This calendar year has already been filled with exciting astronomical events, from a “planetary parade” to the recent total lunar eclipse. This weekend we have a partial solar eclipse on March 29, 2025, when the moon passes directly in front of the sun as seen from Earth. This will appear as though the moon is “taking a bite” out of the sun—the portion that the sun is covered is highly variable depending on the viewer’s location, but in some places as much as 90% of the sun’s disk will be blocked.

Solar and lunar eclipses happen once a year or so, usually separated by about two weeks, during a period known as eclipse season. Normally the tilt of the moon’s orbit means it misses the sun in the sky, passing above or below it as seen from the ground. But when the sun, Earth, and the moon fall into a line we can get a lunar eclipse, then, two weeks later when the moon has moved halfway around its orbit, we see a solar eclipse (or vice-versa).

Unlike a lunar eclipse, when Earth casts its shadow on the moon, in a solar eclipse it is the Earth that falls into the moon’s shadow. In a partial solar eclipse, like what we’ll get on March 29, the moon doesn’t fully block the sun, but instead cuts a chord across it. Because the moon is between the sun and us, during a partial solar eclipse we’re looking at the unlit side of the moon in silhouette against the far brighter sun, so by eye it looks like a perfect but utterly black section of a circle against the solar disk.

Last year's total solar eclipse drew thousands of umbraphiles to the path of totality (the next total solar eclipse is on August 12, 2026 and will be visible from parts of the Arctic, Greenland, and Spain). The partial eclipse won't be as exciting, but it’s still quite striking to see the clockwork gears of the heavens revealing the motions of the heavenly bodies in this way, so it’s well worth checking out.

Which brings us to an important point: Never look at the sun without proper protection. You can very seriously damage your eyes doing so; the ultraviolet and infrared light from the sun can cook your retinae (sunglasses don’t block enough of that light to protect you, either). The best way to observe it is to specially made dark eclipse glasses, but you should get them from legitimate vendors. Don’t just shop online for them because many companies sell cheap and dangerous knockoffs that can still hurt your eyes. The American Astronomical Society keeps a list of approved sellers; most are quite inexpensive, just a few dollars. They also list sellers of binoculars and telescopes designed specifically to view the sun, and filters if you already have your own equipment.

Where and when to see the partial solar eclipse

So who will get to see the partial solar eclipse of March 29, 2025? The best place for viewing is the extreme northeast US and southeast Canada—in southeast Qikiqtaaluk (Baffin Island), up to 92% of the sun will be blocked by the moon. Maine will see 60 – 85% coverage, depending on the exact location. Iceland gets up to 69%, and Greenland as much as 87%, while various locations in western Europe will see from 20 – 40% of the sun blocked by the moon. The Scandinavian Peninsula gets a decent view, with Finland seeing about 20%, Sweden in the mid-20s, and Norway getting as much as 60% (and, mind you, if you stay for a few nights you might also get a chance to see an aurora). Northwest Africa is on the edge of the moon’s shadow, where Morocco, for example, will see about 17% of the sun covered. Even South America gets a (very small) piece of the action; the sun will get nicked by the moon in Suriname and French Guyana, with just 1-2% of its surface blocked.

In the US, Canada, and other western locations, the eclipse happens around sunrise, but the farther east you view it the later in the day it occurs. The entire event, from the moon first starting to edge onto the sun to when it moves off, takes about an hour and a half for the locations seeing the deepest eclipse, while for other sites it may only last half an hour. How much of the sun you’ll see blocked and when the eclipse starts and ends depend strongly on your exact location. Your best bet for information on locations and timings is the terrific Time And Date website. For those in the States, NASA has published a list of when to see the partial solar eclipse in major cities, including the below:

Baltimore	6:55 a.m.
Boston	6:31 a.m.
New York	6:44 a.m.
Philadelphia	6:49 a.m.
Portland, Maine	6:27 a.m.
Washington, D.C.	6:56 a.m.

NASA also has a nice summation of how to see the eclipse, including a somewhat technical overview, and an interesting (if low-res) animation showing the moon’s shadow moving across Earth’s surface for the March 29 event.

If you choose your location wisely, you’ll see a bizarre effect: the crescent sun will rise above the horizon with the “horns” of the crescent pointing upwards (a bit like a lopsided Cheshire cat smile). As the sun clears the horizon it will look as if two triangular suns are rising next to each other. This “double sunrise” will only last a minute or two, so you have to be quick to catch it. It will be visible in extreme eastern Maine, and in southwestern New Brunswick, western Nova Scotia, and eastern Quebec in Canada.

May you have clear skies and an unobstructed view so you can see this wonderful celestial treat—with the proper eyewear, of course.