WHAT ARE ECLIPSES An eclipse happens when one object in space blocks another from view Eclipses happen because planets planets moons and other celestial bodies constantly move through space As Earth moves around the sun in a path called an orbit the moon makes its own orbit around Earth At certain points in each orbit the sun moon and Earth line up in a row During a solar eclipse the moon comes between Earth and the sun for a short time The moon’s shadow falls on Earth’s surface The inner part 4 This artwork shows how the sun moon and Earth align to create an eclipse of the sun as seen on Earth
VOCABULARY Celestial bodies are objects located in the sky such as the moon other planets asteroids and stars of the shadow is called the umbra People watching from within the umbra experience a total solar eclipse In a total solar eclipse the moon appears as almost exactly the right size to completely cover the sun when observed from Earth The outer part of the shadow is the penumbra penumbra People viewing from within the penumbra see a partial eclipse Another type of eclipse happens when Earth comes between the moon and the sun That is called a lunar eclipse In the darkly shaded region umbra a solar eclipse is total in the lightly shaded region penumbra penumbra the eclipse is partial 5
ANCIENT ECLIPSES Some ancient peoples regarded total solar eclipses as omens signs that a disaster was coming They were terrified when the sky went dark in the middle of the day for no reason they could understand The first known record of an eclipse dates back to March 3 1223 BCE The eclipse was seen in the city of Ugarit in what is now Syria Most ancient records come from Greece China and To ancient peoples eclipses were sometimes seen as signs that the gods were angry 6
THINK ABOUT IT Modern astronomers can accurately calculate the dates of past eclipses Many ancient records do not include exact dates of eclipses Why might a historian be excited to find a mention of an eclipse in a historic document Babylonia a region in what is now Iraq Astronomers in Baghdad and Cairo carefully carefully recorded many eclipses between about 800 and 1000 CE In about 1450 European astronomers started making fairly accurate measurements of the time of day or night when eclipses occurred Eclipses are mentioned in ancient works of history literature and science Today these records are useful to both astronomers and historians This page is from a Mayan text written about eight hundred years ago It includes tables of solar and lunar eclipses 7
