On April 8, 2024, a total solar eclipse will appear throughout North America, in Mexico, the United States, and Canada. According to NASA, the first location to experience totality in continental North America will be Mexico’s Pacific Coast at around 11:07 a.m. PDT. This will be the last total solar eclipse in the contiguous U.S. until at least 2044. The path of totality of the eclipse passes through many significant cities throughout the U.S. such as Dallas, San Antonio, Indianapolis, and Cleveland. While New Jersey is not in the path of totality, it is in the eclipse path and will experience a partial solar eclipse.

The last total solar eclipse in the contiguous U.S. was in 2017, but other total solar eclipses have hit North America in 2016 and 2019. This upcoming eclipse in 2024 is the first total solar eclipse happening in the ‘20s decade in North America. The last total solar eclipse in the world was just last year in 2023, when it hit parts of Southeast Asia, Australia, and Antarctica.

A solar eclipse is when the Moon comes between the Earth and the Sun, allowing for the Moon’s shadow to be cast over the Earth’s surface. The shadow has two parts: the umbra and the penumbra. A total solar eclipse can be viewed when you are within the umbra, as no sunlight can penetrate the shadow. In the penumbra, however, sunlight partly penetrates, so only a partial solar eclipse can be seen. The umbra is extremely narrow at the Earth’s surface– typically less than 50 miles wide– while the penumbra can exceed thousands of miles.

The Moon’s shadow traces an ‘eclipse path’ over Earth’s surface, which is the culmination of Earth’s rotation and the Moon’s eastward orbit around Earth. The Moon’s rapid revolution means the eclipse path lasts about four to five hours. This is also why totality in any one area only lasts for about a couple of minutes.

There are three important types of solar eclipses: total, partial, and annular. A total solar eclipse occurs when the Moon completely covers the Sun, only leaving its outer atmosphere, the corona, visible. Partial eclipses occur in the penumbral shadow of the Moon, and can happen when the Moon is not perfectly aligned with the Sun. Annular eclipses happen when the Moon is at its apogee– its farthest point from Earth. The Moon appears smaller at its apogee, and if a solar eclipse occurs even near an apogee, the umbral shadow does not reach Earth. Thus, a ring of sunlight (or ‘annulus’) appears around the Moon.

Solar eclipses always happen during the New Moon– when the Moon is in between the Earth and the Sun. The Moon’s orbit is tilted five degrees relative to the Earth’s orbit, however, meaning solar eclipses do not occur every New Moon. When the Moon actually intersects the plane of Earth’s orbit, it is known as a node. A node that yields eclipses only occurs two times a year. Eclipses happen over a period of time called ‘eclipse seasons’ (34.5 days) during these nodes.

Solar and lunar eclipses usually occur in pairs. The lunar month, the 29.5-day period in which it takes the Moon to go through all of its phases, is 5 days less than an eclipse season. This means that there will always be a New Moon and a Full Moon that leads to a solar eclipse and lunar eclipse respectively during each eclipse season. Since there are always at least two eclipse seasons during the year, there always have to be at least 2 solar eclipses each year. Occasionally, there can be up to 5 eclipse seasons.

While there are numerous super-precise methods of predicting solar eclipses today that organizations like NASA use, the Saros Series has been observed since ancient times. This method takes advantage of the fact that eclipses occur in patterns. A saros is the time between two almost identical eclipses; when the Earth, Sun, and Moon return to the same relative geometry. That time is a 223 lunar month period, about 6585.3211 days, or 18 years, 11 days, and 8 hours. Exactly half of this time (9 years, 5.5 days), a solar eclipse happens after a lunar eclipse or vice versa.

In celebration of the upcoming solar eclipse, there are already many local festivals planned. There are numerous events being held in Texas, especially in Kerrville. There, a Totality Over Texas event is being held at Schreiner University at the Loftis Observatory, and a separate NASA Eclipse Festival at Louise Hays Park. There is also the Total Eclipse Fest 2024 in Cleveland at the Great Lakes Science Center, partnered with NASA Glenn Research Center. These events regularly feature guest speakers and communal events like movies and food. Events being held in Mexico and Canada include The Portal Conscious Eclipse Festival at an ecotourist resort in Mazaltán, and events at the ASTROLab, at the Mont-Mégantic Observatory in Quebec.

Overall, the upcoming solar eclipse is a notable event to look forward to and serves as an opportunity for people to gather and admire the wonders of astronomy.