StarWatch: Moravian College Astronomy

StarWatch for the greater Lehigh Valley

JANUARY 2019

JANUARY STAR MAP | MOON PHASE CALENDAR | STARWATCH INDEX | NIGHT SKY NOTEBOOK

Print Large Sky Charts For 9 p.m. EST: NORTH | EAST | SOUTH | WEST | ZENITH

CURRENT MOON PHASES

Current Solar X-rays:

Current Geomagnetic Field:

1168 JANUARY 6, 2019: Colorful Eclipse to Favor Americas: On August 21, 2017 the moon’s central shadow, the umbra, swept across the continental US from coastal Oregon to coastal South Carolina producing a total solar eclipse that was specifically honed for Americans. In no other location other than the United States did the moon’s shadow touch land. Just a year and a half later, there is another treat in store for us in the New Year, a total lunar eclipse, and the Americas, both North and South, are in the sweetest spots possible. In fact, northern hemispheric observers are favored with the mid-Atlantic states in the most ideal position. The time to pray most fervently for clear skies is the evening of Sunday, January 20 into the morning of Monday, the 21. Unlike solar eclipses where a narrow ribbon of darkness rapidly sweeps across the landscape and observers normally have to travel large distances to be immersed within it, lunar eclipses are leisurely affairs, with the full moon overtaking and slowly moving through the Earth’s shadow which is projected into space. At any moment half of the world can view the eclipse, and since the Earth is spinning, some areas will rotate into the action, watching the moon rise while in eclipse, while other locales will move away from the encounter, seeing the moon set during the eclipse. The Americas, however, will see it in its entirety from start to finish, a duration of 5 hours, 15 minutes for all of the various sequences, with Earth’s umbra falling on the moon for 3 hours, 17 minutes, and with the moon completely immersed in Earth’s shadow for 63 minutes. Whether you live in a large metropolitan area or in a rural location, as long as the weather cooperates, the eclipse should be visible, but more rural locales will still have the advantage. Prior to the start of the eclipse, you’ll be able to witness a landscape or snowscape brightly illuminated by moonlight, with trees and other objects casting distinct shadows on the ground. Gradually, they will become subdued as the full moon “eats” its way deeper into the shadow of the Earth. In addition, the umbra is rarely totally black because sunlight shining along the circumference of the Earth is reddened (scattered) and bent (refracted) into the shadow by the atmosphere through which it must pass, creating various hues of browns, reds, oranges, and even yellows which blend across the lunar terrain. The cornucopia of colors is accented through the use of binoculars and telescopes which allows the eye to consume dozens to hundreds of times the amount of light it would see normally without any optical aid. Finally, there are the heavens themselves, appearing greyish with only the brightest stars visible at the beginning of the eclipse, transforming itself into the beauty of a sky seen at new moon, rich with stars, against the backdrop of an orangey-red orb, the eclipsed moon. For East Coast observers (EST), Luna begins to appear strange by 10:10 p.m., and makes first contact with the Earth’s primary shadow at 10:34 p.m. Totality spans the period between 11:41 p.m. to 12:44 a.m. By 1:51 a.m. Earth’s shadow has released the moon, but a smudge of diminishing grey remains on the portion of the moon closest to the umbra until about 2:15 a.m. Add an hour for Atlantic Standard Time. Subtract one, two, or three hours for Central, Mountain, and Pacific time zones, respectively. More about this must see eclipse next week.

JANUARY 13, 2019: Can’t Miss Total Lunar Eclipse

Grab your binoculars and get ready for one of nature’s most spectacular nighttime events, a total lunar eclipse! Watch the moon this week as it blossoms from first quarter, half on—half off, with its light to the right to a full moon by Sunday of next week, its surface completely illuminated by sunlight and its destination headed for a rendezvous with Earth’s shadow starting at 9:33 p.m., January 20. The shadow of the Earth has two components, the umbra or true shadow (Latin for shade), a narrowing cone of darkness which stretches outward, away from the sun for 750,000 miles. Here the moon receives no direct sunlight. The outer shadow, the penumbra (Latin for light shade), is an expanding cone that brightens as an observer moves away from the umbra. In the penumbra, from the moon’s perspective, only part of the Earth is covering part of the sun. The deeper the moon progresses into the penumbra, the less sunlight is falling on its surface. In any eclipse it is always the moon which is the aggressor. Luna overtakes the sun in a solar eclipse and the Earth’s shadow in a lunar eclipse because its apparent motion in the sky is faster. Viewing with the unaided eye or binoculars, it will be the left or western limb of the moon that will first reveal the decrease in sunlight as the moon moves deeper into the penumbra. Contact with the penumbra occurs at 9:32 p.m., EST, January 20, but it will not be until about 30 minutes later that the moon should look a little funky, greyish on the leading side. I have tried using sunglasses to be able to see this diminution of light a little easier and it worked, giving some practical astronomical value to Cory Hart’s lyrics, “I wear my sunglasses at night.” At the conclusion of the preshow, 10:34 p.m., the dusky leading limb of Luna makes its first contact with the umbra. Here is where the fun begins because the progression of the moon’s surface into the Earth’s shadow is relentless. The distinction between the boundary of the umbra and penumbra can indicate the clarity of the atmosphere along the circumference of the Earth where sunlight is being attenuated. A distinct shadow means very clear/clean air. Most of the time the boundary is fuzzy, but I’ve seen the umbra delineated so clearly that I could see it marching across the lunar landscape in real time, overtaking craters, one by one. You’ll need a telescope for that type of observation. When totality occurs at 11:41 p.m., the moon will probably glow brown red on its leading side which will be deepest into the umbra to red, orange, and yellow closer to its trailing edge. During the next 63 minutes colors will blend and change across the moon’s surface as it traverses the shadow cone with the most subdued illumination occurring at mid-eclipse, just after midnight (12:12 a.m.) on January 21. The moon begins to exit the umbra at 12:44 a.m., has departed the umbra completely by 1:51 a.m., and stealthily leaves and is completely free of the Earth’s other shadow by 2:15 a.m. If the weather cooperates, look forward to an enjoyable evening of memorable sights. For additional information about this total lunar eclipse, read last week’s StarWatch at astronomy.org/StarWatch/January/index-1-19.html#1-6-19 or ahead to astronomy.org/StarWatch/January/index-1-19.html#1-20-19. Much success and clear skies to all!!!

1170 JANUARY 20, 2019: Blood Moon Threatens Universe: Eclipse 2019: Super Blood Moon has Terrifying Link to Biblical “10 Days” Prophecy. Super Blood Wolf Moon to Cause Earthquakes and Volcanic Eruption on January 21, 2019? How the January 21 Super Blood Wolf Full Moon Lunar Eclipse Could Shift the Balance of Power as We Know It. Wow, and I thought it was just a cool total lunar eclipse, the first big astronomical event of 2019, but those are some real titles taken right from the fact fabulous Internet. Don’t be fooled by the “fake news,” and do not try to locate those funny dark glasses that were used to view the August 21, 2017 solar eclipse. Lunar eclipses are perfectly safe to watch with the unaided eye, including through telescopes during all stages. If you can observe the bright, full moon without hurting your eyes, then you can certainly observe the full moon catching up to and passing through the Earth’s shadow. Below are the highlights of January’s 20/21 total lunar eclipse. Subtract one, two, or three hours for Central, Mountain, or Pacific time zones. How colorful the lunar eclipse will be is always difficult to predict, but since the stratosphere is clean, I would bet on a brighter eclipse than a darker one. The reddened light that falls upon the moon results from the sunlight that is refracted (bent) into the shadow of the Earth by all of the sunrises and sunsets which are occurring around the world. Standing on the lunar surface at mid-eclipse, an individual would view the Earth hiding the sun, a solar eclipse, with Sol’s corona surrounding Earth and a paper-thin band of reddened light ringing our planet—magnificent. Magnificent will also be the winter sky with plenty of bright stars surrounding the eclipsed moon. See the online map showing the sky during totality at astronomy.org/StarWatch/January/index-1-19.html along with two other articles highlighting January’s total lunar eclipse. The only uncertainty will be the weather. As this article is being written, prospects east of the Mississippi are not very positive, but improving; however, it will be bitterly cold mostly everywhere. Regardless, I’m praying for clear skies for everyone. PLEASE!

1171 JANUARY 27, 2019: Cold, Cold, Cold Lunar Eclipse: That hot shower felt really good after four hours outside in 11-degree temperatures and wind gusts that occasionally flexed my very sturdy mount and telescope! And yes, my house was right next to where I was observing; and yes, I did go inside occasionally, maybe a little more than occasionally near the end of the eclipse to place my gloved hands on a warm radiator to bring some life back into my shivering body. Was it worth it? Yes, is the obvious answer because to experience the “real thing” is a gift not to be wasted. I was surprised, however, that no one in my neighborhood popped their head outside to take a look. On the other hand, I was pleasantly surprised that about a dozen students in my astronomy classes made observations, and a few of them did so for extended periods of time. The semester had not even started yet, so these were free will gestures. So let’s talk about the eclipse. The air was extremely transparent on January 20, and the eclipse took place high in the south. The brilliant super moon made it difficult to see the penumbra until about 10 minutes before the primary shadow of the Earth, the umbra, made first contact. Even with clouds scudding over the moon, I just could not confirm a definitive sighting. A call from former Moravian student, Alex Pena, queried if I had the right times. I certainly did, but I have to agree with Alex that the penumbra was not as easy to see as expected. When the bright moon began to move into the primary shadow of the Earth at 11:41 p.m., the penumbra became much more discernable, especially over the darker seas of the moon. The secondary shadow against the maria looked like tongues of dusk extending over the lunar landscape. I also found the shadow boundary more distinct than expected and was actually able to witness several small craters go into shadow as the moon advanced deeper into the umbra. About halfway to totality, the shadowed portion of the moon appeared brownish red. I mentally clapped because I thought this was going to be a bright eclipse, but as totality approached, I felt my prediction was far too optimistic. The moon appeared darker than expected, and although there was plenty of color recorded in my photographs, visually Luna appeared a grayish red brown to almost black. However, the full disk of the moon was visible throughout the entire eclipse. There was a brighter white rim at the location closest to the penumbra, but I felt that it remained brighter than expected as the moon pressed deeper into the umbra. My good friend, Adam Jones in Denver, also voiced the same observation a few days later in a phone conversation. Visually, there were no oranges or bright reds, but photographically, vibrant colors came to fore including a bluish region nearest to the shadow boundary. Exposures, however, were much longer than in past eclipses confirming that this was a more subdued event. During mid-eclipse through my telescope, the moon simply appeared gray. Colors were too muted for my observing eye to perceive. As the moon advanced from totality, the shadow boundary was not as distinct, and coloration over the still eclipsed portion of the moon was basically nonexistent. Of course, by that time I felt more like an icicle with brain function probably reduced by 50 percent. Oh, did that warm shower feel wonderful! More about shadows next week. Pictures are online at astronomy.org. When the page loads, click on “this week’s StarWatch” and enjoy the eclipse.

[January Star Map]

[January Moon Phase Calendar]