A total solar eclipse lasts no longer than about ______ minutes.

A total solar eclipse lasts no longer than about ______ minutes.

• A. 5
• B. 7
• C. 3
• D. 10

Answer: (B)

The length of totality in a solar eclipse is set by how long the Moon’s shadow (the umbra) stays over a given spot on Earth as the shadow sweeps across due to the Moon’s orbit and Earth's rotation. Since the Sun and Moon have nearly the same apparent size, the period of full coverage is brief. The geometry can line up to give only a few minutes of totality, with the longest possible total eclipse lasting a bit over seven minutes (about 7.5 minutes). So about seven minutes is the best rounded estimate for the maximum duration. Shorter totals happen frequently, while ten minutes would exceed what is physically possible for a total solar eclipse.

The length of totality in a solar eclipse is set by how long the Moon’s shadow (the umbra) stays over a given spot on Earth as the shadow sweeps across due to the Moon’s orbit and Earth's rotation. Since the Sun and Moon have nearly the same apparent size, the period of full coverage is brief. The geometry can line up to give only a few minutes of totality, with the longest possible total eclipse lasting a bit over seven minutes (about 7.5 minutes). So about seven minutes is the best rounded estimate for the maximum duration. Shorter totals happen frequently, while ten minutes would exceed what is physically possible for a total solar eclipse.