Get Ready for the Solar Eclipse on April 8

Across the country, people are gearing up for the April 8 total solar eclipse, which will be visible in North America along a narrow track that stretches from Mexico through Texas and across the Midwest and New England before ending in the Canadian Maritimes.

If the weather is clear, people positioned along that path will be able to see the moon completely block the sun for up to 4½ minutes, briefly turning day into night. The rest of North America, Central America and northern South America will be treated to a partial eclipse of varying degrees.

According to the GreatAmericanEclipse.com, an estimated 32 million people, or 9.6% of the nation’s population, already live inside the U.S. path of the April eclipse, and tens of millions more reside within a couple of hours’ drive of its track, making it likely to be the most widely watched – and photographed – total solar eclipse in history.

Parts of New York, Vermont, New Hampshire and Maine lie within the path of the total eclipse.

However, people outside the path, such as those in Massachusetts, Connecticut and Rhode Island, will still be able to watch a deep partial eclipse unfold from practically anywhere, provided they have a clear, cloud-free view of the sun.

As seen from the UMass Lowell campus, the partial eclipse will begin at 2:16 p.m., when the moon’s dark edge starts to encroach on the sun. Maximum eclipse occurs at 3:29 p.m., when the moon covers 94% of the sun’s disk, turning it into a razor-thin crescent. The eclipse ends at 4:39 p.m.

As the partial eclipse reaches maximum coverage, the sky will darken dramatically. However, the remaining 6 percent of the sun will still be blindingly bright, so viewers should take the necessary precautions to avoid damaging their eyes.

There are some important things to keep in mind when trying to view a partial solar eclipse.

First, never look directly at the sun without proper eye protection, such as eclipse viewing glasses or a solar filter for your camera, binoculars or telescope. Failure to do so can result in serious eye injury or permanent blindness. A No. 14 arc-welder’s glass filter is also acceptable, but ordinary sunglasses and polarizing or neutral-density filters used in regular photography are not safe and should not be used.

You can purchase inexpensive but safe eclipse viewing glasses, or “eclipse shades,” from companies such as Celestron. The glasses will not only help cut down the sun’s brightness, but they will also block out its harmful ultraviolet and infrared radiation.

An alternative method for safe viewing would be to use the indirect technique – that is, making a pinhole on one side of an empty cardboard box and holding the box up to the sun, without looking at it. You can then project the image of the sun inside the box onto a white sheet of paper taped to the side opposite of the pinhole. The projected solar image would be tiny, dim and fuzzy, but it’s perfectly safe to look at through an open side of the box.

When the partial eclipse is about halfway, you can also look under leafy trees (these may be hard to find in April) or evergreens. The tiny spaces between the leaves or needles act as natural pinholes, projecting dozens of small solar crescents on the shaded ground. Lay down a white blanket or T-shirt to see and photograph the crescents better. Everyday items with small perforations, such as a colander or other kitchen utensils, can be used to project the solar crescents. 

If you want a brighter, sharper solar image, use an unfiltered telescope (or one side of your binoculars) to project a magnified image of the sun’s disk onto a sheet of paper. The projected image can then be safely viewed and photographed. Be sure to cover the telescope’s finder scope and the unused half of the binoculars.

To shoot the partial eclipse through a telescope or telephoto lens, be sure to securely mount a safe solar filter in front of your optics. You can order the correct size of filter from manufacturers such as Celestron.

You can use your point-and-shoot camera or your smartphone to take quick photos of the partially eclipsed sun, but you would have to shoot them through a solar filter, such as that from your spare eclipse viewing glasses. (If you just hold up your pocket camera or smartphone to the sun and try taking snapshots, you won’t be able to record anything because all your photos will be completely overexposed.) Be sure to mount the solar filter securely over your camera lens so it doesn’t fall off.

A better way would be to shoot through a properly filtered telescope. Many science museums, planetariums, astronomy clubs and schools, such as UMass Lowell’s Schueller Observatory on South Campus, will be offering free public solar viewing on April 8. To capture the eclipsed sun through one of the filtered telescopes that day, hold your camera or smartphone and aim its lens directly into the telescope eyepiece. Use the LCD screen to center the sun and zoom in as needed. You can use the camera’s auto-focus and auto-exposure settings, and try to hold the camera as steady as you can while clicking the shutter button.

If you want to use a full-size digital SLR camera on your own telescope, you should attach the camera body securely to the telescope focuser using an appropriate adapter for your camera brand (check with your local camera retailer). To minimize vibrations that could blur your images, use an electronic cable release or remote switch to operate the shutter.

If you miss April’s solar eclipse, you’ll have to be patient for your next opportunity to experience one: The next total eclipse of the sun will not be visible on the U.S. mainland until the year 2044.