Editor’s note: Due to the proximity of the upcoming astronomical event, Larry Scheckel has submitted a special Ask Your Science Teacher for the Jan. 14 Tomah Monitor-Herald.
QUESTION: What is this super blood wolf moon coming up on Jan. 20, 2019?
ANSWER: It sure sounds scary when we see the words “blood” and “wolf” in the description. Assuming clear skies on the evening of Sunday, January 20, 2019, night-sky viewers all over North and South America will be treated to a “super blood wolf moon.” Nothing scary, just a wonderous sight! Let’s break the three terms down.
A super moon happens when two events occur simultaneously; a full moon and its closest approach to Earth. The orbit of the moon around the Earth is not a perfect circle. Its path is somewhat oval, or elliptical. That means that once a month the moon is closer to Earth (perigee) and once a month it is a bit more distant (apogee).
On the night of Jan. 20, the moon will be at its closest point to the Earth in its orbit, and it will appear slightly larger, hence “super.” Those two phenomena, full and close, give the moon the “super” tag. How much bigger? Best estimates are that the Moon will appear to be 14 percent bigger and 30 percent brighter.
What about the “blood” name? That is caused by a lunar eclipse. During a lunar eclipse, the moon moves into the shadow of the Earth. Light from the sun must travel through our atmosphere to get to the moon.
Light is made up of seven colors. An easy way to remember them is: ROY G BIV for red, orange, yellow, green, blue, indigo and violet. The shortest light waves are in the blue region and the longest are red. When light travels through our atmosphere, some of the light is scattered. Dust particles and moisture act as tiny mirrors and reflect light in all directions. The shorter blue waves are scattered or reflected the most, which means we see these reflections from dust particles and moisture. We say the sky looks blue.
During a lunar eclipse, the earth blocks almost all sunlight from hitting the moon. The blue wavelengths are scattered out and the longer waves of red and orange strike the Moon. The Moon takes on that “blood” color. Some people describe it as the color of a penny.
What about that “wolf” name? Native Americans gave each full moon a name. The full moon of January was labelled the “wolf” moon, ostensibly because amid the deep snows and bitter cold of winter, the hungry wolf packs howled away outside Indian villages.
The total lunar eclipse will begin on Sunday, Jan. 20 at 10:45 p.m. with totality about 11:15 p.m. The eclipse will end about 12:45 a.m., the next day of Monday, Jan. 21.
The next lunar eclipse after January 2019 will be May 26, 2021, and it won’t be a super blood wolf moon.
The moon and sun together cause the tides, the rise and fall of sea levels on the Earth. There are two low tides and two high tides every day and roughly six hours from low tide to high tide and vice-versa.
A neap tide occurs around first quarter and third quarter moon. The sun and moon are at right angles to the Earth. The gravitational pull comes from two different directions lessening the difference in sea levels between high tide and low tide.
A spring tide occurs at full moon and new moon. The sun and moon act in the same direction causing greater rise and fall of tide levels.
Those nasty Nazis fire-bombed London on the night of Dec. 29-30, 1940. There was a new moon, and the moon was near perigee. Those two simultaneous conditions gave rise to extremely high and low tides. Formations of 136 Luftwaffe bombers started 1,500 fires at a time of low tide. The water drained out of the Thames River and firefighters could not drag their hoses out into the channel to put out the fires.
The military planners of D-Day, June 6, 1944, choose to storm the Normandy beaches at low tide. German defenses, dug into the sand, went all the way down to the low-tide mark. At high tide, those obstacles would have prevented the landing craft from reaching shore.
Larry Scheckel is a retired Tomah High School physics teacher.