Ephemeris: 04/04/2024 – Viewing the eclipse with pinhole projection.

This is Bob Moler with Ephemeris for Thursday, April 4th. Today the Sun will be up for 12 hours and 57 minutes, setting at 8:14, and it will rise tomorrow at 7:15. The Moon, 3 days past last quarter, will rise at 6:01 tomorrow morning.

If you have eclipse glasses and even if you don’t a good way perhaps the best way to view the solar eclipse is to use projection specifically pinhole projection the pinhole can act like a lens and with something as bright as the sun can cast a good visible image of the sun. Probably the best way to do it is to find a long box and cut a hole in one end. Have one long side open or partially open to view the Sun’s projected image. Cover the hole with aluminum foil and then make pinholes of various sizes, about half inch apart. The bigger the pinhole the brighter the Sun’s image but also the fuzzier it will be. The smaller the hole the sharper and dimmer the sun will be. For the IPR listening area the eclipse will start around 1:58 pm, and end around 4:25 pm.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT–4 hours). They may be different for your location.

Addendum

Pinhole projection is the simplest way to project the Sun’s image.

A long box can be used to project the image inside. The diameter of the pin hole is a compromise between sharpness and brightness of the image.
…The farther the image is projected the larger it is.

The throw of the image can be increased by using a mirror masked with a quarter of a inch or larger hole and sending the image 10 or more feet away.

Telescope projection of the Sun. Use the lowest power eyepiece. Cover the telescope finder. Point the telescope using its shadow. Photo by Eileen Carlisle.

With pinhole projection the Moon will appear to move from the upper right to lower left.