Question

eclipses
directions: respond to each statement on the lines provided.

1. describe the difference between an umbra and a penumbra.
2. explain what causes a solar eclipse.
3. explain what causes a lunar eclipse.
4. explain why lunar eclipses do not occur during every full - moon phase.
5. explain why a solar eclipse does not occur during every full moon phase.

Explanation:

1. An umbra is the fully - shaded inner region of a shadow cast by an opaque object, where the light source is completely blocked. A penumbra is the partially - shaded outer region of the shadow, where only a portion of the light source is obscured.
2. A solar eclipse occurs when the Moon passes between the Sun and Earth, blocking the Sun's light from reaching Earth.
3. A lunar eclipse happens when Earth comes between the Sun and the Moon, casting a shadow on the Moon.
4. Lunar eclipses don't occur every full - moon because the Moon's orbit is tilted about 5 degrees relative to Earth's orbit around the Sun. So, the Sun, Earth, and Moon are not always perfectly aligned during a full - moon.
5. Solar eclipses don't occur every full - moon because of the same orbital tilt of the Moon. The alignment of the Sun, Moon, and Earth required for a solar eclipse (new - moon phase) doesn't happen every month due to this tilt.

Answer:

1. An umbra is the fully shaded inner part of a shadow; a penumbra is the partially shaded outer part.
2. A solar eclipse is caused when the Moon comes between the Sun and Earth, blocking the Sun's light.
3. A lunar eclipse is caused when Earth comes between the Sun and the Moon, casting a shadow on the Moon.
4. Lunar eclipses don't occur every full - moon because the Moon's orbit is tilted relative to Earth's orbit around the Sun, so they aren't always perfectly aligned.
5. Solar eclipses don't occur every full - moon because of the tilt of the Moon's orbit, which means the necessary alignment for a solar eclipse (new - moon phase) doesn't happen monthly.