Notes Eclipses and Tides Eclipses Anything lit by

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.

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.