The Moon Before the Total Eclipse

August 21, 2017


Photographer: David Rojas
Summary Authors: David RojasJim Foster

This photo was captured just two days before today's total solar eclipse. Here the waning crescent Moon accompanies the planet Venus in the early hours of August 19, 2017. Approximately 7 percent of the Moon is illuminated as observed from Guatemala City, Guatemala. 

Today is the day of the Great American Eclipse; the first total solar eclipse visible in the contiguous U.S. in 38 years. As the new Moon passes directly in front of the Sun, its deep shadow (the umbra), will cast an approximately 70 mi (113 km) strip of darkness over the United States, from coast to coast -- from Oregon to South Carolina. Our Moon's diameter is approximately 1/400 of the size of the solar disk. The Moon's distance from the Earth is also about 1/400 of the distance between the Earth and the Sun. So because of this coincidence the Sun and Moon cover the same amount of sky (1/2 degree). Moreover, it permits the Moon to on occasion, every year or two, exactly cover the solar disk as it passes before it. 

It's likely that more people will view the Great American Eclipse than any other solar eclipse in Earth's history. For the remainder of the week, we'll feature images of this eclipse as captured by our viewers. Don't forget to check out our Facebook page for more photos. 

Photo Details: Camera Model: NIKON D3200; Lens: 55.0-300.0 mm f/4.5-5.6; Focal Length: 155.0mm (35mm equivalent: 232mm); Aperture: ƒ/5.0; Exposure Time: 3.000 s; ISO equiv: 800; Software: Adobe Photoshop CC 2017 (Windows).