When the moon moves through its orbit to completely block the light of the sun from hitting Earth over a small track, a total eclipse is produced, according to NASA. During its lunar orbit, the moon can cross between the sun and Earth to cause a partial eclipse, meaning the moon obscures only a portion of the sun. The final type of solar eclipse is the annular eclipse, which means the moon is traveling at an extreme orbit and is not large enough in the sky to block the light of the sun completely. An annular eclipse is characterized by the thin ring of light visible around the moon's silhouette.
The timetable for eclipses taking place on Earth is calculated using the Saros Cycle, according to NASA. A near-identical eclipse takes place on Earth approximately every 18 years and 11 days: the moon takes approximately 18 years and 10 days to complete a total orbit cycle. Because the exact length of the Saros Cycle is 6,585.32 days, an eclipse does not take place on exactly the same spot on Earth until every third Saros Cycle.
The speed of an eclipse varies on Earth depending on the position of the eclipse on the planet. Where an eclipse takes place near the equator, the shadow moves at around 1,100 mph, while an eclipse at the pole has a shadow movement that can reach speeds of around 5,000 mph. During an eclipse, the change in light toward darkness can result in animals preparing for sleep or becoming confused. The visible light in the path of an eclipse is not noticeable until the moon has obscured around 90 percent of the sun, NASA reports.
A solar eclipse on the moon is achieved when Earth passes between the moon and sun. As each day on the moon lasts around 29.5 Earth days, the solar eclipse seen from the moon lasts longer than the 7.5 minutes of an earthbound solar eclipse, NASA reports. During a solar eclipse on the moon, the nightside of Earth is visible.
