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ETSU to host Mercury transit viewing for the public

Contributed • Nov 8, 2019 at 4:03 PM

The planet Mercury will pass directly between the sun and Earth — an event known as a transit — on Monday, Nov. 11. During this event, the planet will be seen as a very small black dot moving slowly across the face of the sun.

East Tennessee State University’s Department of Physics and Astronomy will offer an opportunity for the public to safely view this rare astronomical occurrence, which will begin just after sunrise and end in the early afternoon on that day. From 9:30 a.m. until 12:30 p.m., ETSU astronomers will have telescopes set up on the athletic field adjacent to the Wayne G. Basler Center for Physical Activity on the west side of the university campus.

Since Mercury will only be about 1/180 the size of the sun’s apparent diameter, a telescope will be needed to magnify the image. However, because serious damage to the eye, including blindness, can result from looking directly at the sun without proper eye protection, the telescopes will be equipped with special solar filters to permit safe viewing.

It will take three minutes from the time Mercury just meets the edge of the disk of the sun until the entire small dot is in front of the sun’s disk. At about 10:30 a.m. on Nov. 11, Mercury will be near the midpoint of the transit and closest to the center of the sun.

Although there are 14 transits of Mercury occurring this century, not all will be visible from a given location on Earth. It will be 30 years before another transit is visible from East Tennessee in May 2049.

Astronomers say transits of Mercury are not as historically important as transits of Venus due to its very small, angular size compared to the diameter of the sun.

Visitors should enter the ETSU campus from West State of Franklin Road onto Jack Vest Drive, then turn right onto Go Bucs Trail to park in the large lots adjacent to the athletic field area.

In the event of inclement weather or heavily overcast skies, the transit viewing will be cancelled.

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