What a difference a year makes!
Just a year ago, countless millions across North America were anxiously awaiting the “great North American total eclipse of the sun” on April 8. Now, less than a year later, on Saturday, March 29, another eclipse of the sun will take place, but it’s quite likely that the prospective viewing audience will be considerably smaller.
To produce this eclipse, the moon’s shadow falls chiefly on the north polar regions of Earth. Keep up to date with the latest solar eclipse news and events with our solar eclipse live blog.
Two by two
If you have been keeping track, this will be the second eclipse in less than a month. On March 13-14, we had a total eclipse of the moon. The moon crossed the ecliptic — the apparent path of the sun in our sky — less than 7 hours after arriving at full phase on March 14th, resulting in our natural satellite passing through the shadow of the Earth. It passed quite deeply through the northern half of the Earth’s shadow, resulting in a total eclipse. We call that crossing point a “node.” Also, during that eclipse, the moon crossed the ecliptic going from north to south — the descending node of its orbit.
Two weeks later, on March 29, the moon will arrive at the opposite side of its orbit and cross the ecliptic again, this time at the new moon phase, resulting in an eclipse of the sun.
We call this an eclipse season.
Eclipse seasons last about 37 days, a period of time in which the alignment of the sun and moon can allow for an eclipse to take place at both the full and new moon phases within that more than 5-week period. So, we can always expect an eclipse of the moon to be followed or proceeded by an eclipse of the sun. And on rare occasions (such as in 2018) we can get three eclipses (two partial solar eclipses flanking a total lunar one) occurring during the 29.53-day synodic lunar month, where normally we would only have two.
Almost too early for an eclipse
Being in the same eclipse season, the sun eclipse of March 29 occurs with the new moon passing through the opposite node (the ascending one) of the moon’s orbit. But the moon passes this node almost too early. That is, almost 19 hours after crossing the ecliptic, the moon arrives at new phase but by then the axis of its shadow passes well to the north of Earth. Because the moon is also near perigee (that point closest to Earth in the moon’s orbit), the dark shadow cone of the moon — called the umbra — tapers to well beyond us (by a distance of approximately three times the Earth’s radius), but also completely misses touching our planet, passing 180 miles (290 km) above the North Pole. So, unlike last year, no place on Earth will see the glorious spectacle of a total eclipse, but instead, the moon’s outer shadow (the penumbra) will scrape the top of our globe creating a more modest partial eclipse.
It will be visible in varying extents from northwest Africa, much of Europe (save for some eastern sections), and northwest Russia, as well as Iceland and Greenland. The penumbra also barely grazes South America, producing a small dent in the Sun at sunrise for parts of Suriname, French Guiana and Amada in Brazil.
A sunrise show
Much of North America will see nothing of this eclipse. However, there will also be locations that will see some of it. If you have an atlas of Canada and the United States, draw a line starting from a point near the city of Oakville, Ontario and extend it south, to Virginia Beach, Virginia. All places to the left (or west) of this line will have no view of any part of the eclipse. Meanwhile, those localities to the right (or east) of this line will be able to see at least a part of this eclipse near sunrise. For virtually all locations, maximum eclipse will have already occurred before sunrise, so when the sun first appears above the eastern horizon, the moon’s dark silhouette will be rapidly moving off the sun’s disk.
For example, in Baltimore, Maryland, the sun will rise at 6:58 a.m. EDT with 7.8 percent of its diameter eclipsed. The eclipse comes to an end just four minutes later when the disk of the moon moves completely off the face of the sun.
But take note that the farther north and east you go, the larger the amount of the sun that will be covered by the passing new moon.
And for parts of northern New England and Atlantic Canada, the amount of solar coverage will be quite large and will make for a very memorable sunrise. For the town of Madawaska (pop. 3,900), in far-northern Maine, maximum eclipse closely aligns with sunrise (6:17 a.m. EDT). At that moment, 88.2 percent of the sun’s diameter will be covered and the sun will appear to rise as a strikingly delicate crescent with its cusps pointed almost straight up. If there are no clouds present, it will initially appear as if two “lobster claws” are emerging from beyond the eastern horizon. A few minutes later, the entire crescent sun will appear to sit just above the eastern horizon.
Schedule of events
Local circumstances for this eclipse for 16 selected US locations, courtesy of Dr. Fred Espenak of EclipseWise.com were used to compile the table of local circumstances provided below. All times are Eastern Daylight Time.
|
Location |
Sunrise |
Obscuration |
Eclipse End |
|---|---|---|---|
|
Albany, NY |
6:45 a.m. |
42.1% |
7:08 a.m. |
|
Augusta, ME |
6:28 a.m. |
75.2% |
7:11 a.m. |
|
Boston, MA |
6:34 a.m. |
59.3% |
7:07 a.m. |
|
Concord, NH |
6:36 a.m. |
59.6% |
7:09 a.m. |
|
Dover, DE |
6:54 a.m. |
15% |
7:02 a.m. |
|
Hartford, CT |
6:41 a.m. |
45.8% |
7:06 a.m. |
|
Montpelier, VT |
6:39 a.m. |
56.9% |
7:11 a.m. |
|
New York, NY |
6:47 a.m. |
32.3% |
7:04 a.m. |
|
Newark, NJ |
6:47 a.m. |
31.2% |
7:04 a.m. |
|
Norfolk, VA |
6:58 a.m. |
0.3% |
6:58 a.m. |
|
Philadelphia, PA |
6:52 a.m. |
20.9% |
7:03 a.m. |
|
Providence, RI |
6:36 a.m. |
54.8% |
7:06 a.m. |
|
Springfield, MA |
6:40 a.m. |
47.9% |
7:07 a.m. |
|
Trenton, NJ |
6:50 a.m. |
24.9% |
7:04 a.m. |
|
Washington, DC |
6:59 a.m. |
3.7% |
7:01 a.m. |
|
Worcester, MA |
6:37 a.m. |
53.9% |
7:07 a.m. |
As seen from Atlantic Canada, a large fraction of the sun’s diameter will be eclipsed at maximum eclipse, which will come after sunrise. From Halifax, NS, 85.6% coverage comes at 7:17 a.m.; Fredericton, NB sees 87% at 7:19 a.m. and Saint John’s. NF sees 85.4% at 7:52 a.m.
Be careful!
Once again it needs repeating: to look at the sun without proper eye protection is dangerous. Unlike a total eclipse of the sun, concentrating its excitement into a few fleeting minutes, a partial eclipse can be watched relaxedly from wherever one happens to be. Observations can be made with specially designed solar filters, using eclipse glasses for direct viewing or binoculars, or telescopes of any size so long as they are fitted with solar filters.
Our how to observe the sun safely guide tells you everything you need to know about safe solar viewing and what to look out for. We’ve rounded up some of the best solar eclipse gear deals ahead of the partial solar eclipse so you can safely observe the sun for less.
The pinnacle
Just in case you’re contemplating traveling to where the greatest coverage of the sun by the moon will take place, that will happen in Nunavik in the northern third of the Canadian province of Quebec, 40 miles (65 km) inland from the Inuit town of Akulivik (pop. 680), where the sun will barely clear the southern horizon, with nearly 94 percent of its diameter hidden behind the moon. The normally thick horizon haze could attenuate and redden the sun’s light somewhat giving it the appearance of a narrow slice of cantaloupe melon.
Joe Rao serves as an instructor and guest lecturer at New York’s Hayden Planetarium. He writes about astronomy for Natural History magazine, Sky and Telescope and other publications.
Editor’s Note: If you snap a photo of the partial solar eclipse and would like to share it with Space.com’s readers, send your photo(s), comments, and your name and location to spacephotos@space.com.