Get ready for a lunar occultation Tuesday night. (Photo: GEORGI LICOVSKI, EPA) 
 
 The moon and one of the brightest stars in the sky will play hide-and-seek Tuesday night. 
 
 So grab your telescope or binoculars and get ready for a moon "occultation," which sounds like something perfect for a spooky pre-Halloween night. 
 
 Not as well known as an eclipse or a meteor shower, a lunar occultation occurs when the moon passes in front of a star. Tuesday night, the moon will occult Aldebaran, which is one of the brightest and most colorful stars in the sky, according to Space.com. 
 
 Lunar occultations are either classified as "total" or "grazing," the International Occultation Timing Association reports. 
 
 The "total" occultation is simply a matter of a star vanishing behind the moon and then reappearing an hour or so later, which is what folks in most of the eastern and southern U.S. will see. 
 
 A "grazing" occultation, when the star appears to slide right along the edge of the moon, is especially cool, asSky and Telescope notes: 
 
 "You'll probably see Aldebaran disappear and reappear several times in the darkness just barely off the moon's dazzlingly sunlit north polar region," the magazine said. "Most of the events will be gradual rather than instantaneous, as hills and valleys on the moon's northern limb slide across the face of the giant star." 
 
 Where will you be on the night of October 19th/20th? We'll be watching the Moon occult the bright star Aldebaran: https://t.co/Em6hvXH3typic.twitter.com/HBbZ5OxxfJ — Sky & Telescope (@SkyandTelescope) October 13, 2016 
 
 This so-called "graze line" is only a few hundred yards wide, but it runs right through Los Angeles and Denver, about 50 miles southeast of Las Vegas, and about 30 miles southeast of Minneapolis, Sky and Telescope says. 
 
 YOUR TAKE: Share your photos of the night sky 
 
 These occultations of Aldebaran have been happening once per lunar month in a series that began in January 2015 and will end in September 2018. But most aren't visible in the U.S. 
 
 After this series ends, the next occultation of Aldebaran won't be until 2033. 
 
 As noted above, binoculars or a telescope are needed to fully enjoy the spectacle. 
 
 Skies will be mostly clear across the southern tier of the U.S. late Tuesday and early Wednesday, the National Weather Service predicts:. 
 
 Skies should be clear (blue) across most of the southern tier of the U.S. while clouds (gray) are forecast for portions of the north-central U.S. and the Ohio Valley. This is the sky cover prediction for 2 am ET Wednesday (11 pm PT Tuesday). (Photo: National Weather Service) 
 
 Read or Share this story: http://usat.ly/2emUAuw ||||| Observers in portions of Mexico, Central America, southeastern Canada, the eastern U.S. and southern Europe will see the waning gibbous moon occult the bright naked eye star Aldebaran in the early hours of Wednesday (Oct. 19). 
 
 The waning moon will cross in front of one of the brightest and most colorful stars in the sky on the night of October 18-19 for viewers in the southern and eastern United States, and part of eastern Canada. 
 
 Late Tuesday night (Oct. 18), users of even the smallest telescopes will be glued to their eyepieces as the edge of the waning gibbous moon, 85 percent illuminated, occults the 1st-magnitude star Aldebaran, which forms the bright orange eye of Taurus, the Bull. 
 
 We're currently in the midst of an almost four-year series of Aldebaran occultations. Every month as the moon circles the Earth it passes in front of the star as seen from some part of the world. On the night of Oct. 18-19, the lucky region includes anywhere south of a line running from Los Angeles to about 50 miles south of Las Vegas, through Denver, to 30 miles southeast of Minneapolis, then northeast to Ishpeming Township, Michigan, and continuing to George's Island, Labrador. If you are north of this line (which includes the Pacific Northwest, northern and central California, northern and central Rockies, northern and central Plains), the moon will pass tantalizingly close to Aldebaran, but will not cover it. Observers right on this line, probably less than two-tenths of a mile (three-tenths of a kilometer) wide, will be able to watch Aldebaran graze the bright limb of the moon. [Planets, Constellations and Orionid Meteors In Oct. 2016 Skywatching (Video)] 
 
 Many observers will aim smartphones and camcorders at their eyepieces to capture a video of the event while shortwave radio time signals play in the background. That setup will allow viewers to time the instant when the star vanishes behind the moon's limb, and when it reappears later from behind the other limb, to a few hundredths of a second. 
 
 The International Occultation Timers Association (IOTA) has set up a special web page for the upcoming Aldebaran graze, complete with maps, predicted lunar-limb profiles and other information. 
 
 For prospective viewers in Southern California, Aldebaran will disappear soon after 10 p.m. PDT. In the eastern U.S., it will happen between 1 and 2 a.m. EDT. The star will disappear on the moon's bright side and reappear on the dark side. 
 
 As the moon, three days past full, ascends the eastern sky, Aldebaran will appear to creep up to the moon's bright limb for many minutes, then hang on the sunlit edge of a few seconds — an eerie orange fire among the lunar hills. You'll need a telescope to see it there through the moon's glare. Then, in an instant, it will snap out of view. 
 
 Aldebaran will reappear from behind the moon's dark portion (depending on your location) up to 75 minutes later. This time you may be able to see the event with binoculars, since the star will pop back into view farther away from the dazzling lunar surface. 
 
 IOTA has also created a web page depicting the entire viewing zone (which includes parts of Africa and Europe) and a listing of disappearance and reappearance times for over 1,000 locations — including nearly 300 in the United States. 
 
 For example, what can you expect to see from a rooftop in Philadelphia? The City of Brotherly Love is location #920. The listings are in Universal Time; for Philadelphia this is 5:41:05, which corresponds to 1:41:05 a.m. EDT. At that time, the moon will be 54 degrees high at an azimuth of 122 degrees, corresponding to 32 degrees south of due east. The position angle (PA) is 48 degrees, measured counterclockwise from the top of the moon. This gives the position along the moon's limb where Aldebaran will disappear. 
 
 So 0/360 degrees = 12 o'clock; 90 degrees = 9 o'clock; 180 degrees = 6 o'clock; 270 degrees = 3 o'clock. 
 
 In this case, if the moon was the face of a clock, 48 degrees would correspond to between 10 and 11. For the reappearance: 6:47:39 UT (2:47:39 a.m. EDT); Altitude 64 degrees; Azimuth 148 degrees (SSE) and the PA is 284 degrees. 
 
 The U.S. Nautical Almanac Office provides an alternate occultation visibility map here. 
 
 As I noted earlier, the current series of Aldebaran occultations runs for nearly four years. The current series began Jan. 29, 2015, with an occultation visible from the Arctic regions. The next Aldebaran occultation visible from North America (and Hawaii, too) will come on the night of Dec. 12-13. The series will come to an end Sept. 3, 2018, for Greenland and the Arctic regions. After that, we must wait until Aug. 18, 2033, for the series of Aldebaran occultations to begin. 
 
 Joe Rao serves as an instructor and guest lecturer at New York's Hayden Planetarium. He writes about astronomy for Natural History magazine, the Farmer's Almanac and other publications, and he is also an on-camera meteorologist for News 12 Westchester, New York. Follow us @Spacedotcom, Facebook and Google+. Original article on Space.com. ||||| 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. 
 
 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. 
 
 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! 
 
 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: 
 
 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. 
 
 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. 
 
 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! 
 
 Related 
 
 By David Dickinson - 
 
 David Dickinson is an Earth science teacher, freelance science writer, retired USAF veteran & backyard astronomer. He currently writes and ponders the universe as he travels the world with his wife. 
 
 april 15 2014 total lunar eclipse, april 15 lunar eclipse, blood moon, eclipse history, eclipse ladee, eclipse photography, eclipse saros, eclipse science, eclipse tetrad, eclipse webcast, observing a lunar eclipse, penumbra, selenelion, tax day eclipse, umbra
– Sky watchers will get a bit of a show Tuesday night: People across the Eastern US and much of the Southwest will be able to see the moon move in front of Aldebaran, one of the brightest stars in the night sky, a phenomenon known as a lunar occultation, reports USA Today. Most in the viewing zone will see a "total occultation," in which the star disappears behind the moon. But the real treat comes for residents in certain areas of LA and Denver, who will be able to witness a "grazing occultation," where the star moves along the very periphery of the moon. Those with high-powered telescopes (or perhaps a nice pair of binoculars) should be able to see the star move in and out of view as mountain ranges and craters on the moon rise and fall. In the West, Aldebaran will disappear shortly after 10pm PDT, per Space.com. In the Eastern US, it will happen between 1am and 2am EDT. Astronomy site Sky and Telescope has the nitty-gritty on when and where to look.