How is a solar eclipse visible from Earth's surface?

Answer 1

A moon-sized shadow will fall anywhere behind the Moon as it orbits. At the "new moon" phase, the Moon is between the Earth and the Sun. If the Moon is lined up in the right location, the shadow will cross the Earth. Within the circular shadow, some areas may have a total eclipse.

Areas not directly under the central path will only see part of the Sun obscured. These areas observe a partial eclipse. Polar regions may experience a partial eclipse when the Moon's full shadow (umbra) misses the Earth to the north or south.

If the Moon is nearer to its apogee (farthest from Earth), the apparent size of the Moon from Earth will be smaller than the Sun, and some of the Sun's light will pass around the Moon. This is an annular eclipse.

Answer 2

A solar eclipse occurs when the Moon passes between the Sun and Earth, blocking the Sun's light. When the alignment is perfect, the Moon's shadow falls on a specific region of Earth's surface, creating the eclipse. People within this shadow can witness the eclipse as the Moon partially or completely covers the Sun.