Solar Eclipses

Solar Eclipse Fundamentals

• A solar eclipse occurs when a new moon blocks sunlight from reaching the Earth.
• During an eclipse, the Moon fits almost exactly across the Sun, revealing the Sun's "corona," which is usually not visible.

Frequency and Path of Totality

• Solar eclipses do not occur every month.
• A solar eclipse is visible over only a small portion of the world along a path of totality.
• Compared to lunar eclipses, solar eclipses are very rare at any given location because the Moon is much smaller than the Earth.

Proportions and Angular Size

• The Sun is $400$ times larger than the Moon, but it is also $400$ times as far away.
• Orbits are not perfectly circular, so the distance and angular sizes of both the Sun and the Moon vary slightly between their closest and farthest points.

Annular Eclipses

• As a result of distance variations, some solar eclipses are "annular," meaning the Moon does not fully cover the Sun, leaving a visible ring of sunlight around the Moon.