Factual Information Items
Read the selection from a longer reading passage and answer the items
An eclipse is an astronomical* event in which light from one astronomical body is blocked by another astronomical body, such as the moon or Earth. The sun, Earth, and Earth's moon are all involved in two kinds of eclipses. A solar eclipse occurs when light from the sun is blocked by the moon. For a solar eclipse to occur, the sun, moon, and Earth must be in alignment, with the moon in the middle to block the sun's light. Alignments of this sort are rare and last for only a few minutes, as Earth and the moon continue on their orbits. During an eclipse, people on Earth see the sun with a dark circle cut out of it (partial solar eclipse) or completely blocked by the moon (total solar eclipse) so that sunlight shines only from the edges of the sun; the rest of the light is blocked by the moon. The shadow cast by the moon during an eclipse will darken the sky, especially during a total or near total eclipse. Animals may believe that night is falling. Birds may begin to roost for the night, for example.
A lunar eclipse occurs when sunlight shining on the moon is blocked by Earth's shadow. For a lunar eclipse to happen, the sun, Earth, and the moon must all be in a row, with Earth in the middle so it can block the sun's light and cast a shadow on the moon. The shadow cast by Earth contains two parts, the umbra and the penumbra. The umbra is the shadow cast directly by Earth. The penumbra is a larger area around the umbra where direct light from the sun is blocked but some light is able to get through indirectly. A penumbral lunar eclipse happens when the penumbra cast by Earth slightly darkens the surface of the moon. An umbra I lunar eclipse takes place when the umbra falls on the moon's surface. A lunar eclipse may be partial or total, depending on whether the shadow cast falls completely or partially on the surface of the moon. In a penumbra! total eclipse, the moon may appear partially darkened, and areas of the penumbra may appear darker if they are near the umbra. In an umbral total lunar eclipse, it may appear that the moon has disappeared from the sky for a period.
Generally, a lunar eclipse is visible only at night and when the moon is full. A senelion, a kind of eclipse that occurs under only highly exceptional conditions, is a rare astronomical event. A senelion is an eclipse that occurs when the sun and moon are opposite one another on the horizon and are aligned so that Earth's shadow hits the moon. Thus the sun and the eclipsed moon can be seen simultaneously. This is the only time when the sun and a lunar eclipse will both be visible together. This is also the only time that an eclipse can take place with daylight visible at the same time. The most recent senelion was on December 10, 2010. The next one will not take place for another eighty-four years.
*related to objects in space (stars, planets, moons, etc.)
1. According to the passage, what is the cause of a solar eclipse?