The document discusses the two types of eclipses - solar and lunar. A solar eclipse occurs when the moon passes between the sun and earth, blocking the sun's light. A lunar eclipse happens when the earth passes between the sun and moon, casting its shadow on the moon. The document provides an example of a solar eclipse occurring on the author's sister's birthday and includes a link to a video about lunar eclipses. It also briefly mentions Laika, the first dog launched into space by the Soviet Union on Sputnik 2 in 1957.