StarWatch: Moravian College Astronomy

FEBRUARY 2008

FEBRUARY STAR MAP | STARWATCH INDEX | MOON PHASE CALENDAR

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598 FEBRUARY 3, 2008: Prime Time Lunar Eclipse Set for February 20: I just came inside for a short break after setting up one of my telescopes through which I am hopeful of viewing the Wednesday, February 20 total lunar eclipse. On that evening, the full moon will pass through the Earth’s shadow. The public is cordially invited to join the ASD Planetarium’s StarWatch Team of student and adult observers at the Quakertown Airport, starting at 8:30 p.m., to witness the last early evening total lunar eclipse until September 27, 2015. There will be hot chocolate and hot soup, along with a warm up area, including restrooms. Quakertown Airport is also planning “to take to the friendly skies” for eclipse rides. Of course, these activities are weather contingent, which means that overcast conditions, high winds, or frigid temperatures could cancel the event. A go/no go decision will be posted by 6 p.m. on the day of the eclipse in the red eclipse box at www.astronomy.org. Directions to the Quakertown Airport can be found by clicking on “this week’s StarWatch” button. The next total lunar eclipse visible to Valley residents occurs at the inconvenient hour of 3:20 a.m. on Tuesday, December 21, 2010. So plan on this February’s event unless you’re just a plain masochist or a vampire. On February 20 the moon begins to enter the Earth’s shadow at 8:44 p.m. The eclipse is total by 10:01 p.m. Expect the moon to look spectacular with a reddish brown to yellowish white hue. Small telescopes and binoculars will enhance the spectacle. The moon remains immersed within the Earth’s shadow until 10:52 p.m. when again a very vivid array of colors might be expected. It all depends upon the clarity of Earth’s atmosphere. StarWatch volunteers will provide about 10 telescopes, but the public is encouraged to bring their scopes and binoculars to this event. Clear skies!

599 FEBRUARY 10, 2008: Total Lunar Eclipse Will Be A Treat: You’re invited to view one of nature’s most spectacular events, a total lunar eclipse, on Wednesday, February 20 starting at 8:30 p.m. The Quakertown Airport and ASD Planetarium’s StarWatch Team of student and adult volunteers will offer a wide assortment of high end telescopes for public use that will provide dazzling views of the moon as it passes through the Earth’s shadow. The Quakertown Airport will also supply hot chocolate and yummy soup for the “thermally challenged,” and sponsor night flights to the moon to witness the eclipse from an entirely different perspective. The eclipse pageantry begins at 8:43 p.m. when Luna makes first contact with Earth’s umbra (shadow). Through telescopes, you’ll witness craters being gobbled up as the fast-paced moon relentlessly pushes deeper into the dark. As 9:30 p.m. approaches, the eclipsed portion of the moon may appear a dull coppery red. The full moon’s bright light will become subdued, and fainter stars will begin to pepper the sky completing the brighter winter patterns of Orion, Taurus, the Pleiades, Canis Major, Auriga, and Gemini. In addition, the Big Dipper will be rising, handle down, in the NE. Last to emerge will be the lion, Leo, the area of the sky where the eclipse is occurring. During this time, telescopes will be pointed towards ringed Saturn, only four degrees from the eclipse, and ruddy Mars, as well as other fine winter showpieces, such as the Orion Nebula and the Pleiades. As totality nears at 10:01 p.m., all eyes will once again be focused on the moon. Colors of yellows, oranges, reds, and browns will change minute by minute and will be breathtaking to behold even with just the unaided eye. Read ahead at the URL below for what might be expected during totality. Think clear skies!

600a FEBRUARY 17, 2008: Wednesday Eclipse Set for Quakertown: Lunar eclipse week is upon us! Plan to join the ASD Planetarium’s StarWatch team at the Quakertown Airport on Wednesday evening, starting at 8:30, for a memorable night of stargazing as the moon sweeps through Earth’s shadow. People bringing telescopes should arrive about an hour earlier. Binoculars, a flashlight, extra warm clothing, cameras, and tripods are also welcomed. Realize that clouds, wind, and extreme cold could cancel the event. A go/no go decision will be posted by 6 p.m. Wednesday in the red box at www.astronomy.org. Follow the link and scroll for directions to the airport and more information. The midweek eclipse starts at 8:43 p.m. For the next hour and 18 minutes you’ll watch as the moon relentlessly plunges deeper into the Earth’s shadow. The moon’s eclipsed hemisphere should become coppery in color by 9:30. As totality approaches at 10:01, refraction and absorption phenomena in the Earth’s atmosphere may create hues of yellows, oranges, and reds that will be truly spectacular to watch through telescopes, spotting scopes, and binoculars. How vibrant the colors become varies from eclipse to eclipse. Worldwide volcanic activity, other human-produced atmospheric pollutants, and the depth of penetration of the moon into Earth’s shadow cone affect the hues and brightness of lunar eclipses. Currently, volcanic activity is minimal. More importantly, this is a shallow eclipse, meaning that during mid-totality, 10:26 p.m., the moon will still be very near the shadow boundary. The moon’s five o’clock position, closest to the shadow’s border, could appear orange-yellow while the 11 o’clock location, deepest into the Earth’s shadow, may appear coppery red. Hopefully, you’ll consider joining StarWatch in Quakertown for a fun filled evening of eclipse viewing.

600b FEBRUARY 21, 2008: How Dark is Dark?: How dark is dark? I remember being “trapped” in Sennufer’s tomb, mayor of Thebes in Amenophis II’s reign (18th Dynasty; 1427-1397 BCE), located in the Valley of the Nobles on the West Bank of the Nile at Luxor. The tomb guard, equipped with his kerosene lantern, had disappeared upstairs for “just a moment,” and my wife and I were left in complete darkness and silence for what seemed to be an eternity, but it probably was no more than 10 minutes. We were in the heart of Egypt’s greatest necropolis and that was the scariest dark I have yet experienced. The night sky is never that black, for stars, planets, and even the sky itself gives off a sufficient quantity of light for the fully dark adapted eye to distinguish a myriad of details on the ground. So how dark can it get? In New Mexico and Utah, where I have done most of my summer observing, I have regularly noticed shadows being cast by Venus. I had read about Jupiter being able to accomplish this same feat, but it was not until August 2000 that I made that observation from Chaco Canyon, NM. High in the eastern sky about 4:30 a.m. was Jupiter, Saturn, the Pleiades, Taurus the Bull, and Orion the Hunter beginning his leap over North Mesa. What a glorious sight! My shadow was plainly visible on the ground pointing away from Jupiter. Astronomers say the darkest skies in the world occur in the Australian Outback where the Milky Way is so brilliant that it can cast diffuse shadows on the ground. I witnessed this for myself in the Australian Bush at Siding Spring National Observatory in February 2001. Not only did the brilliant southern Milky Way provide enough illumination to discern ground detail easily, but I was also able to read the lettering on my Mt. Washington sweatshirt. These were surely nights to be treasured and remembered forever.

601a FEBRUARY 24, 2008: Beautiful Red Eclipse: When the first snowflakes were caught in the bright glare of my headlamp, there was already seven thousand dollars worth of equipment set up on the blacktop of the Quakertown Airport. Astronomical equipment and snow do not mix very well, but there was the full moon shining through a thin veil of clouds and other members of the ASD Planetarium’s StarWatch team arriving and wanting to know where to assemble their gear. Snow squalls had occurred in Allentown, Coopersburg, and south of Quakertown, but not in Quakertown. Despite Ed Hanna’s gloomy forecast, someone was looking over us, and the snow never came. About 110 people did brave the bitter chill and snow to witness one of nature’s most beautiful spectacles, a total lunar eclipse. At first contact with Earth’s shadow, conditions were clear, with a little haze. By totality the transparency had improved and a nearly blood red moon stood guard between yellowish Saturn and Regulus of Leo the Lion. It was a darker eclipse than I had expected, but its deep vermillion color made it special. The winter constellations of Orion, Taurus, Canis Major and Minor, and Gemini flowered in brightness. Leo was plainly visible with the eclipsed moon lying near the Lion’s feet. It was a night to be remembered. Special thanks are due to Bob Fowler and Jesse Leayman of the Quakertown Airport for providing us with an observing site and areas in which we could get warm. Thank you also to the StarWatch team: Matt and Marcella Gustantino, John Evrard, Sarabeth Brockley, David Addison, Mike Gross, and Dieruff students, Sean Quigney, Julyssa Nunez, Brendon Heckman, Kate (Fiona) Eisenman, Elizabeth O. Evans, and Charlotte Apiolaza. You were absolutely the best. Click on “this week’s StarWatch” at the URL below for lots of photos.

Photo by John Evrard, Dan's Camera City...

The moon enters the Earth's umbral shadow during this sequence of images taken on the very cold evening of Feburary 20, 2008. Image sequence by Gary A. Becker using a Canon 40D camera...

Lunar Eclipse Party Participants. Photography by John Evrard, Dan's Camera City...

A spectrum of totality during the February 20 total lunar eclipse shows how the area nearest to the shadow boundary rotated as the moon passed through the Earth's main shadow. Photography by Gary A. Becker using a Canon 40D camera...

The Moon in Eclipse, February 20: The eye saw a more even distribution of colors appearing almost blood red. Digital photography by Gary A. Becker using a Canon 40D camera, 2 sec., F/8, ASA 1000, 640mm focal length...

Jan C. Doddy of the Palisades School District took this beautiful unguided one second image of the moon in eclipse using a Canon 1DS Mark II camera with a 400mm lens at F/5.6, ASA 1250.

Lunar Eclipse Party Participants. Photography by John Evrard, Dan's Camera City...

The moon exits the Earth's shadow during the February 20 total lunar eclipse. Through my telescope the shadow boundary looked very distinct. Image composite by Gary A. Becker using a Canon 40D camera...

The moon exits the Earth's penumbral shadow. An observer on the moon would see part of the Earth covering a portion of the sun, thereby creating a partial solar eclipse. The diminution of sunlight closest to the location of the umbra is very evident in these photos. Image composite by Gary A. Becker using a Canon 40D camera...

Lunar Eclipse Party Participants. Photography by John Evrard, Dan's Camera City...

601b FEBRUARY 27, 2008: A Leap of Faith: It’s time to celebrate because this Friday is leap year day when the month of February has 29 days. The concept of a leap-day is really quite simple. Earth’s Tropical year, the interval of time between two successive solar crossings of the spring equinox, happens every 365.2422 days. Anyone familiar with the calendar knows that we give the Earth only 365 days to complete this task. Every year, our planet lags approximately 1/4-day behind schedule in completing its orbital duties. Four years of under correcting add up to approximately one full day, so a leap-day is added to the calendar to bring the Earth’s orbital position back into general agreement with the sun and the seasons. If the calendar did not contain leap years, then the dates of the year would cycle backwards through the seasons in approximately 1500 years. Christmas would still be celebrated on December 25, but gradually this date would slide into the autumn part of Earth’s orbit and then the summer, while the dates of the solstices and equinoxes would become later by about one day every four years. If leap-days occurred on every year divisible by four (Julian calendar), we would overcorrect the calendar by 0.0078 day each year. In just 128 years the calendar would be off by one day, in this case moving the date of Christmas ahead with respect to fixed seasons. Since the date of Easter is set by when the sun crosses the spring equinox, far into the future, Christians could be celebrating Christmas and Easter at the same time. This problem was rectified in 1582 by Pope Gregory XIII when century years not divisible by 400 were dropped as leap years. The 365.2422-day Tropical year became nearer to the value of the 365.2425-day Gregorian year. Still, we overcorrect the calendar by 0.0003 day each year.

Rachael Heinaman (yellow top); you are so dead for those rabbit ears. Allen High School Astronomy Class, Fall 2007... From left to right Cassandra Hernandez, Mario Ramirez, Nathan Gonzalez, Breanna Bretzik, Samuel Serrano, Laura Silvestry, Barbara Snyder, Gavin McElroy, Latham Cohoon, Gary A. Becker, Brandon Beebe, Rachael Heinaman, Anthony Santos, Kelsey Kichline, and Caleigh Miller. Photography by Gary A. Becker...

The Martians Have Landed: Dieruff High School Astronomy Class members, Fall 2007... From left to right, Felipe Resendez, Brian J. Santiago, Gabriella Graham, Jessica Yuos, Elizabeth Evans, Carlos Echeverria, Corey A. Gray, Brendan Hausman, Cassandra M. Turczyn, Gary A. Becker, and Kesha Patterson. Photography by Gary A. Becker...