Other Space News

Partial Solar Eclipse on October 23rd

Image taken January 30th 2014 from the NASA Solar Dynamics Observatory during partial solar eclipse.
Image taken January 30th 2014 from the NASA Solar Dynamics Observatory during partial solar eclipse.

A partial solar eclipse October 23rd 2014 will be observable from most places in North America. The partial solar eclipse will be visible at different times depending on your location. Here in Sacramento California the partial solar eclipse will begin at 1:52pm with the greatest eclipse occuring at 3:16pm and eclipse ending time of 4:32pm. To celebrate this astronomical event here at the Discovery Museum Science & Space Center we will be providing solar eclipse themed planetarium shows between 12:30 and 2:00 and observation areas with some Galileoscopes and other options to observe the eclipse. We will have solar viewing glasses for sale while supplies last. We will be participating in this event until 4pm but the museum will still be open until 4:30pm.

This partial solar eclipse is part of the Saros 153 series of eclipses. This series of eclipses began in July 1870 and will continue up until August 3114 for a total of more than 1200 years. Each Saros series of eclipses are determined by the geometry of the lunar orbit. To explain further the moon orbits our planet at an angle which means it is not always on the ecliptic plane. What this means is if you were to take a model of the sun, earth, and moon and you put a string through the center of the sun and earth (lets ignore the tilt of the earth for now) and pulled the string tight that would be the ecliptic plane. The moon orbits earth at an angle according to this ecliptic plane.

Image Credit: Earthsky.org
Image Credit: Earthsky.org

Observing the diagram above you can see that the moon will only cross paths with the ecliptic at certain times in its orbit. During the time that the moon crosses the ecliptic plane if it happens to be at the exact moment that the sun is in the same location in the sky is when we observe a solar eclipse. Now the Saros series begin when the edge of the moon is just touching the edge of the sun in the sky during a partial eclipse. As time goes on that Saros series of eclipses will begin seeing the moon cover up more and more of the sun up through the point that the moon is just touching the opposite end of the sun. This cycle is what takes over 1200 years and is usually a collection of around 70 solar eclipses. There is usually on average around 40 Saros series of eclipses happening at the same time and lunar eclipses are also part of the same Saros series.


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