Complex sentence: A total solar eclipse will occur on Saturday, August 12,2045, when the Moon passes between Earth and the Sun, thereby totally or partly obscuring the image of the Sun for a viewer on Earth.
Split into simpler sentences: A total solar eclipse will occur on Saturday, August 12,2045. A solar eclipse occurs when the Moon passes between Earth and the Sun, thereby totally or partly obscuring the image of the Sun for a viewer on Earth.