Why The Eclipse Forced A Shutdown Of Lunar Spacecraft’s Instruments

Lunar Reconnaissance Orbiter

While people across North America marvelled at the blood-red moon early this morning, some NASA engineers had a different topic on their minds: making sure the Lunar Reconnaissance Orbiter would survive the period of extended shadow during the eclipse.

LRO uses solar panels to get energy for its batteries, so for two passes through the Earth’s shadow it would not be able to get any sunlight at all. Tweets on the official account show all as well in the first few hours after the eclipse.

“The spacecraft will be going straight from the moon’s shadow to the Earth’s shadow while it orbits during the eclipse,” stated Noah Petro, LRO’s deputy project scientist at NASA’s Goddard Space Flight Center, in a release before the eclipse occurred.

“We’re taking precautions to make sure everything is fine,” Petro added. “We’re turning off the instruments and will monitor the spacecraft every few hours when it’s visible from Earth.”

LRO’s Twitter account asked “Who turned off the heat and lights?” during the eclipse, then reported a happy acquisition of signal after the shadow passed by. “AOS, and sunlight, sweet sunlight! My batteries are charging again before I make another trip to the lunar far side.”

Hear more about LRO’s eclipse journey in the video below. For more information, check out NASA’s LRO website.  UPDATE, 10:28 a.m. EDT: NASA’s Lunar Atmosphere and Dust Environment Explorer (LADEE) spacecraft also is fine after the eclipse, according to its Twitter account.

Webcasts and Forecasts for Tonight’s Total Lunar Eclipse

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

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

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

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

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

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

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

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

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

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

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

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

Video streaming by Ustream

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

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

Video streaming by Ustream

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

Live streaming video by Ustream

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

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

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

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

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

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

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

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

The Science Behind the “Blood Moon Tetrad” and Why Lunar Eclipses Don’t Mean the End of the World

 By now, you may have already heard the latest tale of gloom and doom surrounding the upcoming series of lunar eclipses.

This latest “End of the World of the Week” comes to us in what’s being termed as a “Blood Moon,” and it’s an internet meme that’s elicited enough questions from friends, family and random people on Twitter that it merits addressing from an astronomical perspective.

Like the hysteria surrounding the supposed Mayan prophecy back in 2012 and Comet ISON last year, the purveyors of Blood Moon lunacy offer a pretty mixed and often contradictory bag when it comes down to actually what will occur.

But just like during the Mayan apocalypse nonsense, you didn’t have to tally up just how many Piktuns are in a Baktun to smell a rat. December 21st 2012 came and went, the galactic core roughly aligned with the solstice — just like it does every year — and the end of the world types slithered back into their holes to look for something else produce more dubious YouTube videos about.

Here’s the gist of what’s got some folks wound up about the upcoming cycle of eclipses. The April 15th total lunar eclipse is the first in series of four total eclipses spanning back-to-back years, known as a tetrad. There are eight tetrads in the 21st century: if you observed the set total lunar eclipses back in 2003 and 2004, you saw the first tetrad of the 21st century.

The eclipses in this particular tetrad, however, coincide with the Full Moon marking Passover on April 15th and April 4th and the Jewish observance of Sukkot on October 8th and September 28th. Many then go on to cite the cryptic biblical verse from Revelation 6:12, which states;

“I watched as he opened the sixth seal. There was a great earthquake. The Sun turned black like sackcloth made of goat hair. The whole Moon turned blood red.”

Whoa, some scary allegory, indeed… but does this mean the end of the world is nigh?

I wouldn’t charge that credit card through the roof just yet.

First off, looking at the eclipse tetrads for the 21st century, we see that they’re not really all that rare:

21st century eclipse tetrads:

Eclipse #1 Eclipse #2 Eclipse #3 Eclipse #4
May 16th, 2003 November 9th, 2003 May 4th , 2004 October 28th, 2004
April 15th, 2014*+ October 8th, 2014 April  4th, 2015*+ September 28th, 2015
April 25th, 2032 October 18th, 2032 April 14th, 2033*+ October 8th, 2033
March 25th, 2043* September 19th, 2043 March 13th, 2044 September 7th, 2044
May 6th, 2050 October 30th, 2050 April 26th, 2051 October 19th, 2051
April  4th, 2061*+ September 29th, 2061 March 25th, 2062* September  18th, 2062
March 4th, 2072 August 28th, 2072 February 22nd, 2073 August 17th, 2073
March 15th, 2090 September 8th, 2090 March 5th, 2091 August 29th, 2091
*Paschal Full Moon
+Eclipse coincides with Passover

 

Furthermore, Passover is always marked by a Full Moon, and a lunar eclipse always coincides with a Full Moon by definition, meaning it cannot occur at any other phase. The Jewish calendar is a luni-solar based calendar that attempts to mark the passage of astronomical time via the apparent course that the Sun and the Moon tracks through the sky. The Muslim calendar is an example of a strictly lunar calendar, and our western Gregorian calendar is an example of a straight up solar one. The Full Moon marking Passover often, though not always, coincides with the Paschal Moon heralding Easter. And for that matter, Passover actually starts at sunset the evening prior in 2014 on April 14th. Easter is reckoned as the Sunday after the Full Moon falling after March 21st which is the date the Catholic Church fixes as the vernal equinox, though in this current decade, it falls on March 20th. Easter can therefore fall anywhere from March 22nd to April 25th, and in 2014 falls on the late-ish side, on April 20th.

To achieve synchrony, the Jewish calendar must add what’s known as embolismic or intercalculary months (a second month of Adar) every few years, which in fact it did just last month. Eclipses happen, and sometimes they occur on Passover. It’s rare that they pop up on tetrad cycles, yes, but it’s at best a mathematical curiosity that is a result of our attempt to keep our various calendrical systems in sync with the heavens.  It’s interesting to check out the tally of total eclipses versus tetrads over a two millennium span:

Century Number of Total Lunar Eclipses Number of Tetrads Century Number of Total Lunar Eclipses Number of Tetrads
11th

62

0

21st

85

8

12th

59

0

22nd

69

4

13th

60

0

23rd

61

0

14th

77

6

24th

60

0

15th

83

4

25th

69

4

16th

77

6

26th

87

8

17th

61

0

27th

79

7

18th

60

0

28th

64

0

19th

62

0

29th

57

0

20th

81

5

30th

63

1

 

Note that over a five millennium span from 1999 BC to 3000 AD, the max number of eclipse tetrads that any century can have is 8, which occurs this century and last happened in the 9th century AD.

Of course, the visual appearance of a “Blood of the Moon” that’s possibly alluded to in Revelation is a real phenomena that you can see next week from North and South America as the Moon enters into the dark umbra or core of the shadow of the Earth. But this occurs during every total lunar eclipse, and the redness of the Moon is simply due to the scattering of sunlight through the Earth’s atmosphere. Incidentally, this redness can vary considerably due to the amount of dust, ash, and particulate aerosols aloft in the Earth’s atmosphere, resulting in anything from a bright cherry red eclipse during totality to an eclipsed Moon almost disappearing from view altogether… but it’s well understood by science and not at all supernatural.

The changing colors of a lunar eclipse: a mosaic of four eclipses. Photos by author.
The changing colors of a lunar eclipse: a mosaic of four eclipses. Photos by author.

Curiously, the Revelation passage could be read to mean a total solar eclipse as well, though both can never happen on the same day.  Lunar and solar eclipses occur in pairs two weeks apart at Full and New Moon phases when the nodes of the Moon’s ecliptic crossing comes into alignment with the Sun — known as a syzygy, an ultimate triple word score in Scrabble, by the way — and this eclipse season sees a non-central annular eclipse following the April 15th eclipse on April 29th.

And yes, earthquakes, wars, disease, relationship breakups and lost car keys are on tap to occur in 2014 and 2015… just like during any other year. Lunar eclipses marked the fall of Constantinople in 1453 and the World Series victory of the Red Sox in 2004, but they’re far from rare. We humans love to see patterns, and sometimes this habit works against us, making us see them where none exists. This is simply a case of the gambler’s fallacy, counting the hits at the cost of the misses. We could just as easily make a case that the upcoming eclipse tetrad of April 15th, October 8th, April 4th and September 28th marks US Tax Day, Croatian Independence Day, The Feast of Benedict of the Moor & — Michael Scott take note — International World Rabies Day… perhaps the final 2015 eclipse should be known as a “Rabies Moon?”

So, what’s the harm in believing in a little gloom and doom? The harm in believing the world ends tomorrow comes when we fail to plan for still being here the day after. The harm comes when something like the Heavens Gate mass suicide goes down. We are indeed linked to the universe, but not in the mundane and trivial way that astrologers and doomsdayers would have you believe. Science shows us where we came from and where we might be headed.  We’ve already fielded queries from folks asking if it’s safe (!) to stare at the Blood Moon during the eclipse, and the answer is yes… don’t give in to superstition and miss out on this spectacular show of nature because of some internet nonsense.

The upcoming lunar eclipse next week won’t mean the end of the world for anyone, except, perhaps, NASA’s LADEE spacecraft… be sure not to miss it!

 

Get Ready for the April 15, 2014 Total Lunar Eclipse: Our Complete Guide

 April the 15th: In the United States, it’s a date dreaded by many, as the date to file taxes – or beg for an extension – looms large. But this year, Tax Day gives lovers of the sky something to look forward to, as the first of four total lunar eclipses for 2014 and 2015 occurs on the night of April 14th/15th favoring North and South America.

The circumstances for the April 15th, 2105 eclipse.
The circumstances for the April 15th, 2014 eclipse. The top chart shows the path of the Moon through the umbra, and the bottom chart shows the visibility region (light to shaded areas) Click here for a technical description. Credit:  Eclipse Predictions by Fred Espenak, NASA/GSFC.

This marks the first total lunar eclipse visible from since December 10th 2011, which was visible at moonset from North America, and marks the start of the first of two eclipse seasons for 2014. Totality will last 1 hour, 17 minutes and 48 seconds, and will be visible in its entirety from the central Atlantic westward to eastern Australia. Unlike a total solar eclipse, which occurs along a narrow track, a total lunar eclipse can be viewed by the entire moonward facing hemisphere of the Earth.

Tracing the umbra: a mosaic of the December 2010 eclipse. Photos by author.
Tracing the umbra: a mosaic of the December 2010 eclipse. Photos by author.

The action begins at 4:37 Universal Time (UT)/12:37 AM EDT, when the Moon enters the western edge of the Earth’s shadow known as the penumbra. The Moon will be completely immersed in the penumbra by 5:58 UT/1:58 AM EDT, but don’t expect to see anything more than a faint tan shading that’s slightly darker on the Moon’s northeastern edge.

The real action begins moments later, as the Moon encounters the ragged edge of the umbra, or the inner core of the Earth’s shadow. When does the umbra first become apparent to you? Totality then begins at 7:06 UT/3:06 AM EDT and lasts until 8:24 UT/4:24 AM EDT, with mid-eclipse occurring just south of the center of the Earth’s shadow at 7:46 UT/3:46 AM EDT.

Finally, the eclipse ends as the Moon slides out of the penumbra at 10:37 UT/ 6:37 AM EDT.  Michael Zeiler (@EclipseMaps) has complied a fine video guide to the eclipse:

Field guide to the total lunar eclipse of April 14 – 15, 2014 from Michael Zeiler on Vimeo.

This eclipse is also notable for being part of a series of four lunar eclipses in 2014 & 2015, known as a “tetrad.” NASA eclipse expert Fred Espenak notes that this series of eclipses is also notable in that all four are visible in part or in their entirety from the United States. We’re in a cycle of 9 sets of tetrads for the 21st century, which began with the first set in 2003. Before that, you have to go all the way back to the 16th century for the last set of eclipse tetrads!

4AM EDT. Credit Starry Night Education software.
The position of the Moon within the Earth’s umbra on the morning of April 15th at 4AM EDT/8UT. Credit: Starry Night Education software.

For saros buffs, the April 15th eclipse is Member 56 of 75 of saros 122, which began on August 14th 1022 A.D. and runs out until a final penumbral eclipse of the series on October 29th, 2338. There are only two total eclipses left in this particular saros, one in 2032 and 2050. If you caught the total lunar eclipse of April 4th, 1996, you saw the last lunar eclipse in this same saros series.

Lunar eclipses have turned up at some curious junctures in history. For example, a lunar eclipse preceded the fall of Constantinople in 1453. A 2004 lunar eclipse also fell on the night that the Red Sox won the World Series after an 86 year losing streak, though of course, lunar eclipses kept on occurring during those losing years as well. Christopher Columbus was known to evoke an eclipse on occasion to get him and his crew out of a jam, and also attempted to use a lunar eclipse to gauge his position at sea using a method first described by Ptolemy while studying the lunar eclipse of September 20th, 331 B.C.

A handful of stars in the +8th to +12th magnitude range will be occulted by the eclipsed Moon as well. Brad Timerson of the International Occultation Timing Association (IOTA) has put together a list, along with graze line prospects across the United States. The brightest star to be occulted by the eclipsed Moon is +5th magnitude 76 Virginis across western South America and Hawaii:

Credit: Occult 4.0
The occultation footprint of 76 Virginis during the April 15th lunar eclipse. Credit: Occult 4.0

Note that the bright star Spica will be only just over a degree from the eclipsed Moon, and Mars will also be nearby, just a week past its 2014 opposition. And to top it off, Saturn is just one constellation to the east in Libra!

During the partial phases of the eclipse, watch for the Moon to take on a “Pacman-like” appearance. The Earth’s umbra is just under three times the size of the Moon, and the Greek astronomer Aristarchus of Samos used this fact and a little geometry to gauge the distance to our natural satellite in the 3rd century B.C.

As totality approaches, expect the innermost rim of the Moon to take on a ruddy hue. This is the famous “combination of all the sunrises and sunsets” currently underway worldwide as light is bent through the Earth’s atmosphere into its shadow. It’s happening every night, and during the totality of a lunar eclipse is the only chance that we get to see it.

4AM Credit: Stellarium
Looking to the southwest at 4 AM EDT from latitude 30 degrees north on the morning of April 15th. Credit: Stellarium.

You don’t need anything more sophisticated than the naked eye or “Mark 1 eyeball” to enjoy a lunar eclipse, though it’s fun to watch through binoculars or a low-power telescope field of view. One interesting project that has been ongoing is to conduct timings for the moment when the umbra contacts various craters on the Moon. It’s a curious mystery that the Earth’s shadow varies by a small (1%) but perceptible amount from one eclipse to the next, and efforts by amateur observers may go a long way towards solving this riddle.

Said color of the fully eclipsed Moon can vary considerably as well: the Danjon scale describes the appearance of the eclipsed Moon, from bright and coppery red (Danjon 4) to so dark as to almost be invisible (Danjon 0). This is a product of the amount of dust, volcanic ash and aerosols currently aloft in the Earth’s atmosphere.  During the lunar eclipse of December 9th, 1992 the Moon nearly disappeared all together, due largely to the eruption of Mount Pinatubo the year prior.

A lunar eclipse also presents a chance to nab what’s known as a Selenelion. This occurs when the Sun and the totally eclipsed Moon appear above the local horizon at the same time. This is possible mainly because the Earth’s shadow is larger than the Moon, allowing it to linger a bit inside the umbra after sunrise or before sunset. Gaining some altitude is key to making this unusual observation.  During the April 15th eclipse, selenelion sightings favor the Mid-Atlantic and Greenland where totality is underway at sunrise and eastern Australia, where the reverse is true at sunset.

Want to have a go at measuring the brightness or magnitude of the eclipsed Moon? Here’s a bizarre but fun way to do it: take a pair of binoculars and compare the pinpoint Moon during totality to the magnitude of a known star, such as Antares or Spica.

Note that to do this, you’ll first need to gauge the magnitude extinction of your particular binoculars: NASA’s got a table for that, or you could field test the method days prior on Venus, currently shining at a brilliant -4.2 in the dawn. Hey, what’s a $1,000 pair of image-stabilized binocs for?

And of course, weather prospects are the big question mark for the event. Mid-April weather for North America is notoriously fickle. We’ll be watching the Clear Sky Chart and Skippy Sky for prospects days before the eclipse.

Photography during an eclipse is fun and easy to do, and you’ll have the waxing gibbous Moon available to practice on days prior to event. Keep in mind, you’ll need to slow down those shutter speeds as the Moon enters into totality, we’re talking going down from 1/60th of a second down to ¼” pretty quickly. In the event of a truly dark eclipse, the Moon may vanish in the view finder all together. Don’t be afraid to step exposures up to the 1 to 4 second range in this instance, as you’ve got over an hour to experiment.

Photo by author
Our “eclipse hunting rig…” the DSLR is piggy-backed to shoot stills on the main scope, which will shoot video. Note that the “f/34 field stop” will most likely be removed!  Photo by author

Thus far, only one webcast for the eclipse has surfaced, courtesy of the venerable Slooh. We’ll most likely be doing a follow up roundup of eclipse webcasts as they present themselves, as well as a look at prospects for things like a transit of the ISS in front of the eclipsed Moon and weather forecasts closer to show time.

And speaking of spacecraft, China’s Chang’e 3 lander and Yutu rover will have a fine view of a solar eclipse overhead from their Mare Imbrium vantage point, as will NASA’s LRO and LADEE orbiters overhead. In fact, NASA hinted last year that the April 15th eclipse might spell the end of LADEE entirely…

And thus marks the start of eclipse season one of two for 2014. Next up will be a curious non-central annular solar eclipse over Antarctica on April 29th, followed by another total lunar eclipse on October 8th, and a fourth and final partial solar eclipse of the year for North America of October 23rd.

Watch this space and follow us on Twitter as @Astroguyz, as we’ll be “all eclipses, all the time,” for April… no new taxes guaranteed!

Next up: Heard the one about the Blood Moon? Yeah, us too… join us as we debunk the latest lunacy surrounding the eclipse tetrad!

–      Got pics of the lunar eclipse? Send ‘em in to Universe Today, as a post-eclipse photo round up is a very real possibility!