during the March 20, 2015 SOLAR eclipse, which you can see here.

Universe Today’s David Dickinson said he’s been trying to steer people towards trying to capture an ISS transit during a lunar eclipse for quite some time, and concurred that Thierry’s feat is a first. Dave made a video earlier this year to explain how people might photograph it during the April 2015 lunar eclipse, but unfortunately, no astrophotographers had any luck.

Thanks again to Thierry Legault for sharing his incredible work with Universe Today. Check out his website for additional imagery and information.

You can also see some of Legault’s beautiful and sometimes ground-breaking astrophotography here on Universe Today, such as images of the space shuttle or International Space Station crossing the Sun or Moon, or views of spy satellites in orbit.

If you want to try and master the art of astrophotography, you can learn from Legault by reading his book, “Astrophotography,” which is available on Amazon in a large format book or as a Kindle edition for those who might like to have a lit version while out in the field. It is also available at book retailers like Barnes and Noble and Shop Indie bookstores, or from the publisher, Rocky Nook, here.

A Bloody Beautiful Supermoon Eclipse!

"The red Moon did not disappoint tonight," writes Arnar Kristjansson. Credit: Arnar Kristjansson

Like some of you, I outran the clouds just in time to catch last night’s total lunar eclipse. What a beautiful event! Here are some gorgeous pictures from our readers and Universe Today staff — souvenirs if you will — of the last total lunar eclipse anywhere until January 31, 2018. The sky got so dark, and the Moon hung like a plum in Earth’s shadow for what seemed a very long time. Did you estimate the Moon’s brightness on the Danjon Scale? My brother and I both came up with L=2 from two widely-separated locations; William Wiethoff in Hayward, Wisconsin rated it L=1. All three estimates would indicate a relatively dark eclipse.

Nicely-done sequence of eclipse phases taken early September 28, 2015. Credit: Own Llewellyn
Nicely-done sequence of eclipse phases taken early September 28, 2015. Click to enlarge. Credit: Own Llewellyn

The darkness of the umbra was particularly noticeable in the west quarter of the Moon in the giant volcanic plain known as Oceanus Procellarum. This makes sense as that portion of the Moon was located closest to the center of the Earth’s dark, inner umbra. The plain is also dark compared to the brighter lunar highlights, which being more reflective, formed a sort of pale ring around the northern rim of the lunar disk.

Salute to the eclipse! Credit: Jason Major
Salute to the final eclipse of the current tetrad that began 17 months ago.  Credit: Jason Major

The bottom or southern rim of the Moon, located farthest from the center of the umbra, appeared a lighter yellow-orange throughout totality.

Wide angle view of the Moon during totality in star-rich sky with the Aquila Milky visible at right. Credit: Bob King
Wide angle view of the Moon (lower left) during totality in a star-rich sky with the Aquila Milky Way visible at right. Credit: Bob King

This is just a small sampling of the excellent images arriving from our readers. More are flowing in on Universe Today’s Flickr site.  Thank you everyone for your submissions!

A crowd gather to watch the Moon during partial eclipse prior to totality. Credit: Robert Sparks
A crowd gather to watch the Moon during partial eclipse prior to totality. Credit: Robert Sparks
A hint of the penumbra shows in this photo. Hint: look near left top. Credit: Roger Hutchinson
A hint of the penumbra shows in this photo. Hint: look near left top. Credit: Roger Hutchinson
A bloody Moon iindeed! Credit: Chris Lyons
A bloody Moon iindeed! Notice how dark Oceanus Procellarum (top) appears. Credit: Chris Lyons
"Super Blood Moon". Credit: Alok SInghal
“Super Blood Moon”. Credit: Alok Singhal
Nice montage of images from eclipse start to finish. Credit: Mike Greenham
Nice montage of images from eclipse start to finish. Credit: Mike Greenham
One of the most awesome aspects of the eclipse was how many stars could be seen near the Moon. This picture was taken with a 100mm telesphoto lens. Credit: Bob King
One of the most awesome aspects of the eclipse was how many stars could be seen near the Moon. This picture was taken with a 100mm telesphoto lens. Credit: Bob King
Rare shot of the totally eclipsed Moon and bright meteor. Credit: VegaStar Carpentier Photography
Rare shot of the totally eclipsed Moon and bright meteor. Credit: VegaStar Carpentier Photography
A lucky break in the clouds made this photographer happy. Credit: Moe Ali
A lucky break in the clouds made this photographer happy. Credit: Moe Ali
Mary Spicer made exposures every 5 minutes. During totality the Moon dropped behind a tree so I had to relocate the camera, hence the small gap in the sequence. 35 shots in total, stacked using StarStax. Credit: Mary Spicer
Mary Spicer made exposures of the eclipsed Moon every 5 minutes. During totality, the Moon dropped behind a tree so she had to relocate the camera, hence the small gap in the sequence. 35 shots in total and stacked into one frame using StarStax. Credit: Mary Spicer
The Moon caught after totality between clouds through a small refracting telescope. Credit: Bob King
The Moon caught after totality between clouds through a small refracting telescope. Credit: Bob King
Another nice montage displaying all the partial phases, early, mid and late totality. Credit: Andre van der Hoeven
Another fine montage displaying all the partial phase plus early, mid and late totality. Credit: Andre van der Hoeven

How to (Hopefully) Find Clear Skies for Tonight’s Total Lunar Eclipse

Weather looking a bit iffy tonight? Using the resources described below, you just might be able to escape the clouds. Credit: Bob King

We’ve arrived at eclipse day, so now the big question is, will it be clear? My favorite forecast for major astronomical events reads something like this: Fair skies tonight with light winds and lows in the middle 50s.While I hope that’s exactly what’s predicted for your town, in my corner of the world we’re expecting “increasing clouds with a chance for thunderstorms”.

That’s just not nice. Same by you? Here’s how to find that clear spot if you’re facing bad weather tonight.

One of my favorite cloud-checking sites is the GOES East view of the U.S., Canada and Central America taken from geostationary orbit. Credit: NASA
One of my favorite cloud-checking sites is the GOES East view of the U.S., Canada and Central America taken from geostationary orbit. This map shows the scene at 10:45 a.m. CDT this morning. Credit: NASA

I usually check the GOES (Geostationary Operational Environmental Satellite) images that weather forecasters use to display and animate the movement of clouds and weather fronts during the nightly newscasts. Once I know the location and general drift of the clouds, I get in a car and drive to where it’s likely to either remain or become clear. Depending on the “magnitude” of the event I might drive 50 to 150 miles. If nothing else, doing astronomy guarantees many adventures.

GOES West view of the western U.S., Canada and Hawaii taken at 11 a.m. CDT. Credit: NASA
GOES West view of the western U.S., Canada and Hawaii taken at 11 a.m. CDT. Credit: NASA

You’ll find these most helpful images at either the GOES East site, which features a photo of the entire mainland U.S., Central America and much of Canada, updated every 15 minutes. Since the satellite taking the photos is centered over the 75° west parallel of longitude, its focus is primarily the eastern two-thirds of the U.S. and Canada. For the western U.S., western Canada and Hawaii, head over to the GOES West site.

After you set the width and height to maximum values, you'll get a picture like this which was taken at 11 a.m. CDT and features the upper and lower Midwest. Credit: NASA
After you set the width and height to maximum values, you’ll get a picture like this, taken at 11 a.m. CDT. Credit: NASA

Once there, you’ll be presented with a big picture view of the U.S., etc., but you can click anywhere on the map for a zoomed-in look at a particular region. Before you do, set the “width” and “height” boxes to their maximum values of 1400 (width) and 1000 (height). That way you’ll get a full-screen, nifty, 1-kilometer image when you go in close. All images have a time stamp in the upper left corner given in Universal or Greenwich Mean Time (GMT). Subtract 4 hours to convert to Easter Daylight; 5 for CDT; 6 for MDT and 7 for PDT.

You can check back all day long for fresh photos and watch the march of the clouds over time. Or you can have the site assemble up to 30 of the most recent images into an animation loop and watch it as a movie. Combing current photos, the animation and your local forecast will inform your plans about whether to remain at home to watch the eclipse or get the heck out of town.

Infrared image of the east-central U.S. at 11 a.m. CDT today. Credit: NASA
Infrared image of the east-central U.S. at 11 a.m. CDT today. Clouds can be seen and tracked at night using the infrared channel on the GOES East and West sites. Credit: NASA

When night arrives, you can still get a reasonably good idea of where the clouds are and aren’t by clicking on the infrared channel link at the top of the site. I also like to use the NCAR (National Center for Atmospheric Research Real-Time Weather Data) site. They offer a black and white infrared option that provides a clearer picture. At the site, select your “channel” then click on one of the regional acronyms on the interactive U.S. map.

So far, we’ve been talking about the weather in real time. When it comes to forecasts, one of the most useful tools of all and a true godsend to amateur astronomers is Attilla Danko’s ClearDarkSky site. Click on the Clear Sky Charts link to access interactive charts for thousands of locations across the U.S., Canada and parts of Mexico. For example, if you click on Illinois, you’ll get a list of sky conditions for 105 locations throughout the state. The Chicago link pops up six rows of data-packed squares with colors ranging from deep blue to white.

The cloud cover forecast for Chicago for the next day as depicted in Attilla Danko's Clear Dark Sky site. Copyright: Attilla Danko
The cloud cover forecast for Chicago today Sept. 27 through early Tuesday Sept. 29 as depicted in Attilla Danko’s Clear Dark Sky site. The forecasts can be sponsored for a donation by various groups or individuals. This one is by the Chicago Astronomical Society. Copyright: Attilla Danko

The first row indicates cloud clover with varying shades of blue representing the percentage of clear sky. Medium blue means partly cloudy; white indicates 100% overcast. Additional data sets include sky transparency, seeing conditions, hours of darkness, wind, temperature and humidity. While no forecast is 100% accurate, the reliability of the models Danko uses makes Clear Sky Charts one of best tools available for skywatchers. Want a real treat? If you click on one of the squares in the Cloud Cover row, a large image showing cloud cover at the time will pop up. You’ll also find another, more general interactive cloud forecast graphic at WeatherForYou.com.

Thanks to a helpful reader suggestion, I recently learned of Clear Outside, a forecasting site similar to Clear Sky Charts but worldwide. Be sure to check it out. Satellite imagery like the U.S. GOES East and West is available for European and African observers at Sat24.

So what does the U.S. look like for weather tonight? Mostly clear skies are expected from New York State up through Maine, across the center of the country, the desert Southwest and the Northwest. Expect partly cloudy conditions (with some mostly cloudy spots) for the Upper and central Midwest, and mostly cloudy to overcast skies in the southern and southeastern seaboard states.

But who knows? By using these sites, you might just improve your chances of seeing what promises to be a spectacular lunar eclipse tonight. Some of you reading this undoubtedly have your own favorite weather hangouts. Please share them with us in the comments section. The more the merrier!

As always, if you’re completely shut out, here are a few sites where you can watch it live on the Web:

What Color Is the Moon? A Simple Science Project For Sunday Night’s Eclipse

Depending on how clear the atmosphere is, the Moon's color can vary dramatically from one eclipse to another. The numbers, called the Danjon Scale, will help you estimate the color of Sunday night's eclipse. Credit: Bob King

There are many ways to enjoy tomorrow night’s total lunar eclipse. First and foremost is to sit back and take in the slow splendor of the Moon entering and exiting Earth’s colorful shadow. You can also make pictures, observe it in a telescope or participate in a fun science project by eyeballing the Moon’s brightness and color. French astronomer Andre Danjon came up with a five-point scale back in the 1920s to characterize the appearance of the Moon during totality. The Danjon Scale couldn’t be simpler with just five “L values” from 0 to 4:

L=0: Very dark eclipse. Moon almost invisible, especially at mid-totality.
L=1: Dark Eclipse, gray or brownish in coloration. Details distinguishable only with difficulty.
L=2: Deep red or rust-colored eclipse. Very dark central shadow, while outer edge of umbra is relatively bright.
L=3: Brick-red eclipse. Umbral shadow usually has a bright or yellow rim.
L=4: Very bright copper-red or orange eclipse. Umbral shadow has a bluish, very bright rim.

The Danjon Scale is used to estimate the color of the totally eclipsed moon. By making your own estimate, you can contribute to atmospheric and climate change science. Credit: Alexandre Amorim
The Danjon Scale is used to estimate the color of the totally eclipsed moon. By making your own estimate, you can contribute to atmospheric and climate change science. Credit: Alexandre Amorim

The last few lunar eclipses have been bright with L values of 2 and 3. We won’t know how bright totality will be during the September 27-28 eclipse until we get there, but chances are it will be on the bright side. That’s where you come in. Brazilian amateur astronomers Alexandre Amorim and Helio Carvalho have worked together to create a downloadable Danjonmeter to make your own estimate. Just click the link with your cellphone or other device and it will instantly pop up on your screen.

On the night of the eclipse, hold the phone right up next to the moon during mid-eclipse and estimate its “L” value with your naked eye. Send that number and time of observation to Dr. Richard Keen at [email protected]. For the sake of consistency with Danjon estimates made before mobile phones took over the planet, also compare the moon’s color with the written descriptions above before sending your final estimate.

Graph showing the change in heating of the ground in fractions of degrees (vertical axis) as affected by volcanic eruptions and greenhouse warming since 1979. The blue shows volcanic cooling, the red shows greenhouse warming. Notice the rising trend in warming after 1996. Credit: Dr. Richard Keen
Graph showing the change in heating of the ground in fractions of degrees (vertical axis) as affected by volcanic eruptions and greenhouse warming since 1979. The blue shows volcanic cooling, the red shows greenhouse warming. Notice the rising trend in warming after 1996. Credit: Dr. Richard Keen

Keen, an emeritus professor at the University of Colorado-Boulder Department of Atmospheric and Oceanic Sciences, has long studied how volcanic eruptions affect both the color of the eclipsed moon and the rate of global warming. Every eclipse presents another opportunity to gauge the current state of the atmosphere and in particular the dustiness of the stratosphere, the layer of air immediately above the ground-hugging troposphere. Much of the sunlight bent into Earth’s shadow cone (umbra) gets filtered through the stratosphere.

Volcanoes like Mt. Pinatubo, which erupted in June 1991 in the Philippines, inject tremendous quantities of ash and sulfur compounds high into the atmosphere, where they can temporarily block the sunlight and cause a global drop in temperature. Credit: USGS
Volcanoes like Mt. Pinatubo, which erupted in June 1991 in the Philippines, inject tremendous quantities of ash and sulfur compounds high into the atmosphere, where they can temporarily block sunlight and cause a global drop in temperature. Credit: USGS

Volcanoes pump sulfur compounds and ash high into the atmosphere and sully the otherwise clean stratosphere with volcanic aerosols. These absorb both light and solar energy, a major reason why eclipses occurring after a major volcanic eruption can be exceptionally dark with L values of “0” and “1”.

The moon was so dark during the December 1982 eclipse that Dr. Keen required a 3-minute-long exposure at ISO 160 to capture it. Credit: RIchard Keen
The moon was so dark during the December 1982 eclipse that Dr. Keen required a 3-minute-long exposure at ISO 160 to capture it. Credit: Richard Keen

One of the darkest in recent times occurred on December 30, 1982 after the spectacular spring eruption of Mexico’s El Chichon that hurled some 7 to 10 million tons of ash into the atmosphere. Sulfurous soot circulated the globe for weeks, absorbing sunlight and warming the stratosphere by 7°F (4°C).

A chromolithograph from the German astronomy magazine "Sirius" compares the dark and featureless lunar disk during the eclipse a year after the eruption of Krakatoa (left) with a bright eclipse four years later, after the volcanic aerosols had settled out of the stratosphere (right).
Lithograph from the German astronomy magazine Sirius compares the dark, featureless lunar disk during the 1884 eclipse a year after the eruption of Krakatoa (left) with a bright eclipse four years later, after the volcanic aerosols had settled out of the stratosphere (right).

Meanwhile, less sunlight reaching the Earth’s surface caused the northern hemisphere to cool by 0.4-0.6°C. The moon grew so ashen-black during totality that if you didn’t know where to look, you’d miss it.

Two photos of Earth’s limb or horizon from orbit at sunset before and after the Mt. Pinatubo eruption. The top view shows a relatively clear atmosphere, taken August 30,1984. The bottom photo was taken August 8, 1991, less than two months after the eruption. Two dark layers of aerosols between 12 and 15 miles high make distinct boundaries in the atmosphere. Credit: NASA
Two photos of Earth’s limb or horizon from orbit at sunset before and after the Mt. Pinatubo eruption. The top view shows a relatively clear atmosphere, taken August 30,1984. The bottom photo was taken August 8, 1991, less than two months after the eruption. Two dark layers of aerosols between 12 and 15 miles high make distinct boundaries in the atmosphere. Credit: NASA

Keen’s research focuses on how the clean, relatively dust-free stratosphere of recent years may be related to a rise in the rate of global warming compared to volcano-induced declines prior to 1996. Your simple observation will provide one more data point toward a better understanding of atmospheric processes and how they relate to climate change.

This map shows the Moon during mid-eclipse at 9:48 p.m. CDT. Selected stars are labeled with their magnitudes. Use these stars to help you estimate the Moon's magnitude by looking at the Moon through the backwards through binoculars. Source: Stellarium
This map shows the Moon during mid-eclipse at 9:48 p.m. CDT. Selected stars are labeled with their magnitudes. Examine the Moon backwards through binoculars and find a star it most closely matches to determine its magnitude. If for instance, the Moon looks about halfway in brightness between Hamal and Deneb, then it’s magnitude 1.6. Click to enlarge. Source: Stellarium

If you’d like to do a little more science during the eclipse, Keen suggests examining the moon’s color just after the beginning and before the end of totality to determine an ‘L’ value for the outer umbra.  You can also determine the moon’s overall brightness or magnitude at mid-eclipse by comparing it to stars of known magnitude. The best way to do that is to reduce the moon down to approximately star-size by looking at it through the wrong end of a pair of 7-10x binoculars and compare it to the unreduced naked eye stars. Use this link for details on how it’s done along with the map I’ve created that has key stars and their magnitudes.

The table below includes eclipse events for four different time zones with emphasis on mid-eclipse, the time to make your observation. Good luck on Sunday’s science project and thanks for your participation!

Eclipse Events Eastern Daylight Time (EDT) Central Daylight Time (CDT) Mountain Daylight Time (MDT) Pacific Daylight Time (PDT)
Penumbra first visible 8:45 p.m. 7:45 p.m. 6:45 p.m. 5:45 p.m.
Partial eclipse begins 9:07 p.m. 8:07 p.m. 7:07 p.m. 6:07 p.m.
Total eclipse begins 10:11 p.m. 9:11 p.m. 8:11 p.m. 7:11 p.m.
Mid-eclipse 10:48 p.m. 9:48 p.m. 8:48 p.m. 7:48 p.m.
Total eclipse ends 11:23 p.m. 10:23 p.m. 9:23 p.m. 8:23 p.m.
Partial eclipse ends 12:27 a.m. 11:27 p.m. 10:27 p.m. 9:27 p.m.
Penumbra last visible 12:45 a.m. 11:45 p.m. 10:45 p.m. 9:45 p.m.

Sunday Night: Getting Ready For a ‘Super-Harvest-Blood-Moon Total Lunar Eclipse’

Image Credit:

So, heard the one about this weekend’s impending ‘Super-Harvest-Blood-Moon eclipse?’ Yeah, us too. Have no fear; fortunately for humanity, the total lunar eclipse transpiring on Sunday night/Monday morning is a harbinger of nothing more than a fine celestial spectacle, clear skies willing.

This final eclipse of the ongoing lunar tetrad has some noteworthy events worth exploring in terms of science and lore.

The Supermoon Total Lunar Eclipse of September 27-28 2015 from Michael Zeiler on Vimeo.

The Specifics: First, you almost couldn’t ask for better timing. This weekend’s total lunar eclipse occurs during prime time Sunday night for North and South America, and early Monday morning for Europe, Africa and most of the Middle East. This means the Atlantic Region and surrounding areas will see totality in its entirety. This eclipse occurs very near the northward equinoctial point occupied by the Sun during the Northern Hemisphere Spring equinox in March. The date says it all: this eclipse coincides with the Harvest Moon for 2015, falling just under five days after the September equinox.

Early cloud cover prospects for Sunday night over the contiguous United States. Image credit: The National Weather Service
Early cloud cover prospects for Sunday night over the contiguous United States. Image credit: The National Weather Service

For saros buffs, Sunday’s eclipse is part of lunar saros series 137, member 28 of 81. This saros started back in 1564 and produced its first total lunar eclipse just two cycles ago on September 6th 1979. Saros 137 runs all the way out to its final eclipse on April 20th, 2953 AD.  

And yes, this upcoming total lunar eclipse occurs very near the closest lunar perigee for 2015. How rare are ‘Supermoon’ lunar eclipses? Well, we took a look at the phenomenon, and found 15 total lunar eclipses occurring near lunar perigee for the current century:

Image credit:
Perigee eclipses for the 21st century. To make the cut, a total lunar eclipse needed to occur within 24 hours of lunar perigee.  Image credit: Dave Dickinson

You’ll note that four saroses (the plural of saros) are producing perigee or ‘Proxigean’ total lunar eclipses during this century, including saros 137.

Does the perigee Moon effect the length of totality? It’s an interesting question. Several factors come into play that are worth considering for Sunday night’s eclipse. First, the Moon moves a bit faster near perigee as per Kepler’s second law of motion. Second, the Moon is a shade larger in apparent size, 34’ versus 29’ near apogee. Lastly, the conic section of the Earth’s shadow or umbra is a bit larger closer in; you can fit three Moons side-by-side across the umbra around 400,000 kilometers out from the Earth. Sunday night’s perigee occurs 65 minutes after Full Moon at 2:52 UT/10:52 PM EDT. Perigee Sunday night is 356,876 kilometers distant, the closest for 2015 by just 115 kilometers, and just under 500 kilometers short of the closest perigee that can occur. This is, however, the closest perigee time-wise to lunar totality for the 21st century; you have to go all the way back to 1897 to find one closer, at just four minutes apart.

Image credit:
An 1888 depiction of a total lunar eclipse. Image credit: E. Weib, Bilderatlas de Sternenwelt

Now, THAT was and eclipse!

This all culminates in a period for totality on Sunday night of just under 72 minutes in duration, 35 minutes shy of the maximum possible for a central total lunar eclipse. An eclipse won’t top this weekend’s in terms of duration until January 31st 2018.

 

Here are the key times to watch for on Sunday night:

Penumbral phase begins: 00:12 UT/8:12 PM EDT (on the 27th)

Partial phase begins: 1:07 UT/9:07 PM EDT

Totality begins: 2:11 UT/10:11 PM EDT

Totality ends: 3:23 UT/11:23 PM EDT

Partial phase ends: 4:27 UT/00:27 AM EDT

Penumbral phase ends: 5:22 UT/1:22 AM EDT

Note that one 18 year 11 day and 8 hour saros period later, saros 137 will again produce a perigee eclipse nearly as close as this weekend’s on October 8th, 2033.

The classic hallmark of any total lunar eclipse is the reddening of the Moon. You’re seeing the combination of all the world’s sunsets, refracted into the inky umbra of the Earth and cast upon the surface of the Moon. To date, no human has stood upon the surface of the Moon and gazed upon the spectacle of a solar eclipse caused by the Earth.

Image credit:
The orientation of the Sun and Earth as seen from the Moon during Sunday night’s eclipse. Image credit: Stellarium

Not all eclipses are created equal when it comes to hue and color. The amount of dust and aerosols suspended in the atmosphere can conspire to produce anything from a bright, yellowish-orange tint, to a brick dark eclipse where the Moon almost disappears from view entirely. The recent rapid fire tetrad of four eclipses in 18 months has provided a good study in eclipse color intensity. The deeper the Moon dips into the Earth’s shadow, the darker it will appear… last April’s lunar eclipse was just barely inside the umbra, making many observers question if the eclipse was in fact total at all.

Image credit:
Refraction of sunlight during a total lunar eclipse. Image credit: Raycluster/Public Domain

We the describe color of the eclipsed Moon in terms of its number on the Danjon scale, and recent volcanic activity worldwide suggests that we may be in for a darker than normal eclipse… but we could always be in for a surprise!

Old time mariners including James Cook and Christopher Columbus used positional measurements of the eclipsed Moon at sea versus predictions published in almanac tables for land-based observatories to get a one-time fix on their longitude, a fun experiment to try to replicate today. Kris Columbus also wasn’t above using beforehand knowledge of an impending lunar eclipse to help get his crew out of a tight jam.

Image credit:
A long timelapse of totality during a 2003 total lunar eclipse, back from the glorious days of film. Image credit: Dave Dickinson

And speaking of the next perigee Moon total lunar eclipse for saros 137 on October 8th, 2033…  if you catch that one, this weekend’s, and saw the September 16th, 1997 lunar eclipse which spanned the Indian Ocean region, you’ll have completed an exeligmos, or a triple saros of eclipses in the same series 54 years and 33 days in length, an exclusive club among eclipse watchers and a great word to land on a triple letter word score in Scrabble…

Exeligmos is also the title of one of our original scifi tales involving eclipses, along with Shadowfall.

Image credit:
The 2010 winter solstice eclipse. Image credit: Dave Dickinson

Here’s another neat challenge: the International Space Station makes two shadow passes during the lunar eclipse over the contiguous United States. The first one occurs during totality, and spans from eastern Louisiana to central Maine from 2:14 to 2:20 UT; the second pass occurs during the final partial phases of the eclipse spanning from southern Arizona to Lake Superior from 3:47 to 3:54 UT. These are un-illuminated shadow passes of the ISS. Observers have captured transits of the ISS during a partial solar eclipse, but to our knowledge, no one has ever caught a transit of the ISS during a total lunar eclipse; ISS astros should also briefly be able to spy the eclipsed Moon from their orbital vantage point. CALSky will have refined passage times about 48 hours prior to Sunday.

Image credit:
Projections for ISS shadow passes across the Moon during Sunday night’s eclipse. The first path occurs during totality, and the second during the final partial phases of the eclipse. Image credit: Dave Dickinson/calculations from CALSky

Clouded out? Live on the wrong side of the planet? The good folks at the Virtual Telescope Project have got you covered, with a live webcast of the total lunar eclipse starting at 1:00 UT/9:00 PM EDT.

Image credit:
Image credit: The Virtual Telescope Project

And as the eclipse draws to an end, the question of the hour always is: when’s the next one? Well, the next lunar eclipse is a dim penumbral on March 23rd, 2016, which follows a total solar eclipse for southeastern Asia on March 9th, 2016… but the next total lunar won’t occur until January 31st, 2018, which also happens to be the second Full Moon of the month… a ‘Blue Blood Moon Eclipse?’

Sorry, we had to go there. Hey, we could make the case for Sunday’s eclipse also occurring on World Rabies Day, but perhaps a ‘Rabies Eclipse’ just doesn’t have the SEO traction. Don’t fear the Blood Moon, but do get out and watch the final lunar eclipse of 2015 on Sunday night!

China Plans Lunar Far Side Landing by 2020

This time-lapse color panorama from China’s Chang’e-3 lander shows the Yutu rover at two different positions during its trek over the Moon’s surface at its landing site from Dec. 15-18, 2013. This view was taken from the 360-degree panorama. Credit: CNSA/Chinanews/Ken Kremer/Marco Di Lorenzo. See our complete Yutu timelapse pano at NASA APOD Feb. 3, 2014: http://apod.nasa.gov/apod/ap140203.htm

China plans lunar far side landing with hardware similar to Chang’e-3 lander
This time-lapse color panorama from China’s Chang’e-3 lander shows the Yutu rover at two different positions during its trek over the Moon’s surface at its landing site from Dec. 15-18, 2013. This view was taken from the 360-degree panorama. Credit: CNSA/Chinanews/Ken Kremer/Marco Di Lorenzo.
See our complete Yutu timelapse pano at NASA APOD Feb. 3, 2014: [/caption]

China aims to land a science probe and research rover on the far side of the Moon by 2020, say Chinese officials.

Chinese scientists plan to carry out the highly complex lunar landing mission using a near identical back up to the nations highly successful Chang’e-3 rover and lander – which touched down in December 2013.

If successful, China would become the first country to accomplish the history making task of a Lunar far side landing.

“The mission will be carried out by Chang’e-4, a backup probe for Chang’e-3, and is slated to be launched before 2020,” said Zou Yongliao from the moon exploration department under the Chinese Academy of Sciences, according to a recent report in China’s government owned Xinhua news agency.

Zou made the remarks at a deep-space exploration forum in China.

“China will be the first to complete the task if it is successful,” said Zou.

Chinese space scientists have been evaluating how best to utilize the Chang’e-4 hardware, built as a backup to Chang’e-3, ever since China’s successful inaugural soft landing on the Moon was accomplished by Chang’e-3 in December 2013 with the mothership lander and piggybacked Yutu lunar rover.

Chang’e-3/Yutu Timelapse Color Panorama  This newly expanded timelapse composite view shows China’s Yutu moon rover at two positions passing by crater and heading south and away from the Chang’e-3 lunar landing site forever about a week after the Dec. 14, 2013 touchdown at Mare Imbrium. This cropped view was taken from the 360-degree timelapse panorama. See complete 360 degree landing site timelapse panorama herein and APOD Feb. 3, 2014. Chang’e-3 landers extreme ultraviolet (EUV) camera is at right, antenna at left. Credit: CNSA/Chinanews/Ken Kremer/Marco Di Lorenzo – kenkremer.com.   See our complete Yutu timelapse pano at NASA APOD Feb. 3, 2014:  http://apod.nasa.gov/apod/ap140203.htm
Chang’e-3/Yutu Timelapse Color Panorama This newly expanded timelapse composite view shows China’s Yutu moon rover at two positions passing by crater and heading south and away from the Chang’e-3 lunar landing site forever about a week after the Dec. 14, 2013 touchdown at Mare Imbrium. This cropped view was taken from the 360-degree timelapse panorama. See complete 360 degree landing site timelapse panorama herein and APOD Feb. 3, 2014. Chang’e-3 landers extreme ultraviolet (EUV) camera is at right, antenna at left. Credit: CNSA/Chinanews/Ken Kremer/Marco Di Lorenzo – kenkremer.com. See our complete Yutu timelapse pano at NASA APOD Feb. 3, 2014: http://apod.nasa.gov/apod/ap140203.html

Plans to launch Chang’e-4 in 2016 were eventually abandoned in favor of further evaluation.

After completing an intense 12 month study ordered by China’s government, space officials confirmed that the lunar far side landing was the wisest use of the existing space hardware.

Chang’e-4 will be modified with a larger payload.

“Chang’e-4 is very similar to Chang’e-3 in structure but can handle more payload,” said Zou.

“It will be used to study the geological conditions of the dark side of the moon.”

The moon is tidally locked with the Earth so that only one side is ever visible. But that unique characteristic makes it highly attractive to scientists who have wanted to set up telescopes and other research experiments on the lunar far side for decades.

“The far side of the moon has a clean electromagnetic environment, which provides an ideal field for low frequency radio study. If we can can place a frequency spectrograph on the far side, we can fill a void,” Zou elaborated.

China will also have to launch another lunar orbiter in the next few years to enable the Chang’e-4 lander and rover to transmit signals and science data back to Chinese mission control on Earth.

In the meantime, China already announced its desire to forge ahead with an ambitious mission to return samples from the lunar surface later this decade.

The Chinese National Space Agency (CNSA) plans to launch the Chang’e-5 lunar sample return mission in 2017 as the third step in the nations far reaching lunar exploration program.

“Chang’e-5 will achieve several breakthroughs, including automatic sampling, ascending from the moon without a launch site and an unmanned docking 400,000 kilometers above the lunar surface,” said Li Chunlai, one of the main designers of the lunar probe ground application system, accoding to Xinhua.

The first step involved a pair of highly successful lunar orbiters named Chang’e-1 and Chang’e-2 which launched in 2007 and 2010.

The second step involved the hugely successful Chang’e-3 mothership lander and piggybacked Yutu moon rover which safely touched down on the Moon at Mare Imbrium (Sea of Rains) on Dec. 14, 2013 – marking China’s first successful spacecraft landing on an extraterrestrial body in history, and chronicled extensively in my reporting here at Universe Today.

360-degree time-lapse color panorama from China’s Chang’e-3 lander. This new 360-degree time-lapse color panorama from China’s Chang’e-3 lander shows the Yutu rover at five different positions, including passing by crater and heading south and away from the Chang’e-3 lunar landing site forever during its trek over the Moon’s surface at its landing site from Dec. 15-22, 2013 during the 1st Lunar Day. Credit: CNSA/Chinanews/Ken Kremer/Marco Di Lorenzo – kenkremer.com.  See our Yutu timelapse pano at NASA APOD Feb. 3, 2014: http://apod.nasa.gov/apod/ap140203.htm
360-degree time-lapse color panorama from China’s Chang’e-3 lander. This new 360-degree time-lapse color panorama from China’s Chang’e-3 lander shows the Yutu rover at five different positions, including passing by crater and heading south and away from the Chang’e-3 lunar landing site forever during its trek over the Moon’s surface at its landing site from Dec. 15-22, 2013 during the 1st Lunar Day. Credit: CNSA/Chinanews/Ken Kremer/Marco Di Lorenzo – kenkremer.com. See our Yutu timelapse pano at NASA APOD Feb. 3, 2014: http://apod.nasa.gov/apod/ap140203.html

See above and herein our time-lapse photo mosaics showing China’s Yutu rover dramatically trundling across the Moon’s stark gray terrain in the first weeks after she rolled all six wheels onto the desolate lunar plains.

The complete time-lapse mosaic shows Yutu at three different positions trekking around the landing site, and gives a real sense of how it maneuvered around on its 1st Lunar Day.

The 360 degree panoramic mosaic was created by the imaging team of scientists Ken Kremer and Marco Di Lorenzo from images captured by the color camera aboard the Chang’e-3 lander and was featured at Astronomy Picture of the Day (APOD) on Feb. 3, 2014.

Chang’e-3 and Yutu landed on a thick deposit of volcanic material.

Mosaic of the Chang'e-3 moon lander and the lunar surface taken by the camera on China’s Yutu moon rover from a position south of the lander during Lunar Day 3.   Note the landing ramp and rover tracks at left.  Credit: CNSA/SASTIND/Xinhua/Marco Di Lorenzo/Ken Kremer
Mosaic of the Chang’e-3 moon lander and the lunar surface taken by the camera on China’s Yutu moon rover from a position south of the lander during Lunar Day 3. Note the landing ramp and rover tracks at left. Credit: CNSA/SASTIND/Xinhua/Marco Di Lorenzo/Ken Kremer

China is only the 3rd country in the world to successfully soft land a spacecraft on Earth’s nearest neighbor after the United States and the Soviet Union.

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

Ken Kremer