Notes Eclipses and Tides

Eclipses Anything lit by the Sun also casts a shadow behind it, into space.

Eclipses The Moon and the Earth are so far apart that usually neither one passes into the other’s shadow. Eclipse- when a shadow makes the Sun or the Moon seem to grow dark.

Eclipses Eclipses are named after the object that is temporarily blocked from view. In a lunar eclipse, the Moon is blocked from view. In a solar eclipse, the Sun is blocked from view.

Lunar Eclipse The Moon gets dark during a lunar eclipse because it passes through Earth’s shadow.

Earth’s shadow has two parts: Lunar Eclipse Earth’s shadow has two parts: Umbra: the darkest part Penumbra: the spreading cone of lighter shadow

Lunar Eclipse Just before a lunar eclipse, sunlight shining past Earth makes a full Moon.

Lunar Eclipses Then the Moon moves into Earth’s penumbra and becomes slightly less bright.

Lunar Eclipses As the Moon passes through Earth’s umbra, Earth’s shadow seems to creep across the Moon.

Lunar Eclipses A total lunar eclipse is when the entire Moon passes completely through the umbra. A partial lunar eclipse is when only part of the Moon passes through the umbra.

Solar Eclipses In a solar eclipse, the Sun seems to go dark because the Moon’s shadow falls onto Earth.

Solar Eclipses A solar eclipse occurs when the Moon passes directly between Earth and the Sun.

Solar Eclipses Only locations on Earth in the path of the Moon’s shadow experience a solar eclipse.

Solar Eclipse Only the location in the Moon’s small umbra will experience a total solar eclipse. During a total solar eclipse, the Moon completely blocks out the Sun’s light for a short time, making it almost as dark as night!

Solar Eclipse Some people will travel thousands of miles just for the chance to experience a total solar eclipse.

Solar Eclipses If only the penumbra moves over your location, you will experience a partial solar eclipse, where the Moon covers just part of the Sun.

Solar Eclipses It is always dangerous to look directly at the Sun, so you should never look directly at a solar eclipse.

Tides Water level at a beach changes throughout the day-this is called the tide. There are two high tides and two low tides during every 24 hour period.

Tides Tides occur because the Moon’s gravity changes the shape of the oceans. The Moon pulls hardest on the side of Earth nearest to it, and weakest on the side of Earth farthest away from it.

Tides The Moon’s pull produces a high tide on the side of Earth nearest the Moon. It also produces a high tide on the side opposite the Moon, where the gravitational pull from the Moon is weakest.

Tides Every time Earth completes a quarter turn (6 hours), the tides change. This is why there are two high tides and two low tides during every 24 hour period.