An astronomy-minded friend told me there’s a way to study the sun inside Grand Central Terminal that lets you see sunspots. Is he on the level?
Strangely, yes. This advice comes from John Pazmino of Brooklyn, a founder of NYSkies Astronomy, a discussion group for home astronomy in the city:
Don’t look at the sun itself; that’s always dangerous. Instead, take a plain white sheet of paper to the terminal’s Grand Concourse around 2:30 p.m. or a half-hour each way, when the sun shines straight along Park Avenue. (The exact times vary.) The day should be sunny, clear and cloudless.
The southern wall of the Grand Concourse, facing 42nd Street, has semicircular grills high up, with small curlicued spaces like those in a leafy tree. Many of those spaces act like the aperture of a pinhole camera, reflecting an image of the sun that, when it reaches the floor, will be 8 to 12 inches wide. The smaller grill spaces will produce dimmer but sharper solar images on your paper.
Large sunspots, regions of intense magnetic activity that are cooler than the surrounding surface, will appear as dark blemishes on the solar disk. And the edges of the disk will appear darker, because the edges show mostly the sun’s outer surface, which is cooler than the center.
Learn more of the secrets of Grand Central Terminal and how it changed its neighborhood and the city on July 13 with urban historian Gordon Linzer.