Look, Mommy! Someone ate the moon! The science behind moon phases and eclipse

Moon Phases It takes the moon about 28 days to orbit the Earth. It takes the moon about 28 days to orbit the Earth. During that time, the moon appears to change shape from one day to the next. During that time, the moon appears to change shape from one day to the next. These shapes are known as the phases of the moon. These shapes are known as the phases of the moon. Of course, the moon doesn’t really change shape; it only appears to change Of course, the moon doesn’t really change shape; it only appears to change

The moon appears to grow from right to left. Each phase has a name.

The sun’s light is shown coming from the right. The Earth is in the middle of the diagram.

The dotted line from the earth to the moon represents your line of sight when looking at the moon.

Notice that one half of the moon is always illuminated by the sun.

At certain times we see both the sunlit portion and the shadowed portion -- and that creates the various moon phase shapes we are all familiar with. Also note that the shadowed part of the moon is invisible to the naked eye.

The moon is shown at 8 key stages during its rotation around the earth.

Lunar phases are created by changing angles (relative positions) of the Earth, the moon and the sun, as the moon orbits the earth.

New Moon The new moon occurs when the moon is positioned between the earth and sun. The new moon occurs when the moon is positioned between the earth and sun. The three objects are in approximate alignment The three objects are in approximate alignment The entire illuminated portion of the moon is on the back side of the moon, the half that we cannot see. The entire illuminated portion of the moon is on the back side of the moon, the half that we cannot see.

Waxing Crescent After the new moon, the sunlit portion is increasing, but less than half, so it is After the new moon, the sunlit portion is increasing, but less than half, so it is waxing crescent.

First Quarter Moon The first quarter moon happens when the moon is at a 90 degree angle with respect to the earth and sun. The first quarter moon happens when the moon is at a 90 degree angle with respect to the earth and sun. So we are seeing exactly half of the moon illuminated and half in shadow. So we are seeing exactly half of the moon illuminated and half in shadow. It is called the “first quarter” because the moon is one quarter of the way around its orbit of the Earth. It is called the “first quarter” because the moon is one quarter of the way around its orbit of the Earth.

Waxing Gibbous After the first quarter, the sunlit portion is still increasing, but now it is more than half, After the first quarter, the sunlit portion is still increasing, but now it is more than half, so it is waxing gibbous.

Full Moon At a full moon, the earth, moon, and sun are in approximate alignment At a full moon, the earth, moon, and sun are in approximate alignment Just like the new moon, but the moon is on the opposite side of the earth Just like the new moon, but the moon is on the opposite side of the earth The entire sunlit part of the moon is facing us. The entire sunlit part of the moon is facing us. The shadowed portion is entirely hidden from view. The shadowed portion is entirely hidden from view.

The Full Moon is Beautiful!

Native American Names for Full Moons January - Wolf Moon January - Wolf Moon February - Snow Moon February - Snow Moon March - Sap Moon March - Sap Moon April - Grass Moon April - Grass Moon May - Flower Moon May - Flower Moon June - Strawberry Moon June - Strawberry Moon July - Thunder Moon July - Thunder Moon August - Corn Moon August - Corn Moon September – Harvest Moon September – Harvest Moon October - Hunter's Moon October - Hunter's Moon November - Frost Moon November - Frost Moon December - Long Night Moon December - Long Night Moon

Waning Gibbous After the full moon (maximum illumination), the light continually decreases. After the full moon (maximum illumination), the light continually decreases. The waning gibbous phase occurs next. The waning gibbous phase occurs next.

Third Quarter Moon The third quarter moon happens when the moon is at a 90 degree angle with respect to the earth and sun. The third quarter moon happens when the moon is at a 90 degree angle with respect to the earth and sun. We are seeing exactly half of the moon illuminated and half in shadow. We are seeing exactly half of the moon illuminated and half in shadow. It is called the “third” or “last” quarter moon because the moon is three quarters of the way around its orbit of the Earth. It has only one quarter left to go. It is called the “third” or “last” quarter moon because the moon is three quarters of the way around its orbit of the Earth. It has only one quarter left to go.

Waning Crescent Following the third quarter is the waning crescent, which wanes until the light is completely gone. Following the third quarter is the waning crescent, which wanes until the light is completely gone.

New Moon The moon has made a complete orbit around the Earth. The moon has made a complete orbit around the Earth. It is now positioned between the earth and sun. It is now positioned between the earth and sun. The entire illuminated portion of the moon is on the back side of the moon, the half that we cannot see. The entire illuminated portion of the moon is on the back side of the moon, the half that we cannot see. This whole cycle takes approximately 28 days. This whole cycle takes approximately 28 days.

Review

Moon Folklore In a new moon falls on a Saturday, it was said that there would be 20 days of wind and rain. In a new moon falls on a Saturday, it was said that there would be 20 days of wind and rain. Some farmers believe that crops planted near a full moon will be better than those planted during a waxing moon. Some farmers believe that crops planted near a full moon will be better than those planted during a waxing moon. Wood cut during the new moon is hard to split. Wood cut during the new moon is hard to split. A person born during a full moon will have a lucky life. A person born during a full moon will have a lucky life. A waning moon is an unlucky time to get married. A waning moon is an unlucky time to get married.

Eclipse Have you ever wondered why, at a new moon, the moon doesn't block the sun, and at a full moon, why the earth doesn't block sunlight from reaching the moon? Have you ever wondered why, at a new moon, the moon doesn't block the sun, and at a full moon, why the earth doesn't block sunlight from reaching the moon? The reason is because the moon's orbit about the earth is about 5 degrees off from the earth-sun orbital plane. The reason is because the moon's orbit about the earth is about 5 degrees off from the earth-sun orbital plane.

Eclipse At special times during the year, the earth, moon, and sun do in fact "line up“ At special times during the year, the earth, moon, and sun do in fact "line up“ When this happens it is called an eclipse When this happens it is called an eclipse There are two types of eclipse: solar eclipse and lunar eclipse There are two types of eclipse: solar eclipse and lunar eclipse

Solar Eclipse When the moon blocks the sun or a part of it, it's called a solar eclipse When the moon blocks the sun or a part of it, it's called a solar eclipse The sun seems to disappear The sun seems to disappear Q: What phase does the moon need to be in for a solar eclipse to occur? Q: What phase does the moon need to be in for a solar eclipse to occur? A: It can only happen during the new moon phase when the moon is between the Earth and the sun. A: It can only happen during the new moon phase when the moon is between the Earth and the sun.

Solar Eclipse

Q: Does a Solar Eclipse happen during the day or night? A: It has to happen during the day, because the moon blocks out the sun.

A Total Solar Eclipse occurred on August 1, 2008 One minor catch... One minor catch... To see it you had to be in northern Greenland, the Arctic, central Russia, Mongolia, or China  To see it you had to be in northern Greenland, the Arctic, central Russia, Mongolia, or China 

The Next Total Solar Eclipse will be on July 22, You’ll be lucky to see it if you can travel to... You’ll be lucky to see it if you can travel to... Nepal, Bangladesh, Bhutan, Nepal, Bangladesh, Bhutan, Myanmar and China, and Japan's Ryukyu Islands Road trip! Road trip!

Solar Eclipse

Lunar Eclipse When the earth casts a shadow on the moon, it's called a lunar eclipse When the earth casts a shadow on the moon, it's called a lunar eclipse The moon seems to disappear The moon seems to disappear Q: What phase does the moon need to be in for a lunar eclipse to occur? Q: What phase does the moon need to be in for a lunar eclipse to occur? A: It can only happen during the full moon phase when the Earth is between the sun and the moon. A: It can only happen during the full moon phase when the Earth is between the sun and the moon.

Lunar Eclipse

Why do you think the moon looks red during an eclipse?

2009 Feb 09Penumbral e Europe, Asia, Aus., Pacific, w N.A Jul 07Penumbral Aus., Pacific, Americas 2009 Aug 06 Penumbral Americas, Europe, Africa, w Asia 2009 Dec 31Partial h02mEurope, Africa, Asia, Aus Jun 26Partial h44me Asia, Aus., Pacific, w Americas 2010 Dec 21Total h29m 01h13m e Asia, Aus., Pacific, Americas, Europe 2011 Jun 15Total h40m 01h41m S.America, Europe, Africa, Asia, Aus Dec 10Total h33m 00h52m Europe, e Africa, Asia, Aus., Pacific, N.A Jun 04Partial h08mAsia, Aus., Pacific, Americas

Lunar Eclipse Q: Does a Lunar Eclipse happen during the day or night? A: It has to happen during the night, because the Earth’s shadow blocks out the moon.

There will be a partial eclipse of the moon on December 31, 2009 It will be best seen if you are in the Eastern hemisphere.

Eclipse Roughly 4 to 7 eclipses happen in any given year Roughly 4 to 7 eclipses happen in any given year Most of them minor or "partial" eclipses Most of them minor or "partial" eclipses Major lunar or solar eclipses are relatively uncommon. Major lunar or solar eclipses are relatively uncommon.