By David Ward
In January we will be treated to a total eclipse of the moon. Unlike many astronomical phenomena, this one will be very easy to see. You will not have to set your alarm for the middle of the night and go outside in the snow and the cold at an hour when you are usually all warm and snug in your bed. The eclipse starts conveniently just after dinner.
So what is happening up there to put on a lunar eclipse for us? We do not usually think about it much, but the earth has a shadow. Each of us spends half our lives living in that shadow. We call it night. Our shadow is shaped like a cone and extends almost a million miles out into space. Think of it as the cone of night. Our moon is about 240,000 miles away and every now and then when the sun, the earth and the moon line up just right, the moon moves through that shadow.
If you saw the total eclipse of the sun last summer, you may remember that the moon covered the sun for only a couple of minutes. We had to concentrate all our attention for those few moments and not waste a second of that precious time. The shadow of the earth is bigger than the moon’s shadow so the moon just dawdles in it, allowing us to leisurely experience the whole event. If you get chilly while watching it, do not worry, you will have plenty of time to go inside, brew yourself a cup of hot tea and come back out again to look some more.
Lately it has been all the rage to call an eclipsed moon a blood moon because of the weird-looking red color we see on the moon only during an eclipse. That color is caused by sunlight bleeding through the atmosphere of the earth and shining on the moon’s surface. If you are interested in conspiracy theories, a blood moon is often associated with the end of the world or some other event with dire consequences. Lunar eclipses occur fairly often — two happened in 2018 — and as far as I can tell nothing worse than normal is happening now other than the usual political mess.
Super moon
Also this eclipse coincides with a super moon, meaning the moon is closer to us and appears larger in the sky than normal. Do not get too excited about an extra-big moon, you probably will not be able to tell much difference in its size. However, when the moon is just rising, it always appears larger because it is being magnified by all the atmosphere of the earth you are looking through.
Here are all the details: The date is Jan. 20, 2019. The start of the eclipse when the moon first begins to enter the earth’s shadow is at 7:33 p.m. By 8:41 p.m., the moon is entirely in the earth’s shadow and it stays there until 9:43 p.m. That hour will be the best time to view the eclipse. Then there will be another partial phase and the whole show ends at 10:50 p.m. The moon will be fairly high in the sky and should be easily seen unless you have some high obstructions like trees or a hill in the southeast.
According to the Internet the date of the eclipse has been cloudy 82 percent of the time in Wenatchee since the year 2000. We may see it or we may not, but that is how these astronomical events go. Our next shot will be May 26, 2021.
Usually the night of the full moon, and all-lunar eclipses occur on the full moon, is not a great time for stargazing since all that glare washes out the faint light of the stars. An eclipsed moon is much dimmer and if it is clear, lots of stars will be out. Look for brilliant Sirius, the brightest star in the sky, in the south. Above and to the right Orion, the hunter, is unmistakable with all its bright stars. Even the dim little Pleiades star cluster will not be over powered by the moon’s light.
The only planet visible at eclipse time will be Mars dimly shining in the southwest. If you get up early, Venus is that really bright object high in the southeast at dawn.
Have fun watching the eclipse and do not worry too much about the end of the world just yet. We will probably muddle along for a while longer.
