Final answer:
An annular eclipse occurs when the Moon is farther away from the Earth and cannot cover the Sun completely, creating a ring of light around the dark sphere of the Moon. The range of Earth-Moon distances for which an annular eclipse is possible is greater than approximately 2.78 million km.
Step-by-step explanation:
An annular eclipse occurs when the Moon is farther away from the Earth and cannot cover the Sun completely, creating a ring of light around the dark sphere of the Moon. To determine the range of Earth-Moon distances for which an annular eclipse is possible, we need to consider the angular size of the Sun.
Given that the angular size of the Sun is 0.5 degrees, we can use trigonometry to find the range of distances at which the Moon's angular size is smaller than the Sun's angular size. Using the formula: Angular size = (Diameter of object) / (Distance to object), we can rearrange the formula to solve for the distance:
Distance = (Diameter of object) / (Angular size)
Substituting the values, Distance = (1.39 million km) / (0.5 degrees). Solving for the distance, we find that an annular eclipse is possible at distances greater than approximately 2.78 million km.