More about the Eclipse

More about the Eclipse

A solar eclipse happens when the Moon passes between the Earth and the Sun, blocking some or all of the Sun’s light from parts of the Earth’s surface. During an annular solar eclipse, the Moon is further away and only blocks some of the Sun. A total solar eclipse occurs when the disk of the Sun is completely obscured, briefly allowing us to view the solar corona with the naked eye.

A diagram of an annular solar eclipse. The Sun is on the left, the Moon in the middle, and the Earth on the right. Because the Moon is far enough away from the Earth, the point at the tip of the umbra (the total eclipse shadow) is out in space, not on Earth's surface, meaning that the full Sun is never blocked when viewed from Earth. Areas of maximum eclipse see a bright ring of the Sun visible around the Moon.

A diagram of a total solar eclipse. The Sun is on the left, the Moon in the middle, and the Earth on the right. The Moon is close enough to the Earth that the full light of the Sun is blocked for those in the path of totality, allowing those in the path on the Earth’s surface to view the Sun’s corona.

Figure 1: Diagrams showing the Earth-Sun-Moon geometry of annular (top) and total (bottom) solar eclipses. Not to scale: If drawn to scale, the Moon would be 30 Earth diameters away. The Sun would be 400 times that distance. Image Credit: Rice Space Institute

Eclipses provide a unique opportunity for scientists to study the effects of the Sun’s radiation on the Earth’s surface. Cut off from the Sun’s light, air and surface temperatures drop rapidly, with some observers noting drops of up to 3° Celsius in air temperature during a partial eclipse over the United Kingdom in spring 2015. Called the National Eclipse Weather Experiment, researchers published a paper assessing the citizen science weather observations. Wind speed and direction may change; as early as 1715 Edmund Halley (of Halley’s Comet) noted a “chill and damp that attended the darkness” during an eclipse, and subsequent studies have examined the causes of those changes. Animals within the path of totality react as well, with night creatures awakening while daytime wildlife goes quiet. In addition GLOBE data from the 2017 total solar eclipse were investigated in a book chapter, Validation of GLOBE Citizen Science Air Temperature Observations Using Data from the Great American Solar Eclipse, and a paper Eclipse Across America: Citizen Science Observations of the 21 August 2017 Total Solar Eclipse.

Wondering how (and when) the Eclipse will affect you?

Times for the partial or total phases of the eclipse vary depending on your location; only a small oval of the Earth is directly in the Moon’s shadow at any given time. Below is a tour of NASA's Solar Eclipse map for 2023 and 2024.

Visit NASA's Scientific Visualization Studio for more details and to download the map or this video.

What exactly is an annular solar eclipse?

The video below explains what an annular eclipse is, why it happens, and how it creates a "ring of fire" in the sky.

Get more details or download the annular eclipse video

How can I observe the eclipses?

This video from the Fiske Planetarium outlines the differences between the two upcoming eclipses, discusses best practices for viewing the eclipse, and prepares audience members to have an amazing experience on eclipse day!


How do eclipses help us understand the Sun?

NASA's Eclipse Science page has information about how solar eclipses have helped us understand the structure of the Sun, find evidence for the theory of general relatively, and discover a new element, as well of new areas of research that eclipses can help us explore.