The moon has been Earth's trusty sidekick for billions of years. And as it endlessly cruises around our planet, once in a while this scrappy satellite precisely aligns within Earth's shadow, taking on an eerie, reddish glow. And what's this phenomenon called? A lunar eclipse, of course. These eclipses are actually very simple considering how interesting and different they can be. Basically, the Earth's shadow blocks most of the sunlight from directly shining on all -- or a portion -- of the moon's surface. Earth generates two cone-shaped shadows: The umbra is the dark, center shadow, and the outer, more spread out one is known as the penumbra. The penumbra encases the umbra. Both these cones are cast out from behind the sunlit side of the planet. Consequently, lunar eclipses only occur during the full moon phase. It's important to note that lunar eclipses don't occur during every full moon because of two factors. The first has to do with the differences in the orbital planes between the sun, Earth and the moon. The moon doesn't circle the Earth in line with the Earth and Sun -- instead, its orbit is about 5 degrees off kilter. This means we have total lunar eclipses and partial lunar eclipses depending on our point of view on the Earth. There are lots of different things going on when the shadowy Earth eclipses her celestial companion. The color and brightness of the moon during a lunar eclipse varies according to this planet's atmospheric conditions. None of the sun's light can slip past the bulk of the Earth to shine in the umbra. However, Earth's atmospheric particles (like volcanic ash, dust and water vapor) refract the light and send it on to shine on the moon. The refracted, indirect light is on the redder side of the spectrum, which is why the moon often emits between a deep brown and bright orange hue. On average, lunar eclipses occur up to three times a year, if at all (although three in one year is rare). About a third of these occurrences are the faint penumbral lunar eclipses. Partial lunar eclipses take place about another third of the time and are worth checking out. The rest of the time, total lunar eclipses are wowing crowds of fascinated spectators and astrophotographers. The last lunar eclipse we saw was a penumbral eclipse seen in February 2017. BUT on January 31, 2018 we will be able to see a TOTAL LUNAR ECLIPSE! It's going to be freezing cold, in the dead of winter, possibly a snowstorm, but I am SO excited! We will be able to experience this together. What a wonderful year this has been! A nearly total solar eclipse and a TOTAL lunar eclipse, I just might faint with happiness!
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Mrs. TaylorI love science! Everything about the world is interesting and never boring. I love to study plants, animals, insects, and people. My favorite subjects are my students who are the most unique organisms on the planet! Categories |