Article by Bob Moler
Special Almanac posting by Bob Moler
We will have a calendrical coincidence on January 31st along with a natural event, and just missing another natural event all having to do with the Moon.
The first is that one of the full moons in January fits the definition for a "blue moon", the second full moon in a month. Of course the Moon doesn't actually turn blue. It doesn't really care. Since February is shorter than a lunation, a lunar month, it will not have a full moon. However March will have two full moons like January.
The second is a real event. The Moon being opposite the Sun in the sky, the definition of a full moon, will pass into the Earth's shadow causing a lunar eclipse or eclipse of the Moon. In this case, a total eclipse. A lunar eclipse of some type occurs in about one in six full moons. We only have to be on the night side of the Earth to see it. That's the rub this time, because the eclipse will be in progress at sunrise. The partial phase starts at 6:48 a.m. From about 6:30 on the upper left part of the Moon will appear dusky as the Moon sinks deeper in the Earth's outer shadow, where the Sun is only partially blocked. The Moon will sink farther and farther into the Earth's inner shadow called the umbra until at 7:51 a.m. it will be totally immersed. By then the sky will be quite bright, with sunrise to occur at 8:02. The Moon should completely disappear and will set unseen at 8:04. Folks a few states west of us will see, more than likely, a coppery colored totally eclipsed Moon. A TV preacher some years ago called it a Blood Moon, hoping to sell books about the end times.
The color comes from the sum of all the sunrise and sunsets happening on Earth at that instant. The red sunrise we see is caused by the blue light being scattered out of the Sun's light by molecules in the Earth's atmosphere. It gives us the blue sky. Our atmosphere also bends the Sun's light. When we see the full disc of the Sun just clear the horizon, it's still actually fully below the horizon. The light of the sunrise that passes over our heads continues on, being bent further and becoming redder, and fills the Earth's shadow by the time it reaches the Moon's distance, making the Moon red. Volcanic ash in the upper atmosphere can make the Moon almost disappear during totality.
This full moon is also a so-called "Super Moon". These occur when the full moon is nearest the Earth in its monthly orbit of the Earth. January first's full moon was the closest of the year, you might say a super duper moon. The Moon reached its perigee, closest point or 221,581 miles away 5 hours before the Moon was officially full. This time perigee is the day before full, about 1,500 miles farther away. These are measured center to center. The closest an Elk Rapids observer will be to the Moon on the 31st will be at about 12:30 a.m. at 219,920 miles, subtracting most of the Earth's radius. Of course the Moon won't look that big being high in the south then. By moon set it will retreat to 223,778 miles from an Elk Rapids observer. The increased apparent size of the rising or setting Sun or Moon is an optical illusion. The Moon is closer to us when high in the sky than when on the horizon.
The next lunar eclipse visible to us is next year, on the night of January 20-21, 2019.
Bob Moler ,NASA/JPL Solar System Ambassadors Volunteer
ISEA Schoolship Volunteer Instructor
Ephemeris web page: ephemeris.bjmoler.org
Blog: bobmoler.wordpress.com
Bob Moler's Ephemeris weekdays on Interlochen Public Radio (Volunteer)
Also streaming live on the Internet at ipr.interlochen.org
6:19 a.m. ET on News IPR (This is a new time):
WICA 91.5 FM, Traverse City;
WLNM FM 98.7 FM, Manistee;
WHBP FM 90.1 FM, Harbor Springs - Petoskey
6:58 a.m. ET on Classical IPR:
WIAA 88.7FM, Interlochen;
94.7 FM Traverse City,
WIAB 88.5 FM, Mackinaw City;
WICV 100.9 FM, East Jordan - Charlevoix
We will have a calendrical coincidence on January 31st along with a natural event, and just missing another natural event all having to do with the Moon.
The first is that one of the full moons in January fits the definition for a "blue moon", the second full moon in a month. Of course the Moon doesn't actually turn blue. It doesn't really care. Since February is shorter than a lunation, a lunar month, it will not have a full moon. However March will have two full moons like January.
The second is a real event. The Moon being opposite the Sun in the sky, the definition of a full moon, will pass into the Earth's shadow causing a lunar eclipse or eclipse of the Moon. In this case, a total eclipse. A lunar eclipse of some type occurs in about one in six full moons. We only have to be on the night side of the Earth to see it. That's the rub this time, because the eclipse will be in progress at sunrise. The partial phase starts at 6:48 a.m. From about 6:30 on the upper left part of the Moon will appear dusky as the Moon sinks deeper in the Earth's outer shadow, where the Sun is only partially blocked. The Moon will sink farther and farther into the Earth's inner shadow called the umbra until at 7:51 a.m. it will be totally immersed. By then the sky will be quite bright, with sunrise to occur at 8:02. The Moon should completely disappear and will set unseen at 8:04. Folks a few states west of us will see, more than likely, a coppery colored totally eclipsed Moon. A TV preacher some years ago called it a Blood Moon, hoping to sell books about the end times.
The color comes from the sum of all the sunrise and sunsets happening on Earth at that instant. The red sunrise we see is caused by the blue light being scattered out of the Sun's light by molecules in the Earth's atmosphere. It gives us the blue sky. Our atmosphere also bends the Sun's light. When we see the full disc of the Sun just clear the horizon, it's still actually fully below the horizon. The light of the sunrise that passes over our heads continues on, being bent further and becoming redder, and fills the Earth's shadow by the time it reaches the Moon's distance, making the Moon red. Volcanic ash in the upper atmosphere can make the Moon almost disappear during totality.
This full moon is also a so-called "Super Moon". These occur when the full moon is nearest the Earth in its monthly orbit of the Earth. January first's full moon was the closest of the year, you might say a super duper moon. The Moon reached its perigee, closest point or 221,581 miles away 5 hours before the Moon was officially full. This time perigee is the day before full, about 1,500 miles farther away. These are measured center to center. The closest an Elk Rapids observer will be to the Moon on the 31st will be at about 12:30 a.m. at 219,920 miles, subtracting most of the Earth's radius. Of course the Moon won't look that big being high in the south then. By moon set it will retreat to 223,778 miles from an Elk Rapids observer. The increased apparent size of the rising or setting Sun or Moon is an optical illusion. The Moon is closer to us when high in the sky than when on the horizon.
The next lunar eclipse visible to us is next year, on the night of January 20-21, 2019.
Bob Moler ,NASA/JPL Solar System Ambassadors Volunteer
ISEA Schoolship Volunteer Instructor
Ephemeris web page: ephemeris.bjmoler.org
Blog: bobmoler.wordpress.com
Bob Moler's Ephemeris weekdays on Interlochen Public Radio (Volunteer)
Also streaming live on the Internet at ipr.interlochen.org
6:19 a.m. ET on News IPR (This is a new time):
WICA 91.5 FM, Traverse City;
WLNM FM 98.7 FM, Manistee;
WHBP FM 90.1 FM, Harbor Springs - Petoskey
6:58 a.m. ET on Classical IPR:
WIAA 88.7FM, Interlochen;
94.7 FM Traverse City,
WIAB 88.5 FM, Mackinaw City;
WICV 100.9 FM, East Jordan - Charlevoix