A half-lit moon shows more than a full one, and Ferris State University is setting up telescopes on the Robinson Quad Saturday night, Sep. 19, to show why.

International Observe the Moon Night runs free and open to the public from 8:30 to 10:30 p.m. on the Big Rapids campus. Visitors of any age can walk up, take a turn at an eyepiece, and ask faculty about the view.

The night's main attraction is the terminator, the boundary dividing the moon's sunlit day side from its night side. Near the first quarter, that line cuts across the face of the moon and turns ordinary terrain dramatic.

"Sunlight strikes the surface at a very low angle along this line, causing crater rims and mountain peaks to cast long, dramatic shadows," said Dinesh Shetty, an assistant professor of physics and astronomy who hosts the event.

Shetty said visitors will pick out individual craters in fine detail along with the maria, the dark volcanic plains that form the familiar pattern on the moon's face. A full moon, lit straight on, flattens all of it.

Groups of 10 also rotate through the Rawlinson Observatory dome for tours across the evening. An elevator reaches the third floor, and a short flight of stairs climbs from there to the dome.

Clouds do not cancel the night. Shetty makes the weather call Saturday afternoon and posts it on the observatory website, and someone stationed on the quad will direct arrivals to Room 102 on the lower level of the Science Building, where the evening becomes an indoor observatory tour.

NASA organizes International Observe the Moon Night each year in September or October, timing it to a moon near the first quarter for exactly the shadows Shetty describes. Observers worldwide have marked the night since 2010, and Ferris State's event appears on NASA's Global Participation Map.

The Rawlinson Observatory runs on a public outreach mission year-round. Its equipment includes a large-aperture reflecting telescope on a computer-controlled equatorial mount, scientific CCD and CMOS cameras for live viewing, and planetarium software that puts the view on an indoor display.

Astrophotography has become a growing focus, and workshops there cover low-light camera settings, polar alignment, stacked imaging, and image processing.

Shetty teaches in the Department of Physical Sciences in Ferris State's College of Arts, Sciences and Education, where faculty cover chemistry, industrial chemistry, physics, physical science, geology and astronomy.

The department awards bachelor's degrees in chemistry, biochemistry and industrial chemistry, plus an associate degree in industrial chemistry technology. Working with the School of Education, it also offers a secondary teaching major in chemistry and teaching minors in chemistry and physics. The college offers more than 100 programs across nine departments.

_{Release and photo courtesy of Ferris State University.}